What an organisms does and how it interacts with biotic and abiotic factors in the environmental; the range of physical and biological conditions in which a species lives and the way the species obtains what it needs to survive and reproduce
Ability to survive and reproduce under a range of environmental circumstances
General place where an organism lives
Any necessity of life - water, nutrients, light, food, space, sunlight, etc.
Competitive Exclusion Principle
No two species can occupy exactly the same niche in exactly the same habitat at exactly same time; otherwise, one will "win out" and other will die. Thus, species divide resources (i.e. some live in tops of trees and some in middles)
When prey eats predator; can affect size of prey and predator populations and determine places they can live and feed
When herbivore eats plant; affect both size and distribution of plant populations and determine where certain plants can survive and grow