Influence of historical land use on soil health and terrestrial invertebrate diversity in the Maasai Mara ecosystem, Narok County, Kenya

Land-use change is a major driver of soil degradation and biodiversity loss in savanna ecosystems, with practices such as prolonged grazing and cultivation leaving long-lasting legacies on soil health and ecosystem function. These alterations affect both soil physicochemical proeprties and the diversity of soil organisms. Understanding the interaction between soil physicochemical properties and biodiversity is essential for guiding ecosystem management, particularly in degraded or transitioning landscapes. This study assessed soil biodiversity relationships in two land-use legacy sites in Narok County, Kenya: Maa, previously under prolonged grazing and currently enclosed for ≈ 5 years, and Enarau, a former agricultural area abandoned in 2022. Data were collected at the Maa site from four 50 m by 50 m permanent enclosure plots (three enclosed, one open). From these plots, 13 composite soil samples were created by pooling multiple raw soil cores per plot. In the Enarau conservancy, 31 raw soil samples were collected; 30 from farmland and one from a single control plot. Soil parameters analysed included soil organic carbon (SOC), total nitrogen (TN), available phosphorus (AP), and pH. Biodiversity indicators comprised Shannon-Weiner and species richness indices for invertebrates. Prior to analysis, we assessed normality and homogeneity of variance to verify assumptions for one-way ANOVA and Gaussian generalized linear models (GLMs). Statistical significance of environmental gradients influencing diversity structure, identified via Principal Component Analysis (PCA), was tested using permutation procedures (p < 0.05). Results showed that Enarau had relatively lower SOC (0.95%), TN (0.26%), and AP (4.2 mg/kg), yet exhibited high invertebrate diversity (H’ = 2.73), whereas Maa had SOC (0.12-1.83%), TN (0.12-0.47%), and AP (7.90-8.31 mg/kg) with lower diversity (H’ = 1.40–1.81). Principal Component