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Improving the statistical power in grassland and passerine bird nesting studies: Testing two new technologies

July 25, 2017 3:33 PM

Man looking at birdsGrassland birds, such as dickcissels, meadowlarks, and upland sandpipers, have declined by almost 40% over North America between the late 1960s and today 1968–2011. This decline is being driven by loss or degradation of grassland habitat continent-wide, including replacement of grassland with agricultural land, fragmentation of remaining grasslands, degradation of rangelands in the western US, and re-forestation in the eastern US. Stopping and eventually reversing the loss of grassland habitat will be necessary to halt the decline of North American grassland birds.

An innovative approach to restore grassland habitat for at least some species of grassland birds is called prairie strips. Prairie strips has been developed by the STRIPS team of which I am a member. As a conservation practice, prairie strips converts 10–20% of a field-level watershed in a row-crop field to diverse native perennial contour buffer and filter strips. Research began on prairie strips at Iowa State University in 2005 and has demonstrated that contour strips of dense, thick-stemmed native vegetation is effective at reducing nitrogen runoff by up to 84%, phosphorus runoff by up to 90%, and sediment runoff by up to 96% (click here for a summary of STRIPS science). Early research efforts also showed that birds were 1.5–2.9 times more abundant in fields with prairie strips, but more research on their usefulness to wildlife is needed, including whether prairie strips serve as quality nesting habitat or are functioning as “ecological traps,” or habitat wildlife is fatally attracted to.

Heat map Studying the nest survival of birds that nest in grasslands presents many challenges, including difficulty locating very cryptic nests in large enough numbers to draw robust conclusions. My graduate research on the topic of bird nest survival in prairie strips came with the additional challenge of only having access to 14.8 ha of prairie strips, limiting the total number of nests within the focus land cover that was available for research. For these reasons, my initial investigation of birds nesting in prairie strips has focused on investigating methods of improving nest detection using a thermal imager and obtaining more information from each nest using iButton thermal data loggers. My Master’s thesis presents findings on these two methods for improving nest survival studies.

In my first study, I investigated the effectiveness of using a thermal-imaging camera for locating warm nests against a cool background. I found that having a thermal imager available for use under appropriate conditions did not improve nest detection rates, likely due to prevailing sunny conditions during most survey hours and dense vegetation obstructing the thermal signature from warm nests. It is possible that a study focusing on use of the thermal imager during optimal sunlight conditions might find a significant effect, but my study was a practical test of the imager’s usefulness over the whole of a regular day of field work (approximately 0500–1300 hours). Because I have already invested in the thermal imager, I will continue to use it when conditions allow, but moving forward it will not be a significant part of my strategy to find more bird nests.

NestIn my second study, I evaluated the use of iButton thermal data loggers for determining bird nest success or failure dates. I found that installing an iButton into grass- and shrub-nesting passerine nests did not affect egg hatching rates overall, or for nest parasite egg-accepting or egg-rejecting species analyzed as separate groups. Although I did not find statistically significant differences, a trend in the data from nest parasite egg-rejecting species was suggestive of higher failure rates that may become significant with larger sample sizes. I found that use of iButtons to determine nest failure dates increased sample sizes and resulted in higher estimates of daily survival rate with increased precision. The direction and trend of these findings were supported using a simulation study, although the magnitude of the effect was not as large and greater gains can be made by increasing the number of nests in the sample. Given this finding, in the future I will use iButtons to improve estimates of daily survival rate in the nests of all birds except for nest parasite egg-rejecting species to allow me more time to locate new nests. For nests of nest-parasite egg-rejecting species, I will continue to randomly assign treatments of iButtons or no iButtons to obtain a larger sample and clarify if iButtons are indeed reducing hatching rates.


This is how science works: a continual process of evaluation, methods development, data collection, and refinement, which in time hones in on improved understanding. In my case, this process will inform scientists’ and wildlife professionals’ recommendations for how to best implement prairie strips where grassland bird conservation is a farm-level goal. It is only by establishing supportive habitat that we will be able to stymie the loss of grassland birds.

Matt Stephenson is a graduate research assistant in the LESEM Lab. He is co-advised by Dr. Bob Klaver. He finished his Master's degree in Wildlife Ecology in 2017 and moved directly into a PhD program in the same topic area. His research is supported by funding from the USDA Farm Service Agency, USDA NIFA McIntire-Stennis Program, the Leopold Center for Sustainable Agriculture, and the Iowa DNR Wildlife Diversity Program. 


Staying afloat with PEWI

December 9, 2016 12:00 AM

Screenshot of PEWII’m a programmer on PEWI, a simple web-based learning tool designed to help people understand human-landscape interactions and ecosystem service tradeoffs (see figure below). One day, while working on PEWI’s code, I got pretty curious about whether there were other, similar tools out there. Also, being somewhat competitive by nature, I wondered what ‘the other groups’ were doing. I figured creating watershed tools is probably the vocation of a few, with groups working in this area just a small subset of the scientists and stakeholders interested in the impacts of human decisions on the environment. You can imagine my surprise when I set out to find a few oases in the software desert and, instead, found myself inundated with applications. The good news is that, among the flood of wonderful tools, PEWI still holds a unique place. Here are the results of my exploration.

While a plethora of tools are out there, I found five main tools that compare to PEWI in their intent and usability. These include Model My WatershedPimp Your LandscapeRock Your Watershed!Smartscape, and Watershed Conservation Screening Tool. I spent time learning to use each of them, emailing their developers, and reading model documentation, news releases, archived website snapshots, and published literature. I looked into underlying science; educational use, especially as a curriculum element; and the many facets of the programs’ front ends. Again, as a competitive person, I also spent an inordinate amount of time working my way up the leader boards for the tools that have them, probably to the chagrin of middle schoolers everywhere.

I found that the applications could be quickly divided into two obvious groups: those implemented within a Google Maps interface (Model My WatershedSmartscapeWatershed Conservation Screening Tool) and those, like PEWI, that relied on homemade graphics (Pimp Your LandscapeRock Your Watershed!). The more realistic looking programs were notably less game-like, but did provide feedback that felt instantly credible when compared to the graphics of the game-oriented programs. There was a great measure of overlap between inputs and outputs across the programs with the maximum number of output indicators being 10 while input land types coupled with conservation options generally allowed for 15 to 20 distinct combinations. In terms of learning curves, orientation time ranged between 5 and 45 minutes. You can find my entire white paper comparing the applications here.

Conducting this investigation and writing up the results helped me better understand PEWI’s niche. While its cartoon style may hinder its authority, I found that its scientific buttressing is on par with or exceeding all of the other tools I examined. PEWI has a unique position between totally realistic and totally game like, and has an amazing potential for guiding learning and achieving specific educational goals that just isn’t present in other tools. On the other hand, PEWI is lacking features including urban land use options, a high level customization of conservation practices, and outputs such as those regarding pollinators and economic effects. While PEWI certainly outperforms many of the programs in educational outreach, some have more aggressive initiatives and show there is plenty of opportunity to get PEWI into the hands of those who stand to benefit from its lessons.

Overall, though, for all of these tools there is the question of ‘staying afloat,’ which really is about staying relevant. Even with all of the fantastic and diverse features to be found across these watershed programs, the tools left me hoping for a feeling of forward progress or some electricity in the air around their development. If PEWI continues evolving, especially in expanding its public reach and providing a tool for immediate integration of new science, then it truly will provide something entirely relevant and special. Then, in 3, 5, or 10 years, some unsuspecting undergraduate like myself will sit down on the first day of summer and find a project that is changing both minds and ecosystems.

Noah Hagen is an undergraduate physics major at Iowa State University. He spent the summer of 2016 finalizing the code for PEWI v2 and developing the framework and code for PEWI v3. Stay tuned and you’ll see all of Noah’s amazing work: we expect to release PEWI v3 in the spring of 2017.


Wakonse: Who do you want to be?

June 15, 2016 12:00 AM

Lake Michigan SunsetLearning has been a central part of my life for as long as a I can remember. As a youngster, I learned basic skills, like how to tie my shoes, the colors and alphabet, and how to share with my sister. As a student, I sat in countless classrooms with dozens of teachers and faculty members, learning theories, concepts, facts, and skills. I learned how I learn, and I began applying what I was learning to ask scientific research questions. As a graduate student, I continue to learn and grow as a research scientist, but I’m also experiencing learning in a new way: as an educator.

As a teaching assistant and aspiring faculty member, I’ve been privileged to worked with undergraduate and graduate students in lectures and discussions, in field, bench and modeling laboratories, and in one-on-one mentoring. While I’ve had years of learning experience as a student, my training and growth as a graduate student has focused primarily on learning as a research scientist rather than on learning as an educator. My experiences are similar to other aspiring and current faculty members. For many of the over 1.3 million faculty members across the country, training has focused extensively on their area of research expertise and little on developing their skills to teach students. Faculty members are routinely required to hold doctoral degrees in their field, but are often not required to receive any formal training on teaching, learning, or communicating with students. Accessing teaching materials, receiving training in teaching and mentoring, and developing a community of teaching peers often remain under-prioritized. Nonetheless, aspiring and current faculty members dedicate significant proportions of their professional lives to teaching, mentoring, and advising students.

The Wakonse Conference on College Teaching is an annual conference designed to address some of the teaching, mentoring, and advising gaps for aspiring and current faculty members. The conference draws approximately 100 faculty members, and takes place each May, on the eastern shores of Lake Michigan. The overarching goal of the conference is to support, promote, and share the excitement and satisfaction of teaching – to inspire others and ourselves. The conference has four main objectives: (1) display and discuss teaching talents; (2) learn about themselves as teachers; (3) consider the tasks and issues of creative teaching; and (4) provide meaningful feedback to one another. This May, I was lucky enough to participate in the Wakonse Conference on College Teaching with four other doctoral students from Iowa State.

The conference is different from many of the professional- or research-oriented conference that graduate students and faculty members traditionally attend. Wakonse has far fewer participants, and is held at a summer camp on the shores of Lake Michigan. Consequently, conference participants are encouraged to wear casual clothes and athletic apparel. Conference organization is fluid, conference sessions (e.g., “Creating Community in the Classroom,” “Work Life Balance,” etc.) are organized more like round tables or discussion groups, and extensive time is dedicated to fostering a community among attendees. The hallmark of professional- or research-oriented conferences, the PowerPoint, is notably absent from this conference. In its place, there are lively and impassioned conversations, demonstrations, and activities designed to encourage faculty members to grow, learn, and evolve as educators. 

Wakonse covered a lot of material in a short four days, including things like how to evaluate students effectively, methods and strategies of being an efficient teacher, mentor, and advisor, and how to adapt to students’ learning approaches. These were concrete, tangible things that I had expected a conference like Wakonse to provide – but, the most useful thing I gained from Wakonse was unexpected.

Several of the Wakonse conference leaders are current faculty at the University of Missouri-Columbia. In November 2015, heightened racial tensions over a pervasive university culture of racism cast the University of Missouri into the national spotlight. In the wake of events related to these tensions, the university community was thrust into period of insecurity. Threats of violence were made. People felt unsafe. Conference leaders shared intimate, personal struggles of how this experience altered their perception of their roles as educators. Amidst of backdrop of fear and inequity, the pragmatic hum of teaching seemed to fade, instead replaced with a louder, core voice asking: who do I want to be as an educator, and what do students need from me to be successful?

In building a community of aspiring and current faculty members, the conference cultivated a space that allowed participants to step back from the expected, pragmatic questions of teaching and address this question. Embarrassingly, this wasn’t a question that I’d thought much about – especially in the context of the experiences of my colleagues at the University of Missouri. But, the events that happened at the University of Missouri are not theirs alone; Iowa State, and many other campuses around the country, have experienced deep tensions related to discrimination based on race, gender, religion, and sexual orientation.

These challenges require me to adapt as an educator. Certainly, I need to provide credible and field-appropriate skills, tools, and knowledge to students. I need to help students develop critical thinking skills, to apply the scientific method, and to grow as professionals, and I am committed to being an innovative, engaging, and passionate educator. But, my ability to do those things – to be the best educator I can be – is not just about those pragmatic outcomes. For me, these pragmatic outcomes cannot be addressed without first fostering, and demanding, a classroom community where all students feel respected, valued, supported, and safe. The educator that I want to be not only recognizes the deep, purposeful importance of scholarship and learning, but understands that real human needs of respect, value, support, and safety need to be met if students are going to be successful learners.

WakonseWakonse provided me with pragmatic, applied approaches to many of the day-to-day challenges that faculty members and educators face. Those approaches will be useful as an aspiring faculty member. But most importantly, Wakonse provided me with an opportunity to identify the kind of educator I want to be, to recognize the values that govern my role as an educator, and to begin to think about the skills, tools, and strategies that will allow me to be the best educator I can be. 

The author, Emily Zimmerman (left) is a third-year doctoral student in the LESEM and PLUS Labs. Here she's pictured with fellow Iowa State graduate students and Dr. Joe Johnston, Director, Wakonse Foundation. Photo courtesy of Marissa Holst.  


Field Notes: Musings from the Natural Resource Ecology & Management Department

March 16, 2016 12:00 AM

Each year, Iowa State University’s Natural Resource Ecology and Management (NREM) Department publishes a collection of articles designed to provide a slice of what has been happening in NREM over the past year. The graduate student publication, called Field Notes, highlights undergraduate and graduate research, catches up with recent graduates, and welcomes our new faculty. This past year, I wrote an article for Field Notes detailing part of my doctoral research.Field Notes Cover Picture  The article, titled “Learning how to have our cake and eat it, too: Identifying opportunities for co-production of commodities and ecosystem services in Iowa,” explores how tweaks can be made in agricultural land management to jointly expand economic and environmental opportunities for farmers to co-produce agricultural products and desired environmental benefits (e.g., enhanced water quality).

Environmental benefits, often referred to as ecosystem goods and services, are the benefits that humans receive from natural and managed ecosystems. As many of us are aware of, Iowa is very efficient at producing ecosystem goods associated with agricultural products. Iowa leads the nation in the production of corn, soybeans, eggs, hogs, and ethanol – which collectively generate large economic gains for our state and its residents. Nonetheless, the production of Iowa’s agricultural products often comes at a tradeoff in the context of ecosystem-derived services such as water quality for drinking and recreating. Recent research out of Iowa State University’s Departments of Natural Resource Ecology and Management and Sociology has demonstrated that Iowans desire a more multifunctional agricultural landscape that delivers not only agricultural products, but a broader suite of ecosystem services (e.g., enhanced water quality for drinking water and aquatic life, expanded recreational opportunities, and improved game wildlife habitat) as well.

This is the context for my research: how can tweaks in agricultural land management jointly expand economic and environmental opportunities for farmers to co-produce agricultural products and desired ecosystem services? To get at this question, my research project is examining a spatially-targeted payment for ecosystem service system. Such an approach is designed to identify conservation opportunities for farmers that will improve conditions for water quality and biodiversity at watershed scales, potentially increase average yields and lead to expanded market opportunities and stewardship acclaim.

To learn more about how this research is identifying these opportunities, check out this edition of Field Notes, which can be found online

Emily Zimmerman is a Ph.D. student in the LESEM and PLUS Labs.


Bioacoustics for better bioscience

February 9, 2016 12:00 AM

Bioacoustics Any branch of science comes with its own unique challenges. For landscape ecologists such as us in the LESEM lab, one of these is the question of how to survey wildlife across broad spatial extents, especially with limited time, money, and personnel. Over the years, various technologies have been employed to aid researchers in maximizing results with minimal resources. For decades, animals as diverse as sage grouse, wolves, and manatees have been monitored via aerial surveys using small planes. Secretive species can be tracked using telemetry, and tiny geolocators have been used in countless studies to determine the paths of long-distance migrants. One area of research which has been steadily growing involves using sound recordings of animals to monitor their presence over widespread areas. With this type of monitoring, wildlife species that are inherently difficult to track and study become accessible to scientists.

A classic example of using recordings to improve wildlife knowledge is for whales: many species spend much of their time in deep, murky waters, migrate massive distances, and are generally hard to find. Studying these animals the traditional way (from a boat) is often cost prohibitive, dangerous, and time intensive. Some of the best current techniques involve placement of hydrophones in the habitat or along the migratory route of these whales. Depending on the study, recordings can be collected after a period of time or streamed back to a lab hundreds of miles away for real-time analysis. Studies like this have enabled scientists to gather useful data that otherwise would have been difficult or impossible to obtain. A stunning example of marine bioacoustics in action is the Right Whale Listening Network, a project of the Bioacoustics Research Program (BRP) at the Cornell Lab of Ornithology. A series of buoys equipped with hydrophones constantly monitor the waters of Massachusetts Bay, home to one of the busiest shipping channels in the eastern United States. These buoys provide information on the presence of endangered Right Whales, which is then given to ship captains in order to allow them time to slow down and hopefully avoid colliding with and possibly killing a whale. 

In the LESEM lab, we are taking advantage of the many benefits provided by bioacoustics to study the impact of prairie strips on grassland birds. Currently, we have over 40 Autonomous Recording Units (ARUs; picture above right) placed in farm fields across Iowa and northern Missouri. These units are set to record for one hour at sunrise each morning, which captures the most active singing hour for birds. After several months of recording, we bring the data back into the lab and analyze it. This is done using Raven, a software package developed by the previously mentioned Bioacoustics Research Program at the Cornell Lab. Last spring, I had the incredible opportunity to visit the Cornell Lab for a week to learn how to use Raven. For our research, we use the software to convert our recordings into spectrograms (pictured below). With this process, an hour of listening quickly becomes several minutes of sifting through the visual representation of the soundscape. With some time and training, an observer can soon learn to differentiate between bird songs visually as easily as auditorially. This method opens up huge doors for our research with STRIPSby enabling us to “listen” to birds in dozens of farm fields at the same time.

Looking beyond our immediate use of bioacoustics for monitoring bird response to prairie strips, having these recordings gives us a massive bank of data that can be used for future research. Some questions that could be explored with our data include how birdsong differs in certain locations based on a variety of environmental factors (traffic noise, crop cycles, or weather events), how bird “dialects” change over time in a single location, or whether individuals of the same species display regional song variation across the state. This is part of the beauty of modern bioacoustics research: a permanent record of wildlife vocalizations can be stored, enabling researchers to not only check their own work and that of others in the field, but also to ask questions that other researchers did not have the time or ability to explore with the same data.

Coyote audio data During our first year of collecting audio data, we have recorded some interesting things. On a farm in  Carroll County, we heard a minutes-long chorus of a Coyote (image at right) family as the sun rose. We caught glimpses of the haunting, distinctive whistle of Upland Sandpipers on several farms across the state. We were even able to make out the territorial call of the secretive Northern Bobwhite. I expect to see the field of bioacoustics continue to advance rapidly in both technology and the number of scientists of different disciplines who take advantage of it. The next few decades in the field should be exciting ones, and I can’t wait to see what comes next!

Julia Dale is working on her Master’s degree in Wildlife Ecology in the LESEM lab. She thinks the best time to view prairie strips is at dawn, preferably in early-June.


Find more images of Western Meadowlark (1), Ring-neck Pheasant (2), Upland Sandpiperand vocalizations recorded at STRIPS research sites below.

Western Meadowlark






Ring-neck Pheasant

Upland Sandpiperand Vocalizations


What do Yellowstone National Park, J.K. Rowling’s Remus Lupin, and this post about ecological economics have in common?

July 29, 2015 12:00 AM

Did anyone else read Saki’s short story The Interlopers in high school English class? If not, you can google it; it’s quite short. Here’s a summary: two men, who have feuded their whole lives, are out hunting each other in a forest. Suddenly, a tree falls and traps them both. First, each angrily swears that his group of friends, who are elsewhere in the woods, will kill the other when they arrive. But gradually, as they wait, they decide to end their lifelong feud and become friends. This idea brings them great joy, and they talk of plans to publically declare their friendship. Then they see figures coming over the hill, and eagerly strain to see whose group of friends is coming to free them at last. But the approaching figures are not their friends. The story ends with one chilling word: wolves.

I remember my high school English teacher drawing concentric circles on the blackboard to illustrate the different layers of conflict in this story. The inner circle represented social conflict: person against person and feuding family against feuding family. This conflict is resolved when the two enemies, trapped and helpless, decide to set aside their differences and end their feud. But the outer circle represented the story’s bigger and dominant conflict, with a different resolution: person against nature. Whether or not the two men are friends or foes, they are still subject to the forces of the natural world and are, in fact, doomed.

Saki’s is a dark story, to be sure. This might be why, last fall, I found myself again and again remembering those concentric circles, which I last saw drawn on a blackboard sometime in 2003. But was I in another literature class? No. We were reading about ecological economics.

Readers may be familiar with the basics of the separate fields of ecology and economics. Ecology is the study of the relationships of organisms to one another and their physical surroundings, while economics is the study of the production, consumption, and transfer of wealth. There are different theories about the relationship between the two fields. Neoclassical economics, the dominant perspective in contemporary economics, holds that the natural world is subject to the laws of economics. If neoclassical economists were to draw the two circles of ecology and economy, the former would be inside the latter. Economics dominates ecology; the rules of economics trump the rules of ecology.

In our 509 class last fall, which I’ve written about before, we studied a different perspective: ecological economics. This field holds that the opposite is true: that there are fundamental limits to natural resources, and that these restrict the potential and scope of economic activity. As in Saki’s story, the field of ecological economics states that human systems exist within and are subject to natural systems.[1]

During our 509 class, before we even got a whiff of this concept, we got to smell two very different places: a small grass-fed dairy and a corn ethanol plant. At the dairy farm, we smelled damp grass, wet cow noses, and delicious cheese. At the corn ethanol plant, we smelled the yeasty tang of fermenting corn, and were dwarfed by the scale of the industrial machinery. The contrast between these two visits offers interesting fodder for understanding the ecological economic approach.

Grass-fed dairy cows To illustrate the ecological economic concept of how an economic enterprise is embedded in its surrounding ecology, it is useful to examine how a business thinks about and works with its supporting  ecological systems.During our visit to the diary, we learned that they take great care to preserve and improve the soil quality of their pastures through planting species that will fix nitrogen. They also encourage biodiversity on their farm, whether in their mixture of pasture species, in the organisms in their soil, or in the natural habitat provided by tree lines. The farmers take an ecological approach in managing cattle pests and pasture weeds: they avoid the use of antibiotics for the cattle, schedule the pattern of rotational grazing to control pasture weeds, and manage flies with chickens, fly paper, and oil sprays rather than pesticides. They demonstrated a commitment to management that works with the ecological system it inhabits.

During our visit to the corn ethanol plant and to fields where corn stover is stored, we saw a much smaller emphasis on the ecological impact of business practices. The plant relies on massive amounts of corn in order to function, and we also saw many tons of corn stover harvested from a similar area. That corn is grown in the agroecological systems of the surrounding farms: from seeds, soil, water, air, and sunshine. But the only acknowledgement we heard of the business’ reliance on those ecological systems was in a discussion of the concerns about removal of potassium via corn stover from fields. There was no acknowledgement of the plant’s relationship with local biodiversity, or water quality, or pest management, as there was at the dairy farm. One way they might have done this would have been to offer a higher price to farmers selling corn that they grow in rotation, or that they plant with cover crops, or alongside prairie strips. This would have encouraged farmers to grow corn to sell them while also taking the broader ecological system into account.

Another compelling idea we came across in ecological economics was the contrast of quantitative growth and qualitative development. Daly (2005) argues that quantitative increases of economic activity – for example, the increase in the number of bushels of corn grown per acre – has physical limits and maintaining such growth is unsustainable in the long term. Qualitative development, on the other hand, is economic growth through the improvement in the quality of goods produced without necessarily increasing their quantity.

On our visit to the dairy farm, they demonstrated commitment to qualitative development. Originally they pursued quantitative growth – expanding the dairy herd from two cows to dozens – but it has reached a comfortable size and they have no plans to grow it further.  They instead have focused on qualitative development, such as improving the infrastructure of the farm through installing a wind turbine, and he talked about wanting to switch from disposable plastic milk bottles to recyclable glass.

Corn Fields At the corn ethanol plant, we learned that they are gearing up to produce 55 million gallons of ethanol a year from thousands of acres of corn. We did not hear about plans for further growth, but the plant exists on a landscape where corn ethanol production has increased significantly in the last 10 years, a fine example quantitative growth. We also learned about current research on industrializing the process of breaking down corn stover to make ethanol, a trickier process than making ethanol from corn grain. 

In ethanol production from biomass, a shift in feedstocks would be a potential avenue for qualitative development.  The production of corn, the current feedstock, is associated with various harmful environmental impacts – nutrient runoff, weed resistance to herbicides, soil erosion.  But diversified prairie offers a multitude of environmental benefits: increased habitat for animals and insects, reduced nutrient and soil runoff, reduced need for pesticides.  If ethanol producers could create ethanol from diversified prairie biomass, it would incentivize farmers to plant diversified native prairie.   There could be benefits all around: for farmers, ethanol producers, and Iowa ecology.  While the technology and infrastructure needed for this shift to make ethanol from prairie hay requires a great deal of as yet unrealized investment, the current related efforts in processing corn stover could be an important and informative intermediate stage towards ultimately processing prairie biomass. 

This is only a brief into to the compelling field of ecological economics, and I would encourage everyone to read up on it. The article cited below is a good one, and the full text Ecological Economics by Herman Daly and Joshua Farley is on my reading list after the excellent selections we read in class. And if you haven’t figured it out by now, the answer to the title question is: wolves.

Anna Johnson is pursuing a Master’s in Sociology and Sustainable Agriculture under the direction of Dr. Lois Wright Morton. Prior to enrolling at Iowa State, she worked at the U.S. Department of Agriculture in Washington, D.C.

Daly, Herman E. 2005. “Economics in a Full World.” Scientific American 293(3):100–107.

[1] Note that the lines between “human” and “natural” blur and even merge the more closely they are examined. Humans are certainly “natural” – we are physical, biological beings who eat and breathe and drink water; and the very concept of what constitutes “natural” is, in fact, a human idea. But for our purposes here, we’ll treat the two as distinct.


Who *doesn’t* love nutrient cycling? A SUSTAG 509 reflection

May 6, 2015 12:00 AM

509 at Field of DreamsFor those of you not lucky enough to be a graduate student in Sustainable Agriculture at Iowa State, you should know that one of the major strengths of the program is the class SUSAG 509: Agroecosystems Analysis, or simply “509.”  After being admitted to the program last spring, I was thrilled to find out that I would get to spend a week in August driving around Iowa for credit: “You mean I get to meet Iowa farmers, talk cover crops, soil quality, and corn production?” Maybe that isn’t everybody’s idea of a dream vacation, but as a newcomer to the Midwest and long-standing ag nerd, I was definitely pumped. Since not everyone is lucky enough to be in my program or to have taken this class, I thought I’d share some of the major insights I gained. Spread over two posts, I’ll first discuss nutrient cycling and its role in agroecology, and then examine a couple of the sites on our field trip from the lens of ecological economics.

If you’ve taken an ecology class or pay attention to ecological issues in agriculture, you’re probably familiar with nutrient cycling. Nutrients are the abiotic building blocks of all the living creatures. As such, the management of their movement in agriculture has profound implications for soils, crops, waterways, and the broader landscape. But even on the micro-level, there are many complexities to them. The term “nutrients” represents over a dozen different elements each with a variety of chemical forms. Nutrients can be either available or unavailable for plant uptake, depending on both their chemical form and physical circumstances.

In studying nutrient dynamics within soils, one thing quickly becomes clear: soil organic matter plays an important role. Soil organic matter consists of, essentially, bits of dead things – plants, mostly, but also all other manner of soil biota and their products. While that dead material exists in various stages of decomposition, the early stages of these serve as a food source for a myriad of soil organisms. These soil organisms play a direct and diverse role in the chemical and biological paths that nutrients follow while in the soil (Magdoff, Lanyon, and Liebhardt 1997). Nutrients can become available through such pathways as mineralization of soil organic matter by a variety of organisms, enhancement of plant nutrient uptake directly by mycorrhizal fungi, and nitrogen fixation by bacteria that can be both free-living and symbiotic with plants.

In natural ecosystems, nutrients follow a tight cycle of nutrients, from soil to plant to soil. However, agriculture, by its very nature, has always required the “export” of nutrients (Magdoff et al. 1997). Grain, vegetables, meat, fiber, hay: when they leave the farm, they also remove the nutrients inside them. Long before soil scientists uncovered the chemical pathways of soil nutrients, farmers understood that certain types and frequencies of crops could deplete the nutrients in the soil. For a long time, farmers used biological materials and processes to replenish these nutrients that had been removed from the soil, through such practices as rotating crops and applying manure.

With the advent of chemical fertilizers, this began to change. Farmers were able to stop using biological processes to replace exported nutrients. Anderson (2009)describes how chemical fertilizers became cheap and commonly used after World War II. New crop varieties could be grown closer together but also required higher levels of nutrients, and farmers became more and more dependent on chemical fertilizers. Farmers were no longer dependent on the limits of biological cycles for replenishing nutrients (there’s a maximum level for the amount of manure that livestock produce or the amount of biomass that cover crops create). Instead, the limits to nutrient application were in the supply and price of chemical fertilizer. Fertilizer could easily be applied in excess.

Tim Smith Farm The use of chemical fertilizers as a source of crop nutrients has impacted the Iowa landscape in three ways. First, as we learned on our field trip, chemical fertilizers are at the root of significant water quality issues in Iowa, stemming from the ability to import more nutrients than are needed and used. While concern about nutrient runoff began in the 1960’s in Iowa (Anderson 2009), it still persists today. We met with several folks who work to stem the escape of excess imported nutrients. One of the farmers we met, Tim Smith, discussed the complexities of planting cover crops. Among other benefits, cover crops can curtail the loss of nitrogen by holding it over the winter and then releasing it when tilled just in time for a spring crop to take it up. We also spoke with Chad Ingels of ISU Extension and Outreach, who gave thorough accounts of how denitrifying bioreactors capture nitrate from field runoff (some of Chad’s video footage of bioreactors is herehereherehere, and here). We also visited one of the prairie STRIPS trial sites, and learned how prairie plantings can capture sediment and nutrients in field runoff. Finally, at the Des Moines Water Works, we saw some of the downstream consequences of nutrient runoff: the facility has an expensive backup capability to remove nitrate from river water when nitrate levels are too high (recent news coverage of the related lawsuit can be found here and here).

Second, the use of chemical fertilizers has also impacted livestock management. Magdoff et al. (1997) describe how older agricultural systems cycled nutrients from soil to crop to livestock to people and back within a relatively small geographic space. Crops and livestock depended on each other for nutrition: crops fed livestock, and livestock manure was returned to the soil as a source of crop fertility. Keeping livestock geographically close to crops made sense. We saw modern examples of this on Gibralter Farms in Iowa Falls, which endeavors to produce as much feed on farm as possible. They have economic reasons for doing so – feed is a cost – but another advantage is that the feed and the manure are both geographically proximate. But in Iowa, the crops and the livestock are often quite separate on the landscape: grain is shipped to where livestock live. Livestock manure is often treated as a waste rather than a resource for nutrients, and that concentration of nutrients ultimately causes significant environmental problems with pollution of air and water (Osterberg & Wallinga, 2004). We saw some evidence of these manure issues on our trip: at Couser Cattle Company we learned about how their constructed wetlands are there to catch and filter manure overflows.

Finally, the use of chemical fertilizers can degrade soil health. Healthy soil ecology can benefit crops through improving nutrient availability. But in providing the nutrients via chemical fertilizers, farmers can essentially ignore whether soil organisms are healthy or even present. We learned about this during our trip to the Doolittle Prairie. While corn and soy fields stretch off in every direction, this prairie fragment has never cultivated. Doolittle Prairie was possibly my favorite stop during our whole trip: I got to check “hold prairie soil in my hand” off my bucket list.

Iowa Prairie Soil When we took a detour to a soybean field just next to the Doolittle Prairie, we saw stark differences in soil structure and general tilth resulting from differences in management. The prairie offered a glimpse of the historically rich prairie soil that Mutel (2008) describes, while the soil in the soybean field barely thirty feet away had similarly high organic matter but very poor soil structure and no visible soil organisms. We guessed that that soybean field must be chemically fertilized and regularly tilled to yield such a combination of blocky soil but vibrantly green soybean plants.

Ultimately, managing agricultural systems can be done in accordance with ecological principles. While many farmers currently rely on chemical fertilizer inputs, the cycle in nutrient cycling needs to be re-established. Currently, it is more of a chain: nutrients enter the agricultural system at one end as fertilizer and end up in manure lagoons or in downstream bodies of water. A couple of our class readings examined of how this cycle could be re-established through altering crop and livestock systems. They examine individual and regional (re)integration of livestock and crop systems, and emphasize the importance of meeting farmers’ management goals as well as they would be met in the original system (see Russelle, Entz, and Franzluebbers 2007 for more detail). Another envisioning of an integrated landscape was evaluated in Santelmann et al (2004). Different land management scenarios were evaluated for two regions in Iowa, including one scenario that integrated livestock and crops. They projected that this latter scenario would result in improvements in most ecological, economic, and social factors.

So those are the first round of my takeaways from 509, which combine insights from the field trip with those from in-class discussions that lasted throughout the semester where we learned the theory behind the practices we’d seen firsthand. In interest of full disclosure, you should know that Dr. Schulte Moore was one of the professors. Check back soon for another favorite topic in round two: ecological economics.

Anna Johnson is pursuing a Master’s in Sustainable Agriculture under the direction of Drs. J. Arbuckle and Lois Wright Morton. Prior to enrolling at Iowa State, she worked for several years at the U.S. Department of Agriculture in Washington, D.C.


Anderson, J. L. 2009. “Fertilizer Gives the Land a Kick.” Pp. 51–90 in Industrializing the Corn Belt: Agriculture, Technology and Environment 1945-19722. DeKalb, Illinois: Northern Illinois University Press.

Magdoff, Fred, Les Lanyon, and Bill Liebhardt. 1997. “Nutrient Cycling, Transformations, and Flows: Implications for Amore Sustainable Agriculture.” Advances in Agronomy 60.

Mutel, C.F. 2008. Setting the stage. Pages 1-34 in: the Emerald Horizon: the History of Nature in Iowa. University of Iowa Pres: Iowa City, IA.

Osterberg, D. and D. Wallinga. 2004. Addressing externalities from swine production to reduce public health and environmental impacts. American Journal of Public health 94: 1703-1708.

Russelle, Michael P., Martin H. Entz, and Alan J. Franzluebbers. 2007. “Reconsidering Integrated Crop–Livestock Systems in North America.” Agronomy Journal 99(2):325. Retrieved October 24, 2014 (

Santelmann, M. V. et al. 2004. “Assessing Alternative Futures for Agriculture in Iowa, U.S.A.” Landscape Ecology 19(4):357–74. Retrieved (


Young minds, bright futures

May 1, 2015 12:00 AM

Emily and Students Last summer, I was lucky to be involved in Iowa State University’s Office of Precollegiate Programs for Talented and Gifted (OPPTAG) Summer Exploration Program. The Exploration Program offers students entering grades 8-12 the opportunity to discover new and exciting areas of study not traditionally emphasized in school curriculums. During the week-long program, students are fully immersed in their chosen study, working from 8:30 am to 4 pm, with an additional hour of homework each night. Though there is certainly time for meeting new friends and fun evening activities, the students’ primary focus is academics.

As an instructor, I chose to design and teach a course called, “Sustainable Science: The Future of Food, Energy, and Water.”   The main components of the course included: (1) defining and understanding the concept of sustainability; (2) learning and applying a systems approach to addressing complex, wicked problems; (3) gaining context with respect to food, energy, and water systems through hands-on activities and field trips to local sites (e.g., Ames Water Treatment PlantIowa State University Dairy Farm, Food at First Community GardenBioCentury Research Farm); and (4) using critical-thinking, analytical, and synthesis skills to develop a hypothetical sustainable landscape using the newly released PEWI model.  

Taking a step back, it may seem a bit unclear why a PhD student is spending valuable summer research hours working with middle and high school-aged students; after all these precious summer days are critical for completing field work, for progressing through research goals, and for catching up on that ever-growing reading list. But, teaching these young minds may be one of the most important things that I did last summer. It is these curious, inquisitive faces that are the future of our field, more importantly, of our planet – and it is critical to begin cultivating the passion, skills, and perseverance that will be required of these students to continue our journey toward a more environmentally, economically, and socially sustainable future.

To create that excitement, which will encourage the perseverance to learn new skills, I incorporated techniques that allow students to take a more active role. We pursued learning avenues that allowed students the opportunity to retain information while tapping the diverse suite of strengths that each student brings to the classroom. For example, in my class students had little lecture and few readings, and when I did use lecture or readings to communicate material, the material was always reinforced with discussion and team-based activities (excellent opportunities for teaching others!). In addition, students actively practiced doing using PEWI; designing sustainable landscapes using the model allowed students to apply their knowledge in practice. By talking at students less and engaging in conversation and practice more, students took a more active and enthusiastic role in creating a learning environment that fostered their own development and success.

In addition to engaging young students using alternative teaching methods, there is also a deep need to encourage and facilitate the pursuit of STEM (science, technology, engineering, and mathematics) fields in post-secondary students. As noted in this Science Magazine piece from 2012, we still are not doing a good enough job of ensuring the success of STEM students, particularly the underrepresented minority (women, racial, and ethnic minorities). In fact, less than half of the three million students who enter college with the intent of majoring in a STEM field graduate with a degree in STEM. Many of us in academia should rapidly recognize that a success rate, a grade, of less than 50% is not passing; we are failing at producing the scientists, mathematicians, and engineers required to ensure a sustainable future.  

So, what can be done?  Much like techniques for primary and secondary students, we may need to take a look outside of our normal lens and take advantage of underemphasized tools to ensure the success of our students. According to the Science article, ensuring that students have early access to research opportunities, demanding that introductory courses utilize active learning rather than passive learning (e.g., lectures where just 5% of material is retained), and requiring enrollment in STEM learning communities (opportunities for discussion and teaching peers) are possible steps to create a culture of success among STEM undergraduate students.

We need these young, brilliant minds in order to progress toward a more environmentally, economically, and socially sustainable future. The success of our common future depends on their education – and we need to do better to make certain that the education that we are providing is not only rigorous, but engaging and exciting. Poet W.B. Yeats once said, “Education is not the filling of a pail, but the lighting of a fire.”  So let’s light the fire! 

For more information about PEWI, please contact Carrie Chennault or Lisa Schulte Moore


We're going to grow old together

August 5, 2015 12:00 AM

Old Couple Two months ago, I was fortunate to attend the International Symposium on Society and Resource Management (ISSRM) in Charleston, South Carolina. This year’s ISSRM, which serves as the annual conference for the International Association for Society and Natural Resources (IASNR), was attended by over 450 scientists, government agency managers, non-profit employees, and private consultants from numerous fields, and served as an opportunity to engage with one another on research embedded in social science and natural science pertaining to the environment and natural resource issues. The conference theme this year, “Understanding and Adapting to Change,” provided a relevant lens to examine many pertinent human dimensions of natural resource challenges, including climate change, the food system, urban centers, etc.

The organizers of ISSRM do a particularly nice job focusing on opportunities for graduate students. On the Sunday prior to the conference, graduate students were invited to attend a workshop focused on networking and professional development. In one of the sessions, faculty at academic institutions provided job search and hiring advice to young graduate students, like me, considering careers in academia. While three of the four faculty panelists described the importance of tailoring our applications, organizing our publications, and highlighting our strengths, one faculty member took a different approach: she said that there are often a lot of highly-qualified applicants, but that, at the end of the day, what it really boils down to is that you are selecting a colleague, someone that you’re “going to grow old with.” 

Journal This past week, as I organized my notes from several conferences that I’d attended this summer, I found this quote written in amongst the lines technical advice. I lingered on the quote, thumbing over the page a few times. The idea of “growing old together” is a commitment generally reserved for those individuals that are our partners in life. But this faculty member’s sentiment made me reconsider; maybe “growing old together” shouldn’t just be about our partners? Maybe it should be a social contract of sorts, that should extend well beyond the walls of our most intimate relationships – because, it turns out we are all growing old together, on this same planet, sharing the same outcomes of our cumulative decisions.

Let’s consider a shared resource, water – an increasingly contentious problem in central Iowa. In January, Des Moines Water Works, Des Moines’s water utility, elected to sue ten agricultural drainage districts in Sac, Buena Vista, and Calhoun counties.  These three counties, and their associated drainage districts, are located in the upper watershed of the Raccoon River, which provides the city of Des Moines with its water. The proposed lawsuit contends that row-crop agriculture in these counties is primarily responsible for the high levels of nitrate in the river. Frequent monitoring of the river has shown high levels of nitrate throughout the year. Samples from Sac County have shown nitrate at nearly four times the drinking water standard of 10 mg/L. Such high concentrations of nitrate have well-documented negative environmental and human health impacts. Because of the dangerous human health impacts, Des Moines Water Works has to remove excess nitrate from its drinking water at a cost of approximately $4,000 per day. Just this week, the Des Moines Register published an article highlighting the tension, conflict, and anger that continues to boil around this issue.

But, what if those embroiled in this water quality debate stopped using inflammatory language, stopped using aggressive and deceitful tactics, and instead embraced the notion of “growing old together.” Return with me for a moment to the traditional use of the phrase, “growing old together,” used to refer to a long-term partner. Personally, that phrase conjures important characteristics of a successful relationship: respect, responsibility, and honesty – even in times of disagreement; open communication, where both partners actively engage in listening and hearing one another; a commitment to compromise and to address challenges as a team; and to work alongside one another to better our shared lives. How might the present conflict over water quality change if public officials, industry leaders, and powerful lobbies chose to act based on the principle and characteristics that we’re all growing old together, using the same water resource?

In the spirit of recognizing that we are sharing in the outcomes of our cumulative decisions, choosing to treat one another and the planet with some of the same characteristics that we treat the person that we want to grow old with may allow us to make progress on contentious, yet important issues.  I’d like to end by echoing actor Adam Sandler in his “I Wanna Grow Old with You” serenade from the classic film the Wedding Singer, “Oh it could be so nice, to grow old with you.” 

Emily Zimmerman is pursuing a PhD in Sustainable Agriculture, and is co-advised by Drs. Lisa Schulte Moore and John Tyndall. Her research addresses Payments for Ecosystem Services as a voluntary mechanism to achieve conservation goals in the Corn Belt. A special thanks to Wikimediafor the photo of the old couple.