Implications Of Land Use Land Cover Change On The Biodiversity Of Kibasira Swamp In Kilombero Valley, Tanzania

ABSTRACT

Sustained wetland functioning needs proper land use planning which in its best requires integrated land management. High anthropogenic pressures on the Kibasira Swamp may undermine its potential in biodiversity conservation and ecosystem services provisioning. A study was conducted to investigate the implications of land use/cover on the biodiversity of Kibasira Swamp. Landsat TM and ETM+ images for the period 1990, 1998 and 2011 were used to quantify the changes. Plants and bird species were also assessed using nested plots of 0.08 ha and point count of 50 m radius respectively. The sampling points (plots) were established along 8 transects of 3 km radiating from the Swamp. Information from key informants was collected to assess the past status and trends in biodiversity of the Swamp. Results revealed a 1% and 4% increase in areas covered by water and forests respectively for the periods between 1990 and 1998 whilst Papyrus and cultivated areas decreased by 8% and 3%, respectively in the same period. For the period 1998 to 2011, there was a 35% and 9% decrease in areas covered by water and forests respectively while that of Papyrus increased by 40% and cultivated areas by 8%. Farmlands had higher bird species richness (76 species) than other habitats. However, the Swamp had higher abundance of birds (22 260 birds/km2) than other habitats. Furthermore areas with termite mounds had significantly higher tree species richness than surrounding areas (t = 1.68, P< 0.001). At least 15 tree species were found only in termite mounds. There is a strong evindence that land use/cover in the Kibasira swamp has changed substantially over time due to increasing athropogenic activities especially agriculture. This has resulted into a profound influence on the biodiversity of the Swamp. Measures to contain the anthropogenic activities that are a threat to the biodiversity of the Swamp and the Kilombero wetlands at large are inevitable.