Ground Beetle Response to Prairie Strips and their Potential Ecosystem Service Delivery in Crop Fields

Abstract:

<p>Vegetative conservation practices in the U.S. Midwest promote soil health and reduce&nbsp;<br />
nutrient runoff by adding perennial vegetation within and around agricultural fields. While most&nbsp;<br />
vegetative conservation practices are planted as a monoculture, prairie strips are a relatively new&nbsp;<br />
practice composed of a diverse suite of native grasses and forbs that is expected to support a&nbsp;<br />
diverse faunal community. In this thesis, I describe two experiments conducted in Iowa, USA, to&nbsp;<br />
evaluate the influence of prairie strips on ground beetles (Coleoptera: Carabidae) and the&nbsp;<br />
removal of ground-beetle prey within adjacent corn (Zea mays) and soybean (Glycine max)&nbsp;<br />
fields. The first experiment used a paired design to compare beetle communities in fields with&nbsp;<br />
and without prairie strips and found that prairie strips supported significantly higher beetle&nbsp;<br />
activity-density and greater species richness. The second experiment assessed the effect of&nbsp;<br />
grassed waterways and prairie strips on the ground beetle community and their potential&nbsp;<br />
predation on prey within adjacent crop fields. I found significantly higher activity-density for&nbsp;<br />
ground beetles inside crop fields compared to grassed waterways and prairie strips. I observed&nbsp;<br />
the lowest predation in traps that occurred near multiple prairie strips compared to traps inside&nbsp;<br />
the crop field and adjacent to grassed waterways. I found larger female body length in the paired&nbsp;<br />
prairie strip compared to male beetles in the crop only configuration. I also found pronotum&nbsp;<br />
length was larger in beetles in the paired prairie strip compared to other landscape&nbsp;<br />
configurations. I also observed differences in body mass after lipid removal. Overall, these&nbsp;<br />
studies provide insights into the potential use of prairie strips as both a conservation and an&nbsp;<br />
integrated pest management strategy. Insights from these projects can inform future research on&nbsp;<br />
the strategic integration of grassland land cover within annual crop fields to synergistically&nbsp;<br />
achieve production and conservation outcomes</p>

File: 

vargasandres_2024_msthesis.pdf