The effect of land use and habitat types on the diversity and abundance of beetles (order coleoptera) in Simanjiro district, Tanzania

Abstract

The influence of land use and habitat types on the abundance and diversity of beetles was studied in Simanjiro district, Tanzania during the mid-dry and wet season, (November, 2011 to January 2012). Three methods were employed in data collection namely, pitfall traps, sweep net and ground search, however these methods had significance variation (Kruskal-Wallis H =34.01, P =0. 000). A total of 1716 individual beetles representing 80 species, belonging to 26 families were collected from the sixteen different levels of land use and habitat types. Eight levels of land use were selected. Four of these (Acacia bush land grazing, wildlife breeding zone, lion campus, and ostrich campus) were slightly disturbed, while the remaining (beans plantation, maize farm, human settlement and Illaramatak village- Terrat) were highly disturbed and had no significant difference in there abundances, (Kruskal-Wallis= 4.36, P=074) between them. The remaining eight were, Wooded grassland, secondary vegetation, sparsely wooded grass land and Acacia bush land-black cotton soil which were slightly disturbed. The remaining four (Commiphora wood mixed with grasses, Commiphora wood land, mixed acacia wood land and Illaramatak mixed wooded grassland) were highly disturbed. There was no significant difference in abundance between levels of habitat types as well, (Kruskal-Wallis= 5.44, P=0.61). Therefore, there was no significant variation in there abundances between habitat types and land use. (P= 0.32). Species that were collected from both levels, their abundance decreases from one level to the next depending the availability of resources available. High level of disturbance which showed variation in there abundances and diversity was due to human encroachment and dominance of few species although drought and dung override all these. Therefore land use and habitat types have been recommended in this study to be included in the ongoing long-term monitoring programme since there isn’t any study of invertebrates that has been carried out.