Herbivory in a fragmented tropical forest: patterns from islands at Lago Gatun, Panama
Herbivory in a fragmented tropical forest: patterns from islands at Lago Gatun, Panama
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DOI：
10.1023/a:1016888000369
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发表时间：
2002-09-01
影响因子：
3.4
通讯作者：
Asquith, NM
中科院分区：
文献类型：
--
作者：
Arnold, AE;Asquith, NM
通过对宿主施加密度依赖的死亡率，专业昆虫食草动物被认为有助于维持热带森林中的树木多样性。森林破碎化可能会改变草食动物的模式，但是，这可能有重要的影响，在森林遗迹的树种多样性。为了探索碎片化的草食动物的模式的影响，我们评估了食叶鳞翅目幼虫的树苗的四个重点树种的八个人工，森林岛屿在拉戈加通湖，巴拿马。我们探讨了岛屿面积的重要性，距离更大的土地，暴露于旱季风，树种，和季节在确定比例的新叶受损的毛虫，和比例的叶面积损失的毛虫，在两个干燥和潮湿的季节。我们发现，这两个措施的食草动物与岛屿面积显着增加，岛屿隔离食草动物没有明显的影响，季节和曝光之间的相互作用，树种和季节之间，是重要的决定因素的食草率。此外，我们观察到种特异性的差异，在寄主植物之间的食草动物在各种条件下所施加的碎片。我们的结论是，模式的食草鳞翅目幼虫在这热带森林的碎片敏感。这里考虑的四个树种之间的差异草食动物可能有重要的影响，拉戈加通岛上的树种动态。
By imposing density-dependent mortality upon their hosts, specialist insect herbivores are thought to contribute to the maintenance of tree diversity in tropical forests. Forest fragmentation may alter patterns of herbivory, however, which may have important implications for tree species diversity in forest remnants. To explore effects of fragmentation on patterns of herbivory, we assessed folivory by Lepidopteran larvae on saplings of four focal tree species on eight artificial, forested islands at Lago Gatun, Panama. We explored the importance of island area, distance to larger land, exposure to dry season winds, tree species, and season in determining proportions of new leaves damaged by caterpillars, and proportions of leaf area lost to caterpillars, during two dry and wet seasons. We found that both measures of herbivory increased markedly with island area, that island isolation had no apparent effect on herbivory, and that interactions between season and exposure, and between tree species and season, were important determinants of herbivory rates. In addition, we observed species-specific differences in herbivory among host plants under various conditions imposed by fragmentation. We conclude that patterns of herbivory by Lepidopteran larvae are sensitive to fragmentation in this tropical forest. Differential herbivory among the four tree species considered here may have important implications for tree species dynamics on the islands of Lago Gatun.