What Is an Ecosystem?
ecosystem includes living organisms; the climate, soil, water, and air of the
place where organisms live; and all the interactions of the living organisms
each other and their environment. Climate, soil, water, and other environmental
factors determine what species of trees can survive in an ecosystem.
Ecosystems can be studied in terms of their structures, composition, and processes.
different physical pieces of an ecosystem and their arrangement. In a forest,
examples of structures are large, old trees; young seedlings and saplings;
standing dead trees and snags; and dead trees that have fallen to the forest
Composition: The individual species in an ecosystem. Each ecosystem has a group of species
that are most typical. There are hundreds of tree species
in the world, but only some of these species grow in Alaska, Oregon, and Washington
forests. Each forest type has a group of tree species that are typically found
in it. Some tree species grow only in certain ecosystems. Other species have
wider ranges and are found in several or even many ecosystems. The species
of animals, fungi, and plants other than trees also differ among ecosystems.
ecological processes essential to a forest are universal in all ecosystems.
Plants such as trees sprout from seeds, grow, reproduce more
seeds, and eventually die. Animals are born, eat, grow, reproduce offspring,
and die. Organic matter, both plant and animal, is recycled back into the ecosystem.