Effect of Mining Activities on Vegetation Composition and nutrient status of Forest Soil in Benue Cement Company, Benue State, Nigeria

Mining is essential in the economic development plan of any country endowed with mineral resources. This is due to both internal and external economic benefits that are made available to countries that are involved in the extraction of mineral resources. Internally, there is creation of employment and revenue generation among others while externally; a substantial foreign exchange is available to such countries. However, looking at the socio-economic importance of the industry, most countries lose sight of the ensuing effect that might accrue to an area as a result of mining activities. This study sought to provide an empirical data to ascertain whether or not mining activities has affected tree diversity of the area in general and on vegetation and soil nutrients in particular. In the study diversity indices (Shannon, margalef and Pielou's evenness) all indicated higher values for adjacent site 5 km away from the factory. Soil health indicators investigated revealed significant differences except Potassium, with adjacent site having higher mean values. This study has indicated that tree diversity was higher in the adjacent site and also that soil 5 km away from the factory was healthier than soil within factory site. Construction of shield over factory site is suggested

Composition and diversity of understory plants in the tropical rain forest of Cross River national park (CRNP), Nigeria

The study assessed the composition and diversity pattern of understory in Oban division of CRNP with a view to established the contribution of the understory to diversity of the area. The study was conducted in four land use types: primary forest (core), secondary forest (buffer), farm fallow and plantation. Ten transects of 2000m length each were systematically located in each land use type. Four sample plots of 50×50m were located on each transect at an interval of 500m. Each plot was subdivided into nine 10× 10m subplots for shrubs enumeration and a 1×1m mili-acre plot was located at the center of each subplot for herb enumeration. Flora species composition, distribution and diversity were estimated across the land use types using diversity indices. Primary forest (core) was used as baseline for comparison. A total of 608 understory species in 82 Families were recorded in the study area. The highest numbers of understory species (454) were recorded in the core. Species richness (D) for shrubs was higher in the core (D =24.0). Similarity and species diversity (H’) shrubs, was higher in the core (H’= 4.66) and (H’=3.71) respectively. Herb species composition, Species richness and diversity increased were higher in the farm fallow (D26.23) and (H’=4.577). The highest density/ha for all life forms were recorded in the farm fallow. It is imperative that biodiversity assessment in the area should also give attention to understory composition in the area to enhance their conservation.Key words: Understory, Species, Composition, Diversity, Conservatio