Topic 2: Community Ecology
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What factors in this aquatic community affect the survival of the manatee? Are human choices a factor?
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What interspecific interactions are illustrated below?
Although the interactions of many species influence biological communities, sometimes a few species exert strong control on a community’s structure, particularly on the composition, relative abundance, and diversity of species. This is referred to as a keystone species. This is primarily a function of their roll and position in the food web of that community.
Food Chains are the trophic structures of a Food Web
The structure and dynamics of a community depend to a large extent on the feeding relationships between organisms-the trophic structure of the community. Ecologists can summarize the trophic relationships of a community by diagramming a food web. Each food chain in a food web is usually only a few links long. Why is this? Only about 10% of the energy stored in the organic level is converted to organic matter at the next trophic level.
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Changes in the composition and structure of terrestrial communities are most apparent after severe disturbance, such as a volcanic eruption or a glacier strips away all the existing vegetation. The gradual replacement of other species is a process called ecological succession. There are two basic kinds of succession:
· Primary, and · Secondary. |
Study each picture below and try to identity which type of succession it is. Be prepared to justify your answer.