Delayed Compensation for Missing Keystone Species by Colonization
S. K. Morgan Ernest,*
James H. Brown
Because individual species can play key roles, the loss of species
through extinction or their gain through colonization can cause major
changes in ecosystems. For almost 20 years after kangaroo rats were
experimentally removed from a Chihuahuan desert ecosystem in the United
States, other rodent species were unable to compensate and use the
available resources. This changed abruptly in 1995, when an alien
species of pocket mouse colonized the ecosystem, used most of the
available resources, and compensated almost completely for the missing
kangaroo rats. These results demonstrate the importance of individual
species and of colonization and extinction events in the structure and
dynamics of ecosystems.
Department of Biology, University of New Mexico, Albuquerque, NM
87131 USA.
*
To whom correspondence should be addressed at Program in
Ecology, Department of Biological Sciences, Texas Tech University, Lubbock, TX 79409, USA. E-mail: morgan.ernest{at}ttu.edu
