Correct answer: An environment lacking plant and animal life. Explanation : Primary succession is the colonizing of a new environment that lacks organisms and plant life.
Report an Error. Which of the following best describes when secondary succession occurs? Possible Answers: A previously inhabited environment. Correct answer: A previously inhabited environment. Explanation : Secondary succession can be described as the colonization of a habitat that once supported plant and animal life but was abandoned due to ecological disturbance.
Possible Answers: Secondary succession. Pioneering succession. Primary succession. Correct answer: Secondary succession. Explanation : Primary succession occurs in an environment without previous life, or a barren habitat.
Possible Answers: Lichen. Oak trees. Pine trees. Correct answer: Lichen. Possible Answers: In an environment recently burned by a wildfire. Correct answer: On a newly created volcanic island.
Possible Answers: During the summer. Correct answer: Near early stages of succession. Explanation : Pioneer species are the first species to colonize an environment, and thus would be found in the early stages of succession. Possible Answers: Lava flow. Correct answer: Lava flow. Possible Answers: keystone species. Correct answer: pioneer species. Explanation : The first species to inhabit an area that has been disrupted are called pioneer species.
Copyright Notice. View AP Biology Tutors. Kirsten Certified Tutor. Jeffrey Certified Tutor. Researchers have characterized primary succession in this system, where plant communities progress from pioneer species i.
Both facilitation and inhibition act as mechanisms regulating succession in this system Figure 4b. For example, both Dryas and alders increase soil nitrogen, which increases the establishment and growth of spruce seedlings. However, both Dryas and alders produce leaf litter which can inhibit spruce germination and survival. B Summary of facilitative and inhibitory effects of each successional stage of vegetation on spruce seedling growth.
Figure modified from Chapin et al. A classic study of secondary succession was conducted by Catherine Keever In this study, Keever characterized succession in an old field after agricultural use had ceased.
She observed a predictable shift in plant community composition following field abandonment, with horseweed Erigeron canadense dominating fields one year after abandonment, white aster Aster pilosis dominating in year two, and broomsedge Andropogon virginicus dominating in year three Figure 5. She found that life history strategies of individual species, seed dispersal, allelopathy biochemical production by a plant which alters growth and survival of other plants or itself , and competitive interactions among species, led to this predictable pattern of succession.
Figure 5: Keever's observed pattern of succession in North Carolina agricultural old fields Figured modified from Keever Bazzaz, F. Physiological ecology of plant succession. Annual Review of Ecology and Systematics 10 , Chapin, F. Mechanisms of primary succession following deglaciation at Glacier Bay, Alaska.
Ecological Monographs 64 , Clements, F. Nature and structure of the climax. Journal of Ecology 24 , Connell, J. Mechanisms of succession in natural communities and their role in community stability and organization. American Naturalist , Cooper, W. The recent ecological history of Glacier Bay, Alaska: the present vegetation cycle. Ecology 4, Cowles, H. The ecological relations of the vegetation on the sand dunes of Lake Michigan.
Botanical Gazette 27 , , , , Gleason, H. The individualistic concept of the plant association. Bulletin of the Torrey Botanical Club 53 , Grime , J. Plant strategies and vegetation processes.
Horn, H. The ecology of secondary succession. Annual Review of Ecology and Systematics 5 , Hubbell, S. Huston, M. Plant succession- life history and competition.
Keever, C. Causes of succession on old fields of the Piedmont, North Carolina. Ecological Monographs 20 , Koske, R. Mycorrhizae and succession in plantings of beachgrass in sand dunes. American Journal of Botany 84 , Sakai, A. The population biology of invasive species.
Annual Review 32 , Tilman, G. The resource-ratio hypothesis of succession. Young, T. The ecology of restoration: historical links, emerging issues and unexplored realms. Ecology Letters 8 , Predation, Herbivory, and Parasitism. Characterizing Communities. Species with a Large Impact on Community Structure. Successional Changes in Communities. Effects of Biogeography on Community Diversity.
Community Ecology Introduction. Avian Egg Coloration and Visual Ecology. Conversely, in secondary succession, living things will be re-colonizing a previously inhabited area and therefore the area would have topsoil containing organic matter from the previous inhabitants.
Primary succession takes a longer period of time to be established and completed, i. On the contrary, the secondary succession often occurs relatively faster, requiring only a shorter period of time, like a decade or a hundred years. This is because an area that has just been newly formed would be initially unfavorable for most life forms. The newly formed land, for instance, would lack soil but would be comprised of bare rocks.
This is the starting stage of primary succession. A series of physicochemical changes have to occur until such time that they become more conducive to life. The species that are able to inhabit a newly formed or formerly uninhabited land are called pioneer species and the community that has successfully established and dominated is called pioneer community. A community refers to an ecological unit comprised of a group of organisms or a population of different species that occupy a given area.
A community may refer to a small population inhabiting small areas as in a pond or communities on large geographical areas, which define biome. The settling of a pioneer community marks the start of the colonizing phase of primary succession. Examples of pioneer species are lichens, algae , and fungi. These species are more tolerant and eventually contribute to the formation of the soil by breaking down rocks into smaller particles.
They also provide organic matter to the area. Eventually, the area is laden with thin soil and thus becomes favorable for the growth of higher forms of species.
The next species that colonize and dominate the area are referred to as intermediate species. Examples are grasses and shrubs that can thrive in thin soils. As the habitat improves, a wider range of vegetation and small animals can occupy the area. The final stage is the establishment of a climax community, i. If the habitat is exposed to a disturbance that can bring disruption to its inhabitants, the second succession occurs.
Since the area is already inhabited by plants and animals, the area after the disturbance would likely remain habitable and thus will be easier and available for re-colonization. A third type, called cyclic succession , is a type of succession wherein a group of species replaces a previously dominant species over time without a large-scale disturbance.
The primary succession is important in pioneering the area to create conditions favorable for the growth of other forms of plants and animals. It paves the way for the next successions as the previously thriving organisms could become an essential component of the soil.
Since the pioneer species are more tolerant of a harsh environment, they could put into use the available nutrients and convert them into another form for use by other life forms.
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