The Impact of Browsing and Grazing Pressure on Vegetation Community, Composition and Distribution Pattern in Ikona Wildlife Management Area, Western Serengeti, Tanzania

摘要

The study was carried out at Ikona WMA in the Western Serengeti National Park. It was aimed at assessing the impacts of grazing and browsing by both the domestic and wild animals including human activities on vegetation community structure, composition, diversity and association in Ikona WMA. The vegetation sampling followed Nested Quadrat Sampling Technique. It was found that three-vegetation community types separated based on the effects of browsing and grazing by wild animals, human activities and variation in environmental habitats. Community A dominated by B. aegyptica woodland and highly affected by bush fire, debarking and charcoal making with the lowest species diversity (T4, 1.057- T5, 1.393), B was that of open grassland and was highly affected by elephant browsing and knockdown of most woody species as well as overgrazed by domestic animals, having the lowest species diversity (T1, 1.0412- T2, 1.465) and C was of River Rine community dominated by F. sycomorus (with A. African epiphyte), A. zanzibarica and P. maximum showing healthier habitat with available ground water. C also had the highest plant species composition and diversity (T3, 2.56; T6, 2.5). There was significantly low plant species association between P. Maximum and A. senegal, Acacia seyal, Acacia drepanolobium and B. aegyptica due to effects of wild and domestic animals. It was concluded that, modification of woody community to open grasslands was due to the effects browsing and knockdown of woody species by elephants and grazing by wild and domestic animals as well as human activities in the WMA. Sharing of resources in the pastures is detrimental due to the lack of niche separation and resource partitioning between wild and domestic grazers and browsers.