Chapter 19: Community Dynamics Flashcards
Temporal change in community structure is called ___.
succession
The sequence of communities from grass to shrub to forest is called a ___.
sere
Each of the changes throughout a sere is called a ___, and though they are points in a continuum of vegetation through time, they are often recognizable as distinct communities.
seral stage
True or false: the process of succession is common only to terrestrial environments.
False
These successional species are characterized by high growth rates, smaller size, a high degree of dispersal, and high rates of per capita growth.
Early
These successional species are characterized by lower rates of dispersal and colonization, slower per capita growth rates, and are larger and longer lived.
Late
This form of succession occurs on a site previously unoccupied by a community, like a newly exposed surface after a glacier/lava/ect. moves away.
Primary succession
This form of succession occurs after a disturbance on a site that has been previously occupied, such as a forest after a big fire or an abandoned field that was once cleared for crops.
Secondary succession
Grass growing on a beach is an example of ___ succession.
Primary
This idea of succession was devised by Clements and says that the process of succession represents the gradual and progressive development of the community to the ultimate/climax stage.
Monoclimax hypothesis
This idea of succession was devised by Egler and says that the process of succession at any site is dependent on which species gets there first and is not an orderly process. There is no competition; whoever gets there first prevents others from colonizing there.
Initial floristic competition
This model of succession states that early successional species modify the environment so that it becomes more suitable for later successional species to invade and grow to maturity, so the early ones pave the way for later ones.
Facilitation model
This model of succession involves strong competitive interactions, and no one species is totally superior to the other. The first species to arrive holds the site from all invaders, making the site less suitable for both early and late successional species and holding their place until they die or get damaged.
Inhibition model
This model of succession says that later successional species are neither inhibited or aided by species of earlier stages, so they can invade a newly exposed site, get established, and grow just fine independent of other species there, because they can tolerate a lower level of resources.
Tolerance model
This type of environmental change is a direct result of the presence and activities of organisms within the community.
Autogenic change
This type of environmental change is a feature of the physical environment, governed by physical rather than biological processes.
Allogenic change
Trees changing the amount of light that reaches the forest floor is an example of ___ environmental change.
autogenic
A decrease in temperature with increasing depth in a lake is an example of ___ environmental change.
allogenic
True or false: one feature common to all plant succession is autogenic environmental change.
True
An example of autogenic change in plant succession is ___.
Light changing due to the canopy.
Shade intolerant plants will dominate in ___ succession due to their fast growth rates.
early
In ___ succession, shade intolerant plants will make up the canopy, but no new ones will grow; instead, shade tolerant plants will.
late
Sites that are at different stages of succession are called ___.
chronosequences
True or false: The processes of species colonization and replacement drive succession.
True
If growth rates are slow, displacement occurs ___; if growth rates are fast, displacement occurs ___.
slowly; quickly
This is a pattern of disturbance that doesn’t occur too often and also doesn’t occur too infrequently, so that species diversity is maximized.
Intermediate disturbance hypothesis
True or false: Succession doesn’t occur within heterotrophic species.
False
True or false: Annual fluctuations in temperature will affect secondary succession.
False
True or false: Shifts in environmental changes that occur at periods longer than an organism’s life span will affect secondary succession.
True
Species respond to a wide array of environmental factors that vary spatially and temporally across the landscape, and the interactions among organisms influence the nature of those responses. The product is a dynamic mosaic of communities that occupy the larger landscape.
Ok.
