Long term impacts of grass invasions and fire on community change and plant soil feedbacks

草丛入侵和火灾对群落变化和植物土壤反馈的长期影响

基本信息

批准号：
1029168
负责人：
Carla D'Antonio
金额：
$ 56.5万
依托单位：
University of California-Santa Barbara
依托单位国家：
美国
项目类别：
Continuing Grant
财政年份：
2010
资助国家：
美国
起止时间：
2010-09-01 至 2015-08-31
项目状态：
已结题

来源：
https://www.nsf.gov/awardsearch/showAward?AWD_ID=1029168&HistoricalAwards=false
关键词：
Long term impacts grass invasions

项目摘要

Over the past twenty years, scientists, land managers and the public have come to recognize the dramatic consequences of species invasions. Despite this recognition, few studies have documented long-term ecosystem consequences of invasions when those invasions go unchecked. The proposed research evaluates long-term impacts of fire-promoting grasses in seasonally dry woodlands in Hawai'i. These grasses, originally introduced as pasture forage, escaped into wildlands where they promote the spread of fire. Native species in these sites are not fire-adapted resulting in a dramatic loss of native species and strongly altered nutrient cycling including losses of nitrogen, a critical resource for plant growth. The proposed research uses observations and experimentation to evaluate how invader-induced changes in ecosystem nitrogen cycling that were well documented in the 1990s, have changed over time since invasion and what the consequences of current growth conditions are for native species. Experiments will evaluate nitrogen loss rates over time, changes in soil carbon pools and the consequences of these changes for native and non-native species. Fire-promoting non-native grasses are a significant management concern in arid and semi-arid ecosystems. The results of this research will provide greater understanding of the long-term consequences of not managing these invasions both in terms of fuel loads and soil nutrient conditions and in terms of whether native species will eventually recover in burned invaded sites under fire suppression. Lastly, results will provide site specific information regarding which native species and restoration treatments can be used in sites degraded by fire and grass invasion.

在过去的二十年中，科学家，土地经理和公众已经认识到物种入侵的巨大后果。尽管有这样的认可，但很少有研究记录了当这些入侵未经检查时入侵的长期生态系统后果。拟议的研究评估了夏威夷季节性干燥林地中促进火草的长期影响。这些草最初是作为牧场饲料引入的，逃到了野外，在那里它们促进了火的蔓延。这些地点中的本地物种没有被火化，从而导致本地物种的巨大损失和养分循环的强烈改变，包括氮的损失，氮是植物生长的关键资源。拟议的研究使用观察结果和实验来评估入侵者诱导的生态系统氮循环变化是如何在1990年代进行了充分证明的，自从入侵以来，随着时间的流逝以及当前生长条件的影响是随着时间的变化。实验将随着时间的流逝评估氮损失率，土壤碳池的变化以及这些变化对天然和非本地物种的影响。促进火灾的非本地草是干旱和半干旱生态系统中的重要管理关注点。这项研究的结果将提供对在燃料负荷和土壤养分条件方面不管理这些入侵的长期后果，以及在抑制火灾下被烧毁的入侵地点中恢复的本地物种是否最终会恢复。最后，结果将提供有关哪种本地物种和恢复处理的特定信息，可以在火和草入侵的地点使用。