What makes an ecosystem?

Question

How are natural (occuring in nature, not "man" or artificially comprised) ecosystems defined? What characteristics make up an ecosystem? What is the purpose/function of an ecosystem, and what services can they provide?

Answer 1

Ecosystems are comprised of many characteristics and can exist anywhere in the world, so long as the area they exist within can be defined as "natural" (ie. - not "manmade" or artificially developed). Environmental Scientists define an ecosystem by inquiring into its functions and community members - organisms which are both living and nonliving. These biotic (living) and abiotic (non-living) components are linked together through nutrient cycles and energy flows. Energy enters the system through photosynthesis and is incorporated into plant tissue. By feeding on plants and onto one-another, animals / complex organisms play an important role in the movement of matter and energy through the system, providing integral services to the Earth and the natural area's surrounding environments/communities - That includes us!