Biodiversity is nature’s strategic defence. If it were not so well camouflaged, we might be more careful to preserve it. This hidden hand of variety patrols each layer of the hierarchy of life in the biosphere – genes, species and ecosystems.
Take the simple example of a herd of grazing cattle. Their field is an example of an ecosystem, comprising the animals, plants, insects and all living things for which the field offers a suitable habitat. The range of these species will be one indication of biodiversity in that field.
Species diversity sustains the equilibrium of an ecosystem. The loss of one component, especially an important “keystone” species such as a pollinator, can trigger the breakdown of the whole.
Genetic diversity within the breed of cattle will be apparent from slight differences in physical appearance and temperament of each individual, as well as countless invisible traits. This form of diversity is important because it improves the likelihood that a plant or animal species will be able to adapt to disease, pests or a variation in habitat.
Ecosystems can be smaller or larger than a field. The largest and most familiar – such as lakes, wetlands and mangrove forests – are described as biomes. The incidence of biodiversity varies greatly between biomes, being most intense in tropical forests and in coral reefs.
The bounty of nature is often subdivided into four categories – the provisioning of basic needs such as food and water, the regulation of critical earth systems such as the carbon cycle, the support of formations such as soil and the spiritual inspiration of the natural world. Our dependence on a tiny number of staple crops for food security, on combustion of fossil fuels for heat and transport, and on throwaway consumer goods, are obvious threats to these benefits of biodiversity.
Stability of ecosystems is therefore of particular importance to the top species, homo sapiens, whose rising numbers lack resilience to any disruption in supplies of life’s essentials. The world’s poorest people, 70% of whom live off the land or the sea, have little difficulty in understanding the importance of robust diversity in the natural world. There are 475 million smallholder farms on plots of less than two hectares and 150 million poor people dependent on livelihoods linked with fisheries.
By contrast, industrialised urban environments have distanced the average family from its genetic affinity with the land and sea, physically, economically and emotionally. The innate value of biodiversity has slipped off the human radar, with devastating consequences.
more Biodiversity briefings (updated March 2021)
Causes of Biodiversity Loss
Climate Change and Biodiversity
Conservation of Biodiversity
Solutions to Biodiversity Loss
Sustainable Development Goals for Biodiversity
Biodiversity Access and Benefit-Sharing
Source Material and Useful Links