Structure of the Woody Stands of the Future Pre-Release Site of North African Ostrich (Struthiocameluscamelus(Linnaeus, 1858)) in Koutous, Niger

Abstract

This study aims to investigate the composition and Important Value Index (IVI) of the woody stands of Tchillala, a 130-ha area selected for future North-African ostriches (Struthiocameluscamelus) prerelease in the Koutous region in Niger. The forest inventory method was implemented in 42 plots of 50 m x 20 m (1000 m²) for tree-level observation, using stratified random sampling. For each woody specimen, the trunk diameter, total height and crown diameter have been recorded; thespecimens with a trunk diameter smaller than 5 cm are considered as regenerations. A total of 17 woody species distributed across 10 families have been identified and most of them belongs either to the Mimosaceae (4 species) or the Tiliaceae (3 species). The plants density, domination and frequency were used to determine the IVI: Acacia tortilis and Balanitesaegyptiaca are the species with the highest IVI(118.43 and 88.28 respectively). The woody plants condition assessment has emphasized that trees have been facing natural (uprooting) and anthropogenic (cutting, pruning) threats. Consequently, the diameter class structures within the whole woody species community of Tchilala, as well as of the Acacia tortilis and Balanitesaegyptiaca, are mainly small size trees. The results of this study inform silvicultural management actions that would benefit to the North-African ostrich’establishment in Tchilala and the data collected are considered as possible indicators for long-term monitoring of habitat.