CRB: Direct and Indirect Effects of Key Alien Species in Two Hawaiian Forest Communities

小行星9610413 保护和恢复生物学的一个关键问题是外来入侵物种的作用。虽然发展入侵生态学作为一门预测科学的价值越来越被认识到，但这可能很困难，除非更频繁地使用操纵性实验。在拟议的研究中，操作实验将被用来分析入侵物种的影响，在一个干燥的森林网站上的夏威夷岛的社区长期以来一直注意到他们的干扰倾向的功能。这项研究的目标是确定夏威夷土著社区如何应对外来物种的消失而发生变化。具体而言，实验将确定在受干扰和受保护的栖息地的本地物种的再生潜力。据推测，关键的外来物种对这些森林中本地物种的分布和丰富程度有不成比例的影响。实验地点将设在夏威夷岛上的考普乐胡保护区，在那里，外来的、促进火焰的喷泉草现在很普遍。在清除喷泉草和控制大鼠后，将监测本地和外来物种的招募情况。去除喷泉草和控制老鼠，预计会导致增加招聘的本地树冠，灌木和草本植物物种。还将调查次级影响，如喷泉草抑制的其他外来物种的入侵，以及随着本地物种数量的增加而增加的食草动物水平。夏威夷物种的特有性和濒危程度非常高，这并不是拟议研究的理由;更普遍的意义是增加对外来物种破坏本土植物群落的作用以及主要和次要影响的意义的理解。夏威夷植物群落对外来物种入侵的明显极端敏感性，应该更容易看到外来物种迁移的后果。夏威夷群岛关于外来物种作用的经验教训应广泛适用于其他植物群落。

9610413 Lorence A key issue in conservation and restoration biology is the role of invasive, alien species. Although the value of developing invasion ecology as a predictive science is increasingly recognized, this may be difficult unless manipulative experiments are used more frequently. In the proposed research, manipulative experiments will be used to analyze the effects of invasive species in a dry forest site on the Island of Hawaii where communities have long been noted for their disturbance prone features. The goal of the research is to determine how native Hawaiian communities change in response to the removal of alien species. Specifically, experiments will determine the regeneration potential of native species in disturbed and protected habitats. It is presumed that key alien species have a disproportionate effect on the distribution and abundance of native species in these forests. The experimental site will be located in the Kaupulehu Preserve on the island of Hawaii in an area where the alien, fire promoting fountain grass is now widespread. Recruitment of native and alien species following removal of fountain grass and control of rats will be monitored. Removal of fountain grass and control of rats is expected to result in an increase in recruitment of the native canopy, shrub, and herbaceous species. Secondary effects will also be investigated such as the invasion of other alien species suppressed by fountain grass, and increased levels of herbivory on native species as they increase in abundance. The extraordinarily high degree of endemism and endangerment of Hawaiian species is not justification for the proposed research; of more general significance is an increased understanding of the role of alien species in disruption of native plant communities, and the significance of primary and secondary effects. The apparent extreme susceptibility of Hawaiian plant communities to invasion by aliens should make it easier to see the consequences of removal of alien species. Lessons learned in the Hawaiian Islands about the role of alien species should have broad applicability to other plant communities.