In this module, we learned that communities change over time in a process known as succession. In terrestrial communities, an area that begins with no soil undergoes primary succession whereas an area that begins with soil undergoes secondary succession. In aquatic communities, lakes and ponds can slowly fill in with sediments over thousands of years to eventually become terrestrial habitats. We also learned that the species richness of a community is affected by the latitude of a habitat, the length of time that the habitat has been present, the size of the habitat, and the distance from the habitat to other habitats that serve as sources of species.
Module 21 AP® Review Questions
217
1. Which is true of primary succession?
It starts with bare soil.
As it progresses the number of species initially decreases.
It occurs after forest fires.
It begins with colonization by algae, lichens, and mosses.
It results in an ecosystem of grasses and small plants.
2. The process of succession in lakes
results in a terrestrial ecosystem.
occurs rarely because disturbances are rare.
depends primarily on the fish species within the lake.
progresses fastest in very deep lakes.
has no climax species.
3. Which tree species is a pioneer species in North American forests?
Beech
Fir
Aspen
Maple
Oak
4. Which factor does NOT affect species richness?
Latitude
Survivorship curves
Time
Habitat size
Distance from other communities
5. Which is NOT a factor in the theory of island biogeography?
Dispersing species are more likely to find a large habitat.
Islands can also be isolated areas within a continent.
Large populations are less likely to go extinct.
Larger habitats contain a larger range of environmental conditions.
Islands farther from the continent have more species due to increased speciation.