Published online by Cambridge University Press: 11 September 2009
Definition and evolution of communities
Ecological community is not a term that is used uniformly by all authors, and there is much disagreement about how communities may have evolved. In this section, I discuss definitions given for ecological communities and their evolution.
Giller and Gee (1987) review the different ways the term community is used, and the problems arising from these different usages. Fauth et al. (1996) defined communities as all species co-occurring at the same time, irrespective of taxon; guilds are species that use the same class of resources. They defined assemblages as groups of species of one taxon (e.g., birds) within a community. According to Cornell (2001), communities are collections of species living contemporaneously in the same place, consisting of individuals that are spatially interspersed, with the potential of direct or indirect interaction. Following Whittaker, Levin (1992) points out that “communities” and “ecosystems” are arbitrary subdivisions of a “gradation of local assemblages.” Communities are not well integrated units, because species within them respond individualistically to the environment. Lawton (2000) asks: how many species constitute a community? There is no logical break between populations of single species and of many, and there is a tendency to take several species of a single taxon as comprising a community. Lawton points out that entire communities are almost impossible to study, with the exception of some in very simple habitats such as water-filled tree holes.
To save this book to your Kindle, first ensure [email protected] is added to your Approved Personal Document E-mail List under your Personal Document Settings on the Manage Your Content and Devices page of your Amazon account. Then enter the ‘name’ part of your Kindle email address below. Find out more about saving to your Kindle.
Note you can select to save to either the @free.kindle.com or @kindle.com variations. ‘@free.kindle.com’ emails are free but can only be saved to your device when it is connected to wi-fi. ‘@kindle.com’ emails can be delivered even when you are not connected to wi-fi, but note that service fees apply.
Find out more about the Kindle Personal Document Service.
To save content items to your account, please confirm that you agree to abide by our usage policies. If this is the first time you use this feature, you will be asked to authorise Cambridge Core to connect with your account. Find out more about saving content to Dropbox.
To save content items to your account, please confirm that you agree to abide by our usage policies. If this is the first time you use this feature, you will be asked to authorise Cambridge Core to connect with your account. Find out more about saving content to Google Drive.