Density dependence, spatial scale and patterning in sessile biota
Density dependence, spatial scale and patterning in sessile biota
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DOI：
10.1007/s00442-005-0137-x
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发表时间：
2005-09-01
期刊：
影响因子：
2.7
通讯作者：
Kaiser, MJ
中科院分区：
文献类型：
--
作者：
Gascoigne, JC;Beadman, HA;Kaiser, MJ
在不同空间尺度上，无根生物群可以相互竞争，也可以相互促进，促进和竞争的相互作用是形成空间斑块和格局的关键。我们检查了密度和规模的依赖模式，软沉积物贻贝床。我们在相隔四个数量级的两个空间尺度上跟踪贻贝的生长和密度。在夏季，双方的竞争都很重要。在冬季，在小尺度上存在净促进作用，而在大尺度上没有密度依赖的证据。促进作用的机制可能是由密度决定的防止波浪移动的保护。因此，软沉积贻贝层的种内相互作用在时间和空间上都是不同的。我们的数据支持这样一种观点，即生态系统的模式形成源于大尺度的竞争和小尺度的促进，迄今为止仅在植被系统中得到证实。这些数据和一个简单的启发式模型还表明，在无根生物群中，促进性相互作用是由物理压力介导的，并且相互作用的强度和特征会随着物理压力的时空梯度而变化。
Sessile biota can compete with or facilitate each other, and the interaction of facilitation and competition at different spatial scales is key to developing spatial patchiness and patterning. We examined density and scale dependence in a patterned, soft sediment mussel bed. We followed mussel growth and density at two spatial scales separated by four orders of magnitude. In summer, competition was important at both scales. In winter, there was net facilitation at the small scale with no evidence of density dependence at the large scale. The mechanism for facilitation is probably density dependent protection from wave dislodgement. Intraspecific interactions in soft sediment mussel beds thus vary both temporally and spatially. Our data support the idea that pattern formation in ecological systems arises from competition at large scales and facilitation at smaller scales, so far only shown in vegetation systems. The data, and a simple, heuristic model, also suggest that facilitative interactions in sessile biota are mediated by physical stress, and that interactions change in strength and sign along a spatial or temporal gradient of physical stress.