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

植物组合富集的悖论：三个重要假设的检验

• 批准号: 9903912
• 负责人: Walter Carson
• 金额: $ 3.41万
• 依托单位: University of Pittsburgh
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 1999
• 资助国家: 美国
• 起止时间: 1999-09-15 至 2001-02-28
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9903912&HistoricalAwards=false
• 关键词: Paradox; Enrichment; Plant; Assemblages; Tests

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.

9903912碳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。这一无处不在的富集悖论至少一个世纪前就已经被注意到了，但仍未得到解释。空间资源异质性、定居限制和集合层稀疏这三个突出的假说为植物组合中的富集悖论提供了独立的解释。这项研究将在多年生主导的老田间植物组合中使用实验肥力梯度同时测试这三个假说。这三个假说构成了生态学中的三个主要概念主题，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，这项研究将能够为富集悖论提供一个完整的解释。目前，实验中的肥力梯度正在产生富集悖论，随着肥力的增加，光量和光的异质性急剧下降。这项研究现在正准备测试这三个假设在多大程度上对富集悖论做出了贡献。