Monitoring Stream and Watershed Restoration

Chapter 4: Monitoring Restoration of Riparian Forests

Michael M. Pollock, Timothy J. Beechie, Samuel S. Chan, and Richard Bigley


Riparian forests are among the most biologically diverse portions of the terrestrial landscape and provide numerous benefits to instream habitat (Salo and Cundy 1987; Naiman et al. 1993; Nilsson et al. 1994; Pollock et al. 1998). Among these important benefits are the transport of large wood, fine organic material, nutrients, sediment, water, and thermal energy to the stream network, such that a natural aquatic environment is maintained. Alterations to riparian vegetation can alter or disrupt these watershed processes, which affect instream parameters such as stream productivity and the abundance of desirable fishes (Swanson and Lienkaemper 1978; Bisson et al. 1987; Lienkaemper and Swanson 1987). Riparian forest conditions largely determine instream conditions. Riparian areas also are a necessary habitat component for many wildlife species (Kondolf et al. 1987; Raedeke 1988). The loss of riparian habitat throughout much of North America and elsewhere is extensive, but the number of successful efforts to restore these systems is growing (Boldt et al. 1979; GAO 1988; Mutz 1989; BLM 1991; NRC 1992; Kattelman and Embury 1996; Wissmar and Beschta 1998). Riparian restoration describes a suite of restorative management techniques that can alter forest development in riparian areas for the purpose of improving instream and riparian habitat conditions (Oliver and Hinckley 1987; Berg 1990, 1995; Kohm and Franklin 1997).

Monitoring the effectiveness of these restoration actions requires measuring the response of vegetation in the riparian areas, as well as measuring the physical responses (e.g., stream channels, fish habitat, temperature) and biological responses (e.g., primary production, macroinverterbrates, fishes). Several guidelines for determining what and how to monitor specific instream parameters have been published (MacDonald et al. 1991; Bauer and Ralph 1999; Kaufmann et al. 1999), but aspects of monitoring design for restoration of riparian areas have not been well developed, and consistent criteria for determining the success of riparian restoration efforts are lacking. In particular, there has been little analysis of riparian silvicultural treatments on forest conditions and how those changes affect instream habitat (Beechie et al. 2000). For monitoring fencing and grazing projects (another form of riparian restoration), see Chapter 5.