Short-term variation in forest dynamics: increase in tree density in Boabeng-Fiema monkey sanctuary, Ghana

The rate at which forest change occurs varies with forest types and time. We measured forest change in a small forest fragment in the forest-savanna transition zone of Ghana. A plot-based survey was conducted to assess tree population dynamics over seven years in the core forest of the Boabeng-Fiema Monkey Sanctuary. A total of 561 trees representing 68 species, 63 genera and 28 families were recorded in 2007 as compared to 432 trees, 70 species, 58 genera and 25 families recorded in 2000. There was a significant increase in total stem density by 29.9 percent from 192 stems/ha in 2000 to 248 stems/ha in 2007. The number of trees with a dbh 10-20 cm increased significantly between censuses. There was no change in tree basal area and species richness. The tree families most represented in 2000 and 2007 were Malvaceae, Combretaceae and Leguminosae. The plot-based method was sensitive at detecting finegrained changes in forest structure and composition in this ecological zone over a short period of time. It is therefore important to conduct short-term plot-based surveys in forest fragments, which are often under anthropogenic influence in the forest-savanna transition zone, in order to effectively manage or restore the forest ecosystem.