Land Degradation in Nigeria and Its Impacts on Biodiversity, Ecosystem and Provisioning Services: a Review

Human society the world over is heavily dependent on land and its resources. Humankind’s utilization of land has led to the modification of almost all parts of the earth. When the impact is negative and continuous over a long period of time, it results in land degradation that is the long-term loss of land ecosystem functions and services. Land degradation have become a major global issue especially since the second half of the 20th century. This paper reviews the occurrence, negative effects and strategies for addressing land degradation. Land degradation is extensive, covering approximately 23% of the globe’s terrestrial area, increasing at an annual rate of 5-10 million hectares and occurring in most terrestrial biomes and agro-ecologies, in both low income and highly industrialized countries. Overall, land degradation affects about 1.5 billion people globally. Its processes have been attributed to rapid human population growth and concomitant intensification of land use. Land devastation is largely through overgrazing of rangeland, deforestation, over-cultivation of cropland, large scale expansion of irrigated agriculture, waterlogging and salinization of irrigated land, acidification and nutrient imbalance, overexploitation for fuel wood, climate variation/change, drought, bush burning, pollution, urbanization and industrialization. The negative effects of land degradation includes soil erosion, desertification, loss of agricultural land, low agricultural production and loss of biodiversity among others. It also contributes to poverty, decrease ecosystem resilience and provision of environmental services. Restoration of degraded land can be achieved through vegetal regeneration, agroforestry, mixed farming, strip cropping, and control of overgrazing and burning of forests/bushes. Also, soil conservation measures should be adopted. In addition, there is the need for increased investments in sustainable land management and formulation of good land use policies.