Regional analysis of the impacts of climate change on cheatgrass invasion shows potential risk and opportunity
Regional analysis of the impacts of climate change on cheatgrass invasion shows potential risk and opportunity
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DOI：
10.1111/j.1365-2486.2008.01709.x
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发表时间：
2009-01-01
影响因子：
11.6
通讯作者：
Bradley, Bethany A.
中科院分区：
文献类型：
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作者：
Bradley, Bethany A.
气候变化与非本地入侵物种之间的相互作用可能共同增加对本地生态系统的入侵风险。气候变化带来了风险，因为新的地形在气候上变得适合入侵。然而，气候变化也可能为入侵土地的生态系统恢复创造机会，这些土地在气候上变得不适合入侵物种。在这里，我开发了一种生物气候包络模型，用于美国西部的非本地入侵草（Bromus tectorum），基于其入侵分布。生物气候包络模型以马氏距离为基础，利用最能限制物种分布的气候变量。在测量的降水和温度变量中，对草的预测效果最好的是夏季、年和春季降水，其次是冬季气温。我利用10种常用的2100年大气-海洋环流模式（AOGCMs）的预估，对潜在的作弊草分布进行了敏感性分析。AOGCM对降水的预估变化很大，增加了入侵风险评估的不确定性。降水减少，特别是在夏季，导致适宜的土地面积扩大了45%，增加了蒙大拿州、怀俄明州、犹他州和科罗拉多州部分地区的入侵风险。相反，降水的增加使栖息地减少了70%，从而降低了入侵风险。降水条件对该物种分布的强烈影响表明，仅依靠温度变化来预测植物分布的未来变化可能是不够的。敏感性分析提供了一个框架，用于识别可能限制入侵的关键气候变量，并评估气候变化下的入侵风险和恢复机会。
Interactions between climate change and non-native invasive species may combine to increase invasion risk to native ecosystems. Changing climate creates risk as new terrain becomes climatically suitable for invasion. However, climate change may also create opportunities for ecosystem restoration on invaded lands that become climatically unsuitable for invasive species. Here, I develop a bioclimatic envelope model for cheatgrass (Bromus tectorum), a non-native invasive grass in the western US, based on its invaded distribution. The bioclimatic envelope model is based on the Mahalanobis distance using the climate variables that best constrain the species' distribution. Of the precipitation and temperature variables measured, the best predictors of cheatgrass are summer, annual, and spring precipitation, followed by winter temperature. I perform a sensitivity analysis on potential cheatgrass distributions using the projections of 10 commonly used atmosphere-ocean general circulation models (AOGCMs) for 2100. The AOGCM projections for precipitation vary considerably, increasing uncertainty in the assessment of invasion risk. Decreased precipitation, particularly in the summer, causes an expansion of suitable land area by up to 45%, elevating invasion risk in parts of Montana, Wyoming, Utah, and Colorado. Conversely, increased precipitation reduces habitat by as much as 70%, decreasing invasion risk. The strong influence of precipitation conditions on this species' distribution suggests that relying on temperature change alone to project future change in plant distributions may be inadequate. A sensitivity analysis provides a framework for identifying key climate variables that may limit invasion, and for assessing invasion risk and restoration opportunities with climate change.