Ecosystems provide valuable services that benefit humanity such as provisioning services which provide food, water, fuel and resources; regulating services such as climate, floods, disease, wastes and water quality; cultural services which provide recreational, aesthetic and spiritual benefits; and supporting services such as soil formation, photosynthesis and nutrient cycling. These ecosystem services should be preserved as they are necessary to sustain human life and well-being.

1. Sustainability and Ecosystems: Document 2
Why preserve ecosystems?
Figure 1.1 - Ecosystem services categories
Source: http://www.fao.org/es/esa/pesal/aboutPES1.html