The Paradox of Enrichment in Plant Assemblages: Tests of Three Prominent Hypotheses

[9903912]在生态组合中最显著的模式之一是物种丰富度随着资源可用性的增加而下降。这种普遍存在的富集悖论已经被注意了至少一个世纪，但仍未得到解释。空间资源异质性、定殖限制和组合水平变薄三个假说为植物组合富集悖论提供了独立的解释。本研究将利用多年生占优势的田间老植物组合的试验性育力梯度同时验证这三个假设。这三个假设构成了生态学中三个主要的概念主题，这些主题以前被用来解释多样性和共存的模式。它们并不是相互排斥的，这项研究将能够对富集悖论提供一个完整的解释。目前，实验肥力梯度正在产生富集悖论，随着肥力的升高，光量和光异质性急剧下降。这项研究现在准备测试这三种假设中的每一种在多大程度上有助于丰富悖论。

9903912CarsonOne of the most striking patterns within ecological assemblages is the decline in species richness with increasing resource availability. This ubiquitous paradox of enrichment has been noted for at least a century but remains unexplained. Three prominent hypotheses, spatial resource heterogeneity, colonization limitation, and assemblage level thinning offer independent explanations to the paradox of enrichment in plant assemblages. This research will test these three hypotheses simultaneously using an experimental fertility gradient in a perennial dominated old field plant assemblage. These three hypotheses comprise three major conceptual themes in ecology that have previously been marshaled to explain patterns of diversity and coexistence. They are not mutually exclusive, and this research will be able to offer an integrated explanation of the paradox of enrichment. Currently, the experimental fertility gradient is generating the paradox of enrichment, and light quantity and light heterogeneity decline sharply as fertility rises. This research is now poised to test the extent to which each of these three hypotheses contributes to the paradox of enrichment.