At the ecosystem level, biodiversity provides the conditions and drives the processes that sustain the global economy – and our very survival as a species. The benefits and services provided by ecosystems include:
>> Generation of soils and maintenance of soil quality
The activities of microbial and animal species – including bacteria, algae, fungi, mites, millipedes and worms – condition soils, break down organic matter, and release essential nutrients to plants. These processes play a key role in the cycling of such crucial elements as nitrogen, carbon and phosphorous between the living and non-living parts of the biosphere.
>> Maintenance of air quality
Plant species purify the air and regulate the composition of the atmosphere, recycling vital oxygen and filtering harmful particles resulting from industrial activities.
>> Maintenance of water quality
Wetland ecosystems (swamps, marshes, etc.) absorb and recycle essential nutrients, treat sewage, and cleanse wastes. In estuaries, molluscs remove nutrients from the water, helping to prevent nutrient over-enrichment and its attendant problems, such as eutrophication arising from fertilizer run-off. Trees and forest soils purify water as it flows through forest ecosystems. In preventing soils from being washed away, forests also prevent the harmful siltation of rivers and reservoirs that may arise from erosion and landslides.
>> Pest control
Around 99 per cent of potential crop pests are controlled by a variety of other organisms, including insects, birds and fungi. These natural pesticides are in many ways superior to their artificial equivalents, since pests can often develop resistance to chemical controls.
>> Detoxification and decomposition of wastes
Some 130 billion metric tons of organic waste is processed every year by earth’s decomposing organisms. Many industrial wastes, including detergents, oils, acids and paper, are also detoxified and decomposed by the activities of living things. In soils, the end product of these processes – a range of simple inorganic chemicals – is returned to plants as nutrients. Higher (vascular) plants can themselves serve to remove harmful substances from groundwater.
>> Pollination and crop production
Many flowering plants rely on the activities of various animal species – bees, butterflies, bats, birds, etc. – to help them reproduce through the transportation of pollen. More than one-third of humanity’s food crops depend on this process of natural pollination. Many animal species have evolved to perform an additional function in plant reproduction through the dispersal of seeds.
>> Climate stabilization
Plant tissues and other organic materials within land and ocean ecosystems act as repositories of carbon, helping to slow the build-up of atmospheric carbon dioxide, and thus contributing to climate stabilization. Ecosystems also exert direct influences on regional and local weather patterns. Moisture released into the atmosphere by rainforests, for example, causes regular rainstorms, limiting water loss from the region and helping to control the surface temperature. In cold climates, meanwhile, forests act as insulators and as windbreaks, helping to mitigate the impacts of freezing temperatures.
>> Prevention and mitigation of natural disasters
Forests and grasslands protect landscapes against erosion, nutrient loss, and landslides through the binding action of roots. Ecosystems bordering regularly flooding rivers (floodplain forests and wetlands) help to absorb excess water and thus reduce the damage caused by floods. Certain coastal ecosystems (salt marshes, mangrove forests, etc.) prevent the erosion of coastlines.
>> Provision of food security
Biodiversity provides the vast majority of our foodstuffs. The annual world fish catch, for example (averaging 100 million metric tons), represents humanity’s most important source of wild animal protein, with over 20 per cent of the population in Africa and Asia dependent on fish as their primary source of protein. Terrestrial animals, meanwhile, supply an array of food products: eggs, milk, meat, etc. Wild biodiversity provides a wide variety of important foodstuffs, including fruits, game meats, nuts, mushrooms, honey, spices and flavorings. These wild foods are especially important when agricultural supplies fail. Indeed, wild biodiversity guards against the failure of even the most advanced agricultural systems. For example, the productivity of many of the developed world’s agricultural crops is maintained through the regular assimilation of new genes from wild relatives of these crops. These wild genes offer resistance to the pests and diseases that pose an ever-evolving threat to harvests.
>> Provision of health care
The World Health Organization estimates that 80 per cent of people in the developing world rely on traditional medicines derived mainly from plants. In Southeast Asia, for example, traditional healers use some 6,500 different plant species to treat malaria, stomach ulcers, syphilis, and other diseases. Biodiversity is also critical to the 'formal' health sector of the developed world. A recent survey showed that of the top 150 prescription drugs used in the United States, 118 are based on natural sources. Of these, 74 per cent are derived from plants. Microbes and animal species have also contributed a range of medicines, including Penicillin (derived from the fungus Pencillium notatum) and several drugs – including anesthetics– derived from the skin secretions of tree-frog species. The medicinal importance of biodiversity is particularly impressive considering that only a tiny fraction of earth’s species have been thoroughly investigated for medicinal properties. The investigative process is continually turning up new pharmaceuticals of great promise. A recent study of cone snails, for example, has identified a painkiller that is up to a thousand times more effective than morphine, but without morphine’s addictive properties.
>> Income generation
Needless to say, the above services are all essential to the functioning of the global economy. Yet biodiversity also has great importance as a direct source of incomes and economic development. One example is 'bioprospecting' (the search for previously unknown biotic products of specific utility, such as natural pesticides, anti-fungal toxins and ‘oil-eating’ enzymes). Such discoveries join an impressive list of ‘miscellaneous’ goods provided by biodiversity, including many of our most important building materials, fibres, fuels, waxes, resins, aromatics, dyes and gums. Even in its wholly untapped state, biodiversity does great service to economies through ‘ecotourism’. People taking nature-related holidays contribute at least $500 billion per year to the national incomes of the countries they visit. Florida’s coral reefs, for example, earn around $1.6 billion per year through tourism alone.
>> Spiritual / cultural value
It’s no mystery why people are prepared to spend so much to get close to nature. Human beings instinctively derive aesthetic and spiritual satisfaction from biodiversity. Recent studies have begun to confirm what has always been known: our emotional wellbeing is enhanced by the proximity of natural beauty. The umbilical bond between humanity and biodiversity is reflected in the art, religions and traditions of diverse human cultures: a spiritual heritage that will be lost for all time if its basis – nature itself – continues to be destroyed.
