Influence Of Vegetation Communities On Small Mammal Abundance And Diversity In An Agro-Ecosystem In Isimani Division, Iringa Region, Tanzania

ABSTRACT 

Vegetation communities are home to a number of animals including small mammals, hence any change in vegetation communities will influence their abundance and spatial distribution. This study aimed at investigating the influence of vegetation communities on small mammal abundance and diversity in the Isimani agroecosystem landscape, southern Tanzania. Three study sites selected based on landscape characteristics and vegetation communities were investigated, classified and mapped. Fourteen vegetation communities were mapped and more than 80 trees species and 20 species of herbs were identified during the field survey. A total of 63 Small mammals trapping sites were randomly located in the three sites covering 188 km2 where 507 small mammals of eight different species were trapped. The data obtained were later analysed to get an insight into their relationship. Boosted Regression Trees (BRT) modelling technique was used to establish the relationship between vegetation communities and small mammal abundance and diversity. Small mammals were found in large numbers in cultivated fields and fallowed areas. Trap success was high at high altitudes i.e. on the plateau, shamba rat i.e. Mastomys natalensis contributed for more than 80% of the total number of small mammals recorded. BRT model results showed that altitude was the most important vegetation communities’ predictor variable contributing 45.6% on small mammals’ abundance and (80.2%) on their diversity. Identification and mapping of different vegetation communities across agroecosystem landscape has proven to be very crucial for understanding vegetation - small mammals interactions in agroecological landscapes. This study recommend measures that reduce herbaceous vegetation from fallowed areas and encourage woody vegetation to be taken in order to supress grasses in vegetation bordering farms so as to achieve Ecological Based Rodent Management (EBRM). Also future studies that will investigate how small mammal abundance and diversity can be influenced by different vegetation communities seasonally in agroecological landscapes.