Ecological communities consistent all interacting species populations with any legal system most species populations within an established community such as the African savanna have interacted with one another over a long period of time the interactions that occur between populations in the community fall into three major categories competition in which populations compete for limited resources predation in which organisms have one species kill and eat those of another and symbiosis in which two species populations live together in close association with one another to the benefit of one or both of the species all these interactions act as forces have natural selection on the species populations involved bus populations are given biological community are intertwined with one another in it intricate coevolutionary process however these self-sustaining balance communities developed through gradual changes occurring over long period of time during these period of change one type a community give way to another until a balanced self-sustaining community is established for example none of the Earth’s majestic forests originally began as forest up huge trees rather the land they now cover was initially inhabited by lichen washes grasses and low-growing shrubs it was only after a long period of time that the established forest ecosystems we see today were formed the process by which ecosystems slowly change into balanced self-sustaining communities is called succession what’s now take a closer look at the selective forces of competition predation and symbiosis as well as how self-sustaining communities are created through succession
each species in the community occupies a unique ecological niche them compasses all aspects that species way of life the concept of the ecological niche not only includes a species physical home or habitat one also its food requirements behavior and predators what might be called the species role or occupation within its ecosystem in addition the species niche includes all the physical environmental factors necessary for its survival such as the range of temperatures under which members of the species can survive they want water they require and in the case a plant’s the pH of the soil they can inhabit the type of soil nutrients required and the degree of shade that can be tolerated although no two species can ever occupy exactly the same ecological niche for a sustained period of time the net use a different species often overlap one another the results have overlapping issues its competition