Effects of stream acidification on lotic salamander assemblages in a coal-mined watershed in the Cumberland Plateau

摘要

We studied the effects of acid mine drainage (AMD) from abandoned coal mines on lotic salamanders and environmental conditions in the upper watershed (Cumberland Plateau) of North Chickamauga Creek (NCC; Tennessee River drainage) in southeastern Tennessee, USA, from 1996–97. Study sites (2~(nd)- or 3~(rd)-order reaches) were sampled in an AMD-influenced section (five sites) and in two reference streams (two minimally disturbed sites). A total of 212 plethodontids (premetamorphic larvae) representing four species were collected by kicknetting in riffles (n = 99) and electrofishing in mixed habitats (n = 113). The dusky salamander (Desmognathus fuscus ) was the most abundant species in both AMD and reference reaches ( 80 – 90% of total catches), successively followed by the southern two-lined salamander (Eurycea cirrigera ), spring salamander (Gyrinophilus porphyriticus ), and red salamander (Pseudotriton ruber ). Mining-influenced reaches were characterized by acidic flows (mean pH = 3.8–5.6), zero to low alkalinity, and elevated conductivity, sulfate, hardness, aluminum, and manganese, as well as very low abundances of salamanders. Reference reaches were slightly acidic to circumneutral (mean pH = 6.0–6.9) with low to moderate alkalinity, low levels of conductivity, hardness, sulfate, and metals, and high salamander abundances. Our findings document the impact of acid/metal pollution from past coal mining activities on lotic salamanders in a Cumberland Plateau stream.