Biological Consequences of Ecosystem Fragmentation: A Review

Abstract. Abstrack Resemcb on fragmented ecosystems bas focused mostly on the biogeograpbic consequences of the creation of habitat "islands" of diffrent size and bas provided little of practical value to managers Hom, ecosystem fragmentation causes large changes in thepbysfcal environment as well as biogeograpbic changes Fragmentation generally msults in a landscape that consists of remnant areas of native vegetation surrounded by a mdrlx of agricultural or other developed land As a mul fluxes of radiation, momentum (i.e., wind), water, and nutrients clcross the landscape are altered significantly. These in turn can haw important influences on the biota witbin remnant are- especially at or near the edge between the remnant and the surrounding matrix The isolatfon of remnant areas by clearing also bas important consequences for the biota These consequences vary with the time since isolatioq distance from other remnants, and degree of connectivity with other remnants The influences of pbysical and biogeographic changes are modified by the size, shape, and pition in the landscape of individual remnanQ witb larger remnants being less aduwsely affected by the jhapaentation process dynamics of remnant areas me predominantly driven by factors aris ing in tbe smunding krndscu Management of, and research on, fiagmented ecosystems sbould be directed at understanding and controlling tbese external influences as much as at tbe biota of tbe remnants themselves Tbere is a strong need to develop an integrated appmach to landsea management tbatplaces conservation merues in tbe context of tbe owrall landscape