Resource (biology)

In biology and ecology, a resource is a substance or object in the environment required by an organism for normal growth, maintenance, and reproduction. Resources can be consumed by one organism and, as a result, become unavailable to another organism. For plants key resources are light, nutrients, water, and place to grow. For animals key resources are food, water, and territory. 
Key resources for plants.
Terrestrial plants require particular resources for photosynthesis and to complete their life cycle of germination, growth, reproduction, and dispersal: 
Key resources for animals.
Animals require particular resources for metabolism and to complete their life cycle of gestation, birth, growth, and reproduction:
Resources and ecological processes.
Resource availability plays a central role in ecological processes: