Written by Isabella Oleksy, a 2016-2017 Sustainability Leadership Fellow and Ph.D. student in the Department of Ecosystem Science and Sustainability and Graduate Degree Program in Ecology
It’s a beautiful day. There is not a cloud in the sky, the temperature is perfect, and there is no wind to speak of. You are walking up on what appears to be a crystal clear body of water surrounded by menacing rock formations, towering overhead. This is Sky Pond, an appropriately named waterbody. It is situated at the headwaters of one of the Platte River’s many tributaries. Sky Pond and its surrounding views are the reward for the 5 miles of hiking and 1500 feet of climbing it takes to get here from the trailhead; a reward so sweet that thousands of people make the strenuous round trip each year. As you take a moment to catch your breath while simultaneously having it taken away by what surrounds you, everything stands still, if only for a moment. This place is teeming with life. Depending on the time of year, you may see elk, wildflowers, trout, moose, marmot, big horned sheep, and ill-prepared tourists. Curiosity brings you close to the water’s edge. Upon closer inspection, the crystal clear waters reveal extensive mats of green slime, flowing with the gentle water current. This green slime is everywhere, and it looks like it came straight out of Ghostbusters. You kneel down to take a sample of the green slime. A curious onlooker asks what you are doing, and you look up and quote Dr. Peter Venkman (Bill Murray) himself, “Back off, man, I’m a scientist.” If you’re still following along, this is what I experience on a weekly basis, except I don’t really tell curious onlookers to back off. The scene I am describing is a day in the life of field work in the Loch Vale watershed, and that “green slime” is actually filamentous green algae. I’m trying to figure out why the algae are growing here, because until recently, this sight was more common in a retention pond in Michigan than in a “pristine” alpine lake in the Rockies.
The beauty of the Loch Vale Watershed is no secret. It’s situated in one of the most visited areas of Rocky Mountain National Park, just east of the continental divide. My research is a complement to what my advisor, Dr. Jill Baron, might call her life’s work. In 1983, Dr. Baron established the watershed as a long-term ecological research site with the goal of understanding watershed-scale ecosystem processes and how air pollution and climate-variability affect ecosystem function. At the time, many ecologists were focused on understanding the effects of acid rain. While Loch Vale was not getting hit with acid rain, it was (and still is) getting hit by precipitation carrying particles of nitrogen, sourced from automobile emissions, power plant exhaust, and increasingly even the by-products of industrial agriculture, which are so prominent on the Front Range of the Colorado Rockies.
Nitrogen alone is not exactly a bad thing; it is essential for life. It is the nutrient whose absence is responsible for limiting a plant’s growth. This is precisely why, if you buy into the scourge of the American lawn, you use nitrogen-based fertilizer to make your lawn look greener than the Jones’ next door. The problem is, the Loch Vale watershed and surrounding areas can’t process all of the incoming human-made nitrogen. Mountainous areas are particularly sensitive because there is little plant and forest cover to absorb the excess nitrogen. Since the mid-20th century, mountainous areas in Colorado have been receiving much more nitrogen than is needed for biological uptake. Where does all that excess go? Unfortunately, much of it ends up in surface waters, running downhill into the wetlands, lakes, and streams.
Ecologists and biogeochemists have a range of tools in our toolbox that we can use to answer questions about the natural world. Working in Loch Vale, one of our most valuable tools is in analyzing the high-quality, weekly, long-term measurements of water chemistry and weather data in this watershed. We can ask and answer questions such as does the water chemistry leaving the watershed match the precipitation chemistry entering the watershed (1)? Or, what is the ecological critical load of incoming nitrogen deposition before adverse ecological effects occur (2)? However, how can we assess changes in ecosystem processes for variables that we do not routinely measure? For example, Loch Vale researchers have known for years that surface waters were high in nitrate, but the impacts on aquatic plant life, particularly algae, were not fully understood. For those kinds of questions, we put on our detective hats and pull out our paleo-toolkit.
Paleolimnology is a sub-discipline of limnology (the study of inland waters) that primarily uses lake sediment cores to meticulously reconstruct past environments of inland waters. By analyzing physical, chemical, and biological characteristics of sediment layers deposited in lakes, paleolimnologists can get a glimpse into the past. Sediment core analysis allows us to piece together how lakes are affected by climate on short and long time scales as well as by a numerous other factors such as land-use change (e.g., deforestation), food-web manipulations (e.g., fish introductions), and other human impacts (e.g., acid rain, nitrogen deposition).
The effect of nitrogen deposition on lake algae has been well documented with sediment cores collected across Europe and North America. Most show a pattern very similar to what we have observed in the Colorado Rocky Mountains: for hundreds of years these lakes were home to a diverse flora of diatoms, single-celled algae that spend their life photosynthesizing in the water column and are preserved in sediments when they settle and die because of their strong, silicate shells. Once nitrogen inputs increased, one or two species of diatoms outcompeted the rest and dominate to this day. To our knowledge, no one had observed the green slime until very recently. In Loch Vale, is it new or has it been there all along? Are we still seeing the response of algae to nitrogen or are other factors involved? For my doctoral research, I am further diversifying our paleo-toolkit and looking at not only diatoms, but all algal species, by analyzing a diverse range of algal pigments from layers throughout lake sediment deposits. This technique is useful for reconstructing changes in algal groups through time, especially those that don’t leave us microscopic fossils to count under a microscope, like the green algae we observe today.
Last March, our team of researchers and volunteers embarked on an expedition to The Loch, the subalpine lake in the Loch Vale watershed. With our crew loaded down with sleds and heavy packs full of equipment, what is normally a moderate 2-mile snowshoe hike turned into a strenuous uphill slog. We drilled a hole through the ice over the deepest spot in the lake and dropped a gravity corer into the sediments to obtain a short core of the most recent lake sediments. We used a special device to extrude the mud out of a plastic core tube and sliced the sediments into fine layered intervals for laboratory analysis. In less than a foot of sediment, we captured several hundred years of lake ecological history!
What the sediment core has told us so far is that this prolific growth of slimy green algae is indeed a new phenomenon in The Loch. Recent sediments show strong signs of increased chlorophytes (green algae) and colonial cyanobacteria, with well-preserved but relatively small amounts of those pigments just a few centimeters from the top of the core. Interestingly, The Loch never saw a substantial increase in diatoms, as Sky Pond did, potentially because it is lower in elevation and slightly buffered by the forest surrounding it. While we now can confirm that our recent observations have not occurred within the last several hundred years in this lake, we still do not fully understand why. Luckily for me, my job is to solve this mystery with laboratory and field experiments.
What has changed in the last few decades that might be causing these algal blooms? We know that our surface waters have been warming steadily in the peak of summer, at the rate of about 0.7°C a decade since we began measuring (1). We also know that glaciers, rock glaciers, and permafrost are shrinking and releasing additional nutrients that were previously locked up and frozen (3,4). Could filamentous green algae be appearing because of dust from forest fires and drought? (5) There are a myriad of potential drivers of ecological change in these lakes, and scientists are only beginning to understand how these mountain jewels are changing right before our eyes. Our world is changing rapidly and we don’t fully understand the cost nor the consequences. Luckily, there are people in local, state, and federal government that are seeking partnerships and solutions to minimize the impacts that are within our control, such as air pollution. There are farmers in Colorado who are voluntarily changing their management practices to reduce nitrogen volatilization from their farms. And soon, you too can help us document where these algal blooms are (and are not) occurring across the intermountain West! Simply download WATR2016 from the App Store and document lake conditions as you hike anywhere in the western United States. All submissions will be automatically uploaded to our database on CitSci.org.
(1) Mast, M. A., Clow, D. W., Baron, J. S., & Wetherbee, G. A. (2014). Links between N Deposition and Nitrate Export from a High- Elevation Watershed in the Colorado Front Range. Environmental Science & Technology.
(2) Baron, J. S. (2006). Hindcasting Nitrogen Deposition To Determine an Ecological Critical Load. Ecological Applications, 16(3), 433–439.
(3) Leopold, M., Lewis, G., Dethier, D., Caine, N., & Williams, M. W. (2015). Cryosphere: ice on Niwot Ridge and in the Green Lakes Valley, Colorado Front Range. Plant Ecology & Diversity, 874(March 2015), 1–14. http://doi.org/10.1080/17550874.2014.992489
(4) Barnes, R. T., Williams, M. W., Parman, J. N., Hill, K., & Caine, N. (2014). Thawing glacial and permafrost features contribute to nitrogen export from Green Lakes Valley, Colorado Front Range, USA. Biogeochemistry, 117(2–3), 413–430. http://doi.org/10.1007/s10533-013-9886-5
(5) Neff, J. C., Ballantyne, a. P., Farmer, G. L., Mahowald, N. M., Conroy, J. L., Landry, C. C., Reynolds, R. L. (2008). Increasing eolian dust deposition in the western United States linked to human activity. Nature Geoscience, 1(3), 189–195. http://doi.org/10.1038/ngeo133
Written by Xoco Shinbrot, a 2016-2017 Sustainability Leadership Fellow and Ph.D. student in the Department of Human Dimensions of Natural Resources
Your alarm goes off, the light is creeping into your bedroom, you stumble out of bed and into the kitchen to grab the life-raft that gets most people through the day: a bag of coffee beans. It’s a morning ritual, a culturally embedded, addictive and habit-forming part of waking up. Even the smell of coffee can provide a pleasant refuge from the world outside the comforts of our sheets.
Now imagine a world without that steaming cup of coffee, where you stumble to your kitchen and instead of coffee there is an empty cabinet with a few sad bags of tea. I study how to keep that coffee in your hands.
Farming generally, and coffee farming particularly, is changing rapidly. Coffee likes to grow in very particular climates; it’s a bit like the story of Goldilocks, not too hot and not too cold, just right. This Goldilocks though also needs to live in climates that are not too moist and not too dry. The combination means that there are only certain places, usually mountainous, tropical regions—between 800 and 1,800 meters about sea level—around the world that are suitable to coffee cultivation.
Mexico’s southern states are home to most f Mexico’s production of coffee, with over 250,000 US tons of high quality Arabica bean produced in 2015 (USDA FAS 2015). Mexico ranks as one of the top ten coffee producing nations worldwide. But its farmers have been hard hit by weather –frost, untimely rainfall, excessive humidity, and cyclones – that aside from their direct impacts also facilitate the spread of fungal diseases like coffee rust that can destroy whole farms.
Recently, Mexico’s national agricultural organization, SAGARPA, has given small-scale farmers incentives to adopt strategies to deal with climate-related weather impacts. The climate adaptive strategies are tucked into conservation plans that farmers can sign up for which provide: (1) training on how to decrease impacts of weather and climate, such as how to build living walls to prevent soil erosions; (2) inputs such as coffee-rust resistant plants; and (3) workshops on intercropping with other species like citrus and avocado.
In some programs, farmers receive cash payments for setting aside land for conservation for a contracted period, usually ten to fifteen years. These payments for ecosystem service programs, developed by Mexico’s national forestry commission (CONAFOR), are designed to be win-win for conservation of forests (with benefits for water supply downstream) as well as social outcomes like poverty alleviation. Recent changes in the program have allowed matching from local stakeholders to promote other goals like climate change adaptation strategies for farmers.
In light of the expansion in multifaceted conservation strategies, poverty alleviation, and climate adaptation programs, the question is whether and how these programs are actually providing the benefits to the environment and the farmers that live there.
The vast majority of coffee farmers are considered small scale—most on fewer than 10 acres of land—and rely almost completely on coffee production for their livelihoods. Rural areas are home to over 61% of Mexico’s extreme poor, many with no schooling beyond elementary education (USAID 2011). These conditions affect the way in which natural resources are perceived, sustainability is practiced, and how land management occurs. As traditional methods of coffee production are rapidly becoming less productive, farmers are strongly in need of information and resource sharing programs that teach new methods that suit the changing climates.
Local cooperatives have tended to fill this need by pooling farmer resources together and providing an important source of information. As new government programs are developed it is unclear whether they also improve climate adaptation strategies. By understanding which programs are successful, as well as which people tend to adopt new strategies, government policies can hone in on the most important leverage points.
This is just the first part the puzzle to connect, engage and facilitate healthy social-ecological systems for farmers and for consumers in this quickly changing climate. The impact goes beyond that morning cup of coffee to people’s livelihoods, culture and very identity.
USDA Foreign Agricultural Service. 2015. Mexico, Coffee Annual. Global Agricultural Information Network. Available HERE.
USAID. 2011. USAID Country Profile: Property rights and resource governance, Mexico. Available HERE.
Written by Drew Bennett, a 2016-2017 Sustainability Leadership Fellow and Postdoctoral Fellow in the Department of Fish, Wildlife and Conservation Biology
In 2009, my wife and I moved in with my grandfather in a small town in Oregon’s Willamette Valley. A photo of the three of us taken shortly after the move sits on my desk. I often look at the photo and am reminded of the incredible stories my grandfather shared with us – stories of a time long past. Born in Nebraska, my grandfather’s family lost their farm in the Dust Bowl. With my grandfather and his three young siblings in tow, they moved west in search of a new life. After spending several seasons as itinerant farm workers in California’s Central Valley, they eventually settled in Oregon on the banks of a tributary to the mighty Willamette River.
It was the height of the Great Depression and, like nearly everyone living in their rural community at the foothills of the Cascade mountains, my grandfather’s family was poor. With a river in their backyard, my grandfather would watch salmon on their seasonal runs en route to spawning grounds upstream. At times, the salmon were so thick that he and his siblings used pitchforks to haul them out of the water. In a time of great scarcity, these salmon runs were a seemingly limitless bounty - literally there for the taking. Stacking the fish into huge piles along the shore, there was more meat than a family could eat. To extend the bounty, they dried the fish to feed their chickens. This kept the chickens healthy and allowed them to sell eggs along the roadside to earn a little extra income to supplement the family’s inconsistent work. In hard times, nature helped provide for the family.
It would have been unimaginable to that boy that this abundance would vanish during his lifetime. Impacted by dams, higher river temperatures, and the loss of habitat, only a handful of salmon now make the pilgrimage to spawn in the headwaters of their ancestral river. The Foster Dam, built in 1968, completely blocked salmon passage in this tributary. Today, still lacking a fish ladder to provide passage around the dam, the few returning salmon are collected from the base of the dam, loaded into the back of a truck, and driven around the dam’s reservoir before being dumped back in the river to continue their journey a few more miles upstream. The salmon that still make the trip are hardly enough to maintain a viable population. Instead less hardy fish raised in hatcheries are released to try to increase salmon populations. The salmon migration that was once one of nature’s great marvels has been reduced to a process dependent on continual human intervention.
While my natural tendency is to lament the loss of the wild salmon runs, my grandfather’s story is emblematic of a larger and more insidious phenomenon in our society. This story represents a quintessential example of a shifting baseline, or a change in the reference points we use to judge changes in the environment based on our own lived experiences. If what we perceive is only a small change in our lifetimes, we do not recognize the drastic changes that accrue over generations. Over time, viewing our own experiences as normal, we slowly shift our standards and expectations. There are many other examples, from the gradual decline of the now extinct passenger pigeon, a bird once so numerous in the eastern United States that migrating flocks darkened the sky, to the dimming of stars we see at night as urban areas grow. Each decision made on the path to the salmon’s decline seemed rational and the impacts so minor that few noticed. Our baselines deceived us, and it is only in hindsight that we question our logic.
The photo that sits on my desk connects my own family’s history to the story of the salmon. In the background is a reservoir created by the construction of the Foster Dam. At the time, few would have had concern for the impact of the dam. After all, the dam provided electricity, flood control, consistent water for irrigation, and recreational opportunities. It represented the forward progress of a poor town in the backwoods of Oregon towards a more prosperous future. But Foster was not the only dam built in the Willamette Valley. It is just one of more than 20 major dams in the basin, not to mention the hundreds of levees, dikes, and artificial channels that control the flow of water in the region. Farmers also cleared streamside forests to plant to the river’s edge. Side channels that provided habitat were drained and cultivated. Towns and cities were built on its banks and soil and vegetation were replaced by concrete. While any one of these changes may not have been catastrophic, their combined impact is immense.
Impressive efforts are now underway to restore the Willamette Basin. Hundreds of miles of streamside forests have been replanted. Smaller levees and other barriers to fish passage have been removed. Conservationists in Oregon even won the 2012 Riverprize from the International River Foundation for their efforts. In 2015, the Oregon chub, a small fish that only lives in the Willamette Basin, became the first fish in the United States to be removed from the Endangered Species list after its population recovered. The chub’s recovery was possible in part because of voluntary conservation efforts that engaged farmers in the restoration of backwater channels that provide critical habitat. Indeed, bandages are slowly being placed over the basin’s numerous wounds.
There are many reasons to celebrate the progress that has been made in the Willamette and in many other locations. But my grandfather’s stories still linger in my mind. This is not the basin of his youth. As exciting as recent progress appears, these accomplishments are incremental positive steps in a landscape that, when viewed through a generational lens, still bears deep scars. Are our measures of success too timid? Are we thinking too small? By most measures, the ecological health of the Willamette has significantly improved in my lifetime. But my baseline deceives me. My grandfather’s stories remind me of what was truly lost. We need to hear more stories like his. Stories that humanize this history and connect us to our past. We need these stories to combat our shifting baselines and recalibrate our perceptions.
When I look at the picture on my desk, I sometimes wonder about the stories I will tell one day. Will I celebrate the small victories while ignoring the long-term changes in the landscapes in which I live and work? As a scientist, I use data such as satellite images to ground my perceptions, yet these data typically only go back a few decades at best. These short-term perspectives guide us in making decisions that appear rational today, but blind us to the larger context. Data, while essential, are also limited in shaping public opinion. Our brains are wired to think in stories. It is often strong personal anecdotes that move us to action. In a technological world that connects us more to screens than people, stories help reconnect us with each other and our surroundings. If we knew our ancestors' stories - stories of prairies filled with bison and seas teaming with fish – would we accept the status quo? These stories are our best defense against the insidious shifts that have lulled us into accepting the slow decline of our natural systems. We need these stories to inspire us to strive for what we have yet to achieve.
For more information on salmon issues in the Pacific Northwest, the Nature episode “Salmon: Running the Gauntlet” provides an excellent overview.
To learn more about restoration efforts in the Willamette, several Freshwaters Illustrated short films, such as “Water and Wood”, provide an entertaining introduction.
Written by Becky Gullberg, a 2016-2017 Sustainability Leadership Fellow and Ph.D. student in the Department of Microbiology, Immunology, and Pathology
We’ve all experienced those annoying guests that overstay their welcome. They take up your time and eat your food. Now imagine one 10 times worse, who trashes your house and wrecks havoc. You need to get rid of this guest before everything is ruined. You turn off the heat and crank up the air conditioning to encourage them to leave. Luckily the guest leaves, but they stole your coat and tried to get to your neighbor’s house. You just want them to take your old and tattered jacket rather than your nice one. Perhaps this will prevent them from bothering your neighbor.
Unwelcome houseguests can be parasites. They are very successful at ruining your life and difficult to get rid of. The cells in your body are like little homes for your genetic material and viruses are the unwelcome houseguests. In fact, viruses are completely dependent on host cells. Without the cell, the virus cannot make more viruses and will fall apart without passing on its genetic material.
Viruses are also minimalists. When a virus shows up in a cell to replicate itself, it doesn’t bring much with it. Instead it relies on the cell for its building blocks and energy source to make new viruses – just like an unwelcome houseguest raiding the fridge. Additionally, the virus takes its jacket from part of the cellular membrane and uses that to get into a new cell. If we can trick the virus and change these building blocks, perhaps give them a defective jacket so they freeze when they leave the house; we can stop the spread of the virus to your neighbor.
My lab studies dengue virus (see video) and how it interacts with the cell to make the building blocks it requires. This virus is transmitted from one human to another through the bite of a mosquito. Dengue virus causes a painful fever, quite similar to the flu, but often much worse. In some cases the disease can progress to hemorrhaging, (excessive bleeding, as seen in this picture). This often leads to death. Currently, there isn’t a way to treat this disease and so many people, often babies, suffer unnecessarily.
It has been very difficult to find good treatment options for this disease. It can take a drug 10-20 years to go from a research setting to being used in clinical trials. Along with this comes millions of dollars in research funds. Dengue virus evolves quickly and can gain resistance to drugs that directly impact the replication of the virus. This quickly renders the drug useless and requires starting from square one to find another antiviral treatment. A better option is to use drugs that the virus cannot adapt to so quickly. These drugs could be useful in the clinic for many more years and save the time and money of developing something new.
An attractive approach to making more robust antivirals is using host-targeted drugs. These are drugs that act to change the host cell rather than directly inactivating the virus. Meaning, they change the building blocks of the house that the virus is trying to use for its replication and energy needs. These types of drugs are thought to be more effective for a few reasons.
First, they are less likely to make resistant viruses since it is much harder for viruses to mutate and overcome these drugs. It is very difficult for the virus to adapt to new building materials - thus it won’t be able to assemble and spread.
Second, the cellular proteins that are impacted by these drugs are quite stable meaning the cell isn’t likely to mutate in response to the drug. It is likely that these types of drugs can be used in a clinical setting longer and treat many more people.
Third, since these drugs act to change the host, they may be effective against different types of viruses that have common needs. Many viruses use the same building blocks or energy sources and could be treated with the same drug that depletes these resources.
Since host-targeted drugs impact our cells, it is important to consider their safety. We need to be sure that we aren’t changing the cells irreversibly or unnecessarily. Importantly, a viral infection is an acute and relatively short-lived condition. People wouldn’t have to take these drugs for very long, and thus they can avoid some of the potential toxicity. Additionally, many of these drugs have already been developed to treat other diseases. Some are FDA approved and currently being used, but not against viruses.
It is predicted that global range of dengue virus will continue to grow due to climate change and subsequent spread of mosquitoes that harbor the virus. More cases of this infection without good treatment options means continued loss of productivity and unnecessary suffering. It is important that we find new ways to interrupt these viruses with sustainable treatment options. Changing the energy source or building blocks viruses use to replicate and assemble, may be an effective strategy.
Society may continue to struggle with the challenge of in-laws that overstay their welcome, but we are on the cusp of important breakthroughs in making our cells less hospitable to viruses such as dengue viruses.
Rolling rocks, pushing pebbles, and slinging sand: How rivers change landscapes, and how people change rivers
Written by Derek Schook, a 2016-2017 Sustainability Leadership Fellow and Postdoc in the Department of Forest and Rangeland Stewardship, CSU and Water Resources Division of the National Park Service.
Tumbling down from the mountains, rivers cut across the land on voyages to the sea. Although we primarily think of rivers as transporters of water, an equally significant role they play lurks beneath the water’s surface. Under natural conditions, rivers scour the earth to create landforms and habitats, both in the channel and on the land. However, the ability of rivers to do this is directly affected by human activities. Recent human-induced modifications to rivers are leading the waterways and their dependent species into uncharted territory.
In vast networks that sprawl across the landscape, river systems erode, transport, and deposit rocks of all sizes. The amount of material transported by rivers is massive. For example, every year the Mississippi River deposits 150 million tons of sand, silt and clay (which, when combined with rocks, are collectively termed “sediment”) into the Gulf of Mexico. To picture that quantity, imagine a sediment pile neatly stacked within the confines of a football field. By the end of the year, the pile would ascend 13 miles into the sky, or twice as high as you were on your last flight across the country.
Zooming in from the landscape scale down to the channel itself, the rocks found along river beds provide habitat that supports aquatic-terrestrial food webs, an ecological system well-described in a previous post by Alisha Shah. At the base of the food web are invertebrates that rely on the right size, placement, and stability (or lack there-of) of rocks on the river bed. These invertebrates are eaten by fish, which are eaten by other fish, and these tasty relationships eventually provide food for a variety of terrestrial animals ranging from spiders and warblers to grizzlies and eagles. The river bed itself appears to be comprised of a chaotic assemblage of rocks randomly strewn about. However, the rocks’ positions are determined by physical processes governed by hydraulics (the physics of fluids in motion). Gravity provides the underlying engine that moves both water and rocks downhill, and the burden of potential energy is reduced along each inch of the descent. As water flows with velocity and momentum, it contains kinetic energy capable of destroying natural and manmade structures. Destruction of natural things, such as river banks, can be beneficial to the river and its watershed, but destruction of human infrastructure is problematic.
This destruction of infrastructure, coupled with our desire to harness water for human uses, has led to widespread changes to water and sediment flows. These changes have damaged river health. One change is that flow regulation often allows rocks on the river bed to stagnate. Through time they “armor”, or become increasingly difficult to mobilize because of long intervals between high scouring flows. A locked-down river bed is a worse substrate for bugs and food webs, and also for fish like spawning salmon who form redds among river cobbles.
Along the sides of rivers, people have built walls made out of concrete, metal, and even old cars. These barriers prevent rivers from gathering sediment as they attempt to go about their natural meandering ways. The walls protect human infrastructure in the short term. However, they deprive the river of sediment it would naturally collect from its banks. This, in turn, leaves more energy in the channel and increases the potential for destruction downstream.
Even more disruptive than preventing a river from eroding its banks, damming creates a pronounced barrier to water and sediment transport downstream. Instead of sediment crashing into the dam before it is halted, sediment transport is indirectly prevented. This happens because as water backs up behind a dam, its velocity decreases so the water loses the energy required to transport it. Another way to think about velocity affecting transport capacity is to consider the ease with which fast winds in a tornado can pick up and transport a cow, but a gentle breeze may just make the grounded cow smile.
In addition to the severe alterations dams impose on the timing and magnitude of flows, by denying sediment passage, dams modify the downstream river in two main ways. The first is that reduced sediment transport means the river will retain more erosive energy downstream, which often results in bed incision and channel lowering. Channel lowering separates the river from the floodplain it created. Many floodplain plants need either flooding or river-supported high water tables for their reproduction and growth, so some plants can disappear after sediment transport is modified. As a result, animals living among the vegetation can be forced out too as their habitat is lost.
The second result of dam-induced sediment deprivation is that downstream sediment deposition is reduced in and around the river channel. The consequences of this seemingly mundane process become evident after decades have passed. Like the barren landscape left behind after a volcanic eruption, channel movement followed by sediment deposition creates a clean slate of new land. This land is readily colonized by floodplain plants. For example, sand that deposits on the inside of a river bend provides ideal habitat for regeneration of some floodplain plants such as willows and cottonwoods. These plants eventually mature and become the backbone of biodiverse floodplain ecosystems. Episodic, even cyclic, sediment deposition and forest regeneration sustains floodplain forests that are a mosaic of habitats young and old, big and small.
Sediment transport is one of many issues worth knowing something about when it comes to the complexity of natural systems. We are living in a time of changes that are occurring faster than the natural world has ever seen. Species, ecosystems, and watersheds develop slowly, but they generally have evolved to find a delicate balance of interactions. You might already have your favorite environmental issues to think about, to talk with others about, and even to take action on. To bolster this list, I encourage you to head down to a local river and think about processes occurring beneath the surface. Maybe you’ll be inspired to learn more about the rocks that roll down the river, and the tricky solutions we must find to balance the needs of people and nature. Even if you’re not hooked on the cryptic topic of sediment transport, at the very least you’ll likely enjoy your time along the river and strengthen your bond with nature. And that in itself is a win, both for people and for rivers.
Standing in a cell that could barely hold one person, let alone the 3+ it had restraints for, my eyes darted back and forth from the rusted shackles to the view outside the cell bars. Through the bars, the sun dimly lit the room and I stared straightly at the main house of the Whitney Plantation—the only place dedicated to educating visitors about the plantation experience from the slaves’ perspective—in Wallace, Louisiana. I stood frozen by the discrepancy between the cell and house, the discrepancy between my experiences in America as a privileged white cis woman and those who this cell was intended for. The disparity demonstrates the very unequal and racialized dynamics of Americans’ historical experiences of agriculture, capitalism, and the environment, where expendable Black bodies were violently destroyed in the name of sugarcane profits for White owners. It also demonstrates contemporary relevance, as the auction block cell used to contain Africans as they were sold into slavery bears striking resemblance to modern day jail cells where African Americans are contained as they are pushed into the penal system by our nation’s prison-industrial complex.
Environmental studies, like most sciences, aim to move us forward and are future-focused. This is particularly true of sustainability, which concerns itself with the utilization of our environment and natural resources in a way that preserves them for future generations. But sustainability science is not ahistorical, and we must also engage in reflexivity, that is, critically reflecting on how the past influences the present and the future. Moving forward requires addressing where we’ve come from and where we are.
Here, I reflect on sustainability and environmental racism and justice in our capitalist society. I make the case that moving forward, we must address issues of inequality, specifically, racial inequality, in order to see success in sustainability practices. My focus on the experiences of African Americans should not discount the intersectional realities of environmental injustices–the unequal distribution of benefits and costs in our relationship to the environment–for countless other marginalized and oppressed peoples in the U.S. and worldwide. For example, injustices in our agricultural and food systems continue to exist for migrant workers of color today.
Environmental justice (EJ) scholar David Pellow recently called for an advancement of ‘critical environmental justice studies’ to explore the intersections of the relationship between social categories (like race) with the environment. Pellow (2016) focuses specifically on violence to Black bodies at the hands of the state, noting that:
“Black Lives Matter challenges the scourge of state-sanctioned violence…with a primary emphasis on police brutality and mass incarceration…If we think of environmental racism as an extension of those state-sanctioned practices—in other words a form of authoritarian control over bodies, space, and knowledge systems— then we can more effectively theorize it as a form of state violence, a framework that is absent from most EJ scholarship” (p. 13).
In addition to state-sanctioned violence, capitalism also plays a role in environmental racism and inequality. It serves to tie together the exploitation of Black Americans in our agricultural history, the disproportionate distribution of toxins that environmental justice was founded upon, and the variety of injustices in the urban and built environment (i.e. neighborhood amenities, public housing, food deserts, gentrification, toxic exposures in the home, and the prison industrial complex). Together, these environmental inequalities (among others) represent the issue of intergenerational environmental justice and its evolving manifestation within capitalism. Like neoliberalism’s ruthless impact on our environment, Black lives continue to be utilized and destroyed as part and parcel of our nation’s drive for profit maximization, in a political and economic system that constantly reinvents more covert strategies for oppressing them.
The relationship between race, the environment, and natural resources extends beyond U.S. borders. W.E.B. Du Bois suggested that the concept of race is a socially constructed and politically meaningful tool of capitalism which was born out of modernity. He posited that the capitalist system functioned on the backs of people of color, globally, and that it was the growth of capitalism prompted the development of the chattel slavery system. In 1920, Du Bois wrote that capitalism brought about “a chance for exploitation on an immense scaled for inordinate profit, not simply to the very rich, but to the middle class and to the laborers. This chance lies in the exploitation of darker peoples.” (p. 504-505). These ‘dark nations’ are what today are referred to (devoid of explicit reference to race) as the “Global South,” or less developed countries. Historically, people of color in the Global South bear the biggest burdens of resource development, while receiving very little payoff (Timmons Roberts and Parks 2006). The globalization of neoliberal ideology, then, has been toxic to both the environment and to our people—but its toxicity is felt most heavily by the marginalized. Faber and McCarthy (2003) note that “the most politically oppressed segments of the population” are “selectively victimized” by corporate practices (p. 39).
How is this connected to issues of sustainability? Environmental justice frequently concerns itself with the distribution of environmental burdens and benefits, while sustainability goals are often aimed at reducing environmental burdens. But it is the global capitalist system—a neoliberal system which operates at times both consciously and unconsciously as racist, patriarchal, classist, and heteronormative—that is driving both the volume and the distribution of unequal environmental burdens. Pellow (2016) and others discussion of intersectionality–the understanding interlocking systems of oppression–can help us bridge understandings of environmental justice with sustainability via a discussion of climate justice and just sustainability.
In the context of sustainability and climate change, impacts are often felt “first and worst” by marginalized groups both in the U.S. and worldwide—groups who typically contribute least of all to the problem. On a global scale, these uneven burdens and benefits create a stalemate over how actions to reduce the impacts of climate change can be engaged in, in a fair and equitable way (Timmons Roberts and Parks 2006). As a result, little progress is made. The consequences of this non-action will indeed affect us all, but it will not do so evenly. This is problematic from a day-to-day standpoint, as we know that more equal societies tend to fair better—in terms of health and social problems—than unequal ones. Our sustainability efforts must therefore take into account equity issues from the onset, and must be designed to ensure that climate adaptation efforts work to guarantee the establishment and preservation of a safe environment for all, now, and indefinitely.
So how do we begin to do so? We must acknowledge the systemic root of our environmental problems and their embeddedness in our political and economic system which oppresses in the name of unbridled capitalism. Actors and institutions in power must acknowledge their role in perpetuating oppression and work to deconstruct it. We must continue to focus on inclusive environmental governance efforts, both within and outside of our public service institutions and our current economic system. As an example, executive director of Green 2.0 Whitney Tone has developed directives for diversifying the sustainability C-suite, and points to a diversity checklist organizations can use in their hiring process. We need people of color to gain access to and power over environmental decision making processes, to reflect considerations in decision making that can only come from knowledge gained within the set of their collective historical experiences of environmental oppression. The same is true for all marginalized groups.
Pellow (2016) argues we must also start to conceptualize what it looks like to work entirely outside of our system of state governance. Working to disrupt oppression within a system that creates it can only take us so far. Faber and McCarthy (2003) call for enhanced grassroots strategies to develop a sustainability movement that incorporates justice and equity.
Finally, we must prioritize diversity as imperative for the success of sustainability and science more generally. All of this has been established by scholars and activists of color, but it is critical that we continue to highlight and support these voices. When calls for diversity and inclusivity sprung up in the planning of the Science March on Washington, a barrage of scientists reacted poorly and expressed disdain for the injection of ‘identity politics’ into science. Yet science undeniably is a system of knowledge that was largely developed in a way that privileges people in power, historically, wealthy white men. And in the past it has been repeatedly used to justify discriminatory practices. For those of us whose research reveals that colonization, racism, classism and sexism are indeed scientific and sustainability issues, we have a responsibility to speak up. In addition, (and particularly those of us who wield the most privilege) we have a responsibility to listen. In that spirit, here is a list of leaders of color working on environmental issues.
All of this has become even more urgent as we have witnessed a resurgence of dangerous nationalist and racist ideology permeating through U.S. government leadership. It is this same leadership which threatens the progress of sustainability and environmental science, has deemed the environmental movement “the greatest threat to freedom and prosperity in the modern world,” and has been guided by an ethos not just of “America First,” but “Market First.” Intersectional sustainability efforts, that is, those that consider interlocking systems of oppression, are how we push back on the exploitation of marginalized people and of resources, the economic drivers of our changing climate. To borrow a frank line from Flavia Dzodan’s approach to feminism, “my sustainability will be intersectional, or it will be bullshit.”
Faber, D. and McCarthy, D., 2003. Neo-liberalism, globalization and the struggle for ecological democracy: linking sustainability and environmental justice. Just sustainabilities: Development in an unequal world, pp.38-63.
Pellow, D.N., 2016. Toward a critical environmental justice studies: black lives matter as an environmental justice challenge-corrigendum. Du Bois Review: Social Science Research on Race, 13(2), pp.1-16.
Roberts, J.T. and Parks, B., 2006. A climate of injustice: Global inequality, north-south politics, and climate policy. MIT press.
Written by Anita Küpper, a 2016-2017 Sustainability Leadership Fellow and Ph.D. Student in the Department of Bioagricultural Sciences and Pest Management.
The journey of a tumbleweed
Sometimes skipping, sometimes lurching, seemingly without a sense of direction, a tumbleweed rolls over the prairie in Eastern Colorado. The thick scrub made of scrawny branches is arched so much that it resembles the round shape of a ball. While the harsh and strong south wind sweeps over the treeless plains, it effortlessly propels the weed along its journey. A second tumbleweed joins the sheared plant, chased by the relentless gusts. The two are rolling away, sometimes snagged together, sometimes as distant travel partners. Soon the two of them are no longer alone and a whole flock of detached scrubs stagger over the shortgrass steppe. First in tens, then hundreds and finally thousands they steadily mill ahead, like an armada of withered skeletons. A thick row of snow fences emerges and suddenly interrupts the cheerful march of the tumbleweeds. But other tumbleweeds that have previously come this way already piled up in front of the obstacle, forming a convenient ramp for our shrub, enabling it to climb over and continue its journey over the Great Plains.
Long after our tumbleweed and his companions passed and the landscape had forgotten about their transit, the soil seedbank had not. While the seemingly dead plant jumped over the soil, little three-lobed seeds had detached from the bolls and landed in a wheat field. The following spring after the snow melts and spring temperatures cause seedlings to emerge from the soil by the score, Ken Hildebrandt, a farmer and aerial pesticide applicator in Eastern Colorado, gets ready for another busy season. The constant economic pressure on farmers to produce high yields at low prices on limited space forces them to spray herbicides to avoid weeds from competing with their crops for water, light and nutrients. This particular season was not any different from others except that the herbicide applied killed most of the unwanted plants but not all of them: Despite having been sprayed, a clearly visible trail of sprouts remained growing where our tumbleweed had passed a few months earlier. Why is it that these survived while others did not?
Our tumbleweed got lucky. It had a genetic mutation that allowed it to survive the herbicide. Continuous selection pressure due to the repeated usage of the same herbicide favors plants that evolved to survive an application. When this resistant tumbleweed’s offspring reproduces and the next generation gets exposed to the same herbicide again, the number of resistant plants in the population will increase and at some point replace the susceptible plants, rendering the chemical no longer effective at controlling the weeds. The problem is comparable to that of antibiotic resistance in bacteria: If we re-use the same antibiotic over and over again, we are selecting for the bacteria that have the genetic set-up to survive the application, ultimately leaving us with antibiotic-resistant bacteria only. Similarly, herbicide resistance is a numbers game: If a herbicide gets used very frequently over the course of several years without any alternative ways of weed management techniques it is not a question of if but a question of when resistance will evolve.
A farmer’s struggle
The case of resistant weeds is especially troubling because some plants are able to produce up to a million seeds. So, if the farmer does not detect resistance in his field in time or chooses to ignore it, then he will have a much more severe problem in the next year. “I can see it from the air,” Ken Hildebrandt explains. “At first I didn’t quite understand how everything was dead in the field except for this one trail. The next year I noticed it is three to four times worse than that and five years later the whole field had escaped weeds despite spraying. One plant is enough to start a problem. Some farmers think resistance came over from the neighbor’s field because he didn’t control his fields or only used one kind of chemistry. No one will get excited about one escape in the field, but once it starts to have a monetary consequence the farmers will start to do something about it.”
And the economic impacts resistant weeds can have on crop production are severe. “They can take over the field. Sometimes I can see weeds as high as the crop the farmers are trying to grow. We are having weeds that we can’t seem to get rid of. In the last few years the problem seems to have increased at an exponential rate.” Hildebrandt elaborates further. “Resistance is costing us. I remember the times when you spent a few dollars on chemistry and could clean up a whole field. Now it can cost over 30 dollars an acre because you have to use more expensive combinations to get adequate control. With the price of herbicide as high as it is, it drives down the profit. Production agriculture has to make the farmer money.”
Once weeds have become resistant to a particular herbicide, farmers need to resort to other options to continue producing at high yields. They can either change to a different herbicide mode of action that still works or switch the crop rotation. But if all these possibilities fail, the only option left is to use mechanical cultivation which might include tillage, plowing, disking or sweeping. These techniques have the disadvantage that they deteriorate and dry out the soil, are more labor- and time-intensive and therefore also more costly. Not being able to use herbicides anymore drives up the price of food production, making food less affordable. “It once was more cost-effective to spray a field than to mechanically work it. Now it can be the other way around when we don’t have anything that works, it forces us to go back to the farming practices of the old days. We have come full circle.” Hildebrandt describes. “Farmers are willing to adapt. They try out different things but at some point they are going to run out of options. Right now, farmers are hoping there are new chemistries coming out or some new technology is going to come to help with the problem.”
Ken Hildebrandt spraying a field with his air tractor (Video by Curtis Hildebrandt)
Developing ways to fight herbicide resistance
So what is it that we can do to counteract herbicide resistance? This is where the weed science laboratory at Colorado State University comes in. Here, we are trying to understand how the weeds evolved mechanisms of resistance and how these work. To me doing research on resistant weeds often feels like visiting an inverse crime scene because I study the individuals that survived instead of the ones that were killed. And the question is always: How did the survivors manage to pull this off? What is the strategy that makes them superior to their susceptible peers? Like a detective I am trying to hunt for clues that would give an idea of how the weed managed to survive with the final goal of finding the mutation that is responsible for resistance. Several possible mechanisms of resistance are already known: They range from reduced herbicide uptake or reduced translocation within the weed over plant-internal changes at the herbicide binding site to metabolic detoxification. Often enough weeds come up with mechanisms that we did not know were possible and have little knowledge about.
It is a fascinating area of research because despite us spending a lot of money, weeds seem to have an amazing ability to get around every effort to kill them. It is like a fast-paced arms race, like a game of Elmer Fudd and Bugs Bunny where each party is trying to outsmart the other by being a step ahead. And in the process, we learn a lot about basic science and plant evolution in general. Since herbicide resistance has only been an issue since the 60’s, its research is still in the early stages. But thanks to technological advances in the areas of molecular and genetic sciences many new methods are available to answer these pressing questions.
Ultimately, the aim of these studies is to provide better weed management strategies for farmers and aerial applicators like Ken Hildebrandt. This can be done by developing diagnostic markers for monitoring resistance occurrence and helping to provide the farmers with the knowledge of which herbicides still work before the spraying season starts. The evolution of herbicide resistance in weeds is a human-made problem that will continue to be a challenge because wherever there is selection pressure, individuals with evolved traits to survive the selection pressure will prevail. Therefore, it is questionable if herbicides are a sustainable solution to our problems with weeds as it is just a matter of time until weeds become resistant to a herbicide. However, understanding how herbicide resistance works is a crucial step in preventing further resistance development from happening. This will help prolong the usage of herbicides that are already on the market, keeping food production affordable for years to come.
For more information on weed management and herbicide resistance visit the blogs www.weedcontrolfreaks.com by the weed research group at the University of Wyoming and www.ahri.uwa.edu.au/blog/ by the Australian Herbicide Resistance Initiative (AHRI). Information, graphs and maps on the occurrence of resistant weeds can be found at www.weedscience.org.
Curt Sayles is doing something radical in his part of the world. There are only a handful of farms like his in eastern Colorado. Purple flax, yellow sunflowers, and every conceivable shade of green – it’s a welcome sight to see some color in a landscape of brown wheat and fallowed fields.
Curt grew up farming the conventional way. Farmers in Colorado grow wheat every other year, alternated with a year of fallow, where the land lays bare to store up rainwater for the next wheat crop. It’s been that way ever since the Dust Bowl in the 1930s. But at 60, Curt is experimenting with a greater diversity of crops than conventional wisdom would suggest is possible in his climate, which is famous for wildly variable weather and multiyear droughts. He grows a mix of six different crops at once that his wife and son-in-law move cattle through to graze. He grows this forage mix in rotation with other crops like rye, corn, sunflowers, and millet. And he’s completely eliminated fallow, a daring move for a farmer without irrigation or much rain. It’s not easy trying something new in plain sight of judgmental eyes.
“I quit going to the coffee shop because [other farmers] look at you like you're… I mean you may as well have flown a UFO in because they think you're crazy,” he says.
But Curt is inspired to farm differently. After a trip to Dakota Lakes Research Farm in South Dakota, a group that’s been pushing boundaries in agriculture since the early 90s, Curt became a different kind of farmer. And he’s not the only one who is making changes. Curt is swept up in an excitement that is inspiring thousands of farmers and ranchers around the country to try a new approach. Agriculture is on the brink of another revolution.
A New Vision for Agriculture
Farm-to-table, local food, organic – they all seek to tie the consumer to alternative agriculture. These strategies have societal merit, but they haven’t yet inspired the large-scale changes necessary to repair the hostile relationship between agriculture and the environment. Agriculture needs a vision that improves the land.
That is what the concept of soil health promotes. It seeks to foster a regenerative approach to farming and ranching.
The mindset in conventional agriculture is all about simplification, and it has a singular focus on maximizing this year’s crop yields. It loses sight of the agricultural system as, well, a whole system. You mined your soil organic matter and there are no nutrients left? Buy some more fertilizer. Never mind that building organic matter will not only feed your plants, but also prevent erosion and store more water.
In contrast, soil health is inspired by the way native ecosystems function. It appreciates the whole system. Soil health a philosophy that guides a farmer’s management, such that every action taken on the farm seeks to adequately feed and protect the living organisms in the soil, thus unlocking the enormous potential of soil microbes to release nutrients, create soil structure, build organic matter, and confer drought and disease resistance to plants. In practice, this mindset is realized through four simple principles: minimize soil disturbance, maximize diversity of plants, animals, and soil organisms, keep a living plant root growing as long as possible throughout the year, and maintain residue cover on the soil.
For Curt, these principles are transformational. He eliminated tillage so he doesn’t disturb the soil. By integrating livestock, crop rotation, and a diverse forage mix, he maximizes diversity. And by eliminating the fallow year, he extends the amount of time with a living root in the ground, and maintains residue cover on the soil.
But there is a reason he is only one of a handful of people farming this way in his region. Curt is taking a big risk.
“It’s like a fight all the time.”
Many of the practices associated with soil health have been more quickly adopted “out east,” as Colorado farmers refer to the Midwest, but their adoption has been slower in drier climates. Successfully eliminating fallow or growing a diverse forage mix is much trickier with less water, and no one has developed the recipe for success in eastern Colorado. As a soil health pioneer in this region, Curt realizes it’s not easy.
“Show me the book and formula and I’ll just go do that. Well, there is no book and there is no formula. We're trying to find things that work here. You know winter pea, does that work here or not? It's like a fight all the time. Nothing's easy.”
But without farmers like Curt pushing the limits of diversity, dryland agriculture would be forever confined to one or two crops and years of bare land. Without anyone willing to get rid of fallow, no one would ever know whether it is truly a necessity, or a relic from the years following the Dust Bowl. It would be an admission that there will always be erosion in agriculture, and that the soil is as good as it’s ever going to get.
But soil changes slowly, and it will take time to tell if Curt’s changes have worked. Now, more inspired than ever, Curt is worried he wont have enough time to complete all of his experiments.
“We’ve opened a whole new chapter. I have lots to learn. My biggest fear now is, I'm sitting here at 60. I maybe have 10 more harvests… That's all I've got left. I wish I'd known 20 years ago what I know today.”
Curt’s success with the soil health approach is more important to the Movement than he may realize. In one of the driest and most volatile climates in the country to be a non-irrigated farmer, the obstacles to Curt’s success are greater than just about any farmer in America. If he can make soil health work in Colorado, it will work anywhere.
But the pressure doesn’t rest solely on Curt’s shoulders. He has a close network of other farmers in his region who are undertaking a variety of creative and daring changes on their own farms. Many other farmers and ranchers throughout the US and beyond recognize that soil health may be the way of the future. Universities, government agencies, industry, non-profits, and international experts are responding to the farmers’ excitement to usher in an era of ecological experimentation in agriculture. The age of soil health is here.
Written by Ajit Karna is a 2016-2017 Sustainability Leadership Fellow and Ph.D. Candidate in the Department of Microbiology, Immunology, and Pathology.Can we predict Zika virus transmission to humans and provide sustainable solutions to contain the spread?
I have always been fascinated with viruses, ways to detect them earlier, and stop their spread before they make people sick. In the Animal Disease Laboratory at Colorado State University, we do experiments to explore the role animals play in emerging virus transmission including Zika virus. We do not fully understand the sources of the Zika virus yet. In this blog, I explore options available to bridge scientists and policy makers in the development of sustainable solutions to contain the spread of this virus.
Zika virus is a mosquito borne virus, first discovered in a rhesus monkey in the Ziika forest of Uganda in 1947. Until recently, Zika virus outbreaks have been spotty, but a massive outbreak in Brazil in 2015 and its association with incomplete development of fetal brain (microcephaly) in pregnant women with the Zika virus infection made the current Zika virus outbreak a public health emergency. We do not have fully understood the factors that resulted in this sudden geographic spread and emergence of birth defects. There is no vaccine or medicine available for the prevention and treatment of Zika virus. Transmission (see figure) primarily occurs by the bites of Aedes mosquitoes carrying the virus but the transmission of the virus through sexual contact between person to person increases the likelihood of transmission. The inadequacy of data from previous outbreaks has impeded the science community’s ability to predict the course of Zika virus and inform the policy makers to take evidence-based actions.
The importance of forecasting the next outbreak in human populations and how best to allocate, use and mobilize the monetary, physical and human resources is well demonstrated by the Ebola virus outbreak in West Africa. The predictions can help policy-makers understand the magnitude, duration, and consequences of such outbreaks in human populations, and to manage the outbreaks effectively and sustainably. Even in the absence of detailed data on Zika virus, we can learn a lot from other closely related mosquito borne viruses including dengue virus and yellow fever virus. Database on dengue and yellow fever viruses can be used to derive and synthesize empirical data on outbreak and transmission of Zika virus. The resulting approximated data along with known outbreak patterns of Zika virus can be modeled under different modelling approaches. Using mathematical models, we can figure out some of the unanswered questions, such as the relative role of sexual contact adds to the mosquito bites, and sylvatic, or animal, cycle to the urban cycle in current Zika virus transmission context (see figure). Scientists using the data only on mosquito transmittable viruses need to be mindful that Zika virus is also sexually transmittable. In addition, data on dengue or yellow fever diseases do not reflect observed patterns in Zika. For instance, women have 80% or higher incidence of Zika infection than men in Brazil, perhaps associated with an exponential increase in women visits to a doctor during the epidemic.
The unique property of Zika virus adds complexity in designing a mathematical model to answer several questions. In such situations, mathematical modelers can take into consideration these differences and work through different types of models for (i) only sexually transmitted scenario, (ii) combined sexually and mosquito transmitted scenarios, and (iii) only mosquito transmitted scenario. For (i) and (iii), it will be useful to use data from other purely sexually transmitted disease systems or purely mosquito transmitted disease systems. The combined sexual and mosquito transmitted scenario can be a little tricky to model and even more difficult to parameterize appropriately. Dynamic and compartmental models can be used to formulate hypotheses, and increasing availability of data will allow testing these hypotheses. Among many, one approach to estimate the proportion of sexually transmitted cases compared with the proportion of mosquito transmitted cases of Zika virus is through an integrated biological-behavioral surveillance approach in communities where clinical settings are ongoing. This approach can also be used to untangle human exposure to virus via animal reservoir (sylvatic) compared with urban sources (e.g. Human-mosquito-human transmission). Once we know the incubation period of Zika virus in humans and mosquitoes, frequency of mosquito bites, relative density of the mosquitoes, and proportion of the blood-fed mosquitoes, we can use them to forecast the current Zika virus epidemic in humans. Similarly, the genetic data of the Zika virus isolated from the current and past outbreaks could reveal if the virus from recent outbreaks has new mutations, and may explain the emergence of birth defects that were not observed in previous outbreaks. Before we fully understand the transmission and course of the spread, these models will add possible randomly determined data or pattern that the existing data may not inform, and help scientists inform policy-makers how to respond early.
While prediction of an outbreak is useful, investing in long-term surveillance programs with training, laboratory capacity building, information systems strengthening and community participation could sustainably contain the spread of the Zika virus. Programs based on community participation can build trust and will likely bring more men and women to the health centers to get tested for Zika virus, thereby preventing sexual transmission from infected cases to non-infected person at least to certain extent. At the same time, virus surveillance in mosquitoes and the mosquito control should be ongoing to detect areas of risk for human transmission. In an outbreak situation, subsidizing the cost of hospital visits, contraceptives, or window and door screens could greatly reduce Zika transmission. In addition, constant national and international support is necessary for such programs to be sustainable. The low and middle income countries can face an extra challenge to stop emergence and spread of Zika virus due to their insufficient monetary and trained human resources. Sustainable scenarios also need to be explored while forecasting the next Zika virus emergence and spread.
Zika virus is an urgent example of how scientists take active roles to protect communities facing uncertain challenges. Existing data, theoretical frameworks, epidemiological and ecological methods can help the scientists forecast the spread and future emergence of Zika virus. Just as data from other mosquito-borne viruses can inform predictions of Zika virus outbreaks, Zika virus may contribute vital information to address emergence of future viruses before they result in an epidemic.
As a 5-year-old, one of my favorite things to do was play in the dirt. My cousins and I would make “soup,” a mixture of soil, leaves, twigs, and some unfortunate bugs, with just enough water to easily stir. The “recipes” were endless; from which part of the yard we got the soil, the ratio of twigs to leaves, the addition of a stray earthworm or insect all contributed to different “soups.” As a kid, this play occupied my imagination for hours at a time. As an adult, the interactions of soil and organisms, dead and alive, continue to fascinate me. Just like a hearty stew, soil provides nutrients and energy to all organisms living aboveground, including people, and sustains ecosystems and humanity now and into the future. How, you ask? Well, here are 6 ways soil biodiversity sustains us!
- It’s Alive! Soil is home to ~25% of all described species on Earth. These range from microscopic nematodes and tardigrades to small psuedoscorpians and even larger animals like burrowing owls. But wait, there’s more! The majority of soil species likely have not even been described by scientists. That means soil holds numerous biological mysteries and likely supports far more than 25% of all species on Earth. Soil is a frontier for exploration and discovery, right beneath our feet.
- It grows our food! Some soil organisms people can eat directly, like mushrooms, truffles, and some insects. Other soil organisms help fruits, vegetables, and grains grow by recycling nutrients from dead plant material. All plants, including crops, need nutrients, such as nitrogen, phosphorous, and potassium, from soil. Most soils have limited reservoirs of these nutrients. But dead plants, perhaps from the previous year’s crop, retain many of these nutrients in their tissue. Soil organisms like insects, earthworms, micro-invertebrates, fungi, and bacteria break down dead plant material, releasing nutrients for new plant growth. Soil organisms are critical to recycling nutrients to grow food and support sustainable farming.
- It helps us live long and prosper! Soil organisms impact our health and lifestyles in both negative and positive ways. For example, anthrax, tapeworms, histoplasmosis, and brain encephalitis are all caused by soil organisms, including bacteria, pictured above. Valley Fever, or coccidioidomycosis, is a nasty and often deadly disease caused by the soil fungus Coccidioides immitis native in the southwest USA.
Other soil organisms can cure many diseases. In soil, all these organisms live together in a community. Some organisms have evolved defenses, such as antibiotic compounds, that can minimize disease agents. Antibiotics like penicillin, originate from soil organisms, and can combat many illnesses caused by bacteria or fungi, like pneumonia and strep throat. Soils are also a promising frontier in the development of new pharmaceuticals, which may reduce antibiotic resistance. People around the world, like the child receiving a shot in the photo above enjoy healthy lives thanks to soil organisms.
- It supports wildlife! Nutrient cycling from decomposition also supports food for wildlife that we enjoy viewing, hearing, and in some cases, hunting. Without soil biodiversity, wildlife would not have plants, fruit, and nuts to eat. Much like the effects on people, however, soil can also harbor disease organisms that can make wildlife sick, or even result in death. For example, in July 2016, anthrax, a soil bacterium, released from thawing soil in Siberia killed >1500 reindeer. That’s right, Santa’s sleigh may be running slow this year because of a soil organism!
- It filters water! As water moves through soil, soil organisms use the nutrients and minerals dissolved within it. This effectively removes excess nutrients and some pollutants before water reaches ponds, streams, lakes, rivers, etc. This is important not only for clean drinking water for animals and people (pictured above), but also for healthy fish and other aquatic organisms. In many areas of the US, there is extra nitrogen and phosphorous in surface waters, in part due to run-off of fertilizers from crop fields and lawns. When there is excess nitrogen and phosphorous in water, algae use it grow, consuming large amounts of dissolved oxygen. Reduction in dissolved oxygen can cause fish and other large aquatic organisms to suffocate, generating a “dead zone,” also known as hypoxia. The 2016 “dead zone” in the Gulf of Mexico was estimated to be about the size of Connecticut (5,898 square miles)! Soil organisms can reduce this nutrient load, and the number of algae that grow, keeping our waters oxygenated and healthy.
Soli biodiversity also helps store water in soil. Earthworms, insects, and other animals create tunnels, which allows water to flow into the soil more easily during precipitation events. In addition, soil organisms generate organic matter, made up of the byproducts of biological metabolism (think compost) that gives soils a dark color. Because soil organic matter is charged, it holds water between organic molecules, allowing soil to store more water than clay, slit, and sand particles alone.
- It recycles the air! Before plants covered our planet, cyanobacteria (pictured above) used simple carbon molecules and minerals from rocks as energy sources. This released oxygen, which eventually built up in the atmosphere to levels that could support the evolution of more microbes, plants, fungi, and animals, like us. We still rely on plants and soil organisms to maintain enough oxygen in the atmosphere for us to live. Soil organisms also cycle greenhouse gasses, which trap heat near the surface of Earth (pictured above, bottom panel).
Soil organisms can both pull greenhouse gases, like carbon dioxide, out of the atmosphere and respire carbon dioxide back into the atmosphere. When soil organisms decompose dead material, they use carbon from the tissue as an energy source. Some of that carbon is used for growth and reproduction. That carbon can stick around in soil for weeks, years, decades, or even longer. Some of the carbon is used for respiration, just like when we breath, soil organisms produce carbon dioxide. This adds up to a lot of carbon! As shown above, soils contain 2,300 gigatonnes of carbon. By comparison, respiration by soil organisms contributes only 60 gigatonnes of carbon back to the atmosphere. We can help soil organisms potentially reduce greenhouse gasses in the atmosphere through land management choices like ecosystem restoration, conservation farming practices, and increased urban green space.
Soil organisms are truly the unsung heroes of sustainability. We need them. Wildlife needs them. Fish need them. Ecosystems need them. Soil biodiversity not only sustains life on earth, it is intrinsically fascinating. From bioluminescent fungi (pictured far left) to dog vomit slime mold (pictured top right) and adorable tardigrades (pictured bottom right) soil is home to some awesome living things. It is organisms like these that captured my adult imagination long after my “soup” making days as a kid. The best part is, it is not imaginary at all. The real world beneath our feet is astounding and essential. We all need living soil, so future generations can play and thrive in the dirt.
All images, except the reindeer, are from the Global Soil Biodiversity Atlas and available for free download (pdf) and use! Learn more about soil biodiversity from the Atlas and the Global Soil Biodiversity Initiative.
Written by Stacy Lischka is a 2016-2017 Sustainability Leadership Fellow and Ph.D. Candidate in the Department of Fish, Wildlife, and Conservation Biology.
Imagine you are hiking along a trail, high in Colorado’s Rocky Mountains, taking in the scenery, breathing the fresh air, and hoping you’ll see some wildlife to round out your adventure. It’s a lovely fall day. The sun is shining and the service berries are abundant. You stop to snack on a few berries, and as you look up from foraging, you see a large, black animal, also eating its fill of berries some distance away. You squint, mind racing, trying to figure out what it is that you see. Could it be a bear?
Now, imagine you are taking your dog for a walk down the sidewalk in your neighborhood. Your 5-year old is riding his bike along next to you. Its 5 pm, and the late fall, so its nearly dark. You’re busy trying to keep your son from riding his bike into the street, and hardly notice that many of your neighbors have their garbage cans out on the curb, waiting for tomorrow’s garbage pickup. You turn a corner and walk nearly into a large, black animal eating its fill out of a tipped over garbage can in your neighbor’s driveway. The animal looks up, hears you yell “Oh my god!” and runs off down the street to the nearby natural area. Could that have been a bear?
These two different experiences likely made you feel entirely different things. In the first scenario, you might have felt excitement about seeing a bear in its natural habitat, filling up on natural foods to prepare for hibernation. You probably felt that this interaction was natural, no cause for alarm, and that the bear was behaving in a way consistent with its evolutionary needs. You would probably walk away from this interaction feeling pretty excited that it had happened and ready to brag about it to all of your friends.
The second scenario might have caused you to feel very differently. You might have felt scared by the situation, especially for the safety of your son. You might also have been concerned for the health of the bear, knowing that garbage is not a natural food for bears. You would probably walk away from this situation feeling like there was a problem and maybe planning to call your local wildlife office to report the incident.
Both of these scenarios are common in Colorado and in other states with black bears. Unfortunately, examples like the second scenario have increased alarmingly within the last 10 years. In fact, wildlife managers have reported increases in conflicts between people and black bears in 30 of the 41 states that have bear populations. In Colorado, the total number of human-black bear conflicts reported to Colorado Parks and Wildlife has more than tripled in the past 15 years. Because of this, people like me are spending lots of time and effort to figure out why conflicts occur. Are bear populations increasing, and do more bears on the landscape mean more conflicts with people? Are bears preferentially seeking out human foods over natural foods? Does seeking out human foods hurt or help individual bears and bear populations? What are the best approaches to discourage bears from seeking out human foods? How will changing climate and drought change natural food availability for bears? Exploring the answers to these and many more questions will help us understand how to reduce conflicts between people and black bears, and maintain healthy black bear populations across the U.S. and Canada.
The perfect storm
Researchers and biologists don’t completely understand what is causing the increase in conflicts between people and black bears, but we know human food is a potential culprit. We know that people and bears prefer to live in the same types of areas, especially areas along rivers and in forested areas with lots of natural foods. In LaPlata County, one of the areas with the best quality bear habitat in Colorado, human development has increased by more than 600% since 1970. This means that people are much more widely distributed across the landscape than they have been in the past. As a result, there are fewer areas where bears can be bears without running into people, their homes, their gardens, and their garbage.
We also know that bears evolved to be very efficient food-finding machines. Between July and September each year, bears enter a period called hyperphagia, where they are putting on massive amounts of body fat to prepare for hibernation. In this period, they need to take in approximately 20,000 calories a day. That’s the equivalent of 36 Big Macs, every single day! Bears also have long life spans (more than 20 years in the wild), and readily learn and remember the locations of reliable food sources. Moreover, bears have a very keen sense of smell and can smell foods up to 5 miles away.
When people live in an area, they bring with them a wealth of calorie-dense, plentiful foods such as garbage, gardens, fruit trees, pet foods, bird feeders, and grills. These foods require little energy for bears to find. This creates a literal smorgasbord for bears in many areas. Unfortunately, eating human food can compromise the health of bears and potentially change their natural food-finding behaviors, leading them to be involved in conflicts with people. The outcomes of these interactions for people are usually inconvenient (e.g. having to pick up strewn trash), but the consequences for bears are often lethal, as problem-causing bears are often killed. Conflicts have become so frequent in some areas, that some cities require all residents to own and use a bear-resistant garbage container, which reduces the garbage available to bears.
How you can help
To keep bears acting like bears and maintain the “naturalness” of the areas where we live, we must all take action to prevent bears from getting into trouble with people. You may feel like there is nothing you can do to reduce conflicts or that your actions will not make a difference. I argue that the most effective thing we can do is securing all food available to bears and by convincing our friends and neighbors to do the same. We can make our communities a better place for people and bears to live, just by taking a few simple actions ourselves and helping the idea spread across our communities.
What can you do to reduce your chance of having a bear knock over your garbage can, harass your pets, or damage your fruit trees? It’s simple, really. First, make all of the things that taste delicious to a bear very difficult to access. By securing your trash in a bear-proof container, fencing your fruit trees, keeping pet food indoors, and cleaning your grill, you will remove items that attract bears into urban areas. This will encourage bears to feed in natural areas - where there is more than enough food to keep them healthy and well-fed.
Second, talk about what you are doing with your friends, family, neighbors, co-workers, anyone who will listen! Neighbors tend to develop similar habits over time, especially if they see and hear others talking about their actions. Disaster preparedness research tells us that this sort of social learning is much more effective at motivating action than impersonal information from experts (e.g. city officials, wildlife managers, etc.). Tell them how easy it is to secure your garbage until the morning of trash pick-up. Tell them what a large apple crop you’ve had this year because no bears are breaking limbs off your apple tree. And, most importantly, tell them how your actions have helped you feel in control of your own risk of having a conflict with a bear.
Your actions can, and will, have a real effect on bears. We must all do our part to reduce the food that attracts bears into towns and cities, to keep bears acting wild and safe from the lethal consequences of a free lunch. Please join me in me in ensuring that our communities stay beautiful, natural, and safe places for people and black bears to co-exist.
Written by Stacey Elmore is a 2016-2017 Sustainability Leadership Fellow and Post Doctoral Researcher in the Department of Fish, Wildlife, and Conservation Biology.
About a month ago, I was walking my dogs around the apartment complex for their evening excursion. I bent over to untangle their leashes, and when I straightened up, I heard what can best be described as a “snorty growl” that sounded familiar, but I couldn’t quite place it. And it was very close to my face. I slowly turned my head to the left and locked eyes with a raccoon. The masked critter was also out for an evening jaunt, and had been sitting quietly in the tree – within spitting distance from my head!
As my brain connected the snorty growl with the presence of a raccoon, recognition took hold, and the familiarity became clear. As a post-doctoral researcher for Colorado State University and the U.S. Department of Agriculture’s (USDA) National Wildlife Research Center (NWRC), I encounter this sound frequently during my job duties. Luckily, healthy raccoons usually want nothing more than to be left alone by people, so my raccoon friend and I parted ways with no damage done.
I work with the rabies research group at the NWRC. A large portion of our group’s activities focus on studying the ecology of the raccoon (Procyon lotor) rabies virus, and the wildlife that transmit the virus to people and other animals. My job includes studying how raccoon movement influences the spread of disease, and which rabies management techniques might help to eliminate the virus from certain animal populations. This kind of investigation can not be done without collaboration, however, and I am fortunate to work with scientists from not only the NWRC, but also the National Rabies Management Program, Land and Sea Systems Analysis, Inc. (Quebec, Canada), and Colorado State University.
The Raccoon Rabies Virus
Rabies is an ancient disease that might bring to mind the dogs from the tear-jerking “Old Yeller”, or perhaps the horror movie “Cujo”. The rabies virus causes the disease “rabies”, which leads to inflammation of the Central Nervous System, including the brain. The virus travels mainly through nerves, but in the last stages of disease, it is also found in the salivary glands. When an infected animal bites a person or a pet, the rabies virus can enter the bite wound through the animal’s saliva. Although an encounter with an infected animal might not result in disease, rabies is 100% fatal in those unfortunate individuals that do show symptoms. This fact is scary - and is the reason that rabies is such a concern worldwide. The good news, however, is that rabies is also very preventable in people, pets, and many wildlife species through pre- and post-exposure vaccination, and a little common sense.
There are multiple genetic variants of the rabies virus, and each variant prefers to infect a different animal species. For example, the canine variant, which is what Old Yeller and Cujo likely suffered, no longer circulates in the United States, thanks to responsible pet ownership and dog vaccinations. Other variants, however, such as the ones that circulate in wildlife (bats, skunks, foxes, or raccoons), are not as easy to control. It seems that these species have a very difficult time keeping veterinary appointments!
Luckily for the wildlife, and for the general public, there is a federal program that organizes vaccine appointments on behalf of the animals – the National Rabies Management Program (NRMP). Along with the NWRC, the NRMP is part of the Wildlife Services program of the USDA Animal and Plant Health Inspection Service. The NRMP implements an oral rabies vaccination (ORV) program and other management techniques to control the spread of rabies virus in wild carnivore populations. Of all the rabies virus variants, however, the raccoon rabies virus variant receives the most intensive management. This variant is only found in the eastern U.S. and a vaccination zone stretches south from Lake Erie Maine to northern Alabama.
Every year, the NRMP drops around 8 to 10 million oral rabies vaccine baits from aircraft within targeted zones. To minimize the chance of a bait being picked up by people and pets, the program distributes baits by hand, helicopter, and bait stations in urban and suburban areas. The number of baits distributed in a particular area is determined by how many raccoons are likely to be living there and how many other animals might compete with the raccoons to eat the baits. The goal is to reach as many raccoons as possible to prevent the spread of rabies within and beyond the vaccination zones.
Raccoons populations aren’t declining… So why is this a sustainability problem?
Raccoons are a common, versatile and resourceful wildlife species. Unlike endangered species, whose limited or declining populations are easily linked to sustainability issues, abundant raccoons may seem out of place in this discussion. But, I’d argue that they do relate to sustainability because they are so abundant. Raccoon populations are the most dense in areas with lots of food, especially leftovers from people, and good places to hide during the day. Urban and suburban neighborhoods and parks fit this description, which brings a lot of raccoons into potential contact with a lot of people. When raccoon density is high, a rabies outbreak can move quickly through the population and chances of an encounter between a rabid animal and a person or a pet increase.
If a person is bitten or otherwise contacts the saliva of a potentially rabid animal, post-exposure prophylaxis (PEP) is administered and will prevent disease progression. In this event your local public health department is the first call that a person should make if he or she might have been exposed to a rabid animal. The public health workers will determine if PEP is warranted. Rabies PEP consists of a series of injections and it is very costly - roughly $3000 or more for one exposure event, and it is usually the patient who must pick up the bill. This is the crux of the sustainability issue with North American rabies. If we didn’t have to deal with raccoon rabies, how much of this money could be reassigned for other important and pressing ecological problems? There would still be a need for PEP in the U.S., but perhaps with a much lower frequency.
Recently, the NRMP met with rabies experts and stakeholders, to formulate a plan to eliminate the raccoon variant of the rabies virus from the eastern U.S. over a 30-year period. The plan entails moving the barrier eastward, as ORV efforts clear raccoon rabies from previously infected areas, according to carefully selected criteria. It is an ambitious goal, and also an achievable one. Through ORV activities, raccoon rabies has been largely eliminated from Canada, although the virus constantly challenges the southern regions of border provinces (i.e., Ontario, Quebec, and New Brunswick). Once the U.S. is declared free of raccoon rabies, the extreme need for PEP is expected to decrease over time and funds can be redirected to other sustainability needs. Also, by improving the health of raccoon populations, perhaps some of the fear of wildlife-associated diseases will abate.
But keep an ear out for that familiar snorty growl…the raccoons are not going to leave the neighborhood trash cans alone anytime soon…
Staying informed about rabies is a key prevention method for both people and pets. For more information, please visit the following websites:
The sun wanes as I drive east towards the looming Rocky Mountains, leaving the vast expanse of the plains in my wake. I blast the air conditioning but the hope for comfort seems futile given the amount of time the car baked under the cloudless prairie sky. It’s a typical summer day on the eastern plains of Colorado, which early settlers called the great American desert. Yet fields of lush field crops and small towns punctuate the drive east on Highway 34. The heart of the transformation from desert to agricultural oasis lies in the discovery and exploitation of the Ogallala aquifer.
The Ogallala is the largest aquifer in North America. Developments in pumping technology in the 20th century facilitated the expansion of high capacity groundwater wells across the aquifer, turning the arid high plains into the grain basket of America. However, groundwater pumping rates that exceed natural aquifer replenishment threaten the future sustainability of the resource.
Aquifers around the globe provide vital water resources that allow agriculture to persist despite insufficient rainfall. Climate change compounds the implications of groundwater depletion on global food production by increasing the frequency and severity of drought. The future of the world’s aquifers and their ability to support agriculture depend on the development of management strategies that conserve groundwater for future generations.
The rate of groundwater depletion depends on the underlying characteristics of the aquifer, the density of groundwater wells and the rate of natural replenishment. Variation in depletion rates within an aquifer complicate resource management decisions and diminish the effectiveness of aquifer-scale conservation initiatives. In some areas of the southern Ogallala the water table, the vertical height of the aquifer, has fallen by more than 150 ft., roughly 70%. However, other regions in the northern Ogallala of the Nebraska have seen relatively small decreases in groundwater levels. To conserve groundwater resources, the aquifers of the world need management strategies that recognize this variation as well as the impact of groundwater extraction on the local economy when designing conservation initiatives.
The groundwater pumped from the Ogallala serves as the backbone of the rural economies built around irrigated agriculture. The economic impact of irrigated agriculture extends beyond the profit margins of farmers and ranchers. Irrigation creates jobs and supports local agricultural and consumer service industries. Aquifer conservation measures must account for the important role of irrigation in the local economy and aim to minimize the adverse economic impacts of groundwater management.
My research focuses on understanding how variation in aquifer characteristics influences the costs and benefits of differing management strategies. I integrate hydrologic, agronomic and economic models to investigate how groundwater users respond to conservation policies and changing aquifer conditions. Research results inform stakeholders of the tradeoffs inherent in alternative conservation strategies, allowing groundwater users to choose policies that best fit their community’s long-term objectives. I am currently working on an interdisciplinary research initiative funded by USDA-NIFA which partner economists, hydrologists and agronomists from research institutions across the Ogallala to create sustainable food production systems and rural economies across the region.
Conserving groundwater to meet future food demands and to sustain the agricultural communities built on irrigated agricultural requires management strategies that balance the costs of conservation today with benefits of a healthier aquifer tomorrow. Incorporating localized variation in aquifer characteristics and accounting for the economic impacts of groundwater pumping is paramount in designing policies that find this balance and effectively save groundwater for future generations.
To learn more about the Ogallala interdisciplinary research project visit OgallalaWater.org.
Written by Stacy Endriss is a 2016-2017 Sustainability Leadership Fellow and Ph.D. Candidate in the Department of Bioagricultural Sciences and Pest Management and the Graduate Degree Program in Ecology.
A beautiful landscape:
It’s a morning in late June and I close my eyes, tilting my head into the warmth of the sun just as it peaks over the neighboring foothills. Then I listen.
In less than a minute I hear the beginning crescendo of an apian symphony. First, a persistent high-pitched whine fills my ears, sustained by hundreds of foraging honey bees. I can hear each individual female, not by her sound, but by its absence: her buzzing becomes more staccato, punctuated by brief seconds of silence as she stops briefly to scrounge for food within the newly blooming flowers. Next, a deeper more intermittent hum quickly darts in and out of my hearing. Bumblebees, it seems, are more fickle in how they flit from plant to plant.
My ears tell me this is a thriving, healthy habitat. However, when I open my eyes I am met with a different story. Common mullein overwhelms the landscape, pale green stalks covered in tiny yellow flowers blocking the view of the neighboring creek. Interspersed among these plants are ugly, brown stalks, bleak tombstones of the now-dead plants of last year. Looming above everything else are brief splotches of purple, clumps of musk thistle that haphazardly dot the landscape. Even my feet, I find, are enfolded by waves of gently nodding cheatgrass, the still-green seeds already stuck in the creases of my snakeguards and the eyelets of my boots. I am surrounded by invasive weeds.
Perhaps I should feel disgust for this less than ‘pristine’ habitat. Yet, to me, this is beauty. We often vilify invasive species. But like any good villain they have depth, a complexity that allows for both good and bad.
A story of survival:
If allowed to tell their story, invasive species would undoubtedly be the epic heroes, the unwitting protagonists in a tale of a small population overcoming innumerable barriers to survive and flourish in a foreign land.
Their journey is one of hardship and perseverance. Being brought to a new place is rare, and surviving long enough to reproduce rarer still. As newcomers to their neighborhoods, these plants often have difficulty finding mates, and are more vulnerable to being wiped out by chance events such as floods, lightning strikes, or even the hoof of a passing deer. To make matters worse, thanks to natural selection they are especially equipped to survive in their native habitat, not this drastically different land they now inhabit.
So what is it about these plants that allowed them to overcome the odds? To outcompete the native plants that had successfully survived in these environments for thousands of years?
The key to success:
Invaders often rapidly adapt, quickly changing their looks and personality to better match the unique challenges of their new home. What’s more, these changes are often consistent, predictable regardless of the plant in question. Most invaders grow bigger, produce more but smaller seeds, and reproduce faster than their compatriots back home. Why is it that they often change in the same way?
Similar changes may mean plant invaders face similar challenges. For example, the type of plant-eating insects they must defend against often differs between their old and their new homes. Within a plant’s native habitat they are often eaten by many different insects, but mostly by specialists. Specialists are like the toddlers of the insect world, extremely picky in what they eat, but likely to gorge on what they find good. On the other hand, when plants are brought to a new habitat they lose the specialists that have fed upon them for thousands of years, and are attacked mostly by generalists. If specialists are the toddlers, generalists are the teenagers, game to eat most anything.
Understanding how plants shift their defense in response to specialists and generalists is surprisingly difficult within native populations, as we must first tease apart the separate effect of specialists and generalists, but both are feeding on the same plants at the same time.
However, invasions have offered much needed insight into how plants change when they consistently experience these differences for hundreds of years. Invasions provide two sets plants from the same species that have experienced two very different types of attack: one mostly by specialists and one mostly by generalists. By studying how plants differ between their native and introduced habitats, we can begin to pick out the traits that play an important role in defending against insects, and how flexible they are at adapting to sudden shifts in insect communities.
In addition, plant invaders often must adapt to more than just differences in the insect community. In their new home they often experience new climate, new plant competitors, new pathogens, new pollinators, and many more factors we are only just beginning to understand. In this way, plant invasions are one of nature’s greatest experiments, their differences allowing us to finally understand how plants adapt in response to many, very specific, types of environmental change.
Villains to the rescue
Successful invaders are, for us, often a great source of dismay. They destroy native habitats and overtake farmers’ fields. They increase wildfires, devastate recreational areas, and cost billions of dollars each year in management and lost revenue.
Yet some good may come from better understanding their story. Like invasive species, native plants are engaged in their own epic battle against natural selection. In today’s world of rapid global change, their habitat is changing at an increasingly rapid pace. Climate is shifting. Globalization is increasing. And with these changes come cascading consequences. Changes in climate may alter wildfire or flood regimes. With increasing globalization comes greater development and disturbance of native habitat. As transportation improves, plants and animals often hitch a ride, meaning that native plants must interact with an increasingly novel suite of plants and animals.
All of these new challenges may seem overwhelming. Yet these challenges are the very same barriers already successfully overcome by many invaders. Where many native plants fail, invasions not only succeed, they flourish.
In this way, understanding how plants adapt to their new habitats doesn’t just help manage for future invasions, it can also help protect the native plants we care about. By understanding which traits allow invaders to succeed when they experience a new habitat, we can potentially identify which plants may be flexible enough to adapt in the face of rapid change, and focus on protecting those that are not. Environmental change is inevitable, but least we can be prepared to help our native plants survive and persist.
Standing in the midst of a floral oasis, listening to the cacophony of thousands of beating wings, it is hard for me to feel hate for these invaders. Instead I see survivors, and stand full of admiration. The irony is that we often worry that invaders may be the downfall of native species, but they just may hold the key to their success. Perhaps it is invaders’ more villainous qualities that may actually be their most redeemable. And that if we listen carefully enough to their story, we may just be able to use these qualities to fight for a better, more sustainable future.
Intro photos caption: On the left a honey bee forages for food at a mullein flower, her legs already coated in mullein's orange pollen. On the right is a honey bee look-alike, a two-wing hoverfly stealing some sugary nectar.
Written by Brittany A. Mosher is a 2016-2017 Sustainability Leadership Fellow and Ph.D. Candidate in the Department of Fish, Wildlife, and Conservation Biology.
It’s a tale as old as time. A gal shows up at a local watering hole, feeling hopeful and excited. She’s kissed a lot of toads in her day, which hasn’t been all that bad, but she is still looking for her prince. As the minutes slowly turn to hours, the exhilaration turns to dread. “This can’t be happening”, she thinks to herself. But the longer she waits, the more certain she is that it is happening. This time, like the last, she has been stood up.
In this day and age, toad love is tough love. At a stunning wetland at 11,000 feet in elevation a lovely female boreal toad named Anura has been stood up. And she hasn’t been jilted by just one particular toad with commitment issues. No, she has been abandoned by every male toad.
In late May in the high country of Colorado the snow is just starting to melt. Two days ago Anura made her way out from under the cozy log where she spent the last seven months, and began the kilometers-long trek across the frozen ground to the same wetland where she was born. She’ll wait several days for a mate, but just like last year, she is the only member of her species at the pond. The only visitors she has are human researchers who study declining boreal toad populations.
We, as researchers, are just as confused as Anura is. Boreal toads in Colorado are in trouble, in large part due to an invasive chytrid fungus. Chytrid is responsible for toads vanishing at this wetland and at many others in Colorado. We didn’t expect to find any toads at the pond during this visit. Several years ago, we placed an electronic tag in Anura’s body so that we could identify her, the same way that a veterinarian embeds a microchip in a beloved pet. This year when we scan Anura—like a box of cereal at the supermarket—her unique code pops up. We are shocked to find that this is the same lone female we found here last year.
Why are we so surprised? Last year, Anura’s skin tested positive for chytrid. In toads like Anura, chytrid often carries a death sentence, and we did not expect to see her again. The fact that she made it through the long winter without succumbing to disease makes us wonder if she may carry a form of genetic resistance. It’s heartbreaking that she may not have a chance to mate again, because her genes could be crucial for the survival of this species.
A tiny terror
Chytrid spores swim in water and burrow into the skin of amphibians (frogs, toads, and salamanders) that they encounter. Amphibian skin is like a dish sponge – porous enough that oxygen and moisture can be absorbed. The skin also teems with bacteria that helps amphibians stay healthy. An amphibian whose skin is taken over by chytrid often becomes lethargic, stressed, and can die of a heart attack. So far, chytrid has been related to population crashes of over 200 amphibian species all over the world, including the boreal toad.
With many amphibian species in decline in Colorado and around the globe, captive breeding programs, reintroductions, and translocations have become necessary management actions. Researchers at Colorado State University are teaming up with agencies like Colorado Parks and Wildlife and the National Park Service to learn more about boreal toads and to use research to help make decisions about how to conserve these increasingly rare species that are an important part of healthy ecosystems.
Generally, we find chytrid by capturing toads at wetlands and swabbing their bodies with cotton swabs. Back in the laboratory, we search for chytrid spores on the swabs. If we find the spores, we know that chytrid is present at the wetland and that boreal toads are likely to be in danger. Sampling for chytrid has gotten more difficult as toads have become rarer. Many of the beautiful places once brimming with amorous, chirping toads in the early summer are now silent, with few or no representatives of the species.
Conservation in action
One strategy to restore toad populations is to reintroduce boreal toads raised in captivity to these depleted wetlands where toads no longer roam. But what if chytrid is still living in the water, waiting for its next opportunity to attack? I study how to sample chytrid in pond water before reintroduction events, without needing to catch toads or other amphibians. By pumping pond water through very small filters, chytrid spores that get “caught” can be identified. These filters can help our collaborators find wetlands without chytrid where boreal toad reintroductions might be successful. The data can also give information about how much chytrid is in the water at different sites so that conservation biologists everywhere can learn what kinds of ponds are least hospitable to chytrid. When I was a youngster in upstate New York, far from the toads of Colorado, my father and I would sit on the porch in the early spring and wait to hear the sound of frogs calling. For me, that melody was the first indication that the land was thawing and that summer would come, bringing along with it all of the good things that children look forward to. I didn’t know that I’d someday spend several years of my life trying to understand what was happening at the now silent ponds of Colorado.
A plan for recovery
While this chapter in the book of boreal toads is a sad one, the story isn’t over yet. A group of state, federal, and non-profit wildlife agencies in Colorado (known as The Boreal Toad Recovery Team) is pooling resources and sharing data to make decisions about how best to manage existing boreal toad populations and to create new ones. In California, a frog that was in decline in part due to chytrid has started to recover. And in Colorado, several reintroductions have been attempted and our first success story has emerged: a brand new toad population at a pond without chytrid. With a little help from conservation biologists, these mountain residents may once again find love at our mountain ponds.
Get in touch with Brittany A. Mosher to talk toads! @BAMdoesscience http://brittany-a-mosher.strikingly.com/
This March I was one of several students invited to participate in the annual Congressional Visits Day (CVD) for the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America. This was an exceptional opportunity to learn about our nation’s congressional system, network with other scientists and science advocates from around the country, and lobby for a cause I am passionate about.
Going into the visit, I really had no idea what to expect, so the societies had an orientation at the American Association for the Advancement of Science headquarters in D.C. before the actual CVD. We met our teammates (grouped by geographic region) and got the run-down on what we were asking for from our representatives that we were meeting with the next day. I learned that in the 2008 Farm Bill $700 million was authorized for the USDA Agriculture and Food Research Initiative (AFRI), the premier competitive grants program for food, agriculture, and natural sciences, but only half of that amount was granted last year. Our mission was to ask our senators and representatives to support the full-authorized amount this year, or at least support more than last year! To me this seemed like it would be a pretty straightforward task since the arguments for supporting federal funding of science, or at least funding of agriculture and the rural sector, is bipartisan and important to the states I would be taking with—Colorado and New Mexico. I also have a personal interest in seeing this program grow as I build my career as a soils researcher and funding is limited, so I figured that my enthusiasm and youth would make talking about funding of agricultural research relatively painless.
The evening before the visits we got a schedule of which congressional offices, both from the senate and house sides, we were meeting with and more specifically, which legislative assistants and fellows would be conducting those meetings. We got an early start heading over to our first meeting at the Senate building since the metro was partly down and we heard the line to get through security to enter the building could be long in the morning. Although imposing, the senate building was inspiring—walking down the halls of our nation’s capital and seeing the different state flags in front of each office definitely made me feel a surge of patriotism. I was pretty nervous for the first meeting, but luckily my partner (Dr. Richard Pratt, pictured above) had much experience doing these types of visits and guided me through the visit. Our first meeting was very successful. The legislative fellow was an ecologist and we did not need to convince her of the merits of funding the AFRI research grants and she told us that their office would support the full-authorized amount.
The remainder of the visits had more mixed responses, but they all had a positive tone. In our meetings we particularly tried to focus on issues that were relatable to our states, mainly water resources, which seemed to help in the offices that weren’t necessarily keen on funding scientific research per say, but were interested in sustaining the natural resources in their state. While I became more use to what to expect as the day went on and was less nervous, I would say that my confidence did not necessarily improve. Walking around and listening to the other groups in the offices I realized that everyone there was asking for something they also thought was extremely important, and so standing out was probably difficult. Meandering down the halls of the House I saw men and women of all ages in fancy suits, outdoorsmen with giant beards representing the fish and game, and kids in wheelchairs lobbying for funding of their disease. It was pretty exciting witnessing all of the hustle and bustle associated with congress, but my confidence to impress the offices about the importance of supporting agricultural and natural resource research started to wane as I realized that we weren’t from a group that donated funds to the official’s campaign, nor were we kids in wheelchairs. How do you deny the request of a child in a wheelchair? Despite this realization, I tried to stay as enthusiastic and confident, knowing that our request was something that I believed in, even with varying levels of interest from the staffers in our representatives’ offices.
Overall, I found this experience extremely rewarding as a graduate student and I would highly recommend it to others. Being involved in a situation where you have the power to influence change in an area you consider important is certainly an empowering feeling.
The environmental benefits of eating less animal-sourced foods have been touted so frequently that this advice is “old news”. Suggesting that choosing plant-based diets could Save The World generates little excitement, despite attractive benefits that include less agricultural land use, reduced greenhouse gas emissions, and improved health. However, recent research suggests that the effects of climate change make the advice more important than ever before. Beyond being good for the planet, we now have new reasons for why plant-based diets are important for our health. Human gut microbiota cooperate to transform animal-sourced foods into cancer-promoting toxins, while byproducts of plant foods energize and sooth our digestive tract.
Our digestive tract is populated by trillions of nearly invisible microorganisms, which help us digest food, obtain nutrients, and maintain immunity. These microbes primarily function by fermenting foods we eat to generate energy, creating byproducts that can either promote or detract from intestinal health in the process. A healthy gut community is well balanced in type and number of species, and generates byproducts that energize human colon cells and prevent disease-causing pathogens from entering the system.
Perhaps the most important trait of a healthy gut is an intact protective lining, made up of slimy mucins separating the intestinal cells from harmful organisms or toxins travelling through the digestive tract. Microbial grazing, or selective feeding by microbes on gut surface mucins, can damage underlying cells and degrade this protective lining. Exposed intestinal cells then initiate an inflammatory immune response that can contribute to the development and progression of chronic diseases including obesity, cardiovascular disease, cancer, and diabetes.
The processes by which gut microbial activities affect gut health is being investigated in the Weir Lab at Colorado State University, where I am currently a PhD candidate. Recently, we examined data from a dietary intervention in colorectal cancer survivors, which supplemented one of two high-fiber plant foods, rice bran or navy beans. We wanted to see if these foods have the potential to alter gut microbes and their metabolites and reduce intestinal diseases. The data showed that rice bran consumption might indeed do just that.
Study participants who consumed rice bran had higher populations of the friendly gut microbe Bacteroides ovatus, an organism that competes with and excludes other harmful microbes that target gut mucins as a “favorite food”. B. ovatus prefers fiber components found in rice bran called xylans, which it transforms into beneficial byproducts that control appetite, reduce inflammation, and prevent cancerous tumors. Xylans structurally resemble gut mucins and are only found in plant-based foods. Research by other teams suggests that a diet devoid of xylans and other fiber starves gut microbes, forcing them to resort to feeding on the intestinal lining. Preventing breakdown of intestinal lining and resulting inflammation and immune activity could explain the importance of plant-based foods in human health, but gut microbes don’t transform all foods into beneficial byproducts. In fact, red meat and high fat diets become a source of cancer-causing toxins during microbial digestion.
Research from Oxford University by the Scarborough lab suggests that the benefits of plant-based diets extend far beyond intestinal health. Greenhouse gas emissions are reduced by 29-70% (depending on whether food processing is included) and water usage is also minimized. Given that 70% of water is used for food production and that producing plant foods uses less water, choosing plant-based over animal-based products can become an important part of water conservation. Money can also be saved. The Scarborough team estimates that a global dietary shift toward a plant-based diet could save $1 trillion in health care costs and $30 trillion in lost productivity. They also suggest that climate change will decrease both the global food supply and dietary quality enough to directly cause 500,000 deaths by 2050. As crop yields dwindle due to climate change, the ability of plant foods to maximize production while using less energy will provide a valuable strategy for providing the world with enough food.
In considering an individual’s contribution to global sustainability, few decisions make as much impact as the one we make several times a day when we decide what to eat. Some suggest that in the coming decades up to 740 million lives, or 10% of the world population, could be spared from death due to under-nutrition by reducing or eliminating human consumption of animal-sourced foods. The potential benefits are so profound and widespread that TIME magazine recently published an article titled ‘How a Vegetarian Diet Could Help Save the Planet’. Of course, these benefits aren’t limited to strict vegetarianism; replacing some or most animal foods with plant foods also improves sustainability. Emphasizing plant foods in your diet is a simple yet powerful way to promote personal health, reduce carbon footprints, save water, and feed a growing population in an era of climate change.
Uncertainty, complexity and adaptation: The importance of ecological monitoring for sustainable natural resource management
Even under ideal circumstances, natural resource management is bedeviled by uncertainty. In addition to societal uncertainties—such as market volatility, political pendulum swings, and shifting values— natural resource managers must also wrestle with the inherent complexity of natural systems. It isn’t rocket science—it’s often trickier than that. When NASA astronauts press the launch button, they can be fairly confident it will start a chain reaction that leads to blast off. The properties of each component part and the relationships between them are well understood. They are designed that way. But the ecological systems that support the goods and services we depend on (such as timber, water, and aesthetic values)? Those are more complex. Each is composed of a complex of web of different component parts, many of which we are still struggling to understand. We put a man on the moon in 1969, for instance, but we are just now learning about the specific mechanisms that result in tree death.
The uncertainty inherent in natural systems is also multiplied exponentially by our planet’s changing climate. We know that the average global temperature is rising—and fast. However, we don’t know specifically how the climate will change in a particular place. Will it get hotter, warmer, or maybe even colder? Will it be wetter, or drier? It’s not just averages that matter: the timing and duration of extreme events like heat waves or droughts implications for devastating disturbances such as insect outbreaks or wildfires. And even if we are fairly certain that disturbances and extreme events may increase, there is still a lot of uncertainty about how we can foster adaptation and increase resilience (i.e. make sure natural systems can bounce back after they occur).
One important strategy for reducing uncertainty and fostering adaptation is environmental monitoring. Monitoring involves tracking the status and trend of resource conditions over time. There are two kinds of monitoring that are critical for natural resource management. Long term condition monitoring involves collecting data on important ecological attributes over a long time period in order to establish baseline trends. For example, despite a lot of year to year variability, long term monitoring of precipitation trends can let us know if it’s getting wetter or drier in a specific location, or if there are significant changes in water quality over time. It’s like your vital signs. Every time you go in for a check-up, your doctor checks your pulse and blood pressure. Changes in your vitals over time can signal that something is wrong, and action needs to be taken. If your doctor prescribes medication, he will see you more frequently to make sure you don’t have any side effects. This latter type of check-up is analogous to the other important type of monitoring: effectiveness monitoring. Effectiveness monitoring is essential for understanding the effects of specific management actions, allowing managers to learn about what works (or what doesn’t) over shorter time periods. For example, effectiveness monitoring can help us understand what forest management strategies promote resilience to drought, insects, and disease.
But there are challenges associated with implementing both types of monitoring. In general, monitoring is expensive. Rigorous monitoring often involves intensive on the ground data collection by highly trained field crews, or it requires the installation of expensive measurement devices. Scientists don’t often have incentives to conduct long term condition monitoring, because it may be years before they can publish the results (and they need to publish often). Natural resource managers, such as National Park Superintendents, are also often reluctant to commit to long term monitoring that may not create actionable information until after they leave (especially when funds are tight). Managers are also often wary of funding and implementing effectiveness monitoring. Besides the expertise and cost needed to do it right, there is the danger that monitoring may show that management actions did not have the intended effect. This can turn a management success story (one that got accomplished) to a liability—a particular concern within the often litigious and politically charge context of public land management.
Despite these challenges, there are a lot of promising new tools and approaches that may promote better ecological monitoring and management. For one, there are new institutional strategies for implementing effective monitoring programs. Natural resource management agencies, such as the National Park Service, have institutionalized autonomous and well-funded monitoring programs that support rigorous long term monitoring across multiple units. There are also new technologies, such as remote sensing applications, that utilize satellites to track numerous indicators of change from outer space. Unmanned drones are also another new promising and cost effective tool for monitoring that are just now beginning to be utilized.
Perhaps most importantly, however, is the promise of citizen science. Armed with smart phones, interested individuals can help identify and track the spread of invasive species, or chart bird migrations as they occur, in real time. In addition to the data, citizen engagement is a great way to generate awareness of natural resource management issues, and it may help to build political support for conservation—and monitoring—in an era of increasing change and uncertainty.
Regardless of the method by which data is collected, there is still a critical need for thoughtful people to analyze and effectively communicate the resulting information. Often this requires strategies for delivering the information to multiple audiences, from decision-makers, to the general public. For natural resource management agencies, this will require reaching out to experts in other professions, such as marketing and communication. A few forward-thinking agencies like the National Park Service are already trying to do so, experimenting with different “scorecards” for ecological health and integrity. It is a critical endeavor, and one that may be the most important strategy we have for improving natural resource management in an era of climate change and uncertainty.
Against the breathtaking backdrop of the Canadian Rockies, I am practicing how to kill cattle. Unfortunately, I’m a terrible shot. This much is evident from my target practice sheets, with their undeniable lack of bullet holes.
When I posted this same picture to Facebook, I got an immediate and incredulous response, particularly from friends who had known me in high school and college. Why was I shooting cattle? Why was I upset about missing? How could I – former vegetarian and European history major – be shooting a gun?
To me, the entire exchange was a perfect microcosm of a much larger cultural schism between those who understand the realities of livestock production, and those who don’t. These realities can be jarring for people whose only contact with livestock comes in the form of a plastic-wrapped hamburger patty. For such consumers, the blood, death, feces and carcasses that fill media images capture the attention and prompt the imagination to run wild in dark places. If this is your only window into livestock production, then I understand how you may come to feel negatively towards the meat industry.
These dynamics, however, place the meat industry in a very difficult position. At the same time that consumers are clamoring for increased transparency about the source of their food, they themselves are becoming increasingly disconnected from the reality that their meat was once a living, breathing animal that was raised and killed to provide that same meat. The industry is thus in the unenviable position of explaining a sometimes distasteful and brutal process to a largely naïve consumer public.
There is so much room for misinterpretation within this endeavor. Which brings me back to target practice, and shooting a rifle in the Canadian Rockies. Did you know that scientists have used MRI machines and cadaver heads to identify the most humane way to euthanize cattle? The goal is to create sufficient concussive force such that the bullet hitting the forehead renders the animal unconscious before the bullet pierces the skull and continues its destructive path to the brainstem, where death occurs. It is a humane death, and one that I was attempting to execute in the Canadian Rockies. As a future veterinarian, I want to be able to euthanize an animal in the best way possible. If this necessitates use of a gun, then I will get over my distaste of guns and learn how to shoot humanely -- with the proper bullets, the proper angle and the proper distance from the animal. My greatest fear is not the gun, but failing to properly use the gun on a suffering animal.
And do you know what my second greatest fear is? It is the fear of being misunderstood by my vegan friends on the East Coast because of a picture that I post on Facebook. It is the fear of being dismissed out-of-hand by my food-producing Colorado friends because I did not grow up on a farm and therefore don’t have “street cred” (maybe more appropriately “cowboy cred”)! And at a fundamental level, it is the fear that the cultural divide in which I find myself will prevent us, as a society, from having any meaningful discussion about the future direction of livestock production. If this happens, everyone loses – consumers, producers, animals and the environment.
Because without well-intentioned dialogue between producers and consumers, we lose the immense value that comes from the constant back-and-forth of a system of checks and balances maintained by multiple parties with diverse motivations and concerns. Producers and consumers both play important roles within such a system. For instance, livestock producers have legitimate concerns about the animal welfare and food safety implications of consumer trends such as completely antibiotic-free meat. On the other hand, consumers play an important watchdog role, keeping the industry on its toes and helping to weed out bad actors and less-than-optimal production practices such as use of antibiotics purely for growth promotion. To lose this delicate interplay would be to lose an important driver of continuous optimization of the livestock production system. In the case of antibiotics, I fear that a lack of dialogue could move us to a place where I, as a veterinarian, will be unable to treat a sick animal with life-saving antibiotics. Or, alternatively, that producers will walk away from the table and stop funding voluntary, yet critical research on alternative management strategies to antibiotic use – an area that they are currently pursuing with the help of researchers at CSU. Without dialogue and trust between the food-consumers and food-producers, I fear that the pendulum will swing way too far towards one side or the other.
So let’s work together to prevent that from happening – as some people already are. For instance, outreach programs are cropping up across the US to engage urban youth in farming and agriculture. But understanding is a 2-way street, and it would be great to see “reverse outreach” programs as well, in which kids from rural backgrounds spend a summer in the city, or learn what it’s like to rely solely on public transportation or buy their weekly groceries from a corner store. As columnist Charles Blow wrote in a recent opinion piece, “It’s easy to demonize, or simply dismiss, people you don’t know or see…[and] nearly impossible to commiserate with the unseen and unknown.” What are some ideas that you have for bridging the divide between rural and urban communities?
As agriculture becomes increasingly segregated from most of society, it is my belief that we all have a responsibility to engage in the delicate and important dialogue between the food-producers and the food-consumers. I would challenge you to self-reflect on your relationship with agriculture. What kind of consumer are you? Do you want to know the story behind your steak, or do you prefer to eat it in “blissful ignorance”? Maybe you are a vegan and can contribute your unique experience to the conversation. Whatever your dietary choices, can you identify any preconceived ideas that you hold about “the other side”? What are some questions that you would like to ask someone who may have a very different viewpoint on agriculture? Do you think there are ways that we can get over our mutual mistrust? I would love to hear your thoughts!
Livestock grazing—a widespread land use across the Western United States—can have important consequences for ecosystems and their animal inhabitants. Among such sensitive ecosystems are sagebrush-dominated (Artemisia spp.) communities, whose plant species did not co-evolve with the heavy grazing pressure that can exist today. This has led to conflicts between some scientists and environmentalists who have called for the removal of livestock from these ecosystems, and ranchers whose families have managed livestock on these lands for generations . Although studies have documented the effects of heavy grazing on these plant communities in individual study sites, little is known about the broad scale implications of grazing across this vast landscape.
In sagebrush ecosystems, populations of greater sage-grouse (Centrocercus urophasianus) have declined substantially over the previous half-century [2, 3]. Grazing may affect sage-grouse populations because herbaceous cover provides concealment for nests and food for broods [4, 5]. Recommendations typically call for reductions or delays in grazing to avoid impacting vegetation for nesting sage-grouse, but much of what we know about how grazing affects sage-grouse come indirectly from fine-scale habitat studies . Studies attempting to directly test effects of grazing on sage-grouse are extremely challenging because sage-grouse, a “landscape” species, require an enormous area during their life cycle. But, there could be conditions where livestock grazing is compatible with species such as sage-grouse, and studies are needed to identify these conditions to better inform management and policy.
How could grazing be compatible with sage-grouse, you may ask? After all, herbaceous cover can increase the likelihood of sage-grouse successfully hatching and raising chicks, and livestock remove herbaceous cover through grazing, so it intuitively makes sense that removing livestock should benefit sage-grouse. However, there is reason to suspect this may be overly simplistic and does not consider the complexity of these systems. For example, sage-grouse need forbs to raise their broods  and forb cover can increase brood survival . At moderate rates, grazing can increase the variability in structure and composition of rangelands , and therefore reductions in grazing could have a negative effect on sage-grouse if this reduces forb cover. Furthermore, recent studies have shown that using heavy grazing to characterize impacts may actually be a false comparison, and that well-managed grazing regimes can have equivalent or better outcomes compared to ungrazed pastures [e.g., 9].
After the previous summary, one would be forgiven for thinking this is all too uncertain for making decisions that could affect the fate of species and the livelihood of ranchers. But there is reason for hope that more answers will be available in the coming years. For one, our lab is developing the use of public grazing records to characterize livestock grazing at large spatial scales. Much of the land in the Western U.S. is publicly-owned, and agencies such as the Department of the Interior-Bureau of Land Management maintain records on the timing and intensity of grazing on the grazing allotments that they administer. When we pair this with long-term monitoring of sage-grouse through annual counts of males at breeding display sites (leks), we have the opportunity to investigate for responses of sage-grouse to grazing at an unprecedented scale. At the same time, studies are being conducted to experimentally test the effects of grazing on sage-grouse (e.g., https://idahogrousegrazing.wordpress.com/current-project-status/), which should directly relate the response of vegetation to grazing at multiple scales, and subsequent sage-grouse responses. Results from these and other studies will help agencies and land managers consider potential impacts to sage-grouse when prescribing grazing amounts and timing, and hopefully ensure the continued coexistence of this species with modern ranching operations across the West.