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Examining the effects of species richness on community stability: an assembly model approach
Author(s) -
Wilmers Christopher C.,
Sinha Sitabhra,
Brede Markus
Publication year - 2002
Publication title -
oikos
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.672
H-Index - 179
eISSN - 1600-0706
pISSN - 0030-1299
DOI - 10.1034/j.1600-0706.2002.990218.x
Subject(s) - extinction (optical mineralogy) , interspecific competition , species richness , ecology , ecosystem , stability (learning theory) , variation (astronomy) , global biodiversity , arctic , biology , biodiversity , physics , computer science , paleontology , machine learning , astrophysics
We build dynamic models of community assembly by starting with one species in our model ecosystem and adding colonists. We find that the number of species present first increases, then fluctuates about some level. We ask: how large are these fluctuations and how can we characterize them statistically? As in Robert May's work, communities with weaker interspecific interactions permit a greater number of species to coexist on average. We find that as this average increases, however, the relative variation in the number of species and return times to mean community levels decreases. In addition, the relative frequency of large extinction events to small extinction events decreases as mean community size increases. While the model reproduces several of May's results, it also provides theoretical support for Charles Elton's idea that diverse communities such as those found in the tropics should be less variable than depauperate communities such as those found in arctic or agricultural settings.