According to the Virginia Conservation Network, "between 1992 and 1997, Virginia lost 343,500 acres to development. If current trends continue, Virginia will develop more land in the next 40 years than it has in the past 400 years." The scattered pattern of modern development consumes an excessive amount of land and fragments the landscape, destroying wildlife habitat and migration corridors. Development also degrades water quality and otherwise diminishes ecosystem functions.
Habitat loss is the greatest threat facing Virginia’s biodiversity. As patches of habitat are lost, there is a direct reduction in the area of available habitat. When patches that are lost contain habitat unique to the area, there is also a reduction in habitat diversity and a reduction in populations dependent upon that habitat type.
Fragmentation is a natural consequence of habitat conversion, but current development patterns exacerbate the amount of habitat fragmentation taking place. Dividing a large patch into smaller patches, for example through conversion of some of the habitat to anthropogenic land uses, or imposition of barriers to dispersal such as roads, disproportionately removes interior habitat, reduces population sizes, and reduces the diversity of species dependent on interior habitat conditions. As forests and wetlands are divided and isolated, interior habitat decreases and human disturbance increases. Opportunistic (and generally more common) edge species replace species dependent on interior habitat. Populations in isolated habitats face an increased probability of inbreeding and loss of fitness, as genetic exchange between isolated populations of interior species decreases. Furthermore, populations of many species in small habitat fragments become too small to persist. Even in habitat patches large enough to generally sustain interior species, population reduction or extirpation may occur due to short-term events or random fluctuations in population size, and the farther a habitat patch is from other patches containing populations of interior species, the less likely it is to be re-colonized.
Sometimes a patch of habitat can be in a key location, providing connectivity between other patches. When such a key patch is removed, not only can the individual organisms directly associated with that patch be lost, but there may also be local extinctions in patches that were dependent upon the lost patch for connectivity to additional habitat.
Thus large, unfragmented patches of natural vegetation have benefits that exceed the benefits of equivalent acreage of natural
cover in several separate chunks. In addition to sustaining viable populations of interior species, providing core habitat and
escape cover, and reducing extirpation probabilities, large expanses of natural vegetation also permit natural disturbance regimes
and protect aquifers and streams.
