Biotic and abiotic constraints to revegetation and establishment of functional ecosystem in degraded lands in a tropical environment

Land degradation and deforestation connote loss of biological and economic productivity, and confounds the widespread and increasing need for environmental conservation in the tropics and elsewhere in the world. Vast expanse of land are left bare, degraded and subjected to accelerated erosion and threat of desertification as a result of mining, agricultural and urban development activities in the tropics. Such degradation manifests in form of soil disturbance, accelerate environmental pollution, changes in physical and chemical properties of the soil, loss of forest covers and biodiversity, nutrient cycling and energy balances, and climatic stress factors. The accompanying deforestation brings about shifts in plant community and structure and strongly affect the survival and competitive advantage of native and alien (invaded) plant species. Abiotic stress factors will affect the ec-ophysiological attributes of plant species important to species diversity and adaptation or tolerance to degraded ecosystems characterised by microclimatic gradients and other stress factors. Remediation measures had been achieved through organic wastes amendments, topsoil replacement (soil reconstruction). Biorestoration of degraded landscapes for environmental protection may also be built on the recruitment of native components of biodiversity (tracts of vegetation from existing plant communities and remnants of primary forests and late successional species) for revegetation. In the tropics, there is therefore increasing and urgent need for remediation of degraded lands and to restore productive (functional) ecosystem. These efforts will assist in the development and sustainable management of degraded landscapes for agricultural production, biodiversity conservation and ecosystem health. The recuperation (restoration of the ecological balance and productivity of degraded lands) of degraded ecosystems will provide alternative land uses such as wild life/amenity parks, forest reserves, pasture/range lands and horticultural plantations, and preserve environmental quality. The reclamation and revegetation of degraded/eroded soils will improve ecosystem functioning and arrest further degradation.