Nutritional Value, Socioeconomic Importance and Ecological Contribution of Selected Indigenous Fruit Trees in Savanna Agroforestry Systems of Northeastern Nigeria

Abstract

Indigenous fruit trees (IFTs) are important components of savanna agroforestry systems because they provide food, income and ecological services to rural households. This study assessed the nutritional value, socioeconomic importance and ecological contribution of five indigenous fruit tree species, namely Adansonia digitata L., Balanites aegyptiaca (L.), Delile Parkia biglobosa (Jacq.) R.Br. ex Tamarindus indica L., and Vitellaria paradoxa C.F.Gaertn., across selected communities in northeastern Nigeria. Proximate and mineral compositions were determined using standard laboratory procedures, while household socioeconomic information and woody vegetation data were obtained through household surveys and field inventories. The study assessed moisture, protein, fat, fibre, ash, carbohydrate, energy, calcium, iron, zinc and potassium, together with household utilization, income contribution, tree density, diameter at breast height (DBH), regeneration and woody-vegetation diversity. The reported nutrient values differed among species, with P. biglobosa having the highest crude protein content and V. paradoxa the highest fat and reported energy values. A. digitata had the highest fibre, calcium and potassium values, whereas P. biglobosa and B. aegyptiaca had the highest iron and zinc values, respectively. P. biglobosa and V. paradoxa generated the highest reported mean annual household incomes. Woody-vegetation richness and Shannon diversity were highest at Pindiga and lowest at Jakusko. Regeneration was strongest for B, aegyptiaca and weakest for A. digitata. The findings indicate that IFTs can simultaneously support dietary diversification, rural income generation and conservation of woody vegetation when retained and sustainably managed within agroforestry landscapes. However, the results should be interpreted as evidence of potential contribution rather than direct measurement of household nutritional status or biodiversity conservation outcomes. Khaya senegalensis (Desr.) A.Juss., Vitellaria paradoxa C.F.Gaertn., Tamarindus indica L., and Parkia biglobosa (Jacq.) R.Br. ex G.Don. Subsequent mentions used A. digitata, K. senegalensis, V. paradoxa, T. indica, and P. biglobosa