Species Association Patterns of Prosopis Africana with Woody Species in North Eastern Nigeria Savanna Ecosystem
Rapid deforestation, bush burning, overgrazing, and increasing agricultural expansion have continued to threaten the survival and ecological relationships of indigenous woody species within the savanna ecosystems of North Eastern Nigeria, thereby creating serious concerns for biodiversity conservation and ecosystem sustainability. This study investigated the species association patterns of Prosopis africana with woody species in the savanna ecosystems of North Eastern Nigeria. The study was conducted in three protected areas namely Wawa-Zange Forest Reserve in Gombe State, Yankari Game Reserve in Bauchi State, and Gashaka-Gumti National Park in Taraba and Adamawa States. A systematic sampling technique involving transects, clusters, and sample plots was adopted for data collection. All woody species with diameter greater than 10 cm within the plots were identified and recorded. Species association was analyzed using Chi-square (χ²), Phi coefficient, and Cramér’s V statistics to determine the significance, strength, and direction of associations between P. africana and other woody species. The findings revealed that P. africana had significant positive associations with forty-two woody species across the study areas. Species such as Combretum glutinosum, Dialium guineense, Vitellaria paradoxa, Strychnos spinosa, and Pterocarpus erinaceus showed very high Chi-square and Cramér’s V values, indicating strong ecological relationships with P. africana. Positive Phi values further confirmed strong positive coexistence among the associated species. The study concluded that P. africana plays an important ecological role in maintaining savanna biodiversity and ecosystem stability. The study recommends sustainable conservation practices, afforestation programmes, and effective control of anthropogenic disturbances to preserve the species and associated woody vegetation within the savanna ecosystem.
