1. (in physiology) A method of asexual reproduction, occurring in some plants and invertebrate animals, in which parts of the organism break off and subsequently develop into new individuals. Fragmentation occurs naturally in many plants that produce multiple rooted shoots, each of which, when detached, can form a clone of the parent plant. It also occurs in certain cnidarians and annelids. In some, regeneration may occur before separation, producing chains of individuals budding from the parent.

2. (in ecology) The break-up of an area of habitat into smaller patches. This is most often a consequence of human activity, as when tracts of forest are converted to agriculture, leaving isolated fragments of the original vegetation. Surviving populations of fauna and flora are much reduced in size, and biodiversity tends to decline, particularly in the smallest patches. Remedial steps include provision of wildlife corridors that permit the movement of animals, and even sometimes plants, between fragments.