Ecosystem Services

Ecosystem services are the benefits that people obtain from ecosystems. They are the basis of the economic argument for conserving biodiversity: healthy, diverse ecosystems provide services that would be very expensive, or impossible, to replace.Ecosystem services are usually grouped into four types:1. Provisioning services: products taken from ecosystems, such as food (crops, fish, meat), fresh water, timber, fibres such as cotton, fuel, and medicines. Wild species are also a source of genes for crop improvement.2. Regulating services: natural processes that keep conditions suitable for life. Examples include pollination of crops by insects, climate regulation by forests and oceans absorbing carbon dioxide, purification of water by wetlands, flood control by vegetation, and natural pest control by predators.3. Supporting services: the underlying processes that all other services depend on, such as nutrient cycling, soil formation and photosynthesis (primary production).4. Cultural services: non-material benefits such as recreation, tourism, education, scientific research, spiritual value and wellbeing.Economists try to put a money value on these services, so their loss can be included in decisions about land use. For example, about three quarters of major food crop types benefit from animal pollination, and replacing pollinators by hand would be enormously costly. Ecotourism in coral reefs and rainforests brings income to local communities.More diverse ecosystems generally provide these services more reliably, because several species can perform each role. If one species is lost, others can maintain the service.