Ch. 58.1-58.2

In Community A, species number is 89 and Hs is 1.93. In Community B, species number is 78 and Hs is 2.42. Which of the following statements regarding these communities is true? Choose all that apply.

1. Diversity is higher in community B 2. Species richness is higher in community A

Which factors would you expect to contribute to species richness according to the species-productivity hypothesis?

1. High rainfall 2. High evaporation rate 3. Warm temperatures 4. Large amounts of plant matter produced

A community that is in equilibrium can be characterized by which of the following?

1. It has stable species-richness. 2. It has stable species diversity.

Select the three main hypotheses that account for species richness differences.

1. Species-area hypothesis 2. Species-time hypothesis 3. Species-productivity hypothesis

Which of the following are advantages of using a species diversity index when analyzing a community?

1. The total number of species present is taken into account. 2. The relative abundance of each species is taken into account.

American ecologist Donald Strong's experiment showed that trees found over a large region support more insect species than trees found in a smaller region, even in relatively new tree species such as apple and lime trees. This experiment

1. supports the species-area hypothesis. 2. does not support the species-time hypothesis.

Values of the Shannon diversity index for real communities typically fall between:

1.5 and 3.5

Which of the following describes a community?

A group of organisms of different species occupying the same area at the same time.

The two main obstacles for identifying microbial species are that they are very ___ and researchers have been unable to devise methods for ___ most of them in the laboratory.

Blank One: small, minute, or microscopic Blank Two: growing or culturing

In community A there are three species of butterflies, with the same number of individuals from each species. In community B there are also three species of butterflies, but two species are very rare, with only a very few individuals. The total number of butterflies in the two communities is the same. Which community has higher species diversity?

Community A has higher species diversity.

Consider two hypothetical communities, J and R, both with two species and 90 total individuals. Community J has 2 individuals of the first species and 88 individuals of the second species, while community R has 45 individuals of each species. What, if anything, can be concluded from this data?

Community R is considered more diverse that J

An ecologist is investigating species diversity in two communities. Community T has 172 species and an Hs value of 2.67, while community Z contains 164 species and has an Hs value of 2.83. What can be concluded from this data?

Community T has the highest species richness, while community Z has the highest species diversity

Which of the following statements is correct regarding species diversity?

Community measure that incorporates both species number and relative abundance

What type of ecology is concerned with the movement of energy and materials through organisms and their communities?

Ecosystem

Which of the following would be addressed by ecologists who are studying a particular community? Choose all that apply.

Factors that influence species number Factors that influence species abundance

True or false: Introduced pigs have caused severe disturbance in species-rich North-American forests, as predicted by the the diversity-stability hypothesis.

False

According to the species-productivity hypothesis, in which area would you be most likely to have high degrees of species richness?

In warm and wet areas with high evapotranspiration rate

_______ levels of community stability is usually interpreted by ecologist as a sign of a problem in the community

Low

The ___, ___, and ___ is the most frequently used calculation of species diversity in a community.

Shannon diversity index

The most widely used calculation of species diversity in a community is the:

Shannon diversity index

______ is a count of the number of species present in a community; ______ also takes into account the relative abundance of the different species present in the community.

Species richness; species diversity

This hypothesis predicts that larger regions will have larger populations and a greater range of habitat to support species richness.

Species-area hypothesis

What is ecosystem ecology?

The flow of energy and abiotic materials through biotic components of a community.

Which of the following statements is true about the Shannon diversity index?

The higher the value, the greater the diversity of species in the community

What is biomass?

The total weight of living matter in a given area

In general, which of these main climate zones have the highest species richness?

Tropical regions

When rabbits were introduced into Australia, which has a great diversity of species, they caused major disturbance. This is evidence ______ the diversity-stability hypothesis.

against

The species-___ hypothesis predicts that larger regions will contain more species than smaller regions.

area

The total mass of living matter in a given area is called

biomass

In Tilman's study of grassland stability he found that:

communities with higher diversity produced a less variable amount of biomass from year to year

A(n) ___ is an assemblage of many different species living in the same place at the same time.

community

The study of factors that influence the number and abundance of species in a community is called ___ ecology.

community

Species richness generally increase with

decreasing latitude, from polar regions to tropical regions.

According to the ___-___ hypothesis, high diversity communities are more resistant to disturbance than low diversity communities.

diversity-stability

A community that has little or no change in its number of species and their abundance over a period of time is said to be in

equilibrium.

The rate at which water moves into the atmosphere through evaporation from soil and transpiration from plants is called the:

evapotranspiration rate

True or False: When using species diversity to compare two forests, an ecologist cannot distinguish between a forest that includes rare species in low abundance, versus a forest that includes rare species in high abundance.

false

The species-area hypothesis for species richness predicts that smaller areas will contain _______ species and that a larger area will generally contain _______ species.

fewer; more

The diversity-stability hypothesis proposes that:

high diversity communities are more resistant to disturbance than low diversity communities

The experimental data of Latham and Ricklefs' studies showed that the species-productivity hypothesis:

is supported by patterns of tree richness in North America but can not be applied for broad comparisons between continents

In general, the effect of a disturbance on a community is expected to be

less drastic in a species-rich community than a species-poor community.

This graph illustrates that variation in plant community biomass is: (Coefficient of variation for plant community biomass (y) and average plant species richness (x)).

lower in plots with greater plant species richness

A likely explanation of Tilman's findings of stability and diversity relationship in grasslands is that:

more diverse communities are more likely to contain disturbance resistant species

Species-rich communities are generally considered to be _______ communities with low species richness.

more stable than

Areas with more mountains generally have:

more variable habitats and higher species richness

An important reason why many new introduced species cause so much disturbance in communities is that:

natural prey-predator balances doesn't exist

The species richness of a community refers to the:

number of different species

Invasive species often thrive in new environments because they have no natural

predators or enemies

Community stability is an important consideration to ecologists. A decrease in the stability of a community over time is a sign of:

problems in the community

According to the species-___ hypothesis, species richness can be predicted by the total amount of plant material produced over time.

productivity

Research by Latham and Ricklefs showed that patterns of tree richness in North America support the species-___ hypothesis; however, the pattern does not hold for broad comparisons between continents.

productivity

The number of species present in the community is designated by the term species ___. In contrast, the term species ___ refers to both the number of species and their relative abundance.

richness, diversity

The species richness of microbial samples can be analyzed using DNA ____ methods.

sequencing

Species richness will be lower in a ______ area than in a _____ area according to the species-area hypothesis.

smaller; larger

___ ___ can be considered the community measure that incorporates both species number and relative

species diversity

Community ecologists address factors that influence:

species number and abundance

The number of different species in a community is known as its

species richness

The ______ effect predicts a positive correlation between the size of an area and the species richness within it.

species-area

The observation that the number of species tends to increase with increasing area is called the ___-___ effect.

species-area

Community ecology is the

study of factors that influence the number and abundance of species in a community.

The species-productivity hypothesis predicts that species richness will be higher in areas with:

the greatest production by plant material

The three main hypothesis for explaining differences between species richness in different geographical areas are the species-___ hypothesis, the species-___ hypothesis, and the species-___ hypothesis.

time, area, productivity

Plant productivity refers to the

total weight of plant material produced over time.

Strong's studies of species richness in insects in trees in Great Britain supports the species-area hypothesis because it showed that:

trees found over large areas support more insect species than trees found in smaller areas

The most plausible hypothesis to explain why species richness is generally higher in mountain regions is that mountains generally have:

variable habitats

American ecologist David Tilman conducted an 11-year study of grassland plots in Minnesota. This study revealed that:

variation in community biomass decreases with increasing species-richness