To maintain and improve environmental stability for proper functioning of ecological systems.
Biological diversity includes a combination of species and richness; species interactions; interactions between organisms and the non-living components of the environment; behaviour; life-history and physiological diversity; physical diversity of a habitat, made up of the diverse shapes and movements of different organisms. Integrity and stability is the sum of all the biological diversity interacting with the different habitats or ecosystems in an area. It is in maintaining this complexity in ecosystems that there is environmental stability. Consequently, ecological services of value to human society are provided.
Ecological services are functions beneficial to humanity derived from ecosystems, include improvement of air and water quality, maintenance of hydrological regimes, soil generation, soil and watershed protection, recycling of nutrients, energy supply, carbon sequestration and oxygen release. The variety of biological organisms in ecosystems helps to stabilise the environment.
Losing diversity means losing the ecosystem resilience, leading to adverse effects on human communities. A balance of species and genetic diversity is necessary to uphold the cyclical relationships within ecosystems and hence maintain ecological services to the human community.
Many ecological processes have been impaired or endangered, resulting in such impacts as increased run-off, soil erosion, reduced rates of nutrient uptake, lack of pollination, eutrophication of water-bodies and changes in species composition. The loss of genetic diversity will seriously impair the ability of species to adapt to new stresses such as climate change and the introduction of non-native species.