Community relaxation in fragmented landscapes: the relation between species richness, area and age

Authors
Citation
A. Gonzalez, Community relaxation in fragmented landscapes: the relation between species richness, area and age, ECOL LETT, 3(5), 2000, pp. 441-448
Citations number
37
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Environment/Ecology
Journal title
ECOLOGY LETTERS
ISSN journal
1461-023X → ACNP
Volume
3
Issue
5
Year of publication
2000
Pages
441 - 448
Database
ISI
SICI code
1461-023X(200009)3:5<441:CRIFLT>2.0.ZU;2-#
Abstract
Estimates of species loss due to habitat destruction are normally based on calculations employing the species-area relation, S = cA(z). The validity o f this approach is based on the assumption that the value of the exponent ( z) defining the slope of the species-area relation in nonfragmented communi ties is at a steady state and that z is thus a constant. However, departure from such an assumption renders this approach unreliable. Here I report th e results from a natural field experiment using "model" bryophyte-based mic rolandscapes designed to follow the species richness dynamics of microarthr opod communities postfragmentation. Community isolation due to fragmentatio n initiated a delayed community relaxation process and resulted in substant ial local extinction. Over the period of the experiment z declined in the c ontrol communities and yet remained fairly stable in the fragmented communi ties. I conclude that predictions of species loss due to habitat fragmentat ion that do not take into account the fact that often z may not be a consta nt may lead to error-prone predictions of future species loss.