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.

摘要

受到严重威胁的非洲 miombo 林地的可持续性取决于它们保持充分自然再生的能力。本研究的重点是坦桑尼亚基图兰加洛森林保护区的再生动态以及围栏、整地和间伐等造林处理的影响。应用混合模型在一组永久性试验地块上分析了九年观察期内茎数的变化。茎的总数显着减少（从 29 800 公顷^-1到 19 100 公顷^-1），但主茎的数量显着增加（从 9 300 公顷^-1到 11 100 公顷^-1) 在观察期间。空再生地块（4 m ²再生地块上的零苗和树苗）的比例最初非常低（7.3%），并在研究期间进一步下降至 5.3%。较高的林分密度与较低的再生密度有关。围栏意味着通过减少动物干扰，主茎的数量增加更多，但茎的总数急剧下降。调查结果表明，Kitulangalo 的森林正在从过去的滥用中恢复过来，并可能朝着更可持续的林分结构和可持续性发展。