Soil moisture in forest island and adjacent ecosystems in Sub-Saharan Region

Abstract

Forest islands are widely distributed throughout West Africa savanna landscape. Stated as direct outcome of anthropogenic activity, these mosaics are often found around villages and are known for their unique and luxuriant characteristics of tropical rainforest. Althought significant studies focus on their ecology, works on edaphic factors that govern their establishment are very scare. The objective of the current study was to evaluate soil moisture dynamics in forest islands compared to that of surrounding savannas and farmlands at five sites located along a precipation gradient in Burkina Faso. For two years, from 2016 to 2017, soil moisture was monitored at a depth of 0-80 cm using a neutron probe. The results highlighted a seasonal pattern ranging from 42±2% during the heavy rainy month (August) to 16±1% during the dry season (October-November). Significant differences in soil moisture content soil water profile and water stock at depth 0 to 80 cm were recorded between locations and land use patterns. In general, soil moisture was on average 58% less in forest island than in croplands across sites. Soil moisture content was lower in topsoil (0-20 cm) compared to deeper soil (40-80 cm). The Study demonstrated evident link of soil moisture dynamic with rainfall and the vegetation pattern.