Volkov Igor, Banavar Jayanth R, Hubbell Stephen P, Maritan Amos
Department of Physics, 104 Davey Laboratory, The Pennsylvania State University, University Park, Pennsylvania 16802, USA.
Nature. 2003 Aug 28;424(6952):1035-7. doi: 10.1038/nature01883.
The theory of island biogeography asserts that an island or a local community approaches an equilibrium species richness as a result of the interplay between the immigration of species from the much larger metacommunity source area and local extinction of species on the island (local community). Hubbell generalized this neutral theory to explore the expected steady-state distribution of relative species abundance (RSA) in the local community under restricted immigration. Here we present a theoretical framework for the unified neutral theory of biodiversity and an analytical solution for the distribution of the RSA both in the metacommunity (Fisher's log series) and in the local community, where there are fewer rare species. Rare species are more extinction-prone, and once they go locally extinct, they take longer to re-immigrate than do common species. Contrary to recent assertions, we show that the analytical solution provides a better fit, with fewer free parameters, to the RSA distribution of tree species on Barro Colorado Island, Panama, than the lognormal distribution.
岛屿生物地理学理论认为，由于物种从大得多的集合群落源区迁入与岛屿（当地群落）上物种的局部灭绝之间的相互作用，一个岛屿或一个当地群落会趋近于一个平衡物种丰富度。哈贝尔对这一中性理论进行了推广，以探讨在有限迁入情况下当地群落中相对物种丰度（RSA）的预期稳态分布。在此，我们提出了一个生物多样性统一中性理论的理论框架以及RSA在集合群落（费希尔对数级数）和当地群落中分布的解析解，当地群落中稀有物种较少。稀有物种更容易灭绝，一旦它们在当地灭绝，重新迁入所需的时间比常见物种更长。与最近的观点相反，我们表明，与对数正态分布相比，该解析解以更少的自由参数能更好地拟合巴拿马巴罗科罗拉多岛上树木物种的RSA分布。
