Masters Thesis
Alien plant are plant species introduced in a new area outside their native range and when spread beyond the place of introduction, they become invasive thereby suppressing regeneration of native plants. There is little empirical evidence explaining the effects of the extent of spread of alien plant on regeneration of native tree species. This study was conducted in Amani Botanical Garden (ABG) to assess the effects of selected alien plants on recruitment of native tree species. A combination of a Petri dish experiment and two field experiments were used to assess the effects of allellopathic compounds, and the extent of spread of the selected alien plants on recruitment of native tree species namely Isoberlinia scheffleri, Funtumia africana and Macaranga capensis. The results showed that neither invasion stages nor allellopathic compounds had effects on germination of Funtumia africana. However, soil organic matter content had positive influence on germination of Funtumia africana. There was no significant influence of spread of alien plants on the recruitment of native tree species richness and abundance. Therefore, further studies are recommended to assess the effect of other factors such as light intensity, temperature, predation and thickness of leaf litter on germination of native tree species in Amani Botanical Garden, Tanzania.