BIO 206 Midterm 1: Biomes, Abiotic/Biotic Factors, & The Effect of Sunlight on Weather

Based on slides from 9/5

Terrestrial biomes

• broad geographical regions dominated by similar ecosystems

• categorized by dominant plant forms (trees, shrubs, grasses) and climate (temperate, tropical)

Boreal forest (taiga)

• type of biome that features a closed canopy of trees

• low productivity (slow growing) and diversity (all tall plants with cold resistant features)

• low rainfall

Temperate forest

• type of biome that features a closed canopy of trees

• moderate productivity and diversity since climate doesn't support year round photosynthesis

• moderate rainfall

• dominated by deciduous trees

Artic tundra

• type of biome that features permafrost

• low productivity (slow growing) and diversity (no trees, all low growing plants)

• low rainfall

grassland

• type of biome that features dense grasses (since very dry)

• less productivity than forests

• moderate rainfall

savanna/shrubland/woodland

• type of biome that features dense grasses and shrubs/trees

desert

• type of biome that features extremely low productivity (plants who exist have no leaves, spines, or leaves with waxy coatings). and is very dry

• low rainfall

tropical rainforest

• type of biome that features high diversity, productivity, and biomass

• plants have broad leaves

• high rainfall

abiotic factors

Nonliving components (both past and present) of environment that affect organisms (wind, sunlight, soil, temperature, water, weather, climate change, etc)

biotic factors

Living components (both past and present) of environment that affect organisms (plants, animals, bacteria, fungi, etc)

Latitudinal variation

less sunlight further from the equator and more sunlight closer to the equator impacts temperature, air circulation, and precipitation

Hadley cell

• exists at the equator

• Warm air rises, creating a low-pressure zone

• As the warm moist air rises, it cools and condenses (forming clouds and rain)

• The cool air moves towards the poles

• The cool air falls, creating high pressure regions

Ferrel cells

• Dry air sinks at 30° latitude, creating high pressure and dry weather

• Air rises at 60° latitude, creating low pressure and

• Air goes back to 60° latitude

Vertical circulation cells

Cause

• Differential heating of the earth

• Coriolis Effect

• Unequal distribution of land and ocean

Effect

• Establish zones of high and low pressure

• Transfers heat from the equator

• Creates climatic zones

Coriolis effect

• The illusion that fluids curve due to the Earth's rotation

Intertropical Convergence Zone (ITCZ)

where two Hadley cells meet

Seasonal sunlight

• Spring: Equator faces sun

• Summer: Northern Hemisphere faces sun

• Fall: Equator faces sun

• Winter: Southern Hemisphere faces sun

How do mountains affect rain?

• West: Moisture laden air blows onshore from the Pacific Ocean

• Air rises over mountains and cools; rain falls

• East: dry air creates desert conditions

How do ocean currents convey thermal energy?

• Water has an extremely high specific heat (absorbs heat in summer and releases heat in winter)

• Ocean currents flow in gyres, clockwise direction in the Northern Hemisphere and in a counterclockwise direction in the Southern Hemisphere

• Warm water is delivered to colder latitudes and colder water is delivered to warmer latitudes

Thermal inertia and oceans

• Thermal inertia: how slowly or quickly something heats up or cools down

• Air temperatures on land show greater seasonal variation than temp on oceans

What effect do humans have on biomes?

• Humans tend to settle in temperate forests, so climate change is greater in these areas