Exam 44: Ecological Communities

Conservation of critical parts of food webs is important because removal of these critical species may

A biologist is interested in tracking community changes along environmental gradients.If he measures the species turnover of plant communities from sea level to the top of a mountain,he is measuring changes along a(n)_______ gradient.

The notion of species diversity incorporates which factor(s)?

If a disturbance in a community is strong enough to push it over a "tipping point," the community will fail to return to its original condition and instead will undergo a(n)_______,forming a new type of community.

Use the following to answer questions : Refer to the graphs below. -As shown in graph A,numbers on an island or other isolated natural area become stabilized (reach equilibrium)when the rate of colonization by new species equals the rate of extinction.Based on graphs B and C,how does size of islands and distance from the mainland (near vs.far)affect the stabilization of species numbers?

As the volcanic island of Krakatau was repopulated,which types of species would most likely have been the last to colonize the island?

Long-term stable climatic conditions in tropical regions are often cited as one reason for high species diversity at these low latitudes.Which of the following consequences of a more stable climate has not been proposed as a likely mechanism explaining increased species diversity in the tropics?

A highly diverse community may have representatives of many functional groups,or niches,which makes the community more efficient at using resources.This structural component is known as _______.

Net primary productivity (NPP)of a community is approximately equivalent to

The theory of island biogeography can be applied to oceanic islands as well as to other types of habitat islands.For which of these habitats,however,would it be least relevant?

Species richness results in increased numbers of functional groups,or niches,in a community,because having more species

Under stress,a community loses a number of species.When the stress is removed,the species composition recovers and then stabilizes.During this process,what will be the most likely effect on net primary productivity?

Which of these habitats has the highest species richness?

In Brazil,corridors have been left to connect some fragmented forest patches to undisturbed forest.This form of forest management is beneficial because it

In 1883,a volcanic eruption on the Indonesian island of Krakatau eradicated most life from the island.Over the following years,plants and animals arrived from nearby landmasses to recolonize the island.The process that enables recolonization of devastated island communities such as Krakatau is called _______.

Consider two natural communities: a pond in the Midwest and a coral reef off the coast of Florida.Describe the boundaries for each of these ecosystems and how the boundaries might be different.

In natural communities,the number of species generally _______ as one moves away from the equator.

More than a thousand species of frogs live in the Amazon rainforest.They live in varied habitats,from the forest floor to the highest levels of the canopy.In this situation,the factor that most likely is having a direct effect on species diversity is

The goods and services provided to humans from biological organisms and the communities in which they interact are known as _______.

Explain the difference between highly technological methods of growing coffee and traditional coffee growing that relies on more ecological methods.What techniques are used in traditional coffee growing,and how do these techniques use principles of community ecology? Answer Key