Community ecology is the study of the distribution, abundance, demography, and interactions between populations of coexisting species within a community. The structure of a community refers to its diversity, population sizes, appearance, and interactions between species. Ecological succession describes predictable changes in the composition or structure of a community over time and occurs through primary succession in lifeless areas or secondary succession where a previous community was removed.

1. Zoljargal Jargalsaikhan

2. Community is a group of populations interacting and inhabiting a certain area. It is a complex mixture of different populations that exist together Community ecology is the study of the distribution, abundance, demography, and interactions between populations of coexisting species.

3. The structure of a community refers to its: Diversity – the number of different species Populations – how many of each species there are Appearance – size and distribution of species Interactions – what jobs the species play within the community and how they interact with each other

4. NATIVE SPECIES are those species that typically live and thrive in a particular ecosystem and have been present there for a long period of time. NON-NATIVE SPECIES are species which are either deliberately or accidentally introduced into an ecosystem INDICATOR SPECIES are species which are particularly sensitive to environmental change and so serve as signs of early warning of damage to a community KEYSTONE SPECIES are species that play a more important role in an ecosystem than would be suggested by their population

5. Ecological Succession It refers to more or less predictable and orderly changes in the composition or structure of an ecological community

6. There are two main types of succession Primary Succession It occurs in essentially lifeless areas Secondary Succession It occurs in areas where a community that previously existed has been removed

7. A transitional zone between two communities containing the characteristic species of each Example – Wetlands

8. The edge effect is a term used to describe the various consequences on vegetative communities. These edges can be natural or human induced.

9. The ecological niche involves both the place where an organism lives and the roles that an organism does in its habitat