Effects of Mulching, Fertilizer, Seeding and Seedling Treatments on Plant Species Recovery in Kondoa Irangi Hills, Tanzania

Fertilization, mulching, imported seed bank seeding and seedlings were applied to triplicates of 1m x1m plots at Chakwe and Gubali sites in Kondoa Irangi Hills, Tanzania. Responses tested were seedling recruitment, species turnover, species’ biomass, mortality of seedlings, total number of perennial and woody species recruited and leguminous species. There were high significant correlations of 0.85 and 0.87 between seedling recruitment and mortality in both sites, indicating that other factors, probably aridity, rather than prevailing site conditions were likely to be important determinants of mortality. Inorganic fertilization was not an efficient means of improving short-term productivity, seedling recruitment or increased number of species. In other words, fertilization was negatively correlated to the above factors mentioned. Mulching treatment had an effect of increasing mortality of non-woody species and selectively favoring the establishment of woody species. The interactions between seeding, seed bank and seedlings treatments increased the overall number of species (species turnover) in the study area. Direct sowing of seeds with desired traits into the soil to enhance seedling recruitment and species diversity is recommended over imported seed bank due to the costs involved in mobilizing large volumes of soil as well as availability of proper seed bank soil. Tanz. J. Sci. Vol 36 2010, 19-30