Systematic Composition, Life Forms and Chorology of Agroforestry Systems of Aguié Department, Niger, West Africa

Abstract

Floristic data, life form, and chorotype identification play an important role in planning, management and conservation of vegetation regimes. This study attempted to determine the systematic composition, life forms, and chorology of Aguié department in Niger. We used a systematic sampling approach to inventory vegetation within the agroforestry systems of the Aguié department in August and September 2013. The size of the terrestrial plots was 50 mx 50 m while the aquatic plots were 4 mx 4 m. We recorded 272 plant species belonging to 52 families and 161 genera. The family Poaceae is represented the highest number of species (45) followed by Fabaceae (30), Mimosaceae (16), Caesalpiniaceae (15), Euphorbiaceae (11), and Cyperaceae (10). The Shannon Weaver Diversity Index (H’) calculated based on 51 plots was 2.55 bits. Therophytes (142) species (54.41% of therophytes species) are the dominant life forms in the study area followed by Phanerophytes 83 species (31.25%), Chamephytes 15 species (5.88%), Hydrophytes 9 species (3.30%), and Geophytes 7 species (2.5%). Hemicryptophytes and Lianas account for 3 and 4 species respectively. Chorological analysis of the inventoried flora revealed that Sudano-Zambezians (SZ) are represented by 55.28% (136 species) followed by Congolese-Sudano-Zambezians (GC-SZ) 30.48% (75 species), Sudano-Zambezians -Saharo-Sindians (SZ-Sah.S) 7.31% (16 species) and 10 (4.32%) for introduced species which indicates the anthropogenic impact on the flora of Aguié department. The analysis of biological spectrum reveals that the phytoclimate is therophanerophytic. The domination of therophytes indicates that Aguié department is a dryland area while the dominance of phanerophytes expresses the management and conservation practices within the agrosystems of Aguié department. We recommend further research that examines at the impact of land use activities on the dynamics of agroforestry systems of Aguié department.