Regeneration Dynamics and Structural Changes in Miombo Woodland Stands at Kitulangalo Forest Reserve in Tanzania
Elifuraha Elisha Njoghomi, Sauli Valkonen, K. Karlsson, Markku Saarinen, Wilson Ancelm Mugasha, Pentti Niemistö, C Balama, R. E. Malimbwi
Abstract
The sustainability of the seriously threatened African miombo woodlands depends on their capability to maintain sufficient natural regeneration. This study focused on the regeneration dynamics and the impacts of silvicultural treatments of fencing, site preparation, and thinning in the Kitulangalo forest reserve in Tanzania. Mixed models were applied to analyze the change in number of stems during the nine-years observation period on a set of permanent experimental plots. There was a significant decrease in the total number of stems (from 29 800 ha−1 to 19 100 ha−1) but a significant increase in the number of main stems (from 9 300 ha−1 to 11 100 ha−1) during observation period. The proportion of empty regeneration plots (zero seedlings and saplings on a regeneration plot of 4 m2) was initially very low (7.3%) and decreased further during the study period to 5.3%. Greater stand density was associated with lower density of regeneration. Fencing implied a greater increase in the number of main stems but a sharper drop in the total number of stems by reducing animal disturbances. The findings indicate that the forests at Kitulangalo are recovering from past abuse and likely developing toward more sustainable stand structures and sustainability.