Aremnant natural area, also known asremnant habitat, is an ecologicalcommunity containingnative flora and fauna that has not been significantlydisturbed by destructive activities such asagriculture,logging,pollution,development,fire suppression, ornon-native species invasion.[1] The more disturbed an area has been, the less characteristic it becomes of remnant habitat. Remnant areas are also described as "biologically intact" or "ecologically intact."[2]
Remnant natural areas are often used asreference ecosystems inecological restoration projects.[3]
A remnant natural area can be described in terms of its natural quality orbiological integrity, which is the extent to which it has the internalbiodiversity andabiotic elements to replicate itself over time.[4] Another definition of biological integrity is "the capability of supporting and maintaining a balanced, integrated, adaptive community of organisms having aspecies composition,diversity, and functional organization comparable to that of the naturalhabitat of the region."[5] Abiotic elements determining the quality of a natural area may include factors such as hydrologic connectivity or fire. In areas that have beendredged,drained, ordammed, the altered hydrology candestroy a remnant natural area. Similarly, too much or too littlefire can degrade or destroy a remnant natural area.[4]
Remnant natural areas are characterized by the presence of "conservative" plants and animals—organisms that are restricted to or highly characteristic of areas that have not been disturbed by humans.[6] Tools to measure aspects of natural areas quality in remnant areas includeFloristic Quality Assessment and theMacroinvertebrate Community Index.
In the upperMidwestern United States, remnant natural areas date prior toEuropean settlement, going back to the end of theWisconsinian Glaciation approximately 15,000 years ago.[1] Diverse remnant plant community examples in that region includetallgrass prairie,beech-maple forest,savannas,bogs, andfens.[7] Remnant natural areas inIllinois have largely been classified by theIllinois Natural Areas Inventory as Category I "high quality terrestrial or wetland natural communities."[8]
InAustralia, remnant habitats are sometimes called "bushland," and include communities such as forest, woodland, grasslands,mallee, coastalheathland, andrainforest.[9]