Open AccessRandom processes and geographic species richness patterns: why so few species in the north?
Author(s) -
Bokma Folmer,
Bokma Jurjen,
Mönkkönen Mikko
Publication year - 2001
Publication title -
ecography
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.973
H-Index - 128
eISSN - 1600-0587
pISSN - 0906-7590
DOI - 10.1034/j.1600-0587.2001.240106.x
Subject(s) - species richness , body size and species richness , ecology , species distribution , macroecology , randomness , genetic algorithm , geography , biology , habitat , statistics , mathematics
In response to the suggestion that the latitudinal gradient in species richness is the result of stochastic processes of species distributions, we created a computer simulation program that enabled us to study random species distributions over irregularly shaped areas. Our model could not explain latitudinal variation in species richness of New World mammals and created species richness patterns that differed dramatically from previous stochastic models. The interplay of speciation and species migration in our simulation generated the highest species richness in the middle of a landmass, not in the middle of its latitudinal stretch as was found in previous one‐dimensional models. The discrepancy between the results of this study and previous empirical studies suggests that the effect of randomness in species‐richness distribution is on a continental scale restricted by other, dominant determinants that limit the effect of chance.