Any physical or biological change occurring in the perimeter zone of a habitat related to its immediate surroundings. Such edge effects are particularly marked at artificial boundaries, for instance when fragments of forest remain after surrounding forest is cleared. In this case the edges of the forest fragment are exposed to higher light levels, stronger winds, lower humidity, and greater temperature fluctuations. These factors in turn affect the makeup and diversity of the forest community living on or near the edges; also, species from surrounding areas may colonize the perimeter or act as predators of the forest inhabitants. Edge effects become proportionately greater in extent as the area of the habitat fragment decreases.