Persistence of Stream Fish Assemblages: Effects of Environmental Change
Persistence of Stream Fish Assemblages: Effects of Environmental Change
复制标题
溪流鱼类群落的持续存在：环境变化的影响
作者：
S. Ross;W. J. Matthews;A. Echelle
了解生态群落的时间稳定性和持久性对于理解生物相互作用在维持群落结构中的重要性至关重要。在此，我们考虑了两种鱼类组合的时间稳定性和持久性，一种位于俄克拉荷马州南部一条严酷的草原溪流布莱尔溪，另一种位于阿肯色州奥沙克地区较为温和的溪流派尼溪。正如存在数据所表明的，在大约十年内，这两个流组合的持久性都很高。根据丰度测量确定的群落稳定性表明，与松树溪相比，布莱尔溪的总体鱼类区系变化更大。 1980 年，俄克拉荷马州东南部发生严重的夏季干旱，导致布莱尔溪 (Brier Creek) 的鱼类热死。尽管一些物种受到了暂时的影响，但严酷的夏季并没有对整个石南溪鱼类群落产生持久影响。然而，与下游站相比，定期进行夏季干燥的上游站在上游物种特征组内的物种数量排名表现出更大的变异性。在某些情况下，Piney 溪和 Brier 溪的站级变化都很显着，尽管前者的整体动物群在物种丰富度排名上没有显着变化。因此，地理尺度可能对组合稳定性和持久性的评估产生重大影响。我们建议，在缺乏对组成物种栖息地范围的详细了解的情况下，对组合稳定性的评估应至少基于流域内的几个地点。
Knowledge of temporal stability and persistence of ecological communities is critical to an understanding of the importance of biotic interactions in the maintenance of community structure. Herein we have considered temporal stability and persistence of two fish assemblages, one in Brier Creek, a harsh prairie stream in southern Oklahoma, and the other in Piney Creek, a more benign stream in the Arkansas Ozarks. Persistence, as indicated by presence data, was high for both stream assemblages over approximately one decade. Assemblage stability, as determined from measures of abundance, indicated greater change in the overall fish fauna of Brier Creek than that of Piney Creek. Southeastern Oklahoma had a severe summer drought in 1980 resulting in heat death of fishes in Brier Creek. Although some species were transiently affected, the harsh summer did not have a lasting effect on the Brier Creek fish assemblage overall. Upstream stations subjected to regular summer drying, however, showed greater variability in numerical species ranks within a characteristic suite of upstream species, compared with downstream stations. Station-level changes in both Piney and Brier creeks were significant in several cases, even though the overall fauna of the former did not change significantly in species-abundance ranks. Thus, geographic scale may have had a major effect on the assessment of assemblage stability and persistence. We suggest that, in the absence of detailed knowledge of home ranges of component species, an assessment of assemblage stability should be based on at least several localities within a watershed.