Van de Meutter Frank, De Meester Luc, Stoks Robby
Laboratory of Aquatic Ecology, Katholieke Universiteit Leuven, Ch. Deberiotstraat 32, B-3000 Leuven, Belgium.
Ecology. 2007 Jul;88(7):1687-95. doi: 10.1890/06-0333.1.
A recent challenge in community ecology is to understand under what conditions local and regional processes may be more important in shaping community structure. We investigated the role of dispersal mode and generation time for communities of macroinvertebrates in two sets of connected ponds during three consecutive years. We found no evidence that generation time affected metacommunity structure, possibly because statistical power was limited because the range of generation times present was small. In contrast, we found that the spatial structure of the macroinvertebrate metacommunities differed with dispersal mode in one of two sets of ponds. Passive dispersers showed positive distance-dissimilarity correlations, suggesting mass effects via the pond connections. These correlations did not stretch beyond the first pond downstream suggesting that, in this chain of connected ponds, intervening ponds effectively buffered dispersal. Active dispersers did not show any consistent spatial pattern, possibly because intensive over-land dispersal homogenized the metacommunity. Thus, although pond connections probably equally promoted dispersal of actively and passively dispersing macroinvertebrates, the implications for the structure of their metacommunities may depend on their dispersal mode. We conclude that dispersal mode has the potential to affect the mechanisms that are integral to metacommunity structure.
群落生态学最近面临的一个挑战是了解在何种条件下，局部和区域过程在塑造群落结构方面可能更为重要。我们连续三年研究了两组相连池塘中大型无脊椎动物群落的扩散模式和世代时间的作用。我们没有发现世代时间影响集合群落结构的证据，这可能是因为存在的世代时间范围较小，统计效力有限。相比之下，我们发现在两组池塘中的一组里，大型无脊椎动物集合群落的空间结构因扩散模式而异。被动扩散者呈现出正的距离-相异度相关性，这表明通过池塘连接存在质量效应。这些相关性并未延伸到下游的第一个池塘之外，这表明在这条相连池塘链中，中间的池塘有效地缓冲了扩散。主动扩散者没有表现出任何一致的空间模式，这可能是因为密集的陆地扩散使集合群落同质化。因此，尽管池塘连接可能同样促进了主动和被动扩散的大型无脊椎动物的扩散，但对它们集合群落结构的影响可能取决于它们的扩散模式。我们得出结论，扩散模式有可能影响集合群落结构所不可或缺的机制。
