SGER: Postfire Community Structure and Species Area Relationships

这项提案是要求从SGER计划中获得资金，用于研究今年夏天在亚利桑那州和新墨西哥州发生的大火中烧毁的查帕拉尔灌木丛中的火灾后植物反应。 这一要求具有紧迫性，因为这项工作需要在今年9月开始。 虽然对加州查帕拉尔的火灾后立即反应进行了广泛的研究，但对美国西南部的这些查帕拉尔林分知之甚少。 加州的查帕拉尔有一个独特的短暂的火后植物群，包括数百个主要是一年生的物种来自长寿的种子库，这些物种中的绝大多数是特有的加州。 有理由相信，立即灾后反应是不同的亚利桑那州和新墨西哥州查帕拉尔的立场，并占主导地位的草本和木本多年生植物。这些美国西南部的查帕拉尔的立场是什么，他们可以潜在地告诉我们的因果关系背后的物种面积关系的兴趣。 以前的研究表明，一年生为主的加州灌木丛表现出非常不同的物种面积关系，然后多年生为主的澳大利亚灌木丛。 有证据表明，不同的优势度-多样性曲线揭示的群落结构在物种面积关系中起作用，生活型差异被假设为物种面积关系的主要决定因素。 美国西南部的查帕拉尔森林将为这一想法提供一个独立的测试。 这个项目的另一个方面是预测的差异功能类型的火灾反应在这些夏季降雨灌丛相对于夏季干旱灌丛在加州。 两个主要的干扰功能类型的竞争关系，reprouters与播种机预测这两个气候制度之间的不同。

This proposal is to request funds from the SGER program for research to study postfire plant response in chaparral shrublands burned during the massive fires this summer in Arizona and New Mexico. There is an urgency to this request because the work needs to be initiated this September. While extensive research has been conducted on the immediate postfire response of California chaparral, relatively little is known about these Southwestern U.S. chaparral stands. Californian chaparral has a unique ephemeral postfire flora comprising hundreds of mostly annual species derived from long-lived seed banks, the vast majority of these species are endemic to California. There is reason to believe the immediate postfire response is different in Arizona and New Mexico chaparral stands, and is dominated by herbaceous and woody perennials.These Southwest U.S. chaparral stands are of interest for what they can potentially tell us about causal factors behind species area relationships. Prior studies show annual dominated California shrublands exhibit very different species area relationships then perennial dominated Australian shrublands. There is evidence that community structure revealed by very different dominance-diversity curves play a role in the species area relationship and life form differences are hypothesized to be the primary determinate of species area relationships. The Southwestern U.S. chaparral stands will provide an independent test of this idea. An additional dimension of this project is the predicted differences in functional type response to fire in these summer rain shrublands relative to summer drought shrublands in California. The competitive relationships of the two main disturbance functional types, reprouters vs. seeders are predicted to differ between these two climate regimes.