Insects in Grassland Ecosystems

Abstract Insects serve as ecosystem engineers in grasslands. Their impacts are comparable in scale to those of mammals, but because they are so much smaller, their roles and influences are not always as obvious. The roles that insects play in grasslands are as diverse as Class Insecta itself, including herbivory, pollination, seed dispersal, soil profile modification, nutrient cycling, parasitism, and serving as intermediaries between plants and wildlife in food webs. In the context of their effects on grassland wildlife species, insects serve as essential food resources for many species of birds, bats, reptiles, mammals, amphibians, fish, and other insects. Insects also have significant effects on the habitat structure available for wildlife because they can, on the one hand, enhance the productivity of grassland vegetation, but alternatively, they have the power to completely defoliate a grassland. From the perspective of food webs, insects play multiple roles. They can serve as food for wildlife, but they also can serve as parasites, vectors of disease, and decomposers. Ecological changes in grasslands due to events such as fire, grazing, herbicide or insecticide application, and habitat fragmentation or loss can affect both wildlife and insects. For that reason, ecologists are often interested in linking the study of a particular wildlife species to the associated insect community. Insects are simply less visible ecological engineers, continually interacting with wildlife, and modifying the habitat where they coexist with wildlife in grassland ecosystems.