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Dissertation Research: Herbivory and the Evolution of Habitat Specialization in Amazonian White Sand and Clay Forests

论文研究：亚马逊白沙和粘土森林的食草动物和栖息地专业化的演变

基本信息

批准号：
0206196
负责人：
Phyllis Coley
金额：
$ 0.96万
依托单位：
University of Utah
依托单位国家：
美国
项目类别：
Standard Grant
财政年份：
2002
资助国家：
美国
起止时间：
2002-06-01 至 2004-05-31
项目状态：
已结题

来源：
https://www.nsf.gov/awardsearch/showAward?AWD_ID=0206196&HistoricalAwards=false
关键词：
Dissertation Research Herbivory Evolution Habitat

项目摘要

Tropical forests include a diversity of habitats, which has lead to specialization inplants. Near Iquitos, in the Peruvian Amazon, nutrient-poor white sand forests are foundimmediately adjacent to nutrient-rich clay forests, each harboring a unique compositionof habitat specialist trees. Why does habitat specialization occur? Our hypothesis is thatthe combination of impoverished soils and herbivory creates strong selective pressure forplant defenses in white sand forest. Species that have not evolved high levels ofantiherbivore defense are therefore at a disadvantage in white sand forests and excludedby herbivores.To test whether herbivores select for higher optimal antiherbivore defense inwhite sand plants, we are comparing defense investment in 33 species from 6 genera thatinclude several phylogenetically independent pairs of closely-related white sand and clayspecialists. In addition, we have established a reciprocal transplant experiment tomanipulate the presence of herbivores and directly test to what degree herbivoresmaintain the low overlap in species composition between the two forest types. Ifherbivory has a significant effect on habitat specialization, it will suggest a new way thatherbivores may influence plant evolution: by sharpening habitat boundaries due to abioticfactors and thereby increasing the potential for habitat specialization.

热带森林包括多种多样的栖息地，这导致了植物的专业化。在秘鲁亚马逊的伊基托斯附近，营养贫乏的白沙森林与营养丰富的粘土森林毗邻，每个森林都有独特的栖息地专用树木组成。为什么会出现生境专门化？我们的假设是贫瘠的土壤和草食的结合为白沙森林的植物防御创造了强大的选择压力。因此，没有进化出高水平的反食草动物防御的物种在白沙森林中处于不利地位，并被食草动物排除在外。为了验证食草动物是否在白沙植物中选择了更高的最佳反食草动物防御，我们比较了来自6属的33个物种的防御投资，其中包括几个系统发育上独立的白沙和粘土专家对。此外，我们建立了一个互惠移植实验来操纵草食动物的存在，并直接测试草食动物在多大程度上维持了两种森林类型之间物种组成的低重叠。如果食草动物对生境专门化有显著影响，那么这将为食草动物影响植物进化提供一种新的途径：通过非生物因素使生境边界清晰化，从而增加生境专门化的可能性。