Ecology - Change in Communities Final Flashcards
What are some of the effects of increasing water temperatures on corals in the Indian Ocean?
high water temperatures driven by large-scale climate change have caused coral bleaching (loss of symbiotic algae)
what is responsible for dissolving the skeletons of corals
increased ocean acidification
In what ways might biotic agents of change lead to changes in community structure over time
Biotic interactions can result in replacement of one species with another
* Diseases can initiate community change by causing death or slow growth of a species
* Ecosystem engineers or keystone species can influence community change
what kind of community is described as a plant community that does not allow for further colonization
closed community
what is an open/ individualistic view of community organization
seeing the relationship of coexisting species as simply the results of similarities in their requirements and tolerances and partly the result of chance
Under what conditions are the discontinuities between communities fairly well defined?
but usually they are found where there are sharp physical boundaries such as the aquatic -terrestrial transition
who viewed the process of succession as organisms and the environment interacting to shape succession
Charles Elton
How did Charles Elton view the process of succession?
organisms and the environment interact to shape succession
what type of succession involves the serial replacements of species that occur as a result of changing geophysical and chemical forces, that is, they are driven by external forces
Allogenic succession
what is an example of an allogenic succession
conversion of salt marshes into woodlands
what type of succession occurs on newly exposed landforms, in the absence of gradually changing abiotic influences
autogenic succession
what succession occurs in aquatic habitats
as lakes fill in with organic matter
hydrarch succession `
what is the establishment and development of plant communities in newly formed habitats previously without plants is called primary succession
primary succession of allogenic successin
what is an example of primary succession of allogenic succession
primary succession that occurs on exposed till left by glaciers in southeast alaska
what is the return of an area to its natural vegetation following a major disturbance
secondary succession of allogenic succession
where can a secondary succession of allogenic succession be seen
plowed fields in the eastern United States were abandoned by farmers moving west after the frontier was opened up in the 19th century that it has been called old field succession
which type of autogenic succession can be seen without the use of plants
primary
which type of autogenic succession already had plants involved
secondary
What are the most common “pioneer organisms” in the process of primary succession and what is their role in this process
lichens
What is the facilitation model of successional dynamics?
species replacement is facilitated by previous stages that make modifications in the abiotic environment
What is the tolerance model of successional dynamics?
assumes earliest species modify the environment, but in neutral ways that neither benefit nor inhibit later species
State the inhibition model of successional dynamics.
early species modify conditions in negative ways that hinder later successional species
* In this model, species replacement is inhibited by the residents until they are damaged or killed
* The only possibility for new growth/colonization in this successional sequence arises when a disturbance leads to dominating species being destroyed, damaged or removed!
How does the replacement of species occur in the inhibition model of successional dynamics?
species replacement is inhibited by the residents until they are damaged or killed
How did Sousa (1979) test the inhibition model of successional dynamics
algae growing on boulders in the intertidal zone of the California coast
