Habitat Characteristics. EMR have been found in a variety of wetland habitat types across their range, including bogs, fens, shrub swamps, wet xxxxxxx, marshes, moist grasslands, wet prairies, peatlands, coniferous forests and floodplain forests (Xxxxxx 1972, Xxxxxx 1986, Xxxxxxx 1991, Xxxxxxxxxxx and Prior 1992, Xxxxxxx 1995, Xxxxxxxxx 1996, Xxxxxxx 1997, Sage 2005). At many locations, EMR also move from wetlands to drier upland sites during certain parts of the year to forage, disperse, gestate, and even hibernate in some cases (Xxxxxxx and Xxxxxxx 1982, Xxxxxx 1986, Xxxxxxxxxxx and Prior 1992, Xxxxxxx 1995, Xxxx 0000, Xxxxxxx 0000, Xxxxxxxxx pers. comm.). Suitable upland habitat types range from forest edges and openings, savannahs and prairies to xxxxxxx, old fields and some agricultural lands. Analysis of the various habitat types utilized by EMR across its range indicates that structural characteristics of a site appear to be more important for determining habitat suitability than vegetative characteristics (Xxxxx 1992). In southern Michigan, all known sites appear to have the following three components: (1) open, sunny areas intermixed with shaded areas, and (2) areas in the vicinity where the water table is at or near the surface, and
Habitat Characteristics. Riparian habitats (includes streamside native vegetation) have been mostly lost to urbanization within the Xxxxxx Creek basin. Riparian buffers (i.e., preservation of streamside native vegetated areas) are one of the most significant measures for mitigating the impacts of urbanization and helping to restore habitat for salmon, steelhead and coastal cut-throat trout. Optimally, riparian buffers should be 100 to 200 feet wide. This corresponds to one to two site potential tree heights based on the site potential tree height, which is the expected height of coniferous trees upon maturity (200 years). This averages 170 feet in much of the Pacific Northwest, but may exceed 200 feet in areas such as the Olympic Peninsula or the redwood zone in California (Xxxxxx et al., 1996). Most of the riparian habitat in Xxxxxx Creek is much less than 100 feet in width. Riparian buffers can moderate downstream flood peaks by temporarily storing stormwater. Streamside vegetation provides shade and maintains cool water temperatures. Vegetation roots contribute to soil cohesion that stabilizes banks and filters sediment chemicals and nutrients from upstream sources. Trees supply large wood to the channel that maintains channel form and improves in- stream habitat complexity. Trees and shrubs contribute leaves, branches, and terrestrial insects that sustain aquatic invertebrates upon which salmonids feed. Large woody debris (LWD) from riparian buffers is critical to Pacific Northwest streams and plays a dominant role in forming pools, trapping spawning gravels, providing habitat for aquatic organisms and creating a more complex stream environment. LWD forms dammed and scour pools that create slow water habitats and provide refuge for fish during high- and low- flow events. Pools provide holding areas for spawning salmon, and pool tailouts are important spawning areas. Xxxxxx Creek is lacking in both large woody debris and pool habitat. Studies (Xxxx, 2001; Xxxx, 2002) of stream restoration projects involving the placement of LWD and boulders indicated that salmonids responded positively to wood placement. These studies showed that the largest fish population increases were seen in those streams that had the largest increase in pool area and wood loading, suggesting that large changes in physical habitat are needed to detect a significant fish response. Lack of nutrients has been shown responsible for depressed productivity in many watersheds in the Pacific Northwest (Xxxxxxx, 19...
Habitat Characteristics
