Chapter 7: Terrestrial Ecosystems

Question 1

Characterize the climate of regions containing Arctic and Alpine tundra.

Answer 1

low temperatures, low precipitation and a short growing season

Question 2

What is cryoplanation and how is it important to the development of tundra landforms?

Answer 2

• frost action
• alternate freezing and thawing of surface layers creates unique land forms, this is more important than erosion in wearing down the arctic landscape

Question 3

What is permafrost and how does it affect life in the arctic tundra?

Answer 3

• permanently frozen layer of ground

- it is an impenetrable barrier to drainage and plant roots, making all water move above it and hard for plants to grow

Question 4

What are solufluction terraces and how do they form?

Answer 4

• supersaturated soils that creep down hillsides
• formed when surface layers meet and cover the landscape with shallow ponds because all the water sits on top of the permafrost layer

Question 5

Why is the Arctic tundra a fragile biome that is slow to heal from human caused damage?

Answer 5

because any slight damage from humans can cause the permafrost to melt and because of the slow rate of plant growth and decomposition, it is very slow to heal

Question 6

Lost some of the herbivores and carnivores found in the arctic tundra biome

Answer 6

Herbivores: muskox, carribou, Arctic hares, lemmings
Carnivores: snowy owls and Arctic foxes

Question 7

List three ways in which alpine tundra differs from Arctic tundra.

Answer 7

• permafrost layer rarely develops in Alpine tundra regions
• Alpine plants require shorter periods of daylight
• Alpine plants propagate themselves by seed rather than vegetatively

Question 8

List some of the mammals found in Alpine tundra areas of the western US.

Answer 8

marmots, pikas, mountain goats, big horn sheep, elk

Question 9

Characterize the Krummholz and where it is found.

Answer 9

• it is the edge of the tree line that has stunted and gnarled trees that form dense thickets that are impossible to walk through
• it is found south of the Arctic tundra and below the alpine tundra (transition zone between forest and tundra)

Question 10

What is muskeg and where is it found?

Answer 10

• grassy flooded bogs

- found in coniferous forests

Question 11

Characterize the plants of the boreal forest.

Answer 11

lots of coniferous trees (spruce, pine, fir, larch, hemlock) with heavy bark and needle-like leaves, so they can withstand severe winters and drought, and moss with an understory of low shrub

Question 12

List some of the mammals found in the boreal forest.

Answer 12

elk, moose, wolverine, timberwolf and lynx

Question 13

what kind of trees dominate the higher and lower elevations of the montane coniferous forests of Canada and the US?

Answer 13

higher: spruces and firs
lower: ponderosa pines

Question 14

What is the temperate rain forest and where is it found in North America?

Answer 14

• includes the world’s largest trees (sitka spruce, western hemlock and redwoods)
• along the Pacific coast from Alaska to California

Question 15

Characterize the pinon-juniper woodlands of western North America.

Answer 15

Dry climate where pinon pines and juniper grow; open growth of small trees with a well-developed understory of grass and shrubs

Question 16

Where are the southern pine forests found in the US and what are they used for?

Answer 16

• along the costal plains of the South Atlantic and Gulf states
• used for the production of lumber and paper products

Question 17

Characterize the temperate deciduous forests of the US and describe the climate conditions under which they form.

Answer 17

• second and third growth with deciduous trees

- there is fairly high rainfall throughout the year

Question 18

Give three reasons why tropical rainforests are being cleared.

Answer 18

trees cut for lumber (valuable hardwood), mining, and space to raise cattle

Question 19

Why are tropical rainforest soils so poor?

Answer 19

leaching of nutrients because of all the rainfall and decomposers break down organic matter and return it quickly to plants

Question 20

What is “slash-and-burn” agriculture and what are its consequences for tropical rainforests?

Answer 20

• trees are cut and burned to release their nutrients into the soil, then seeds are planted and crops are harvested and the land is abandoned once it becomes infertile
• the land may never recover because the sun bakes the soil like concrete

Question 21

Give three important reasons for preserving tropical rainforests.

Answer 21

• to preserve biodiversity
• it helps prevent global warming
• to preserve plants that have medicinal purposes

Question 22

Why are tropical rainforest trees so often buttressed?

Answer 22

to help support the tree in shallow poor developed soil

Question 23

What are lianas and epiphytes?

Answer 23

• climing plants (vines) that hang from trees
• climbing plants that grow on the trunks and limbs
• both found in tropical rainforests

Question 24

Where are rainforests found today?

Answer 24

Amazon basin, equatorial Africa, Indonesia, New Guinea, Central America & Australia

Question 25

Describe the environmental problems experienced by tropical dry forests and their consequences.

Answer 25

they have regressed to savannas and grasslands or have been converted to agricultural or grazing land because of human disturbance

Question 26

Give four names used to describe grassland communities around the globe.

Answer 26

Prairie: North America
Steppe: Asia
Pampas: South America
Veldt: Africa

Question 27

Characterize grassland biomes in terms of climate and where they are found.

Answer 27

found over extensive areas in the interiors of continents where moist air from the sea is blocked by mountain ranges; areas with high rates of evaporation and periodic severe droughts

Question 28

Distinguish between sod-formers and bunch grasses

Answer 28

sod-formers: grasses that develop a solid mat of grass over the ground
bunch grasses: grasses that grow in bunches with space between them occupied by other plants

Question 29

Distinguish between tallgrass and shortgrass prairie and where each is found in the US.

Answer 29

tallgrass: from forest-grassland ectone in WI, IN, IL to MN, eastern SD, KS and NE; trees and shrubs common along rolling hills which is mostly farmland now
Shortgrass: west of tallgrass; strong winds, light/frequent rainfall, high evaporation, beneath roots is a permanent dry zone

Question 30

What is the “Dust Bowl” of the 1930s and what caused it?

Answer 30

• Western prairie’s top soil being blown away in massive clouds
• caused by strong winds, drought and poor farming practices

Question 31

Characterize tropical savannas and where they are found.

Answer 31

• grasslands with varying degrees of tree and shrub cover growing in soils low in nutrients and moisture
• cover broad, semi-arid plains of Africa, South America and Australia

Question 32

List some mammals found in the African savanna.

Answer 32

Zebras, gazelles, lions

Question 33

What are shrubs and for what type of environmental conditions are they adapted?

Answer 33

• plants with woody persistent stems, no central trunk, and a max height of six meters
• adapted to surviving periodic fires and low nutrient levels in the soil

Question 34

Characterize a “Mediterranean climate” and the type of vegetation it supports.

Answer 34

• mild rainy winters and long hot dry summers

- growth of tough, small broad-leaf shrubs and trees with heavily waxed leaves that grow together

Question 35

Characterize the chaparral biome and where it is found.

Answer 35

-it is a “Mediterranean climate” in North America found covering over six million acres in Southern California

Question 36

How is fire important to this biome?

Answer 36

It clears away old growth making room for the new and recycles nutrients, some plants even require fire to germinate

Question 37

Characterize the northern desert shrub community and where it is found.

Answer 37

continental climate with hot summers and prolonged winters found in the Great Basin of North America

Question 38

Why are most deserts located under high pressure areas?

Answer 38

that is where descending air masses are heated and dried, so evaporation exceeds precipitation. Precipitation requires rising air that cools and loses its moisture

Question 39

Under what conditions do temperature inversions form?

Answer 39

the atmosphere is heated from below then winds blow cool ocean air and it becomes colder than the air above it; the warm air floats over the cold

Question 40

How do “rain shadow” deserts form?

Answer 40

on the leeward side of mountain ranges because as the wind blows up the windward side, it cools at the adiabatic lapse rate and the rain falls before it hits the leeward side

Question 41

Characterize the climate and plants of deserts.

Answer 41

• low rainfall, high evaporation, and wide daily fluctuations in temperature, when rain does fall it is too heavy to be absorbed
• succulents (cacti) with water storing tissues, woody plants that lose their leaves during the dry season

Question 42

What types of organisms form a living crust on the surface of desert soils and how are they important to the ecology of this biome?

Answer 42

lichens, green algae & cyanobacteria

-they add to the primary productivity and have high rates of nitrogen fixation

Question 43

What is desertification and what are its consequences?

Answer 43

grasslands being converted into dry wastelands due to human activities
-this increases the area where nothing grows