Chapter 26: Large-scale Patterns of Biological Diversity

Question 1

Refers to the variety and variability of life on Earth;

Defined in terms of the variability within species, between species, and between ecosystems

Answer 1

biological diversity

Question 2

Describe:

diversity over geological time

Answer 2

Over geologic time, there have been dramatic long-term evolutionary changes in patterns of global diversity, largely as a result of speciation and global extinction;

The fossil record suggests a pattern of increasing diversity over the past 600 million years

Question 3

Describe:

mass extinction

Answer 3

2 notable periods of mass extinction:

• The end of the Permian, when more than 90% of marine invertebrates disappeared from the fossil record
• The Cretaceous period, which saw the extinction of dinosaurs

Question 4

Describe:

latitudinal patterns of diversity

Answer 4

In general, species richness decreases from the equator toward the poles for both aquatic and terrestrial organisms;

Deviations from the general latitudinal gradient of species richness are also observed for certain taxonomic groups, particularly for groups that are associated with species environments or resources

Question 5

Describe:

spatial extent and diversity

Answer 5

In general, species richness increases with increasing area

Question 6

Number of species in a given area

Answer 6

species richness

Question 7

Describe:

environmental energy and diversity

Answer 7

For terrestrial vertebrates (mammals, reptiles, birds, amphibians), regionally:
- Species richness correlated with potential evapotranspiration (PET)

For plant species, regionally:
- Species richness correlated with actual evapotranspiration (AET)

For marine environments:
- Geographic patterns of species diversity correlated with mean sea surface temperatures

Question 8

The amount of evaporation that would occur if a sufficient water source were available;

An index of integrated thermal energy input to the ecosystem

Answer 8

Potential evapotranspiration (PET)

Question 9

The flux of water from the terrestrial surface to the atmosphere through both evaporation and transpiration;

A function of both the atmospheric demand for water brought about by the input of solar energy to the surface (PET) and the supply of water from precipitation;

As such, it includes the constraints imposed by the availability of soil water on transpiration

Answer 9

Actual evapotranspiration (AET)

Question 10

Describe:

ecosystem productivity and diversity (for terrestrial environments)

Answer 10

Geographic patterns of both terrestrial plants and animals are positively related to net primary productivity;

Like patterns of species richness, terrestrial NPP decreases with increasing latitude

Question 11

Describe:

ecosystem productivity and diversity (for marine environments)

Answer 11

The general pattern for marine environments appears opposite that observed for terrestrial environments;

Patterns of species diversity for marine organisms are inversely related to ocean primary productivity

Question 12

Describe:

latitudinal patterns of diversity and ecosystem productivity

Answer 12

Latitudinal patterns of diversity appear to be influenced by the seasonality of primary productivity rather than by total productivity per se

Question 13

The variety of organisms occurring in a given place or habitat

Answer 13

alpha diversity

Question 14

Diversity (differences in species composition) among communities in a geographic area

Answer 14

beta diversity

Question 15

Differences among similar habitats in widely separated regions

Answer 15

gamma diversity

Question 16

Restricted to a given region

Answer 16

endemic

Question 17

Region of unusually high species diversity

Answer 17

hotspot