Ecosystem services for crop protection in bean fields in Moshi rural, along the slopes of Mt. Kilimanjaro Northern Tanzania

Abstract

The natural ecosystem, in and around bean fields potentially offer beneficial services that assist bean productivity. This study was conducted to investigate the distribution of beneficial invertebrates and plants and their conducive environmental conditions in bean fields in Moshi rural, along the slopes of Mt. Kilimanjaro Northern Tanzania. Four farms were chosen on the basis of four factors which were elevation, crop diversity (mixed crop farming), forestation level (farming in grasslands, woodlands and bush land areas), and cropping intensity (most land converted to farming with little bush land, farm-fallow mosaic, small areas of farming with mostly bush/fallow land). Beneficial insects were collected monthly using pan traps. Five traps were placed in the crop plants and the other five traps were placed in the field margin. The insects collected were identified to the functional group level. Plants found associated with beneficial insects were also collected for identification. Monitoring of the insects’ visits to plants was done and photos were taken. It was observed that elevation, time of the year (month), field margin plant species, rainfall and temperature affected the type, richness and diversity of invertebrate communities. There are great spatio-temporal differences in invertebrates’ groups associated with ecosystems services delivery, particularly pollination and pest management functions. The results indicated that there was significant difference (P ≤ .05) among sites in terms of the abundance and richness of invertebrates present. Rainfall and temperature had a potential influence on invertebrates’ groups. In most cases, the highest populations of insects were found in the field margins and edges (P ≤ .05). From this study it can be recommend that it is essential to preserve field margins and edges, cultivate plant species that attract beneficial insects and devise agro-environment strategies to support them.