Floristic Diversity and Ecological Characterization of the Habitat of Crocodylus suchus in the Niger River in the Niamey Region

Abstract

Sustainable management of freshwater reptiles in West Africa Sahel is affected by great data scarcity, regional data gaps mostly about the crocodile’s species like Crocodylus suchus. Thus, this study addresses these gaps by determining the floristic diversity and characterizing the habitat of Crocodylus suchus in the Niger River in the Niamey region. We used a systematic random sampling for the floristic inventory using the Brun-Blanquet method. We recorded 58 plant species belong 22 families and 43 genera with a predominance of Eichhornia crassipes (12.32%) and Echinochloa stagnina (12.42%) which varies significantly across the area (P < 0.05). The others have a frequency of 5% or less. Approximately 40 species have a low frequency, with a percentage less than 1%. The macrophytes are 58.54% dicotyledons and 41.46% monocotyledons. The most represented families are Poaceae (29.76%), Convolvulaceae (16.10%), followed by Pontederaceae and Cucurbitaceae at 13.41% and 12.93%, respectively. Ecosystem classification based on species richness revealed two distinct groups of habitats, with similarities between the islands and the right bank. The results also showed that the observation frequency and cumulative mean cover of species vary very significantly across the area (P< 2.2e-16). Dominant species such as Echinochloa stagnina, Mimosa pigra and Eichhornia crassipes have high cover at 1.95%, 1.86%, and 1.33%, respectively. The dominant families are represented by stable and prolific species, with an abundance of prolific species in the Convolvulaceae family. This study has characterized the floristic diversity of the crocodile habitat, highlighting the dominant species and plant communities present. Further research would be useful to better understand the environmental factors and ecological processes that influence the floristic composition and structure of plant communities in this habitat. Management and conservation strategies could be developed to maintain biological diversity and prevent negative impacts on the ecosystem, taking these results into account.