A Regional View of the Margin: Salmonid Abundance and Distribution in the Southern Appalachian Mountains of North Carolina and Virginia

Abstract

in the southern Appalachian Mountains, native brook trout Salvelinus fontinalis and introduced rainbow trout Oncorhynchus mykiss and brown trout Salmo trutta are at the southern extremes of their distributions, an often overlooked kind of marginal habitat. At a regional scale composed of the states of Virginia and North Carolina, species were found to be distributed along latitudinal and elevational gradients. Native brook trout remain most common and abundant, decreasing both from north to south and from high to low elevations. Sympatry increases to the south, where rainbow and brown trout become more successful. For the region as a whole and within major drainages, allopatric and sympatric brook trout were generally found at higher elevations and rainbow and brown trout at lower elevations. Among drainages, elevations at which allopatric brook trout and rainbow trout are found generally increased to the south. A measure of effective elevation, which adjusts elevation for latitude, most clearly separated allopatric and sympatric brook trout from allopatric rainbow and brown trout.

Distribution patterns and trophic characteristics of salmonids and native species inhabiting high altitude rivers of Pampa de Achala region, Argentina

“…This pattern agrees with what was observed at other high and cold basin areas (Rahel & Hulbert, 1991;Flebbe, 1994;Taniguchi et al, 1998). Platts & McHenry (1988) showed that O. mykiss was well adapted to a greater range of stream habitats, which supports our finding that this species was found across different altitudes in Pampa de Achala streams.…”

THE EVOLUTION OF SPECIES' DISTRIBUTIONS: RECIPROCAL TRANSPLANTS ACROSS THE ELEVATION RANGES OFMIMULUS CARDINALISANDM. LEWISII

“…The environmental gradient from the center to the edge of elevation and latitude ranges is also similar, with temperature and length of growing season decreasing to the north and at higher elevations, although the rate of change in environmental parameters across space is greater for elevation than for latitude gradients. Indeed, a change of 100-200 m in elevation is roughly equivalent to a change of one degree in latitude (Criddle et al 1994;Flebbe 1994). Due to the steepness of the environmental gradient across elevation, for a given dispersal distance, individuals encounter a more different environment than if dispersing across latitude, making it more likely that marginal populations may be swamped by centrally adapted phenotypes at elevation range boundaries than at latitudinal range boundaries (Kirkpatrick and Barton 1997).…”

The Influence of Habitat Characteristics on the Longitudinal Distribution of Brook, Brown, and Rainbow Trout in a Small Midwestern Stream

“…Previous studies of trout distribution and abundance have described a longitudinal gradient of species composition with brook trout in the headwaters, rainbow trout at intermediate gradient and elevation, and brown trout farthest downstream. These studies have been conducted in mountain stream habitats with stream gradients 2 6% (Magoulick and Wilzbach 1998, Strange and Habera 1998, Flebbe 1994, Larson and Moore 1985, Grad and Flittner 1974.…”