Woody species composition and growth form in Lema Forest Reserve, Arewa Local Government, Kebbi State, Nigeria

Abstract

Rapid increase in population around Lema Forest Reserve has led to increasing pressure on floral resources which affected their composition and growth form. This study assessed the composition and growth form of woody species in Lema Forest Reserve using transect and quadrat methods. A total of 50 quadrats (20m×20m) were laid along 5 transects of 2 km length. All woody species encountered within the quadrats were identified and enumerated and their height and DBH measured. Frequency, density, dominance, basal area and importance value index (IVI) of each species were also calculated. A total of 195 stems belonging to 28 species and 14 families were identified and recorded. The dominant species were Bauhinia thonningii, Cassia sieberiana and Combretum ghasalense, while the dominant families were Fabaceae and Combretaceae. The results show that the stems are generally of medium to low height, with Adansonia digitata, Ficus polita, Khaya senegalensis and Vitex doniana having the highest mean height. Similarly, 57% of the stems have a diameter of above 70 cm, indicating that they are generally mature and big. However, tree density in the reserve is low (390/ha^-1) due to anthropogenic pressure in the form of selective logging for fuelwood, browsing by animals and extraction of medicinal plants. There is thus the need for collaborative efforts for conserving the reserve.