Spatially disjunct effects of co-occurring competition and facilitation
Spatially disjunct effects of co-occurring competition and facilitation
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DOI：
10.1111/j.1461-0248.2005.00822.x
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发表时间：
2005-11-01
期刊：
影响因子：
8.8
通讯作者：
Hobbie, SE
中科院分区：
文献类型：
--
作者：
Dickie, IA;Schnitzer, SA;Hobbie, SE
人们对站点内竞争性和促进性交互的同时发生和影响知之甚少。在这里，我们展示了森林边缘的空间分离竞争和促进作用，树木通过在 12 至 20 m 处明显增加的外生菌根感染对幼苗生长产生有益影响，而靠近树木的幼苗生长与树冠闭合呈负相关。因此，在中等距离处，幼苗生长最大化。促进性相互作用是非线性的：距离树 15.7 m 以内可最大限度地提高幼苗菌根感染；而竞争效应与冠层闭合相关，冠层闭合与距离有关，并且通常与密度相关。这些模式导致在树木密度较低时树木密度与幼苗生长呈正相关，而在较高密度时由于竞争而呈负相关。空间模型表明，植物群落是正相互作用和负相互作用的镶嵌体，这可能有助于种群稳态和植物多样性。
Little is known of the co-occurrence and implications of competitive and facilitative interactions within sites. Here we show spatially disjunct competition and facilitation at forest edges, with beneficial influences of trees on seedling growth via increased ectomycorrhizal infection apparent from 12 to 20 m while closer to trees seedling growth is negatively correlated with canopy closure. As a result, seedling growth is maximized at intermediate distances. Facilitative interactions were nonlinear: being within 15.7 m of a tree maximized seedling mycorrhizal infection; while competitive effects were correlated with canopy closure, which was related to distance and generally scales with density. These patterns result in a positive correlation of tree density and seedling growth at low densities of trees, and negative correlation at higher densities because of competition. A spatial model suggests that plant communities are a mosaic of positive and negative interactions, which may contribute to population homeostasis and plant diversity.