TITLE:
Analysis of the Spatiotemporal Trends in the Ecological Impacts of Wetlands on the Vitality and Diversity of the Flora in the Ziama Biosphere Reserve from 2000 to 2024 in the Republic of Guinea
AUTHORS:
Zaou Soropogui, Pépé Monemou, Nadège Adoukè Agbodjato, Demba Aïssata Samoura, Aïssata Camara
KEYWORDS:
Vitality, Floristic Diversity, Anthropogenic Pressure, Correlation, Normalized Difference Vegetation Index
JOURNAL NAME:
Journal of Environmental Protection,
Vol.17 No.10,
October
28,
2026
ABSTRACT: The Ziama Biosphere Reserve (ZBR) is recognized as one of the largest areas dense rainforests in the Republic of Guinea due to its biodiversity. Owing to its low-altitude topography, it serves as one of the main habitats for African forest elephants in Guinea. However, this forest ecosystem faces significant anthropogenic pressure, leading to the degradation and fragmentation of its natural habitats. The objective of this study was to analyze the impact of anthropogenic pressure associated with the exploitation of low-lying areas on the condition and diversity of vegetation in the Ziama Biosphere Reserve (ZBR). To achieve this objective, we collected LANDSAT satellite imagery was obtained data from the website http://earthexplorer.usgs.gov/. We selected six spectral bands (B2, B3, B4, B5, B6, and B7) based on their relevance to this study. The calculated of Normalized Difference Vegetation Index (NDVI) allowed us to characterize the condition and dynamics of the vegetation based on the difference in reflectance between the near-infrared and red bands. Correlation coefficient was calculated to identify the main factors associated with vegetation condition in the reserve. The results showed that NDVI values were relatively similar in 2000 (0.3595 - 0.8544) and in 2010 (0.3192 - 0.8539), whereas a marked decrease was observed in 2024, with values ranging from 0.1202 to 0.2517, indicating substantial degradation of vegetation cover. Regarding changes in the vegetation index, the linear trend revealed a continuous decline in the NDVI over the 2000-2024 period. Strong negative correlations were also observed between the NDVI and fallow land, as well as between the NDVI and low-lying areas, with correlation coefficients (r) ranging from −0.910 to −0.692. These results highlight a gradual decline in the vitality of the vegetation cover associated with changes in land-use categories, particularly in low-lying areas. The sustainable conservation of the ZBR therefore requires improved management of low-lying areas, a reduction in human pressures, and the implementation of strategies for restoring degraded habitats.