4. Terrestrial Biomes

Question 1

Define biome

Answer 1

Major divisions of land environment based on specific climate with common plant species. They usually evolve and boundaries can be subjective.

Question 2

Define terrestrial biome

Answer 2

Large terrestrial regions on our planet with a similar climate and vegetation.

Question 3

What distorts biome distribution away from the latitudinal arrangement of climate cells?

Answer 3

Tall mountain ranges (mountain shadows) and uneven distribution of wanted and land mass

Question 4

What are terrestrial biomes defined by?

Answer 4

•Geography (latitudes/climate cells)
•Mean annual temperature (MAT)
•Mean annual precipitation (MAP)
•Predominant vegetation (food & habitat for the rest of the ecosystem)

Question 5

What is a Walter Lieth diagram?

Answer 5

A chart displaying monthly mean average temperature and precipitation and their relative values. Provides information about a biomes seasonality, climate properties, and periods of drought

Question 6

What absolute values are in a Walter Lieth diagram?

Answer 6

•Monthly/annual mean temperatures
•Monthly/annual mean precipitation
•How much of the year is frost free
•Variability of temperature and precipitation throughout the year
•Locality’s elevation above sea level
•Sum of annual precipitation

Question 7

What relative information is in a Walter Lieth diagram?

Answer 7

•When periods of drought/excessive rain occur

Question 8

What relationship between monthly precipitation and monthly average temperature indicates a drought and lack thereof respectively?

Answer 8

Drought: temperature >2× precipitation

Lack of drought: temperature <2× precipitation

Question 9

Describe the biome characteristics of a tropical rainforest

Answer 9

•High annual & monthly mean temperatures
•High mean annual precipitation
•Low seasonality
Biomass-rich, evergreen forest vegetation.

Question 10

Describe the biome characteristics of a desert

Answer 10

•Low or high mean annual temperature
•Very low mean annual precipitation
•Strong to moderate seasonality
•Sparse, short-stature, treeless vegetation

Question 11

Describe the biome characteristics of a temperate grassland

Answer 11

•Low annual temperature
•Low annual precipitation
•Strong seasonality in temperature
•Tree-less vegetation, grasses and shrubs
•Very fertile soil (agriculture)

Question 12

Describe the biome characteristics of a temperate forest

Answer 12

•Moderate annual temperature
•High annual precipitation
•Moderate seasonality in temperature
•Forest vegetation (deciduous & broadleaf or coniferous)

Question 13

Describe the biome characteristics of a boreal forest

Answer 13

•Very low annual temperature
•Moderate annual precipitation
•Strong seasonality in temperature
•Coniferous forest vegetation
•Extensive wetland and peatland vegetation

Question 14

Describe the biome characteristics of a tundra

Answer 14

•Very low annual temperature
•Moderate annual precipitation
•Moderate seasonality in temperature and precipitation
•Low shrub/grass vegetation, tree-less, permafrost

Question 15

What is a Whittaker diagram?

Answer 15

A chart that displays biomes as a function of mean annual precipitation and mean annual temperature

Shows the MAT and MAP range for each biome

Question 16

Why do desert biomes have such a wide range of temperature conditions?

Answer 16

Because of the existence of hot and cold deserts

Question 17

What is a hot desert?

Answer 17

•Caused by the hot, dry air of Hadley cells
•Warm all year

Question 18

What is a cold desert?

Answer 18

•Dry because of the rain shadow effect and continentality
•Found along higher latitudes

Question 19

What is soil?

Answer 19

A complex mixture of organic and inorganic material. Most terrestrial life depends on it

Question 20

How is soil formed?

Answer 20

Weathering
•Mechanical: breakdown of rock into smaller particles from water, wind, and plants
•Chemical: processes such as solution, hydrolysis, and oxidation

Question 21

What are the 5 soil horizons?

Answer 21

O- organic
A- surface
B- subsoil
C- substratum
R- bedrock

Question 22

What comprises the organic horizon of soil?

Answer 22

Accumulated organic material, especially decomposed plant and animal material. Dense roots

Question 23

What comprises the surface horison of soil?

Answer 23

Well weathered fertile layer containing mineral and organic content. Mostly humidified organic content. Roots reach into the layer

Question 24

What comprises the subsoil horizon of soil?

Answer 24

Mostly mineral material from upper layers, clay, iron, aluminum oxides deposited by water

Question 25

What comprises the bedrock horison of soil?

Answer 25

Unweathered bedrock that will eventually become the rest of the soil

Question 26

What are the 3 sublayers of the organic horizon of soil?

Answer 26

L- litter horizon
F- fermentation horizon
H- humic horizon

Question 27

What comprises the litter horizon?

Answer 27

Plant elements with little to no decomposition

Question 28

What comprises the fermentation horizon?

Answer 28

Moderately decomposed but still identifiable plant matter

Question 29

What comprises the humic horizon?

Answer 29

Well humidified material decomposed by water. Plant material is difficult to identify

Question 30

What influences the depth of soil? What is significant about deeper soil?

Answer 30

•Slope
•Weathering
•Parent materials
•Vegetation

Roots can penetrate deeper and the soil can hold more water/minerals

Question 31

What do soil organisms do?

Answer 31

•Form soil structure
•Regulate soil moisture
•Perform gas exchange & carbon sequestration
•Nutrient cycling
•Decompose dead matter
•Control plant growth