THE NICHE AND COMPETITION

How to easy learn to study The niche and competition

The niche concept

Within a community, each organism occupies a particular bio-logical role, or niche. The niche an organism occupies is the sum total of all the ways it uses the resources of its environment, including space, food, and many other factors of the environment. A niche is a pattern of living. The zebras you see in the African savanna community  occupy a complex niche featuring open grassland and seasonal migration when food and water become scarce in dry seasons. Sometimes organisms are not able to occupy theirentirc niche because some other organism is using it. We call such situations, when two organisms attempt to use the same resource, competition. Competition is the struggle of two organisms to use the same resource when them is not enough of the resource to satisfy both. However, just because two species occur in the same community and appear to use similar resources does not necessarily mean that they compete. Wildebeests also graze in the savanna alongside zebras, eating the same grass and drinking the same water, but for migrating herds these resources are not scarce. The lives of these two species differ in many other ways important to their survival so that they are not in competition.

 Interspecific Competition

 Interspecific competition refers to the interactions between individuals of different species when both require the same scarce resource. Interspecific competition is often greatest between organisms that obtain their food in similar ways; thus, green plants compete mainly with other green plants, herbivores with other herbivores, and carnivores with other carnivores. In general, competition is more acute between similar organisms than between those that are less similar.   you will learn that interspecific competition can prevent a species from occupying all of its niche—what is possible becomes limited by the realities of sharing a community with other species using the same resources. The white-colored barnacles you see in figure 2.18 would have no trouble covering the entire surface of this ocean rock, but don't in fact do so, because the species of mussel competes with them for space, a very important limiting resource.

Intraspecific Competition 

It is important to distinguish interspecific competition, which occurs between members of different species, from intro-specific competition, which occurs between individuals of a single species. The two seedlings in
re competing for the same resource, sunlight. The taller one, by growing faster, may ultimately shade out the shorter one.