PI: Belovsky, Gary Institution: University of Notre Dame
This LTREB project continues monitoring and manipulations of grasshopper populations that have been conducted in four habitats in Montana for 17, 15, 14 and 10 years, respectively. The monitoring measures grasshopper, predator, and plant abundances, along with nutrients and plant production. The manipulations vary grasshopper density and predation on grasshoppers to assess impacts on nutrients and plant production. Grasshoppers are dominant herbivores and influence nutrients and plant production. Because grasshopper abundance varies dramatically between years, grasshopper influence also varies. Grasshopper herbivory can influence a habitat by either diminishing nutrients, which decreases plant production, or by increasing nutrients, which increases plant production. The purpose of this study is to understand how grasshoppers and their predators affect nutrients and plant production.
Long term databases like this study are critical for assessing how ecosystem structure (species abundances) influence ecosystem function (nutrients and production). This is a central question in ecology with several applications. First, grasshoppers are widely considered to be pests that must be controlled. This study assesses when control may be beneficial or even detrimental. Second, the study helps to understand the human impacts on ecosystems for conservation and restoration. Finally, educational benefits accrue by involving high school, undergraduate and graduate students, especially Native Americans.
