Factors Affecting Competitive Dominance of Rainbow Trout over Brook Trout in Southern Appalachian Streams: Implications of an Individual-Based Model
作者:
MarkE. Clark,
KennethA. Rose,
期刊:
Transactions of the American Fisheries Society
(Taylor Available online 1997)
卷期:
Volume 126,
issue 1
页码: 1-20
ISSN:0002-8487
年代: 1997
DOI:10.1577/1548-8659(1997)126<0001:FACDOR>2.3.CO;2
出版商: Taylor & Francis Group
数据来源: Taylor
摘要:
We used an individual-based model to examine possible explanations for the dominance of rainbow troutOncorhynchus mykissover brook troutSalvelinus fontinalisin southern Appalachian streams. Model simulations were used to quantify the effects on interspecific competition of (1) competitive advantage for feeding sites by rainbow trout, (2) latitudinal differences in stream temperatures, flows, and daylight, (3) year-class failures, (4) lower fecundity of brook trout, and (5) reductions in spawning habitat. The model tracks the daily spawning, growth, and survival of individuals of both species throughout their lifetime in a series of connected stream habitat units (pools, runs, or riffles). Average densities of each species based on 100-year simulations were compared for several levels of each of the five factors and for sympatric and allopatric conditions. Based on model results and empirical information, we conclude that more frequent year-class failures and the lower fecundity of brook trout are both possible and likely explanations for rainbow trout dominance, that warmer temperatures due to latitude and limited spawning habitat are possible but unlikely explanations, and that competitive advantage for feeding sites by rainbow trout is an unlikely explanation. Additional field work should focus on comparative studies of the reproductive success and the early life stage mortalities of brook and rainbow trout among Appalachian streams with varying rainbow trout dominance.
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