Contribution of restoration activities to ecosystem functioning in silvopastoral system of Gishwati-Mukura landscape in Western Rwanda

Abstract

This research examines changes in soil arthropods and the soil chemical properties due to silvopasturc management systems. The general objective was to evaluate the contribution of Landscape Approach to Forest Restoration and Ecosystem Conservation projects to improve soil fertility and ecosystem functioning in silvopastoral sites of Gishwati-Mukura landscape dominated by A/nus accuminata. The research was conducted on an 86.6-ha made of four different sites located in silvopasturc of Gishwati• Mukura landscape of Rwanda. Soil arthropods were collected by the use of pitfaJI and hand sort methods, and analyzed to the family level by the use of dichotomous keys. Soil cores were collected and put in bags according to the sites and later take to the Laboratory of plant and soil analysis for the analysis of chemical properties. After data analysis, a total of soil and leaf-litter arthropos individuals of arthropods distributed in six orders and eigth families was found. Results indicated high soil cementation due to the increase in soil organic matter resulting from animal manures and litter accumulation favored by A/nus accuminata trees. The data suggest an impact of A/nus accuminata tree plantation and grazing system on soil C, P and N. Results showed positive influence of A/nus accuminata on soil total nitrogen, and available phosphorus in the sites of Arusha and Yungwe. No impacts observed in the sites of Nkomane and Busuku. We concluded that A/nus accuminata tree species biomass contributes more in maintenance of soil biological and chemical properties, and ecosystem functioning in silvopasture of Gishwati-Mukura landscape of Western Rwanda. Through improving soil organic carbon, organic matter, soil total nitrogen, soil total and available phosphorus and soil and leaf-litter arthropods.