Data from: Limits to species richness in terrestrial communities

Are communities limited by biotic interactions, or are they random draws from regional species pools? One way to tell is to compare total species counts in geographic regions to average counts in ecological samples falling within those regions. If species richness is limited regionally, then the relationship should be curvilinear even in a log-log space. Local data pertaining to trees and 10 groups of animals are analyzed to test this hypothesis. Most relationships are indeed curvilinear. To explain these patterns, a simple model is proposed that invokes biotic interaction-limited speciation or immigration rates combined with extinction or extirpation rates that fall as the number of occupied patches increases. Local and regional richness come into balance as the rates trade off, causing global richness to also be limited. Surprisingly, however, the data for trees break the pattern, suggesting that the great adaptive radiation of seed plants may still be unfolding.

Usage Notes
ReferencesReferences to publications yielding Ecological Register data recordslimits_to_species_richness_references.tar.gzRegistersEcological Register data files for ants, bats, birds, butterflies, dung beetles, frogs, large mammals, lizards, mosquitoes, small mammals, and treeslimits_to_species_richness_registers.tar.gz

生态群落是否受到生物相互作用的限制，抑或它们是否是区域物种库中的随机抽样？一种区分方法是对地理区域中的总物种数与该区域内的生态样本平均数进行比较。若物种多样性在区域层面上受到限制，则即使在双对数空间中，这种关系也应呈曲线关系。通过对树木和10种动物群体的本地数据进行分析，以检验这一假设。实际上，大多数关系确实呈现出曲线关系。为了解释这些模式，提出了一种简单的模型，该模型涉及生物相互作用限制的物种分化或移民率，以及随着占据区域的数量增加而降低的灭绝或灭绝率。随着这些比率之间的权衡，本地和区域多样性达到平衡，从而造成全球多样性的限制。然而，令人惊讶的是，树木的数据打破了这一模式，这表明种子植物的巨大适应性辐射可能仍在进行中。