Fish community responses to drying disturbances in an intermittent stream: a landscape perspective
Fish community responses to drying disturbances in an intermittent stream: a landscape perspective
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DOI：
10.1111/j.1365-2427.2007.01800.x
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发表时间：
2007-09-01
影响因子：
2.7
通讯作者：
Kelly, David J.
中科院分区：
文献类型：
--
作者：
Davey, Andrew J. H.;Kelly, David J.
1. 避难所对于受干扰环境中个体、种群和群落的持续存在至关重要，但很少有研究考虑避难所在景观中的位置如何与组成物种的行为反应相互作用，以确定干扰事件对移动动物的影响。2．在塞尔温河（一条中游间歇性河流）上进行了为期 18 个月的定量电捕鱼调查，以确定到保护区的方向和距离如何影响鱼类种群对干燥的反应，以及景观环境如何与水流持久性相互作用以产生群落的空间模式。3。总体而言，在干燥时期鱼类在常年河段避难的倾向，以及在重新湿润时从这些避难所重新定殖的速度和程度，取决于到避难所的方向和距离以及组成物种的行为。4．在上游，随着河流自下而上干涸，坎特伯雷星河鱼 (Galaxias vulgaris)、高地恶霸鱼 (Gobiomorphus breviceps) 和褐鳟 (Salmo trutta) 向上游洄游至永久水域，但频繁的干涸和大多数物种缓慢的重新定居结合起来，在间歇性河段产生了一个鱼类群落，其数量和质量与邻近的常年河段的鱼类群落不同。5。在下游河流中，随着河流自上而下干涸，鱼类似乎并没有向下游迁移到永久水域，但干涸事件的频率较低，并且来自下游保护区的高地恶霸和鳗鱼（安圭拉属）更快地重新定居，使得间歇性河段的鱼类群落在长时间湿润期间与邻近常年河段的鱼类群落融合。 6。鱼类密度和物种丰富度随水流持久性增加的纵向模式被解释为特定物种对干旱事件的反应和河流景观中保护区的空间位置的产物。
1. Refugia are critical to the persistence of individuals, populations and communities in disturbed environments, yet few studies have considered how the position of refugia within the landscape interacts with the behavioural responses of component species to determine the influence of disturbance events on mobile animals.2. An 18-month quantitative electrofishing survey was undertaken on the Selwyn River, a stream that is intermittent in its middle reaches, to determine how the direction and distance to refugia affect the response of fish populations to drying, and how landscape context interacts with flow permanence to produce spatial patterns in communities.3. Overall, the propensity of fish to take refuge in perennial reaches during drying episodes, and the rate and extent of recolonization from these refugia upon rewetting, depended upon the direction and distance to refugia and the behaviour of component species.4. In the upper river, Canterbury galaxias (Galaxias vulgaris), upland bullies (Gobiomorphus breviceps) and brown trout (Salmo trutta) migrated upstream to permanent water as the stream dried from the bottom up, but frequent drying and slow recolonization by most species combined to produce a fish community in intermittent reaches that was quantitatively and qualitatively different to that in neighbouring perennial reaches.5. In the lower river, fish did not appear to migrate downstream to permanent water as the stream dried from the top down, but a lower frequency of drying episodes and faster recolonization by upland bullies and eels (Anguilla spp.) from downstream refugia allowed the fish community in intermittent reaches to converge with that in neighbouring perennial reaches during prolonged wetted periods.6. Longitudinal patterns of increasing fish density and species richness with flow permanence are interpreted as the product of species-specific responses to drying events and the spatial position of refugia within the riverscape.