Ecosystem Services (Benefits)

Ecosystem services are the benefits people derive from nature — Robert Costanza and colleagues (1997) described them as the benefits provided to humans through the transformation of environmental assets (land, water, vegetation, atmosphere) into a flow of essential goods and services. Studying ecosystem services matters because, without a clear understanding of these benefits and how to sustain them, the future flow of goods an ecosystem provides is put at risk. Costanza's team put a number on this: they estimated the average global value of ecosystem services at around US $33 trillion a year in 1997, and a later 2011 update raised this figure to about US$125 trillion a year — a roughly four-fold increase over that period. The full range of ecosystem benefits is generally sorted into four categories. Provisioning services are the direct material goods an ecosystem yields — food, fibre and fuel, genetic resources, bio-chemicals, fresh water and medicines. Regulating services are the ways an ecosystem keeps environmental processes in balance — resisting biological invasion, supporting herbivory and pollination, dispersing seeds, regulating climate, pests, disease and erosion, purifying water, and protecting against natural hazards. Supporting services are the underlying processes that make every other service possible — primary production, providing habitat, cycling nutrients, forming and retaining soil, producing atmospheric oxygen, and cycling water. Cultural services are the non-material benefits people draw from nature — spiritual and religious value, knowledge systems, education and inspiration, recreation, aesthetic value, and ecotourism. Mangrove ecosystems illustrate several of these at once: they offer nursery …