ABUNDANCE OF MACROFAUNA IN DENSE SEAGRASS IS DUE TO HABITAT PREFERENCE, NOT PREDATION
ABUNDANCE OF MACROFAUNA IN DENSE SEAGRASS IS DUE TO HABITAT PREFERENCE, NOT PREDATION
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DOI：
10.1007/bf00384788
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发表时间：
1986-01-01
期刊：
影响因子：
2.7
通讯作者：
WESTOBY, M
中科院分区：
文献类型：
--
作者：
BELL, JD;WESTOBY, M
两种主要的假设相互竞争，以解释为什么当海草密度减少时，猎物的丰度会减少。一种观点认为，捕食者在密度较低的海草中更容易成功；另一个是猎物对栖息地的选择。在野外实验中，我们减少了在有捕食者和没有捕食者的情况下海草的密度，以区分这些假设。当对海草（Zostera capricorni）进行控制时，所有六种猎物物种（Bathygobius kreffti、Alpheus pacificus、A. leviusculus、Macrobrachium intermedium、Nectocarcinus tuberlosus和Thalamita sima）的丰度在存在和不存在捕食者的情况下同时下降。我们得出结论，海草床内猎物丰度与芽密度的相关性与猎物对稠密海草的栖息地偏好有关。我们报告了另一个支持这一结论的实验，并表明栖息地偏好是在最早的机会中行使的。然而，栖息地偏好可能是由捕食压力决定的。
Two main hypotheses compete to explain why prey abundance decreases when seagrass density is reduced. One proposes that predators are more successful amongst seagrass of lower density; the other invokes habitat choice by prey. We reduced the density of seagrass in the presence, and in the absence, of predators in a field experiment to discriminate between these hypotheses. When seagrass [Zostera capricorni] was manipulated abundances of all six prey species [Bathygobius kreffti, Alpheus pacificus, A. leviusculus, Macrobrachium intermedium, Nectocarcinus tuberculosus, and Thalamita sima] decreased simultaneously both in the presence and in the absence of predators. We conclude that correlations of prey abundance and shoot density within a seagrass bed are proximately due to habitat preference of dense seagrass by prey. We report another experiment which supports this conclusion and shows that habitat preference is exercised at the earlierst opportunity. However, the habitat preferences may have been selected by predation pressure.