Structure, Composition and Plant-species Diversity in Umabdalla Natural Reserved Forest, South Kordofan – Sudan

This research was conducted in Umabdalla Natural Reserved Forest, South Kordofan. The main objective of this research paper was to assess the tree species diversity in the area and to estimation the changes over successive periods using a ground inventories. Forest inventory in the year 2011 was carried out to constitute 248 sample plots of 0.1 hectare and compared with the previous inventories of 1998 and 2007 carried out by the Forests National Corporation (FNC). Tree species changes were measured. Data from forest inventory and social survey were analyzed using excel 2007 and SPSS version 18. The results showed that the forest is rich in tree species biodiversity where 53 species were recorded. However, the results indicated significant increase (p >0.05) in the number of trees/ha during 1998 to 2007. The analysis of climate data showed that the limiting period where enhancement of species diversity and regeneration occurred was between mid-June and Mid October of the rainy year. During this period strong positive correlation between climate factors was observed. The study concluded that human activities were the main factors influenced diversity and regeneration of trees in the forest.