Geo-spatial evaluation of soil physicochemical parameters and macro-faunal abundance under different land-use patterns within a botanical garden setting in southern Nigeria

Botanical gardens hold a distinct advantage in tackling ecosystem restoration challenges. A geo-spatial evaluation of soil physicochemical parameters and macro-faunal abundance were examined, under different land-use patterns in the University of Ibadan Botanical Garden, once in the late dry season and early wet season of 2024. At each of 45 sampling points, temperature, pH, particle size distribution, electrical conductivity (EC), and organic carbon (OC) were determined. Spatial distribution mapping of diversity, abundance and physicochemical parameters was done using ArcMap 10.8. Data were analysed using ANOVA, Tukey post-hoc tests and PCA. Diversity indices were also calculated. A total of two hundred macrofauna belonging to nine orders and twelve families were collected from the three sections, the Arboretum, Ornamental and Horticultural sections of the garden over the sampling period. This included two unidentified annelids. In the late dry season, Families Spirostreptidae and Formicidae were most prevalent, while Eudrilidae was most prominent in the early wet season. Shannon–Wiener diversity index, Margalef species richness, Pielou’s evenness, Simpson’s Dominance Index and Sorensen’s Coefficient of Community ranged from 0.20 to 1.61, 0.32 to 1.61, 0.28 to 1.03, 0.09 to 0.80 and 0.25 to 0.60 respectively across each section and seasons. Distinct patterns and outliers in each season were observed, driven by varying physicochemical parameters and macro-faunal distribution. This, and the significant differences (p<0.05) observed in EC, pH, and clay content suggest that soil properties are highly responsive to seasonal changes and land-use patterns. These variations can influence soil fertility, water retention, and habitat suitability, ultimately affecting macro-faunal abundance and distribution in the Botanical Garden. Understanding these interactions can better enhance ecosystem function and resilience, ensuring the long-term sustainability of the Garden. Future research should focus on further elucidating these relationships and exploring how specific management interventions can optimise both soil health and biodiversity.