Elephants are not the most dominant species in African grasslands, yet they influence community structure. The grasslands contain scattered woody plants, but they are kept in check by the uprooting activities of the elephants. Take away the elephants, and the grasslands convert to forests or to shrublands. The newly growing forests support fewer species than the previous grasslands. Which of the following describes why elephants are the keystone species in this scenario?

Community ecology is a branch of ecology that studies the factors that affect biodiversity and community structure. It examines the interactions between organisms in a habitat, including the distribution, structure, abundance, and interactions between coexisting populations.  Community ecology seeks to answer questions such as: How does the depth of a lake affect the complexity of the community living within it? Why do some places have more species than others? Is there competition in nature?   Community ecology focuses on interactions between populations as determined by specific... Show more

Community ecology is a branch of ecology that studies the factors that affect biodiversity and community structure. It examines the interactions between organisms in a habitat, including the distribution, structure, abundance, and interactions between coexisting populations. 

Community ecology seeks to answer questions such as:
How does the depth of a lake affect the complexity of the community living within it?
Why do some places have more species than others?
Is there competition in nature?  

Community ecology focuses on interactions between populations as determined by specific genotypic and phenotypic characteristics. These interactions include predation, herbivory, parasitism, detritivory, mutualism, and commensalism. 
Community ecology has a long history of studying the stability of ecological systems. Species interactions underlie ecosystem functions such as nutrient cycling and influence ecosystem structure.

Related Test: Basic Biology Practice Test: Population Ecology

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