Stream Macroinvertebrate Response to Clearcut Logging

Why study response of stream invertebrates to watershed disturbances such as clearcut logging? Stream invertebrates can be excellent integrators of changes in such ecosystem phenomena as changes in the food base of ecosystems. For example, a number of invertebrate taxa appear to track changes in food resources (Hawkins et al. 1982; Fuller et al. 1986; Wallace and Gurtz 1986; Feminella and Hawkins 1995; Wallace and Webster 1996; Wallace et al. 1997; Jackson et al. 2007). Many taxa also exhibit substrate-specific as well as taxon-specific responses to physical alterations, such as sediment addition (Gurtz and Wallace 1984; Zweig and Rabeni 2001). Benthic invertebrates can also play important roles in many ecological processes (Wallace and Webster 1996), and in whole ecosystems, benthic invertebrates often display early and dramatic responses to manipulation (Reice and Wohlenberg 1993). Thus, assessment of benthic assemblages can be a valuable means to detect disturbance and long-term recovery from disturbance. Furthermore, knowledge of a change in the community structure of invertebrates offers an additional mechanism for detecting changes in ecological processes through time. Unfortunately, there have been few studies of the response to clearcut logging within the same stream over many years. Rather, such changes are occasionally inferred from examining multiple streams draining catchments that are in different stages of recovery.