Crawford Kerri M, Crutsinger Gregory M, Sanders Nathan J
Department of Ecology and Evolutionary Biology, 569 Dabney Hall, University of Tennessee, Knoxville, Tennessee 37996, USA.
Ecology. 2007 Aug;88(8):2114-20. doi: 10.1890/06-1441.1.
Ecosystem engineers affect ecological communities by physically modifying the environment. Understanding the factors determining the distribution of engineers offers a powerful predictive tool for community ecology. In this study, we examine whether the goldenrod bunch gall midge (Rhopalomyia solidaginis) functions as an ecosystem engineer in an old-field ecosystem by altering the composition of arthropod species associated with a dominant host plant, Solidago altissima. We also examine the suite of factors that could affect the distribution and abundance of this ecosystem engineer. The presence of bunch galls increased species richness and altered the structure of associated arthropod communities. The best predictors of gall abundance were host-plant genotype and plot-level genotypic diversity. We found positive, nonadditive effects of genotypic diversity on gall abundance. Our results indicate that incorporating a genetic component in studies of ecosystem engineers can help predict their distribution and abundance, and ultimately their effects on biodiversity.
生态系统工程师通过物理方式改变环境来影响生态群落。了解决定工程师分布的因素为群落生态学提供了一个强大的预测工具。在本研究中，我们探究了一枝黄花束瘿蚊（Rhopalomyia solidaginis）是否通过改变与优势寄主植物高茎一枝黄花（Solidago altissima）相关的节肢动物物种组成，在一个弃耕地生态系统中发挥生态系统工程师的作用。我们还研究了一系列可能影响这种生态系统工程师分布和丰度的因素。束瘿的存在增加了物种丰富度，并改变了相关节肢动物群落的结构。瘿丰度的最佳预测因子是寄主植物基因型和样地水平的基因型多样性。我们发现基因型多样性对瘿丰度有正向的、非加性的影响。我们的结果表明，在生态系统工程师的研究中纳入遗传成分有助于预测它们的分布和丰度，以及最终它们对生物多样性的影响。
