Biotic and Chemical Defense Systems of Myrmecophytic Cecropia

本文将从亚马逊热带雨林中与食草动物和象征性蚂蚁的植物关系的角度，对杉生植物的生物和化学防御系统的种间、环境和发育差异进行研究。在秘鲁东南部的温带温室和移植花园中，将在高光照和低光照条件下从种子开始种植六种天蚕的幼苗。蚂蚁吸引性状，叶片单宁浓度和韧性将被监测与植物性能有关，特别是生长速度和叶片寿命（被认为决定了化学和抗防御的投资模式）。移栽秧苗在有和没有食草动物的情况下的表现数据将检验这些树木栖息地特异性的特定假设。短期盆栽实验将测试1)四种特殊共生蚂蚁的栖息地和寄主特异性；2)寄主资源供给率作为共生关系物种组成的决定因素；3)生境和物种特异性对不同蚂蚁的取食率、寄主性能、群体生长和繁殖的影响。利用自然幼苗种群来研究蜂王选择寄主的物种特异性和寄主排除某些蚂蚁的机制。研究结果将被综合，以验证以下假设：植物资源环境决定可预测的替代性防御系统投资模式，防御投资模式决定反植物协会的物种组成。研究结果将有助于基础生态科学，也将增加关于热带森林生物多样性的知识基础。//

Interspecific, environmental and development differences in biotic and chemical defense systems of myrmecophytic Cecropia trees will be studied in relation to plant associations with herbivores and symbotic ants in Amazonian rain forest. Seedlings of six Cecropia species will be grown from seed under high and low light regimes in temperate greenhouse and transplant gardens in southeastern Peru'. Ant attracting traits, leaf tannin concentrations, and toughness will be monitored in relation to plant performance, especially growth rates and leaf lifetimes (thought to determine the pattern of investment in chemical and ant-defense). Performance data on transplanted seedlings with and without herbivores will test specific hypotheses for habitat specificity in these trees. Short-term experiments with cultivated seedlings will test for 1) habitat and host specificity in four specialized symbiotic ants; 2) rates of host resource supply to ants as a determinant of the species composition of symbiotic relationships: 3) habitat and species specificity in effects of different ants on herbivory rates, host performances, and colony growth and reproduction. Natural seedling populations are used to investigate species specificity in host choice by queens and host mechanisms for excluding certain ants. Results of studies will be synthesized to test hypotheses that: plant resource environments determine predictable patterns of investment in alternative defense systems and patterns of defense investment determine the species composition of ant-plant associations. Findings will contribute to basic ecological science and will also add to the knowledge base on the biodiversity of tropical forests. //