Using prairie strips to understand the value of diversifying agricultural landscapes: Reflections from an LTER Fellow

MSU graduate researcher, Lindsey Kemmerling, is a PhD student in Dr. Nick Haddad’s lab at Michigan State University’s Kellogg Biological Station.

Society today faces three immense ecological challenges: preventing the loss of biodiversity, adapting to climate change, and sustainably supporting a growing population. Humans have caused a global biodiversity crisis, with new studies continuing to reveal stunning rates of biodiversity decline across the entire tree of life. Simultaneously, we are presented with the challenge of sustainably and equitably supporting a growing human population. So, what can we do to create an Earth that supports both biodiversity and people?

Lindsey hanging out (collecting manure) with the KBS cows.

Agriculture currently occupies over 38% of the world’s land area, with a projected increase in crop demand of 100-110% from 2005 to 2050. A challenge for biodiversity conservation is that a majority of agricultural landscapes today are input-intensive monocultures, relying on chemical and energy intensive inputs to produce a single good. In order to both conserve biodiversity and produce food and fuel, input-intensive agricultural landscapes must transition into diversified multifunctional landscapes. Methods of diversification in working landscapes involves creating large mosaics of diversified landscape patches including increasing genetic diversity of crops, implementing crop rotations and cover crops, diversifying the number and complexity of crops within the landscape, and increasing natural habitat within or surrounding crops.

An increase in natural habitat in agricultural landscapes increases habitat for a range of species, and can increase connectivity among habitat areas for some species that are otherwise relegated to protected areas. In addition to the benefits for biodiversity, diversified landscapes provide important ecosystem functions that promote agricultural yield, including water purification, increased soil health, carbon sequestration, and pollination. The multitude of goods and functions increases resilience as climates shift and extreme weather events become more common. This approach works to maximize ecosystem services and functions, and optimize the tradeoffs among conservation and socioeconomic goals. 

One method of increasing natural habitat in agricultural landscapes in the Midwest is establishing prairie strips on row crop farms. This practice consists of retiring a strip of farmland and restoring it by sowing perennial native vegetation. Prairie strips reduce soil erosion, improve water quality, support biodiversity, and provide other functions to the farm and the farmer. And just this year, they became eligible for the USDA Conservation Reserve Program, increasing farmers’ access to resources for implementing prairie strips.

Ally Brown bagging flower heads to exclude pollinators- our way of measuring pollination services.

While it’s evident that prairie strips provide great environmental and social benefits, the mechanisms in which prairie strips create tradeoffs and synergies for biodiversity, ecosystem functions, and yield is largely unknown. The addition of prairie strips in the LTER last year provided the perfect experimental setup for me to test this. I am working with a group of LTER researchers to measure these tradeoffs for different methods of crop management in the LTER. 

I focus on three main ecosystem functions: decomposition, pollination, and soil carbon and nitrogen. To measure decomposition, I collect manure from the KBS dairy farm and place it in the different treatments to see how much is removed over a week long period. I also bait traps with manure to see what dung beetles are interested in the manure in each treatment. These measures provide insight to how habitable each treatment is for different dung beetle species and the ability for each treatment to suppress pathogens, cycle nutrients, and create soil organic matter. 

To measure pollination, I work with Ally Brown to grow black eyed susan plants, then place them in the different crop treatments when their flowers are open. After they have finished flowering, we bring them back to a greenhouse, collect their seeds, and measure the difference in the germination rates of their seeds to get an idea of how the crop treatments affect the pollinators for these plants. We also set out traps to get an idea of which pollinators are visiting each crop treatment. Pollinators are important for conservation and for the reproduction of plants in the broader landscape. 

Transporting black-eyed Susans from the greenhouse to the LTER for measuring pollination services. Makes for the prettiest truck around!

LTER researchers collect soil carbon and soil nitrogen data, which provides information on each crop management’s carbon sequestration potential and the quality of soil habitat for microbes and other soil fauna. They also measure crop yield in every treatment, which is essential for assessing the potential to optimize conservation and socioeconomic goals.

In addition to measuring the biodiversity of dung beetles and pollinators, other LTER researchers and I work together to measure the biodiversity of additional taxon. Jackson Helms, Jamie Smith, Stephanie Clark, and Katie Knupp collect and identify ant communities in the LTER. Michaela Rose collects and identifies spiders in the LTER. And we all work together to survey butterfly communities across the LTER. 

Over the next few years, this collaborative effort will produce a comprehensive evaluation of biodiversity and ecological outcomes for each management strategy that I hope can aid in policy and farmer decision making. It is imperative that our current policies and economies built upon input-intensive methods of production transition into systems that are sustainable for biodiversity and for people. I hope to provide insight needed to make that transition possible.