Define an ecological community, ecological niche and describe the major factors determining the species in a community
- Communities include all populations of all species living within a particular area.
- Physical structure of communities, either due to prevalent forms of vegetation, or the physical characteristics of substrate (particle size, fluid flow, etc.) determines potential species composition.
- each species has a particular niche, or role in the community
- some species become more dominant than others. Species that become so dominant as to determine what other species are included in a community are keystone species
Describe how biodiversity is measured, and what factors predict the biodiversity of an area.
- biodiversity has two components: richness and evenness.
- Species richness of a habitat changes predictably with area and distance from other populations of species.
- Island Biogeography theory predicts the relationship between species richness of a patch and that patch's area and distance to other patches.
Define ecological succession and describe what determines the changes seen in ecological communities over time.
- disturbance, such as fire, storms, drought removes parts or all of the biological community
- Communities pass through a series of temporal changes called ecological succession (primary or secondary).
- Disturbance resets this sequence to an earlier point and is important in maintaining diversity.
- The typical flora seen in a biome is determined by the successional sequence and the frequency and type of disturbance.
Define the basic types of interspecific interactions and provide an example of each. Describe how they may affect population and ecosystem dynamics.
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