Hydrogeologic delineation of habitats for endangered species: the Comal Springs/River System |
| |
Authors: | J C Crowe J M Sharp Jr |
| |
Institution: | (1) Department of Geological Sciences, The University of Texas at Austin, Austin, Texas 78712, USA, US |
| |
Abstract: | We delineate 18 distinct habitats for the endangered fountain darter in the Comal Springs/River system based upon a combination
of vegetative, geologic, and hydrologic criteria. Comal Springs are the largest natural discharge from the Edwards aquifer
of central Texas; they issue along faults which penetrate the confined portion of the aquifer. The springs are the head of
the Comal River which is an important economic and recreational resource to the local community. The spring/river system is
the home of the fountain darter, a federally listed endangered species. Previous studies of this system were on a large scale
and lacked detail necessary for characterization. The fountain darter and other fauna in the Comal Springs/River system are
threatened by the possibility of diminished flows and the concomitant habitat change. The 18 habitats are defined by the dominant
species of vegetation, the substrate, and the flow conditions. Human alterations and spring discharge control the morphology
of the river and the substrates. Stream velocities determined substrate conditions and, thus indirectly, the distribution
of vegetation and habitats. In this system, hydrochemical parameters were uniform as were the soils adjacent to the stream;
these factors were not important to the habitat delineation. The range of stream velocities necessary to maintain the habitats
can be estimated with the Hjulstrom diagram. The darters were associated with a number of these habitats. We surmise that
significant alteration of the system's habitats will occur if discharge conditions change.
Received: 22 January 1996 · Accepted: 4 March 1996 |
| |
Keywords: | Edwards aquifer Fountain darter Habitat Endangered species |
本文献已被 SpringerLink 等数据库收录! |
|