Trunk cutting initiates bottom-up cascades in a tri-trophic system: sprouting increases biodiversity of herbivorous and predaceous arthropods on willows
Trunk cutting initiates bottom-up cascades in a tri-trophic system: sprouting increases biodiversity of herbivorous and predaceous arthropods on willows
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DOI：
10.1111/j.2006.0030-1299.14251.x
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发表时间：
2006-05
期刊：
影响因子：
3.4
通讯作者：
Masahiro Nakamura;H. Kagata;T. Ohgushi
中科院分区：
文献类型：
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作者：
Masahiro Nakamura;H. Kagata;T. Ohgushi
我们研究了砍伐树干对柳树和柳树两种优势树种再生反应的影响，以及随后对草食性和捕食性节肢动物群落结构(丰富度和物种丰富度)的影响。我们研究了随机选择的每种柳树的10对采伐和未采伐(对照)树。田间观察表明，树干被剪断后，嫩枝从根部萌发，发育迅速。这些枝条持续生长到7月份，产生侧枝和叶子，而未砍伐的树木上的当年枝条到4月份基本上停止生长。在7月份，砍伐树木的上部叶片比未砍伐树木的叶片不那么坚韧，水分和氮素含量更高。两种柳树的食草性节肢动物和捕食性节肢动物的叶片消耗量、丰富度和物种丰富度均显着高于未砍伐树种。总体而言，砍树干使柳树节肢动物群落内的相对丰富度和物种丰富度至少增加了两倍。我们的结论是，砍伐树干造成的严重物理损害通过自下而上的级联效应大大增加了草食性和捕食性节肢动物的生物多样性。
We examined the effects of trunk cutting on the regrowth responses of two dominant willow species, Salix eriocarpa and S. gilgiana, and the subsequent effects on the community structure (abundance and species richness) of herbivorous and predaceous arthropods. We studied ten randomly selected pairs of cut and uncut (control) trees of each willow species. Field observations showed that when the trunks were cut, shoots sprouted from the base and developed rapidly. These shoots continued to grow until July, producing lateral shoots and leaves, whereas current-year shoots on uncut trees essentially stopped growing by April. In July, the upper leaves of cut trees were less tough and had a greater water and nitrogen content than leaves of uncut trees. Leaf consumption and abundance and species richness of both herbivorous and predaceous arthropods were significantly greater on cut trees than on uncut trees in both willow species. Overall, trunk cutting resulted in at least a two-fold increase in both relative abundance and species richness within the arthropod community on the willow species. We concluded that the severe physical damage caused by trunk cutting greatly increased the biodiversity of herbivorous and predaceous arthropods through bottom-up cascading effects.