The Prairie Builders: Reconstructing America’s Lost Grasslands
5 The Living Environment
Interdependence of Life
For Grades: 6-8
Learning Goal 1a
In all environments, organisms with similar needs may compete with one another for limited resources, including food, space, water, air, and shelter.
Learning Goal 1b
The world contains a wide diversity of physical conditions, which creates a wide variety of environments: freshwater, marine, forest, desert, grassland, mountain, and others. In any particular environment, the growth and survival of organisms depend on the physical conditions.
Learning Goal 2
Interactions between organisms may be for nourishment, reproduction, or protection and may benefit one of the organisms or both of them. Some species have become so dependent on each other that neither could survive without the other.
Learning Goal 2b
One organism may scavenge or decompose another.
Learning Goal 3
Given adequate resources and an absence of disease or predators, populations of organisms in ecosystems increase at rapid rates. Finite resources and other factors limit their growth.
Learning Goal 4
All organisms, both land-based and aquatic, are interconnected by their need for food. This network of interconnections is referred to as a food web. The entire earth can be considered a single global food web, and food webs can also be described for a particular environment. At the base of any food web are organisms that make their own food, followed by the animals that eat them, then the animals that eat those animals, and so forth.