the sequence of communities forming in an originally lifeless habitat
a fungus and an alga living in a mutualistic relationship
a community that does not undergo further succession
succession that occurs where a disturbance eliminates most organisms but does not destroy the soil
a state of balance between opposing forces
suggests that ecosystems may be sensitive to very small changes, and that the initial state of an ecosystem is crucial to its later development
Which is a disturbance of an ecosystem?
The rates of extinction are increasing.
What effect is the growing human population likely having on the biosphere?
Since the grass community shows primary succession, it is not a diverse community and, hence, even a small disturbance may cause a drastic change.
Why is the grass community vulnerable to even small disturbances?
a climax community.
A mature, stable and diverse ecosystem is called __________.
Secondary succession occurs where a disturbance eliminates most organisms but does not destroy ________.
formation of a new species.
The abundance of new, unfilled niches on newly formed island often leads to _______.
Many islands have large bird populations.
Birds can reach newly formed island more easily than land mammals. Which is a result of this ability?
The many interactions among the components of an ecosystem make the system stable. Parts of an ecosystem react through these connections to stabilize changes in other parts.
Why is an ecosystem stable and how does it react to a change in one of its parts?
fly over water.
Birds are more common in island communities than mammal because many birds can ________.
help form soil.
Lichens are important to an ecosystem because they ______.
Which is not a disturbance of an ecosystem?
Through aquatic succession, a clear lake may evetually become __________.
A new mountain lake just formed by a retreating glacier. The lake starts out with little nutrients or life, but over time it begins to support a variety or species. Which type of succession does this describe?
If an ecosystem is disturbed, goes out of balance, and cannot return to a state of equilibrium, species living ther will most likely ________.
Thought the are constantly changing, ecosystems are naturally ________.
One small change in an ecosystem can lead to drastic results.
When applied to ecology, what does the new science of chaos imply?
Secondary succession occurs in an area where the community has been destroyed and soil has been _______.
an increase in the human population
Which is the likely cause of the current increase in rates of extinction?
ecosystems adjust to new conditions.
Stability returns to disrupted ecosystems because _______.
An ecosystem is like a machine the cycles matter by using _____.
a cooled lava field
Primary succession can occur in which habitat?
Which organism is an example from a pioneer community?
Equilibrium is best defined as a state of ________.
A new mountain lake just formed by a retreating glacier. The lake starts out with little nutrients or life, but over time it begins to support a variety of species. Which type of succession does this describe?
the evolution of mamals
What did the extinction of the dinosaurs lead to?
Primary succession occurs in new habitats without ______.