Ch 5: Biomes - Global Patterns of Life

ENVR-1401

How will the changing climate affect the regeneration of young trees in deciduous northeastern forests?

Nutrient availability will decrease.

Reason: Accelerated decomposition due to shorter winters will reduce nutrient availability for young seedlings, hindering regeneration.

An ecological community with distinct temperature and precipitation patterns is called a(n)

Biome

What two characteristics are the most important in determining the distribution of a biome?

Temperature and precipitation

Common attributes of tropical moist forests include ample _____ and uniform ______.

rainfall; temperatures

A graph that displays the plot of precipitation and temperature variation over a year for a given location is called a ______.

climograph

What characteristic of deciduous northeastern forests is most impacted by shorter and unpredictable winters?

Which of the following is the best definition for the term biome?

Environments that have similar climate, growth patterns, and vegetation

Biomes are differentiated by temperature and precipitation. Which of the following answers correctly ranks the biomes from high to low precipitation and high to low temperature?

Tropical rainforest, boreal forest, tundra

Which of the following is not a characteristic of a tropical seasonal forest?

Dry year-round

Tropical moist forests all have abundant moisture and uniform

temperatures

What information is displayed on a climograph for a given location?

The long-term average of the temperature and precipitation for each month

What is the difference between grasslands and savannas?

Savannas have a sparse tree cover in addition to the grass-covered areas.

Deserts occur where ______.

precipitation is rare and unpredictable with usually less than 30 cm of rain per year

The controlling factor in determining where grasslands will occur as a terrestrial biome is the ______.

Amount of rain the region receives

Reason: A desert gets less rainfall than a grassland, and a forest gets more rainfall than a grassland.

A community with drought-tolerant forest species, hot temperatures year-round, and low precipitation for most of the year except for periodic rain to support tree growth describes the ______ biome.

tropical seasonal forest

Which of the following characteristics produce a temperate shrubland?

☐ Cool, moist winters

☐ Hot season coincides with a dry season

Deciduous trees

Trees that lose their leaves seasonally

Coniferous trees

Trees that are cone-bearing

A grassland receives too little rain to support a forest. If the grassland starts to get enough rain to support a sparse tree cover, the grassland may transition into a ______ over time.

savanna

The biome that is defined by unpredictable and low (under 30 cm per year) precipitation rates is the _____ biome.

desert

Coniferous forests…

☐ They support forestry in many areas

☐ Moisture can be scarce due to cold temperatures or seasonal drought.

☐ The soils are sandy.

Under which conditions do temperate grasslands exist?

Where there is enough rain to support abundant grass but not enough for forests

Reason: Temperate grasslands occur in regions where the rainfall supports the growth of grasses but is insufficient for the development of forests.

The giant California redwoods occur in locations that receive abundant rainfall and have mild temperatures year-round. These locations are ______.

temperate rainforests

An area known for hot, dry summers and cool, moist winters would most likely be a ______ biome.

temperate shrubland

Deciduous temperate forests tend to occupy climates that are ______ than climates where there are coniferous temperature forests.

moister and more moderate in temperature

Trees in temperate forests have thin, waxy leaves that help reduce moisture loss, as this biome commonly is located in areas with limited moisture.

coniferous

What characteristics are associated with temperate rainforests?

☐ They receive abundant rain.

☐ Foggy conditions are common.

In Russia, a boreal forest often mixes with open tundra to create what is known as the ______.

taiga

The best definition for the term tundra.

A treeless landscape occurring at high latitudes

What organisms form the base of the marine ecosystem?

Phytoplankton

Reason: Phytoplankton are free-floating algae and photosynthetic organisms which obtain energy from sunlight.

Select the characteristics that contribute to vertical stratification in aquatic ecosystems.

☐ Light decreases with depth.

☐ Temperature decreases with depth.

The tundra has a growing season of only ______ months and can experience ______ at any time of the year.

two to three; frost

Why are phytoplankton a key part of the marine ecosystem?

They form the base of the marine food web.

How is marine productivity best described in the open ocean?

It can be described as a biological desert because of the low productivity.

How do excess nutrients in coastal areas contribute to the creation of dead zones?

They stimulate bacterial growth that consumes almost all oxygen in the water.

Vertical stratification occurs in aquatic ecosystems due to decreasing _____ and _____ with depth.

sunlight; temperature

Which of the following organisms have a symbiotic relationship and work together to form living reefs?

Colonial animals (coral polyps) and photosynthetic algae

Reason: The symbiotic relationship involves the algae absorbing some of the waste carbon dioxide and the corals protecting the algae with their hard structures.

What is the greatest threat to coral reefs?

Climate warming, which causes coral bleaching

Coral bleaching occurs when ______.

Elevated water temperatures cause corals to expel their symbiotic algal partners

Reason: Elevated water temperatures and other forms of environmental stress can cause corals to expel their symbiotic algal partners.

Because of the lack of nutrients, biological productivity is often low in ______.

The open ocean

Reason: The open ocean is often compared to a desert because of the low levels of biological productivity.

Locations in the ocean where excess nutrients support rapid bacterial growth and a resulting removal of dissolved oxygen from the waters are called ______ zones.

dead

Coral reefs are formed by plants.

False

Reason: Coral reefs are formed by colonial animals (coral polyps) and photosynthetic algae (not plants).

Which of the following are threats to the rich, diverse communities found in coral reef biomes?

☐ Excess nutrient runoff from land

☐ Destructive fishing methods

☐ Introduced pathogens and predators

☐ Trash and sewage

When corals are stressed by increasing ocean water temperatures, they often expel their algal symbionts. This process is called coral ______.

bleaching

Reason: Without algae in their structure, corals appear whiter because they are composed of calcium carbonate. The loss of the algae can result in the death of the coral.

Which of the following are true with regards to mangroves?

☐ They help stabilize shorelines

Reason: Mangrove roots anchor sediment

☐ They grow in salt water

Reason: Mangroves are found on ocean coasts

☐ Their forests serve as critical nursery grounds for many crustaceans and fish

Loss of natural nursery grounds for fish and shrimp

Ecosystem threat

Clear-cutting of mangrove forests for fish farms

Aquaculture threat

Removal for timber

Commercial threat

What are tide pools?

Depressions in rocky shorelines that are flooded with water at high tide and retain some of the water at low tide

The low, narrow, sandy islands that form parallel to a coastline and that are supplied by a steady source of sediment from the nearby continental shelf and river outlets are called _____ _____.

barrier islands

Select the human activities that destroy barrier islands.

☐ Walking on dune grass
☐ Creating roads that cut through dunes

Why are mangroves considered critical nurseries for marine species?

They provide a habitat for young fish and shrimp.

Identify reasons that correctly explain why tropical coastal mangroves have been cleared.

☐ They have been cleared to make room for shrimp and fish ponds.
☐ They have been cut down for firewood.

Characteristics of tide pools

☐ They experience extreme conditions as they are flooded with cold ocean water at high tide and hit with desiccating sunshine at low tide.
☐ They occur in rocky shorelines

What are barrier islands? They are ______.

low, narrow, sandy islands that form parallel to a coastline

Why are freshwater ecosystems biologically important?

☐ Most terrestrial species rely on them for survival.
☐ They support high levels of biodiversity.

What happens when people walk or drive vehicles over dune grass on barrier islands?

It destroys the stabilizing vegetative cover and accelerates erosion.

Bacteria that live in anoxic or low-oxygen conditions in marine sediments are ______ bacteria.

anaerobic

Reason: Anaerobic means without oxygen.

Vegetated land surfaces which are saturated or submerged in water for at least part of the year are called ______.

wetlands

What makes temperate forests particularly vulnerable?

They are highly habitable for humans

Which of the following best describes the role of wetlands in supporting biodiversity?

Wetlands support many species that can live nowhere else, including amphibians, fish, aquatic plants, and many insects and birds.

Reason: Wetlands are crucial for biodiversity as they provide a unique habitat for species that cannot survive in other environments.

Why have most of the world's great grasslands been converted to farmland?

due to their level ground and rich soils

What characteristic defines anaerobic bacteria?

They do not use oxygen (O2).

Having been filled, drained, converted to farmland, or lost due to coastal erosion, the loss of _____ worldwide has been extensive.

wetlands

How can the presence of water in wetlands best be described?

The land surface is saturated or submerged for at least part of the year.

Reason: Wetlands are characterized by having the land surface either saturated or submerged with water for at least part of the year.

Grasslands…

are high productivity

Temperate forests…

are highly habitable

Temperate shrublands…

are rare

What is the leading factor responsible for land conversion in temperate biomes?

agriculture

Migratory birds have suffered due to the loss of _____ across the world because they have been drained and filled in for other land uses. The area covered by these ecosystems is half what it was 100 years ago in the U.S.

wetlands

What is the main reason grasslands are one of the most disturbed biomes?

Grasslands tend to make good farmland