Soil properties influence on diversity and structures of dominant woody species in riparian forests in Southwestern Nigeria

Abstract Interplay between soil variables with structural and diversity indices of riparian vegetation needs to be explicated towards the conservation of this highly productive riparian forest ecosystems amidst pronounced anthropogenic activities in Southwestern Nigeria. The study was carried out in Osun State, Southwestern Nigeria. Nine sites were used for this study, within each site, ten plots (0.25 ha in size) were marked out and each plot was placed systematically, giving a total of 90 plots. Ten soil samples were collected in each plot at top (0-15 cm) and sub (15-30 cm) soil levels using soil auger and to analysed for the physicochemical properties. Woody species were identified and classified. Euphorbiaceae and Apocynaceae are the most occurring families with Musanga cecropioides, Pterocarpus santalinoides, Rothmannia hispida and Jateorhiza macrantha being dominant in the riparian sites. The soil variables correlated positively with structural parameters markedly density rather than diversity indices across study sites. Soil pH, P, TOC, OM were key edaphic factors that affected the vegetation dynamics of these ecosystems. Policies and decision making should take cognisance of these key nutrients supporting dominant species, towards conservation amidst ecological succession ongoing across the riparian forest sites.