Interactions between biotic and abiotic factors are critical in determining population dynamics and maintenance of ecosystem processes and functions in tropical forests. This study aimed to assess the relationships between soil chemical properties and tree species diversity at Kibutuka Miombo woodland ecosystem in Liwale, Tanzania. Data were collected from circular plots (n = 33) of 15 m radius each. Soil samples were collected to 20 cm depth while tree DBH and their botanical names were recorded. We used standard methods to determine soil chemical properties while Shannon-Wiener diversity index was used to estimate tree species diversity. Analysis was done by using SAS software and excel spread sheet. Tree species from genus Combretum, Milletia and Acacia were the most dominant. This ecosystem had 102 tree species with H’= 4.06 indicating high diversity. The high values of CEC (20.11±1.37 cmolkg-1) and SOC (1.58±0.04%) of this ecosystem indicates that it is rich in soil nutrients. Tree species diversity was significantly and positively related to SOC (P< 0.05, though it was weak r = 0.07). There was no relationship between species diversity with other soil chemical properties. This means that while species diversity depends on climate it is also linked to SOC. Therefore, proper management of Miombo woodland ecosystems would increase SOC storage and contribute to high diversity together with climate change regulation.
Keywords: Soil chemical properties, species dominance, species richness and tropical forests