Video Introduction

Lesson Essential Questions

What are the major biomes in the world?

What factors are used to classify biomes?

How does an organism’s adaptation help it to survive in its biome?

WHAT IS A BIOME?

• The biosphere is divided into major areas called biomes

• Biomes – large regions of the Earth with similar o climate (abiotic factors)o plantso animals

• Terrestrial biomes – land based

• Aquatic biomes – water based

MAJOR TERRESTRIAL BIOMES

TERRESTRIAL BIOMES: RELATIONSHIP TO CLIMATE ZONES

• Terrestrial biomes are determined by climate zones

• Three major climate zoneso Polaro Temperateo Tropical

MAJOR FACTORS THAT DETERMINE CLIMATE

1. Average temperature

MAJOR FACTORS THAT DETERMINE CLIMATE

2. Average amount of precipitation

Annual Mean Precipitation

MAJOR FACTORS THAT DETERMINE CLIMATE

3. Average amount of solar radiation (angle of incidence)

OTHER FACTORS THAT DETERMINE CLIMATE

• Proximity to large bodies of water & mountain ranges

• Prevailing global wind patterns

Gulf Stream shown in orange

GEOGRAPHIC LOCATION OF CLIMATE ZONES

Climate zones are determined by geographic factors such as

• Latitude – the distance north or south of the equator measured in degrees

• Altitude – the height (elevation) above sea level

RELATIONSHIP BETWEEN BIOMES, LATITUDE, & ALTITUDEAn increase in altitude has the same effect on climate as an increase in latitude

Poles, 90° N or S

SUMMARIZE: WHAT ARE THE MAJOR ABIOTIC FACTORS THAT ARE USED TO CLASSIFY LAND BIOMES?

• Temperature

• Precipitation

• Sunlight

Soil quality is affected by an interaction of abiotic and biotic factors. Examples:

• Tundra: Permafrost; soil is thin and nutrient-pooro Permanently frozen (permafrost) because of the cold

temperatures (abiotic)o Thin and nutrient-poor because there are fewer

organisms (biotic) to die, decay, and contribute to soil quantity/quality

• Tropical Rainforest: Soil is thin and nutrient-pooro Warm, humid conditions (abiotic) encourage fast decay &

recycling of nutrients from dead organisms (biotic) back into the soil

o Frequent rains (abiotic) wash away topsoil & nutrients

SOIL QUALITY: ANOTHER ABIOTIC FACTOR USED TO CHARACTERIZE TERRESTRIAL BIOMES

• Temperate Deciduous Forest:o Plenty of fallen leaves (biotic) to decay & enrich the soilo Holds moisture due to composition = humus (biotic) + clay

(abiotic)Soil Quality: Thick layer of fertile, nutrient-rich topsoil

• Desert:

o Little rain (abiotic) to wash away minerals; they tend to accumulate

o Fewer organisms (biotic) to die, decay, & contribute organic matter

Soil Quality: Soil is mineral rich but low in organic matter

CHECK YOUR UNDERSTANDING:GUESS THE SOIL QUALITY OF THE TEMPERATE DECIDUOUS FOREST & THE DESERT

BIOMES ALSO CLASSIFIED ACCORDING TO BIOTIC FACTORS: ADAPTATIONS OF MAJOR PLANT & ANIMAL LIFE

• Similar kinds of plants (flora) & animals (fauna) exist within a distinct biome, even though the biome may not be geographically contiguous.Ex.: Desert plants from different areas of the world are thick & fleshy.

• Why? Even though organisms may be geographically isolated and not related to each other at all (different species), they evolve to have similar adaptations that are favorable for their unique environments. Example: Thick, fleshy plants retain moisture, helping them survive dry, desert conditions. How would leafy plants fare in a desert environment?

Native to Australia Native to US Native to South AfricaAustralian, US, and South African

deserts are geographically isolated

SUMMARY OF THE SIX MAJOR TERRESTRIAL BIOMES

AQUATIC BIOMES• Aquatic biomes make up the largest ecosystem on Earth

o Marine (saltwater)o Freshwater (<1% salt content)

• About 75% of the Earth’s surface is covered in water

• Important abiotic factors = % dissolved O2 and CO2, temperature, intensity of light, and dissolved minerals all affect life in the water

• Aquatic biomes are also the most stable ecosystem on Eartho Stable temperature – water can absorb and release large

quantities of heat with little temperature changeo Very biodiverse (marine biome has the greatest biodiversity

of all biomes) – stability increases with diversity; communities that contain more species will vary less through time in response to various disturbances

MARINE BIOME• Saltwater

• Ocean salinity (salt content) ~ 3% salt

• All oceans of the world are connected, making the marine biome the largest biome on earth

• The most photosynthesis on earth occurs in the ocean (phytoplankton, kelp, algae)

• Includes open ocean, coral reefs, shores, & estuaries (where river meets ocean = varying salinity, varying water depth due to tides, high nutrients)

FRESHWATER BIOME• Low salinity (< 1% salt)

• Flowing (lotic) = rivers & streamsFaster flowing water = more dissolvedoxygen, less nutrients

• Still (lentic) = ponds, lakes, and wetlandsLess dissolved oxygen, more nutrients

• Wetlands are areas of standing (still) water that support aquatic plants. Marshes, swamps, and bogs are all wetlands.

• Still water accumulates dead plants & sediment on the bottom and will eventually fill in to become a terrestrial biome.

SUMMARY

At the bottom of your last page of notes, summarize what you have learned about

terrestrial and aquatic biomes.