Biotic factors are interactions associated with living organisms. They can also influence the distribution of organisms in an ecosystem.

Examples of biotic factors are:

• competition for environmental resources
• grazing - too little leads to dominant plants outcompeting other species, too much reduces species numbers overall. Both decrease biodiversity
• predation - a reduction in predators can lead to an increase in prey. High numbers of prey can lead to overgrazing, which can reduce biodiversity
• disease
• food availability