Monitoring tropical forest fragmentation in the Zagne-Tai area (west of Tai National Park, Cote d'Ivoire)

Deforestation west of the Tai National Park over the last 3 decades has been dramatic, with forest cover of rural areas decreasing from 89.6% in 1974 to 6.7% in 2003. The process comprised 3 major steps. During the 10 first years, deforestation was limited to a ca. 5 km band each side of the main north-south track. From 1984 to 1990 there was a massive increase in deforestation whose front met the limits of the protected areas, leaving many forest fragments of various sizes forming a mosaic in the landscape. From 1990 to 2003 these fragments were further deforested by being either totally destroyed or reduced in size, or further split into smaller units. During these latter 13 years their number was halved, their average area was reduced by an 8th, and their total area reduced by an 11th. In addition, a moving cost analysis has indicated that most of the area could now be out of reach for forest species dispersion. This critical situation may be explained by the increase of population pressure (due to internal increment as well as massive immigration) causing increased land cultivation and a growing trend to permanent cash crop cultivation, which removed important surfaces from the traditional shifting cultivation cycle. Without the implementation of a forest fragment protection policy local population demands for wood and non-timber forest products would likely be entirely dependant on protected areas in the future. Furthermore, deforestation pressure is likely to reach the protected areas which had, until recently, remained relatively untouched (despite a minor deforestation peak between 1984 and 1990).