DYNAMICS OF INTERMITTENT STREAM HABITAT REGULATE PERSISTENCE OF A THREATENED FISH AT MULTIPLE SCALES

作者：Theodore R. Labbe, Kurt D. Fausch · 发表于：Ecological Applications · 年份：2000 · DOI：10.1890/1051-0761(2000)010[1774:doishr]2.0.co;2 · 被引用次数：372 · 研究领域：Fish Ecology and Management Studies、Hydrology and Sediment Transport Processes、Hydrology and Watershed Management Studies

Traditionally, threatened species management has emphasized conservation of individual populations and has assumed that abundance within suitable habitats is primarily governed by local environmental factors. However, recent research has revealed that landscape-level processes such as disturbance, dispersal, and habitat patch mosaic structure may also strongly influence local populations. We studied the population and habitat dynamics of a threatened fish, the Arkansas darter (Etheostoma cragini) at four spatial scales (pool, reach, segment, watershed) in two intermittent Colorado plains streams. At each scale, information on hydrology, habitat, and fish populations was combined to evaluate factors influencing darter persistence. At the pool scale, Arkansas darters persisted in most permanent pools during summer drought, tolerated extremes of hyperthermia and hypoxia, and were extirpated only when pools dried. Deeper pools had a higher probability of persisting during summer drought. At the reach scale, survival measured during an intensive mark–recapture study was high in a stenothermal spring pool, but low in associated downstream pools that froze during winter and had harsh, variable thermal regimes during summer. However, juvenile darters hatched earlier, grew faster, and were relatively more abundant in the warmer downstream pools compared to juveniles in the spring pool, where older fish dominated. Movement rates between the two habitats were relatively low, but adult d...