Exam 17: Community Structure

The species within a community interact with one another either directly or indirectly.

The characteristics of a community are generally not dependent on the spatial scale at which the community is examined because communities are tightly integrated groups of species.

The organismic concept views communities as clusters of species associating together as an interacting,integrated component.

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

A straight-line diagram illustrating the flow of food energy from prey to predator is referred to as a food ________.

In a well-stratified lake in summer,the subsurface layer of water,which is characterized by a steep and rapid decline in temperature with depth,is called the

Dominance is the converse or opposite of diversity.

Zonation within a community is typically the result of differences in the

The aphotic zone of a lake is inhabited primarily by phytoplankton.

An ecologist samples the abundance of various species along an environmental gradient and fails to find clusters of species.Instead,peaks of abundance of dominant species are merely randomly spaced segments along a continuum.This distribution of species supports the

In a forest community,the layer in which most photosynthesis occurs is the

In a food web diagram,________ species feed on no other species but are fed upon by others.

The boundaries between communities are usually sharply defined and easily discerned.

The view developed by H.A.Gleason that communities result from similarities in species' requirements and tolerances for environmental factors is referred to as the ________ concept of communities.

Most communities have many common species and a few rare species.

Dominant species tend to be more abundant than other species because they

Changes in the physical and biological structures of communities as one moves across the landscape are referred to as ________.

The removal of a keystone species from a community typically results in an increase of diversity.

Within a food web,herbivores are considered to be

In a well-stratified lake,the thermocline refers to a steep and rapid decline in temperature relative to the waters above and below.