Abstract:
Urban vegetation stands as a pivotal ecosystem for the provision and support of ecosystem
services in towns and cities leading to the attainment of SDG 11: “Make cities and human
settlements inclusive, safe, resilient and sustainable.” In pursuit of this goal, this study aimed at
determining the present urban tree species richness, diversity and carbon stock potential in
Lilongwe City, Malawi. Six distinct urban forest types were identified: Cemeteries, Institutional
lands, Parks and Recreation, Residential, Riverine, and Roadside/Avenues. Stratified random
sampling was done in order to come up with the required number of samples. For
parks/recreation and cemeteries sample plots of 20m x 20m and 10m x 10m were laid
respectively. For roads and riverine, sample plots were laid side by side of 20m x 20m at an
interval of 500m. For institutions and residential areas, a total count of trees was done and the
area for each was measured. In each sample plot/area, a full tree inventory was conducted. A
total of 4,031 individual trees was recorded comprising of 166 tree species across all six forest
types, with five species common to all forest types. Residential forests recorded the highest tree
species richness with 87 and Riverine was the least with 15. Only 38 tree species were found in
parks/recreation, 37 in residential, 15 in institutional lands, 4 in road/avenue, and 1 in
cemeteries. Furthermore, the Rẻnyi diversity profile for residential forests was above the profiles
of the other forest types signifying it being more diverse than others; albeit with an uneven
distribution of individual tree species, primarily attributed to the dominance of Mangifera
indica. Similarly, the shape of profiles for other forest types were less horizontal. An even
distribution of individual species in an ecosystem signifies a healthier ecosystem critical in
sustaining ecosystem services. Carbon stock estimation revealed a mean of 51.67±5.27 t/ha with
7.21% uncertainty, and significant differences (P<0.001) among forest types. Pairwise analysis
demonstrated non-significant differences (P>0.05) in carbon stock estimation between
institutional and cemetery forests, recreation and residential forests, as well as riverine and
avenue forests. Therefore, the present results suggest that all six forest types are disturbed and
need appropriate management. Hence the study outcomes offer a foundation for informed
decision-making by town planners. There is also need for a comprehensive study to estimate
carbon emissions, particularly in Lilongwe's industrial areas, to address the holistic
sustainability of the city's urban environment
