Chapter 2 Concepts and Biomes Review

A study set of flashcards covering climate processes, soil science, pedogenesis, climate diagrams, and major terrestrial biomes based on the provided notes.

What drives climate?

The sun.

What is the global energy balance equation?

Ein = Eout.

What percentages of sunlight are reflected and absorbed by Earth?

About 30% reflected; about 70% absorbed in the biosphere.

What happens to absorbed solar energy?

It is absorbed primarily as heat; photosynthesis is insignificant.

hemispheres and seasons

• the two hemispheres have opposite seasons due to the tilt of the Earth's axis. As the Earth orbits the Sun, one hemisphere is tilted toward it, experiencing summer, while the opposite hemisphere is tilted away, experiencing winter.

• constant tilt is 23.5 degrees

How is heat dissipated to balance energy input?

By reradiation as longwave heat, plus conversion to wind and evaporation.

What effect does the Coriolis force have on atmospheric circulation?

It breaks up air circulation into Trade Winds, Westerlies, and Polar Easterlies.

• polar westerlies at the north and south pole

• westerlies between the trade winds and polar easterlies

• northeast and southeast trade winds are near the equator

the coriolis effect causes the winds in the northern hemisphere to be deflected to the right of their direction of travel and winds in the southern hemisphere to be deflected to the left.

ocean currents

due to

1. air currents

2. also due to absorbed solar energy by water

3. strongly influenced by continental positions

Which factors influence regional climate and biomes?

1. Atmospheric circulation

2. ocean currents

3. topography

4. vegetation

What causes a rain shadow and windward–leeward moisture differences?

The Orographic effect; air rises on the windward side causing rain and leaves the leeward side drier.

Name the five crucial ecological roles of soil.

1. Medium for plant growth

2. recycling system for nutrients and organic wastes

3. water supply and purification

4. engineering medium

5. habitat for soil organisms

What are the major soil horizons in a typical profile?

• O organic horizon (litter in various stages of decay)

• A first mineral horizon (accumulation of organic matter)

• E eluviation (loss of clay)

• B illuviation (accumulation of clay)

• C weathered parent material (chemical weathering)

What does CLORPT stand for in pedogenesis?

Climate, Organisms, Relief, Parent material, Time.

What is pedogenesis?

The process of soil formation influenced by climate, organisms, relief, parent material, and time.

What is the purpose of the soil texture triangle?

To classify soils by proportions of sand, silt, and clay

What are soil drainage classes?

Range from well-drained to very poorly drained; drainage varies with landscape position (uplands to wetlands).

What is a hydric soil?

A soil that is saturated with water long enough to develop hydric properties and support hydrophytic vegetation.

What composition corresponds to 55% clay, 32% silt, and 13% sand on the texture triangle?

Clay 55%; Silt 32%; Sand 13%.

Name the major terrestrial biomes discussed.

Tropical rainforest; Tropical dry forest; Tropical Savanna; Desert; Mediterranean woodland/shrubland; Temperate grassland; Temperate forest; Boreal forest (Taiga); Tundra.

What are the climatic and soil features of Tropical Rainforests?

• Near the equator (within ~10°)

• little monthly temperature variation

• high, evenly distributed rainfall (2000–4000 mm/yr)

• leached soils

• mycorrhizae aid nutrient uptake

• high biodiversity and vertical layering

How do Tropical Dry Forests differ from Tropical Rainforests?

• Dry forests have more seasonal rainfall and soils richer but more erosion-prone

• extensive human clearing; share many species with rainforests

What are the key features of Tropical Savanna?

• Located roughly between 10°–20° latitude

• wet and dry seasons

• droughts can cause wildfires

• soils with low water permeability

• grasses favored

• livestock production common

Desert biome features?

• Major bands at ~30° N/S; about 20% of Earth's land

• water loss exceeds precipitation

• soils low in organic matter

• sparse to absent vegetation

• animals adapted

• high biodiversity in some deserts

What defines Mediterranean Woodland and Shrubland?

• Found on most continents except Antarctica

• cool, moist fall-winter-spring

• hot, dry summers

• moderately fertile soils

• evergreen, fire-tolerant vegetation

• history of human intrusion

Temperate Grassland features?

• Widespread

• annual rainfall 300–1000 mm

• periodic droughts

• nutrient-rich deep soils

• dominated by herbaceous vegetation

• large roaming ungulates

Temperate Forest features?

• Mostly between 40° and 50° latitude

• rainfall 650–3000 mm

• fertile soils

• long growing seasons with deciduous plants

• short seasons with conifers

• high biomass

• many human population centers

Boreal Forest (Taiga) climate and features?

• Northern Hemisphere

  • ~11% of land

• thin acidic soils

• evergreen conifers

• relatively high animal density

• historically low human intrusion

• short growing season

• great temperature variation

Tundra climate and features?

• Covers lands north of the Arctic Circle

  • cool and dry with short summers

    • 200–600 mm precipitation

• low decomposition

• supports many native mammals

• limited historical human intrusion

Mountains: 'Islands in the Sky' concept?

• Mountains act like islands

• climate changes with elevation

• soils are thin and well-drained

• flora and fauna shift with elevation

• altitude mimics latitude

• mountain ranges in north and south america run north to south

• mountain ranges in europe and asia run east to west

North-facing vs. South-facing slopes climate differences?

• South-facing slopes are sunnier, warmer, drier with greater temperature fluctuations

• north-facing slopes are cooler and moister

• different affects plant/animal distributions and deer behavior

  • deer use N facing slopes in the summer

  • use S facing slopes in the winter and spring bc less snow, earlier spring, and warmer

Macroclimate vs. Microclimate?

• Macroclimate is the general regional climate

• microclimate is the local climate around organisms (within about 1 m of the ground)

  • climate surrounding organism parts such as

    • a single leaf

    • insect parasite on an animal

    • organ of the body

How are climate diagrams structured?

Temperature on the left axis; precipitation on the right axis; 10°C equals 20 mm; lines show water availability; adequate moisture when precipitation exceeds temperature.

What does The Whittaker Biome Classification relate?

Relates mean temperature and precipitation to plant distributions and biomes (The Whittaker Graph).

How does elevation affect climate in mountains?

• Altitude mimics latitude

• climate changes with elevation

• soils are thin and well-drained

• flora and fauna shift with elevation

What is eluviation (E) and illuviation (B) in soils?

Eluviation (E) is the loss of clay and other materials from a horizon; illuviation (B) is the deposition of those materials in a lower horizon.

What do soil horizon letters O, A, E, B, C represent?

O organic horizon

A mineral horizon with organic matter accretion

E eluviation

B illuviation

C weathered parent material

water vapor and temperature

• low temp air is saturated by low water vapor and water vapor pressure is low

• high temp amount of water air holds at saturation and saturation water vapor pressure increases

vegetation biomes of the western US

• mountain ranges: rockies, cascades, coastal, and serra nevada

  • cool conifer forest!

• rapid change in vegetation based on altitude/elevation

tree diversity

• south east has the most tree diversity while the west has barely any tree diversity

• similar trend for tree endemics