HABITAT FRAGMENTATION, PERCOLATION THEORY AND THE CONSERVATION OF A KEYSTONE SPECIES

Many species survive in specialized habitats. When these habitats are destroyed or fragmented the threat of extinction looms. In this paper, we use percolation theory to consider how an environment may fragment . We then develop a stochastic, spatially explicit, individual-based m odel to consider the effect of habitat fragmentation on a keystone spe cies (the army ant Eciton burchelli) in a neotropical rainforest. The results suggest that species may become extinct even in huge reserves before their habitat is fully fragmented; this has important implicati ons for conservation. We show that sustainable forest-harvesting strat egies may not be as successful as is currently thought. We also sugges t that habitat corridors, once thought of as the saviour for fragmente d environments, may have a detrimental effect on population persistenc e.