Biogeochemical Influence of Cutter Ants on Secondary Forests of Eastern Amazonia

摘要：9408927，PI-NEPSTAD：次生林是美洲热带地区人类开垦和利用土地增加的副产品。这些土地中的大部分可用于农业或牧场的时间有限，导致这些土地中的大部分恢复为次生林。关于这些次生林的形成和结构，还有许多东西有待了解。与原始森林相比，次生林中的切叶蚁数量高出10至100倍。它们在某些树种的落叶和作为土壤物理和化学性质的改良剂方面发挥着重要的生态作用。该项目通过描述有和没有蚂蚁种群的地点的巢穴、土壤和树木生长来调查切割蚁的生物地球化学影响。 这项研究很重要，因为它考虑了在这些生态系统中占主导地位的食草动物的作用，这些生态系统在人类利用和遗弃后正在恢复。热带生态系统土壤的地下过程是影响其恢复的主要因素。切叶蚁很可能在改善土壤条件以促进森林重建方面发挥关键作用。这项研究将开始，以解决这种潜在的相互作用，并测试的假设，这种多产的无脊椎动物提高树木生长在这些过渡生态系统。

Abstract: 9408927, PI-NEPSTAD: Secondary forests are the by-product of increased human clearing and utilization of land in the tropical regions of the Americas. The limited time duration in which much of this land can be kept in agriculture or pasture causes much of this land to revert to secondary forest. Much remains to be learned about the formation and structure of these secondary forests. Leafcutter ants are found to be incident at 10 to 100 fold higher numbers in secondary forest compared to primary forest. They play important ecological roles in defoliation of selected tree species and as modifiers of physical and chemical nature of the soils. This project investigates the biogeochemical influence of cutter ants by characterizing nest sites, soils, and tree growth at sites with and without ant populations. This research is important because it considers the role of the dominant herbivore in these ecosystems which are recovering after human utilization and abandonment. Belowground processes in the soils of tropical ecosystems are major controls on the recovery of these ecosystems after disturbance. The leafcutter ant may well play a crucial role in improving soil conditions to facilitate forest re-establishment. This research will begin to address this potential interaction, and test the hypothesis that this prolific invertebrate enhances tree growth in these transitional ecosystems.