Chapter 20 Succession and Stability Flashcards
Ecological succession would occur after the ______.
retreat of a glacier leaving bare ground
removal of trees after a major avalanche
formation of new rocks from volcanism
Succession taking place on a newly formed volcanic island is ______.
primary succession
A major spring flood in a river removed all of the vegetation along the stream bank but left the soil largely intact. The subsequent return of the community is known as ______.
secondary succession
After surveying a northern forest near glaciers, it becomes apparent that forest dominated with hemlock trees rarely changes in the absence of disturbance. This would be an example of ______.
a climax community
Gleason thought ______ played a larger role in the development of climate communities than Clements did.
chance
After a disturbance, plant communities will change over time. This is known as ______.
succession
When succession takes place on newly exposed geological features, it is known as ______.
primary succession
During community succession, which of the following changes are likely to occur?
changes in the composition of species
increases in species richness
When disturbance severely disrupts a community but not the soil, the succession that takes place is known as ______.
secondary succession
The set of succession study areas at Glacier Bay, Alaska, represents a ______.
chronosequence
An older community that appears to remain stable in the absence of disturbance is called a ______.
climax community
Unlike Gleason, Clements thought the species composition of the climax community was ______.
highly predictable
In the study by Reiners et al. (1971) study, their oldest site was dominated by
picea
In a community undergoing primary succession, species richness ______.
increases rapidly during the first years
Studies on succession have historically focused on ______.
succession leading to a climax forest
The study sites at Glacier Bay, Alaska, include a set of similar forests, but at different ages. This represents a ______.
chronosequence
The Piedmont Plateau of eastern North America has many areas of ______ succession.
deciduous forest undergoing secondary
When fields were abandoned in Piedmont Plateau of eastern North America, one of the first colonizing species was ______.
crabgrass (Digitaria sanguinalis)
Pioneer communities recently established from the retreat of glaciers are typically dominated by
Epilobium, Equisetum, and Salix.
Similar to Glacier Bay, during succession, the species richness of woody plants in the Piedmont Plateau ______.
increases in a logarithmic pattern
During the later stages of primary succession, ______.
species diversity begins to plateau or decline
Similar to forests, species richness in the intertidal zone ______.
increased following a logarithmic pattern
Studies showed the rate of succession was the fastest ______.
in a desert stream
Many areas of the Piedmont Plateau in eastern North America were ______
clearcut and later abandoned. They are now undergoing secondary succession.
Sycamore Creek in Arizona generally has low flows; however, flash floods ______.
remove organisms from the creek
are a source of disturbance
can initiate succession
After about 150 years of secondary succession in the Piedmont Plateau of eastern North America, which types of plants become dominant?
oaks and hickory
Nearly 2 months after intense flooding occurred in Sycamore Creek (Arizona), the diversity of diatoms and algae ______.
began to decline
The increase in species richness in Glacier Bay and the Piedmont Plateau can be described as ______.
logarithmic
During succession, ecosystem properties ______.
change along with the changes in diversity and composition of species
Sousa showed that succession on intertidal boulders was ______.
similar to forest succession; species richness increased with time
Studies by Chapin et al. 1994 at Glacier Bay indicate that
all the major soil horizons increase over time.
The difference in the time of succession between the intertidal zone and primary succession in Glacier Bay as describe by Sousa is about _____.
1,000 years
In Sycamore creek, succession ______.
begins after frequent floods disturb the community
After intense flooding in a stream, what are the first organisms to colonize the streambed?dia
diatoms
In the Hawaiian Islands, Hedin, Vitousek, and Matson used a chronosequence to show that soil organic matter ______.
increased in the soil for the first 150,000 years
During primary and secondary succession, ecosystem properties that can change include ______.
nutrient retention
primary production
biomass
Based on the study of Hedin et al., as the Hawaiian Islands age, total nitrogen ______.
is lower at sites that are 1.1 million and 1.4 million years old compared to sites that are 150,000 years old
During primary succession at Glacier Bay, Chapin et al. 1994 has shown that total soil depth
increases over time.
Weatherable phosphorous, in the Hawaiian Islands, is ______.
typically depleted in about 20,000 years
In the Hawaiian Islands, nutrient availability changes over time when ______.
more phosphorous is retained in the ecosystems
phosphorous becomes the limiting nutrient
After flooding occurred in Sycamore Creek, AZ, Fisher’s group found that ______.
invertebrates and algal biomass increased rapidly for at least the first 2 weeks
Early studies of the soils in the Hawaiian Islands indicate that ______.
primary production is initially limited by nitrogen
During succession in Sycamore Creek, AZ, nitrogen ______.
retention increased rapidly and eventually leveled off after about 28 days
On the Hawaiian Islands, soil nitrogen ______.
varies almost precisely with total organic matter
In the Hawaiian Islands, primary production in older soils is limited by ______.
phosphorous availability
In 1916, Clements proposed ______ as the major mechanism of succession in ecological communities.
facilitation
Which of the following best describes the change in rates of nutrient loss in the Hawaiian islands over 4 million years based on the work by Hedin et al.?
Rates of nitrogen loss progressively increase, while rates of phosphorous loss decrease.
During the early states of succession in streams, ______.
algal biomass increases rapidly
During the early stages of succession, pioneer species ______.
colonize new habitat and modify it so that it facilitates the establishment of later succession species
According to Grimm (1987), during the early stages of stream succession in Sycamore Creek, dissolved inorganic nitrogen ______.
entered and left the stream in roughly equal amounts
A model of succession that proposes that any species, including dominant species in later succession, can colonize at any time without affecting future colonization, is known as the ______ model.
tolerance
The ______ model makes the assumption that even late successional species can colonize an area early in succession.
inhibition
Connel and Slatyer (1977) proposed three models of succession that include ______.
tolerance
inhibition
facilitation
In Sousa’s experiments in the rocky intertidal zone, he removed middle successional species from rocks and found that ______.
late successional species recolonized the rocks
The inhibition model predicts that ______ susceptible to various sources of mortality.
early successional species are more
A model of succession that proposes pioneer species are able to colonize new habitat first is called the ______ model.
facilitation
Open space in the rocky intertidal zone along the Oregon coast is created by ______.
winter storms that generate high waves
Based on Connell and Slatyer’s tolerance model of succession, ______.
pioneering species do not facilitate colonization
later successional species are more tolerant of the conditions found in later successional stages
In the rocky intertidal zone along the Oregon coast, the establishment of Phyllospadix is dependent on ______.
the presence of middle successional algae
The inhibition model predicts that ______.
early colonists prevent the colonization of later arrivals
In 1979, Sousa removed middle successional species from experimental plots which were then colonized by late successional species. This result supported the _____ model for succession.
inhibition
Keever (1950) showed that succession in the Piedmont depends on ______.
the facilitation and inhibition model
If early successional species are susceptible to various sources of mortality, it would support the ______ model.
inhibition
In the spruce stage, growth rates and survivorship are low due to ______.
inhibition
Open space in the intertidal zone along the Oregon coast is often colonized first by ______.
Ulva in May
Some communities are stable because they ______.
lack disturbance
are resistant to change
are resilient
Turner (1983) found that Phyllospadix seeds were all attached to middle successional algae. This observation supports the _____ model.
facilitation
The lack of change in a community is known as ______.
stability
After surviving a hurricane, a mangrove forest maintains its basic structure and functioning. This community is ______.
resistant
In the Piedmont Plateau of the eastern United States, Keever’s 1950 experiment demonstrated that ______.
Aster is important for the growth of Andropogon
the growth of Aster is inhibited by Erigeron
Some forests have frequent fires every 3–5 years that remove much of the ground cover. However, most species return to their previous abundances, restoring diversity and ecosystem functioning within a year. This is an example of ______.
resilience
During primary succession, the alder stage facilitates spruce seedlings by ______.
increasing organic matter in the soil
If a community lacks disturbance or can recover from a disturbance, then it may be ______.
stable
The community in the Park Grass experiment has remained stable for over 150 years. This indicates that ______.
the species composition has remained relatively unchanged
A community that remains the same over time is termed
stable
Based on results of the Park Grass Experiment, grasses were most dominant when ______ added to the plots.
no fertilizers were
If a community maintains its structure and function when facing disturbance, then it is ______.
resistant
If a community is affected by a disturbance, but returns to its original state, then this community is ______.
resilient
In the Park Grass Experiment, the proportion of plants, including grasses and legumes, vary from year to year based mainly on ______.
annual variations in precipitation
For nearly 150 years, there have been no new colonizations in the Park Grass Experiment. This provides support that this community is ______ on at least one dimension.
stable
When analyzing the Park Grass Experiment at the individual species level, the community appeared to be ______.
unstable
The Park Grass Experiment demonstrated that fertilizing with nitrogen, phosphorous, potassium, sodium, and magnesium ______.
increased the proportions of plants other than grasses
reduced the dominance of grasses
When a piezometer measures a positive vertical gradient, this would indicate ______.
water flow from the streambed to the stream
Although there is annual variation in the proportion of grasses, legumes, and other plants in the Park Grass experiment due to changes in precipitation, the proportions of the three groups ______.
were very similar over the course of the study
In Sycamore Creek, Arizona, algal production is often higher in regions ______.
with positive vertical pressure
upwelling
Sycamore Creek in Arizona was found to be more stable in areas with ______.
positive vertical hydraulic gradients
How we determine community stability is a function of the ______.
spatial scales involved
level of resolution when a community is analyzed
time scales involved
Valett’s team found that Sycamore Creek was stable after intense flooding because ______.
the spatial arrangement of downwelling and upwelling areas remained constant
When a piezometer measures a negative vertical gradient, this would indicate a(n) ______.
downwelling zone
Regions in Sycamore Creek, Arizona, with higher nitrate concentrations are associated with ______.
upwellings and have higher algal production
Stability in Sycamore Creek, Arizona, is due in part to the ______.
stability of the underlying bedrock
Based on Valett’s (1994) work on Sycamore Creek, Arizona, algal communities in upwelling zones were found to be more ______.
resilient to disturbance
Restoration ecology seeks to restore damaged ecosystems to acceptable levels of ______.
biodiversity
physical structure
ecosystem function
Match a factor that affects the time and course of succession with the correct description of that factor’s influence on succession.
Physical and chemical stressors = Potentially reduce plant establishment
Plant establishment = Limited by the availability of suitable “safe” sites
Interspecific plant interactions = may inhibit or facilitate establishment and growth
Plant dispersal rates = can limit site colonization by poor dispersers
Intense flooding in Sycamore Creek, Arizona, ______.
had no effect on the locations of upwelling and downwelling allowing for community stability
In order to limit the drying of soils in restoration plots of tropical forests, it is best to add ______ to the soil surface.
forest floor litter
Reason: The forest floor litter limits evaporation rates and eventually adds organic matter to the developing soil.
In Sycamore Creek, Arizona, regions of upwelling and thus community stability are associated with ______.
areas where the bedrock is close to the surface
______ ecology focuses on ways to improve the effectiveness of ecological restoration.
Restoration
Total soil carbon increases faster in restored forest roads if they are ______.
recontoured first
By protecting vulnerable plants until they are well established during restoration what factor of restoration would be most affected?
herbivory
Identify effective methods that should be used when restoring tropical forests.
Add forest floor litter.
Encourage many bird-dispersed seeds.
Add nitrogen-fixing plants
How does the recovery of former logging roads differ if the roads are recontoured rather than just being abandoned?
Recontoured roads recover faster.
