Agroecosystems are essential for biodiversity conservation given they comprise 40% of the Earth’s land surface. The U.S. state of Iowa provides an interesting case for studying biodiversity conservation as agricultural land uses dominate, covering 86% of its land area. While governmental and non-governmental conservation organizations focus on expanding the number, extent, and quality of reserves – an important land sparing strategy – public conservation lands comprise just 2.5% of the state. Iowa’s agriculturally productive soils, climate, and associated high land costs imply that reserves will comprise only a small portion of the state for decades to come: land sharing strategies are also needed. We study prairie strips as a land sharing conservation practice. In 2019, prairie strips were codified as farmland Conservation Practice 43 (CP-43) under the U.S. federal Conservation Reserve Program. They are defined as diverse perennial vegetation, oriented linearly within row crops fields, not exceeding 25% of the cropland area per field.
Results/Conclusions
Our initial research on small agricultural catchments indicated that, compared to areas entirely farmed with corn and soybean row crops, establishing prairie strips on 10% of a field resulted in 2.6-fold higher insect taxa richness, 3.5-fold higher pollinator abundance, 2.1-fold higher native bird species richness, and 2.1-fold higher abundance of bird species of greatest conservation. We are now studying the biodiversity conservation impacts of prairie strips integrated on commercial-scale corn and soybean fields. Initial results indicate prairie strips provide improved habitat compared to other farmland features for multiple wildlife taxa, including monarch butterfly, native bees, and several native bird species. Characteristics of prairie strips that appear to contribute to biodiversity conservation include the presence of perennial cover with a higher diversity and expanded phenology of flowering plants. The landscape effects of prairie strips on species movement and demographics cannot yet be quantified as prairie strips are limited in number and extent at present.