1,231 research outputs found

    Ground Arthropod Abundance in Switchgrass and Diverse Prairie Agroenergy Crops

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    The University of Northern Iowa’s Tallgrass Prairie Center converted corn and soybean fields in the Cedar River Natural Resource Area to four mixes of perennial tallgrass prairie species. Research plots were randomly seeded with one of four treatments of native prairie vegetation including a switchgrass monoculture and a 32-species prairie mix. We studied ground arthropod abundance in Switchgrass and the 32-species prairie mix at various distances from the nearest woody edge using pitfall traps. We hypothesized that a 32-species Prairie mix would support greater numbers of ground arthropods than a Switchgrass monoculture and that ground arthropod abundance would be greater in traps set closer to a woody edge. Our results indicated little difference in arthropod abundance between the Switchgrass and Prairie plots. Arachnid captures were greater nearer to a woody edge, but catch rates of other arthropods studied did not vary with distance from a woody edge

    Grassland Bird Nest Survival in Perennial Agroenergy Crops

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    Previous research had been done in 2011 and 2012 regarding bird nest survival rates in the Cedar River Natural Resource Area in Washburn, IA. Further analysis of bird nest survival rates was done in this study to research how nest age, calendar date, soil type, and vegetation type influence the success or failure of these nests. New nests were identified in the prairie plots of the Cedar River Natural Resource Area and added to the previous sample size from the original study. A sample size of 97 bird nests total and 67 Dickcissel nests –SPAM (Spiza Americana) were used. The new nests were checked every 3-4 days and a fail or success was noted. The data was then analyzed using R statistical analysis to calculate correct logistic exposure models. The results for all nests showed that success was influenced by the nest age. A new nest had a 10% lower chance of success than an older nest. For all nests, the calendar date with which the nest was laid also influenced the successfulness. Nests laid in early may had a higher chance of surviving than nests laid in late season. Soil type and vegetation effects differed from all nests and the Dickcissel nest samples. However, for both sample sizes there was a much higher chance of success in 2011 than 2012 with the nests in the biomass vegetation mix having a better chance of survival than only grass
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