Decision support for restoration and management of Service-owned native prairies: Implications for grassland bird communities
Temperate grasslands are considered one of the most altered terrestrial ecosystems in the world. Remaining prairies have been increasingly degraded by fragmentation, encroachment of woody and exotic plants, and suppression or misapplication of defoliation disturbances (e.g., fire, grazing, haying). More than 100,000 ha of native tallgrass and mixed-grass prairies are managed by the US Fish and Wildlife Service (FWS) in the northern Great Plains. Although prairies in this region evolved with grazing, fire, and climatic variability, management of FWS grasslands often has been passive and involved extended periods of rest (i.e., no disturbance). Extended rest has been implicated as a contributing factor in large-scale invasions by woody vegetation, smooth brome, Kentucky bluegrass, and other cool-season exotic plants. In 2008, the USGS and the FWS initiated a collaborative effort, the Native Prairie Adaptive Management Project (NPAM). NPAM employs the principles of adaptive management (i.e., iterative cycles of decision making, management action, and monitoring) to evaluate and improve management practices that address invasive plant issues and restoration efforts on FWS grasslands over time. Realistically, shifts in vegetation through time may influence habitat quality and quantity for grassland birds, which have exhibited widespread declines in North America. In 2011, we initiated a three-year study that piggybacks on the ongoing NPAM effort in order to develop competing models for the response of grassland breeding birds to management treatments. The primary objectives of this study are 1) to assess the response of grassland birds to various management treatments (rest, fire, grazing) that are being implemented to restore vegetation composition on FWS-owned grasslands, and 2) to explore the effects of vegetation structure and composition as mechanisms for triggering grassland bird responses to management.
Lawrence D Igl