Processes of Forest Fragmentation ant Its Impacts

Abstract

Forest fragmentation is a widespread phenomenon and is recognized as one of the major threats to biological diversity. It  is a process by which  large expanses of forests are converted into smaller tracts of forest surrounded by a matrix of habitats unlike the original in ways that reduce or eliminate the ability of the forest to provide ecological, economic, and social benefits, causing a disruption in continuity of the natural landscape. Natural and anthropogenic factors can lead to forest fragementation. The natural causes include storms, fires and aging. Numerous anthropogenic factors can also account for forest fragementation. Among other things land use, infrastructure construction, urbanization, land tenure and socioeconomic factors can account for forest fragementation. Based on theoretical predictions and small scale empirical studies, forest fragementation is presumed to have a wide range of socio-economic and environmental effects. It can jeopardize goods and services from forests, pose health threat, promote invasive species and threaten biodiversity. Forest fragmentation is presumed to lead to biodiversity erosion via habitat loss, increased edge effects, and negative interactions with species from surrounding non forest patches, the effect of non-random sampling of the original forest, modifying species’ population dynamics, altered ecosystem inputs and outputs, increased isolation of forest populations, and invasion by exotic species. Fragmentation can also restrict pollinator movement, which may reduce gene flow and result in increased inbreeding. One of the major outcomes of forest fragementation is edge effect. Edge effects include decreasing humidity and increasing light and temperature which may ultimately affect plant recruitment and survival. In addition, adjacent ecosystems experience flows of energy, nutrients and species across their mutual boundary. As a result, the species composition, structure and ecological processes of an ecosystem near the line of contact with another ecosystem may be changed. Edge effect can also include elevated wind turbulence. Biotic effects can be extremely diverse and include the proliferation of secondary vegetation along forest margins, invasions of weedy or generalist plants and animals, alteration of ecological processes such as nutrient cycling and energy flow.

Keywords forest, fragmentation, biodiversity, biological