NAME: ______BLOCK: ______DATE:______
Directions: Determine if the statement is true. If it is not, rewrite the italicized part to make it true.
______1.The interactions of abiotic and biotic factors result in conditions that are suitable for some organisms but not for others.
______2.Food availability and temperature can be limiting factors for a particular organism.
______3.A limiting factor is any biotic or abiotic factor that restricts the existence, number, reproduction, or distribution of organisms.
______4.At high elevations where the soil is thin, vegetation is limited to small shallow rooted trees.
______5.Factors that limit one population in a community may also have an indirect effect on another population.
______6.Tolerance is the ability of an organism to withstand fluctuations in biotic and abiotic environmental factors.
______7.A population of deer would become smaller as conditions move away
from optimal toward either extreme of the deer’s range of tolerance.
______8.Different species may have different ranges of tolerance.
Directions: Use each of the terms below just once to complete the passage.
Climaxprimary decades succeed pioneer
Succession species slows down
The natural changes and ______replacements that place in the communities of ecosystems are known as ______. It can take ______or even centuries for one community to ______, or replace, another. When new sites of land are formed, as in a lava flow, the first organisms to colonize the new area are ______species. This colonization is called ______succession. The species inhabiting the area gradually change. Eventually, succession ______and the community becomes more stable. Finally, a mature community that undergoes little or no change called a ______community develops.
Directions: the statement below describes the secondary succession that occurred within an area of YellowstoneNational Park. Number the events in the order in which they occurred.
______17.Grasses, ferns, and pine seedlings inhabited the area.
______18.Annual wildflowers grew form the bare soil.
______19.A fire burned thousands of acres of land.
______20.A climax community of lodgepole pines developed.
______21.Bare soil covered the area.
Directions: Answer the following questions completely using he picture of primary succession on the next page.
22. What do ecologists mean by the term succession?
23. How is secondary succession different from primary succession?
25. What is a climax community, and which organisms in the picture represent this type of community?
26. Based on the picture, if you hiked through a patch of land that contained a pine forest into an area that contained only ferns, shrubs, and grasses, would you be moving from an older to a younger community or vice versa? Explain.
27. Which parts of the ecosystem had to be established before the primary succession shown in the picture could occur?
Succession Diagram