RUI: Mechanisms Underlying Alien Grass Effects on Dry Forest Ecosystem Change - Changing Availability of Variable Water Sources

非本土的非洲喷泉草已经侵入了夏威夷干燥森林的林下层，它现在正在导致本土树苗的死亡和成熟树木的生产力下降。 这一生态系统完全转换为外来草原将导致高度的生物多样性丧失，自然生态地球化学循环的破坏，许多文化上重要的植物灭绝，但这些外来植物的影响机制知之甚少。我们将确定如何fountaingrass改变本地树木获得雨水，以及这种影响如何转化为生产力的变化。 特别强调的是树木从小暴雨中获得水-这可能为较大事件之间的持续活动提供必要的水。未来的研究将调查光和营养的资源竞争。我们的长期目标是全面了解导致生态系统功能转换和改变的机制。 夏威夷干旱森林有利于实现这一目标，其结果可能适用于其他干旱地区的生态系统。

Non-native African fountaingrass has invaded the understory of Hawaii's dry forest; it is now causing death of native tree seedlings and productivity decline in mature trees. Total conversion of this ecosystem to alien grassland would result in high biodiversity loss, disruption of natural biogeochemical cycles, and extinction of many culturally important plants, yet mechanisms underlying these alien-plant impacts are poorly understood.We will determine how fountaingrass alters native-tree access to rainwater, and how this impact translates into productivity changes. Particular emphasis will be placed on tree access to water from small rainstorms - which may provide water necessary for sustained activity between larger events. Future research will investigate resource competition for light and nutrients. Our long-term objective is a comprehensive understanding of mechanisms that cause conversion and alteration of ecosystem functions. The Hawaiian dry forest is conducive to this goal and results may be applicable to other aridland ecosystems.