Ecology Ch. 20

Ecological succession would occur after the: formation new rocks from volcanism; removal trees after a major avalanche; retreat of a glacier leaving bare ground

The inhibition model predicts that early colonists prevent the colonization of later arrivals

A community that remains the same over time is termed stable

During succession, ecosystem properties change along with the changes in diversity and composition of species

Connel and Slatyer (1977) proposed three models of succession that include inhibition; tolerance; facilitation

When analyzing the Park Grass Experiment at the species level, the community appeared to be: unstable

In the Hawaiian Islands, nutrient availability changes over time by more phosphorous is retained in the ecosystems; phosphorus becoming the limiting nutrient

During the later stages of primary succession the rate of increase for species diversity begins to plateau

Some communities are stable because they are resilient; lack disturbance; are resistant to change

During primary succession at Glacier Bay, Chapin et al. 1994 has shown that total soil depth increases over time

During community succession, which of the following changes are likely to occur? Changes in the composition of species; increases in species richness

As the community at Glacier Bay goes from a pioneer community to the spruce stage, organic content of the soil increased; moisture content increased

Liken’s group in 1969 observed that nitrogen loss during succession returned to predisturbance levels in less than 5 years

During the early stages of succession, pioneer species colonize new habitat and modify it so that it facilitates the establishment of later succession

If early successional species are susceptible to various sources of mortality, it would support the: inhibition model

Based on Connell and Slatyer’s tolerance model of succession, later successional species are more tolerant of the conditions found in later successional stages; pioneering species do not facilitate colonization

An older community that appears to remain stable in the absence of disturbance is called a: climax community

In the Piedmont Plateau of the eastern US, Keever’s 1950 experiment demonstrated that Aster is important for the growth of Andropogon; the growth of Aster is inhibited by Erigeron

Early studies of the soils in the Hawaiin Islands indicate that primary production is initially limited by nitrogen

In the Hawaiian Islands, Hedin, Vitousek, and Matson used a chronosequence to show that organic matter increased in the soil for the first 150,000 years

After surviving a hurricane, a mangrove forest maintains its basic structure and functioning. This community would be considered: resistant

During the steady state phase of ecosystem recovery, biomass will fluctuate around a mean level

During primary and secondary succession, ecosystem properties that can change include: biomass; nutrient retention; primary production

After nearly two months, the diversity of diatoms and algae began to decline

Similar to forests, species richness in the intertidal zone increased following a logarithmic pattern

The rate of succession can be fastest on rocks in the marine intertidal zone

After about 150 years of secondary succession in the piedmont, which types of plants become dominant? Oaks and hickory

During primary succession, the alder stage facilitates spruce seedlings by increasing organic matter in the soil

Valett’s team found that Sycamore Creek was stable after intense flooding because the spatial arrangement of downwelling and upwelling areas remained constant

Succession taking place on a newly formed volcanic island would be known as: primary succession

How we determine community stability is a function of the: level of resolution when a community is analyzed; time scales involved; spatial scales involved

Stability in Sycamore Creek, Arizona, is due in part to the stability of the underlying bedrock

If a community is affected by a disturbance, but returns to its original state, then this community would be considered resilient

Based on Valett’s (1994) work on Sycamore Creek, Arizona, upwelling zones were found to be more resilient to disturbance

Regions in Sycamore Creek, Arizona, with higher nitrate concentrations are associated with upwellings and have higher algal production

The Park Grass Experiment demonstrated that fertilizing with nitrogen, phosphorus, potassium, sodium, and magnesium increased the proportions of other plants; reduced the dominance of grasses

When fields are abandoned, one of the first colonizing species is: crabgrass

Sycamore creek generally has low flows; however, flash floods are a source of disturbance; can initiate succession; remove organisms from the creek

After intense flooding in a stream, what are the first organism to colonize the streambed? Diatoms

Souse showed that succession on intertidal boulders was similar to forest succession, species richness increased with time

Calcium and potassium losses in a recovering ecosystem can remain elevated even after 7 years of succession

Intense flooding in Sycamore Creek, Arizona, had no effect on the locations of upwelling and downwelling reaches

A model of succession that proposes pioneer species are able to colonize new habitat first is called the: facilitation model

In Sycamore Creek, Arizona, algal production is often higher in regions with positive vertical pressure

When succession takes place on newly exposed geological features, it is known as: primary succession

Turner (1983) found that Phyllospadix seeds were all attached to middle successional algae. This observation supports the: facilitation model

Many areas of the Piedmont in eastern North America were clearcut and later abandoned

Open space in the rocky intertidal zone is created by winter storms that generate high waves

Similar to Glacier Bay, during succession, the species richness of woody plants in the Piedmont Plateau increases in a logarithmic pattern

Based on the study of Hedin et al., as the Hawaiian Islands age, total nitrogen is lower at sites that are 1.1 and 1.4 million years old compared to sites that are 150,000 years old

The types of birds typically found in the first two years of secondary succession are typically associated with grasslands

In 1979, Sousa removed middle successional species from experimental plots which were then colonized by late successional species. This result supported the inhibition model for succession

Although there is annual variation in the proportion of grasses, legumes and other plants in the Park Grass experiment, the proportions of the three groups were very similar over the course of the study

During the early states of succession in streams, algal biomass increases rapidly

The community in the Park Grass experiment has remained stable for over 150 years. This indicates that the species composition has remained relatively unchanged

Requirements to study community stability include: long time scales

When disturbance severely disrupts a community, the succession that takes place is known as: secondary succession

Pioneer communities recently established from the retreat of glaciers are typically dominated by Epilobium, Equisetum, and Salix

In a community undergoing primary succession, which group of plants took about a century before species richness began to plateau? Mosses and liverworts

The study sites at Glacier Bay, Alaska, include a set similar forest, but at different ages. This represents a chronosequence

A pioneering plant would be a plant that is the first to colonize newly created habitat

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

In the Hawaiian Islands, primary production in older soils is limited by: phosphorus availability

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

Which group of plants continued to increase in diversity throughout primary succession? Low shrubs and herbs

The piedmont of eastern North America has many areas of deciduous forest undergoing secondary succession

Based on Johnston and Odum (1956), the changes in avian diversity closely resemble the increase in woody plant diversity

A major spring flood in a river removed all of the vegetation along the stream bank. The subsequent return if the community is known as: secondary succession

During succession in Sycamore Creek, AZ, nitrogen retention increased rapidly and eventually leveled off after about 28 days

The first plants to grow in an area where new substrate has been created would form a: pioneer community

The increase in species richness in Glacier Bay and the Piedmont Plateau can be described as: logarithmic

Turner (1983) found that Phyllospadix seeds were all attached to middle successional algae. This observation supports the: facilitation model

Open space in the intertidal zone is often colonized first by Ulva in May

One major problem that faced ecologists trying to study community stability is that: long time scales are required

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

In the rocky intertidal zone, the establishment of Phyllospadix is dependent on the presence of middle successional of middle successional algae

When a piezometer measures a positive vertical gradient, this would indicate water flow from the streambed to the stream

Many of the insects that live in Sycamore creek are terrestrial as adults

When a piezometer measures a negative vertical gradient, this would indicate a downwelling zone

After a flood in Sycamore Creek, how did aquatic insects recolonize the stream? Many of the adults are terrestrial, and laid eggs in the stream after the flood