Flathead Lake Biological Station, The University of Montana, 32125 Bio Station Lane, Polson, MT 56860, U.S.A.
J Fish Biol. 2014 Jul;85(1):132-50. doi: 10.1111/jfb.12286. Epub 2014 Apr 28.
This study explored the relationship between riverine physical complexity, as determined from remotely sensed metrics, and anadromy and genetic diversity in steelhead or rainbow trout Oncorhynchus mykiss. The proportion of anadromy (estimated fraction of individuals within a drainage that are anadromous) was correlated with riverine complexity, but this correlation appeared to be driven largely by a confounding negative relationship between drainage area and the proportion of anadromy. Genetic diversity decreased with latitude, was lower in rivers with only non-anadromous individuals and also decreased with an increasing ratio of floodplain area to total drainage area. Anadromy may be less frequent in larger drainages due to the higher cost of migration associated with reaches farther from the ocean, and the negative relationship between genetic diversity and floodplain area may be due to lower effective population size resulting from greater population fluctuations associated with higher rates of habitat turnover. Ultimately, the relationships between riverine physical complexity and migratory life history or genetic diversity probably depend on the spatial scale of analysis.
本研究探讨了河流物理复杂性（通过遥感指标确定）与虹鳟鱼 Oncorhynchus mykiss 的溯河洄游和遗传多样性之间的关系。溯河洄游的比例（流域内溯河洄游个体的估计比例）与河流复杂性相关，但这种相关性似乎主要是由流域面积与溯河洄游比例之间的负相关关系所驱动。遗传多样性随纬度降低，在只有非溯河洄游个体的河流中较低，并且随着洪泛区面积与总流域面积之比的增加而降低。由于与离海洋更远的河段相关的迁移成本较高，较大的流域中溯河洄游可能不太频繁，而遗传多样性与洪泛区面积之间的负相关关系可能是由于与更高的栖息地周转率相关的更大种群波动导致有效种群规模降低所致。最终，河流物理复杂性与洄游生活史或遗传多样性之间的关系可能取决于分析的空间尺度。
