Ecosystem restoration is often focused on reconstructing or improving plant communities with the implicit or explicit assumption that consumer communities will re-assemble without assistance. Ongoing management following initial restoration activities is likely to further shape consumer communities. Insect monitoring represents an opportunity to examine how consumer communities respond to restoration and management because of their high taxonomic and functional diversity, range of specialist to generalist niches, and rapid population responses to environmental change. We monitored ground beetle (Coleoptera: Carabidae) communities in a chronosequence of restored tallgrass prairie from 2013-2019. Sites varied in management with prescribed fire and re-introduced bison, allowing us the opportunity to test (1) how consumer communities undergo successional changes as restoration age, (2) how they respond to strategies aimed at increasing habitat heterogeneity such as grazing management, and (3) whether functional trait descriptors of the community add information beyond taxonomic metrics such as richness.
Results/Conclusions
Ground beetle abundance and richness are initially very high in new restorations, but these rapidly decline as disturbance-tolerant species disappear from sites. Abundances slowly increase a decade after restoration activities, but older sites support a small number of species. These declines in taxonomic diversity are reflected in measures of functional diversity because communities become dominated by a small number of large, flightless, carnivorous species. Bison presence shifts community composition, and heterogeneity due to grazing and other bison activities may delay some of the declines in diversity by reducing the dominance of carnivorous beetle species. Monitoring a chronosequence over time provides both a long-term view of community change and individual time-series data for each site. This strengthens managers’ ability to predict how insect communities in a new restoration will change over time by quantifying successional patterns and the among-site variation in these patterns. Given the importance of insects in trophic webs and their contributions to ecosystem services, understanding their community changes could improve forecasting of ecosystem functions in restorations.