Usages Socioeconomiques Des Espèces Ligneuses Au Sahel: Cas De Guidan Roumdji Au Niger

Woody species are of multiple use in the department of Guidan- Roumdji, in Niger. The present study carried out in Garin-yahaya and Tsayin-daka aims to identify the woody species, their different uses and to determine their present state. Data collection methodology consisted of a floristic inventory at the level of 80 plots and ethnobotanical surveys on a sample of 250 respondents. 46 species, divided into 38 genera and 22 families, were recorded. There were 24 species used in food, 19 fodder species and 38 others species used in the treatment of several ailments in the area. Also, in handicrafts and construction, a dozen species are used respectively against 19 others species in the production of wood energy. These diverse and wide-ranging uses, associated with the effects of climate change, affect the woody species populations. Thus, in the area, 25 species are declared extinct, 18 and 14 others are respectively considered threatened and rare. The study also reported on woody species management practices in the area, including the conservation of 7 local species and the introduction of 11 exotic species because of various products and services they provide. Also, 96% of the local population practices the trees’ farming natural regeneration management (FNRM) in their farms for various reasons. This would be a start in the sustainable and rational management of forest resources in the area with the maintenance of several woody species in the area

Species diversity and distribution of ruderal flora on landfills in Maradi city, Niger

Waste management continues to be a critical environmental issue in cities. It impacts on the well being of the population, the environment and the biodiversity. In the city of Maradi, in Niger, more interest is given to the problem in order to understand the whole waste management system. It is in this context that this study is carried out to investigate on the role of ruderal flora on the municipal solid wastes dumpsites and landfill sites in Maradi city. The specific objectives are to determine the floristic diversity and distribution of ruderal flora on the municipal solid waste disposal sites, and to identify potential species that can play an important role in the phytoremediation of these sites. In total, 65 species belonging to 52 genera and 24 families were recorded. These species can be categorised into two groups containing anthropic and nitrophilic species according to the ascending Hierarchical Classification (AHC) at 25% similarity. Characteristic species of the first group G1 are Amaranthus viridis and Cucurbita pepo, and Datura innoxia and Cucumis melo for the second group G2. Other ruderal species, namely Amaranthus spinosus L., Amaranthus viridis L., Celosia trygina L., Datura innoxia Mill., and an introduced woody species, Cuphea hyssopifolia Kunth., found are not included in the Maradi city list of species. Datura innoxia, Amaranthus viridis and Amaranthus spinosus are species known to tolerate different degrees of pollution and their ecology should be further study to better understand how they can be used for phytoremediation on this kind of sites