The study provided an updated checklist of tree species found within Forestry Research Institute of Nigeria, Umuahia premises. A total of 103 taxa belonging to 89 genera and 32 families were identified and documented. The family Fabaceae is the most diverse with 17 species. It was closely followed by the families: Sterculiaceae (8), Meliaceae (7), Moraceae (7), Euphorbiaceae (6) and Annonaceae (5). These six (6) families contributed about 48.5% of the tree flora diversity or 40.8% of the genera. About 34% of the encountered tree species are non-native and are naturalized to the region. Economic fruit trees registered were 34 taxa or 33.0% of the total tree list. Conservation status of each taxon determined using the IUCN Redlist V. 2014-2 classification showed that 3 endangered and 9 vulnerable tree species were recorded from the study area. Efforts should be intensified toward conservation of this important ‘Green Area’ in view of the challenging impact of global climatic change effect.
Key Words: Checklist, Non-native taxa, Naturalized, Conservation, Endangered species