Exam 16: Community Structure

The layer of a forest that contains tall shrubs, small trees, and young trees is called the

Ecologists have a variety of useful sampling and statistical techniques for delineating and classifying communities.

A species that has a disproportionate effect on other species in its community relative to its abundance is referred to as a keystone species.

The species diversity of a community is defined by both the number of species and the evenness of the species' relative abundances.

There is considerable evidence that community structure is influenced by species interactions.

Within a community, a group of species that carry out similar functions or exploit the same resource is called a(n)________.

In a forest community, the site where decomposition occurs and decaying organic matter releases nutrients for reuse by plants is called the forest ________.

Why is it important to know the species composition along with species richness, when comparing communities?

Defining boundaries between communities is generally

The physical structure of terrestrial communities is usually defined more by the plants than the animals present.

The ________ concept suggests that, if a cluster of species repeatedly co-exist, they function as an integrated unit within the community.

Food ________ are diagrams of communities that depict the trophic relationships among species.

The group of species that occupies a given area is called a(n)________.

Food webs are useful for depicting ________ interactions among species in which the interaction between two species is mediated by an intermediate species.

The control of an herbivore population by a parasitoid is an example of top-down control.

Basal species in a food web do not feed on other species.

Indirect interactions occur when

When a single or few species are most prevalent in a community, the species are called ________.

Explain why defining the boundaries of a community can sometimes be very difficult. Do you think this detracts from the usefulness of the concept of community?

A diagram that describes the interactions between species within a community, focusing on which species eat which other species, is called a