Community (ecology)In ecology, a community is a group or association of populations of two or more different species occupying the same geographical area at the same time, also known as a biocoenosis, biotic community, biological community, ecological community, or life assemblage. The term community has a variety of uses. In its simplest form it refers to groups of organisms in a specific place or time, for example, "the fish community of Lake Ontario before industrialization".
Edge effectsIn ecology, edge effects are changes in population or community structures that occur at the boundary of two or more habitats. Areas with small habitat fragments exhibit especially pronounced edge effects that may extend throughout the range. As the edge effects increase, the boundary habitat allows for greater biodiversity. Urbanization is causing humans to continuously fragment landscapes and thus increase the edge effect. This change in landscape ecology is proving to have consequences.
Vortex d'extinctionEn écologie, et dans l'étude de la dynamique des populations, la notion de tourbillon d'extinction, spirale d'extinction ou vortex d'extinction (« Extinction vortex » pour les anglophones) correspond à une catégorie de modèles utilisés pour comprendre, décrire ou catégoriser la dynamique et les causes d'extinctions d'espèces et de groupes d'espèces. Ces modèles sont utilisés par des biologistes de la conservation et certains généticiens et écologues. Elle décrit le tourbillon.
