BIOL 208: Lecture 4 Slides - Biomes

*****How are terrestrial biomes divided?

Climate, Distinguished primary by its PREDOMINANT VEGETATION

****What 2 things affect the predominant vegetation?

1. Temp

2. Precipitation

****Why is vegetation the predominant decider on biome?

Plants = Primary producer = Food + habitat base for rest of ecosystem

• the animals that live in the region depends on the vegetation available both as food + housing

***Mean Annual temp + sum of precipitation is affected by what 2 things?

1. Solar radiation

2. Atmospheric cells

True or false: SOIL highly influences the biome?

True

Define soil

complex mixture of organic + non-living inorganic material upon which most terrestrial life depends

***Soils are formed through a process called?

WEATHERING

Define weathering?

Slow breakdown of bedrock (parent material) into smaller + smaller fragments to produce soil particles (i.e. Sand, silt, clay)

***What are the 2 types of weathering?

1. Mechanical: water, wind, roots + temp change

2. Chemical: Chemical reactions

***What are the 2 types of chemical weathering reactions? Define them.

1. Solution: soluble minerals dissolve in water (eg. Lime stone to Ca + HCO3)

2. Hydrolysis: Water reacts with minerals to form new compounds (clay + soluble salts)

***Define a climate diagram + what info does it normally give?

Describes climate at a locality

• Describes absolute + relative information about average temp + precipitation

• Location

• Elevation

****What do the red dots mean + what do the blue dots mean? What does it mean if a month is shaded red?

Red = monthly temp (left axis)

Blue = Monthly precipitation (right axis)

Shaded month = average minimum temp = ABOVE ZERO

*****What does a minimum temp above zero mean?

H2O is not frozen = Biological activity (growth season)

****What are the 3 things we can learn from the absolute values on the climate diagrams?

1. How variable is temp + how high/low

2. How much of year = frost free (shaded)

3. How variable is precipitation + how much

******What are the 2 things we can learn from the relative arrangements of the curves on a climate diagram?

1. When do periods of extensive rain occur

2. When do periods of drought occur

****In relation to the relative arrangements of the curves of a climate diagram; what do dark blue areas, light blue areas and yellow areas mean?

Dark blue = excessively moist periods (precipitation axis shifts)

Light blue = More moisture per degree of temp

Yellow = More evaporation than precipitation = drought

****What are the 6 biomes focused on in this course? Which are relevant to Canada?

1. Tropical rain forest

2. Desert

RELEVANT TO CANADA

1. Temperate grasslands

2. Temperate forests

3. Boreal forests

4. Tundra

****Around what latitudes do TROPICAL RAIN FORESTS normally exist?

Between 10 degrees N+S of Equator

*****What is the Temp, Seasonality, Precipitation, Soil, biomass/productivity, and diversity, vegetation of TROPICAL RAIN FORESTS?

Temp = high

Seasonality = low (little variance in temp if any)

Precipitation = VERY HIGH (dark blue areas on climate diagram)

Soil = Acidic, Nutrient poor + Thin organic layer

Biomass = RICH + high in primary productivity

Diversity = MOST DIVERSE biome

Vegetation: Evergreen, vines, epiphytes

****Why is the SOIL in Tropical rain forests so poor in nutrients and lacking in organic matter?

Decomposition rate of organic material = always high because of environment = break down all nutrients + low organic matter

High precipitation = wash out all nutrients + erode soil

****Where do nutrients tend to be tied up in the rain forest?

In LIVING TISSUES (take up any nutrients available in soil ASAP)

****Around what latitudes do DESERTS normally exist?

30

*****What is the Temp, Seasonality, Precipitation, Soil, biomass/productivity, and diversity, vegetation of DESERTS?

Temp = variable depending on location (hot tends to be around 30 degrees latitude)

Seasonality = Moderate - Strong (VARIES)

Precipitation = ALL Low

Soil = low in nutrients + organic matter

Primary productivity = LOWEST

Vegetation: Sparse, short vegetation, mostly treeless

****Where in the desert can you find slightly higher levels of organic matter?

Under bushes/ shrubs

****Around what latitudes do TEMPERATE GRASSLANDS normally exist?

30 - 55

*****What is the Temp, Seasonality, Precipitation, Soil, biomass/productivity, and diversity, vegetation of TEMPERATE GRASSLANDS?

Temp = mean = Low (dragged down by cold winters)

Seasonality = Strong (warm summers + cold winters)

Precipitation = Low - moderate

Soil = VERY FERTILE + GREATEST amount of organic matter

Vegetation = Predom. grass + herbaceous vegetation

• Trees + shrubs are limited near streams

Primary productivity = relatively high

What are temperate grasslands also known as?

Prairies

Fill in the blank: Due to the VERY FERTILE SOIL, temperate grasslands is the biome with the highest ____.

LAND LOSS

• conversion to crop lands or pastures

• risk erosion of soil

****Which season has the highest precipitation for TEMPERATE GRASSLANDS?

SUMMER

*****WHY are the grasslands dominated by grass and why are trees only by streams?

NOT ENOUGH PRECIPITATION for trees

+

FIRE CYCLING (grass grows back faster)

****Around what latitudes do TEMPERATE FORESTS normally exist?

Around same as grass lands = 30 - 55

*****What is the Temp, Seasonality, Precipitation, Soil, biomass/productivity, and diversity, vegetation of TEMPERATE FORESTS?

Temp = mean = Moderate

Seasonality = Moderate (warm summers + mild winters)

Precipitation = HIGH

Soil = VERY FERTILE

Vegetation = Deciduous or Coniferous

Primary productivity = relatively high 2nd after rain forest

Biomass = GREATER Than or equal to Tropical forest

Diversity = high but less than tropical rain forests

****During Which Seasons is there the most precipitation for TEMPERATE FORESTS?

WINTERS

= Prone to moderate drought

• precipitation is lower when temps rise

****What decides on the TYPE OF FOREST (deciduous or coniferous) in TEMPERATE FORESTS?

Climate/ seasonality

• Harsher = Coniferous

  • dryer, colder or hotter

• More moderate and higher precipitation = Deciduous

****Around what latitudes do BOREAL FORESTS normally exist?

50 - 65

*****What is the Temp, Seasonality, Precipitation, Soil, biomass/productivity, and diversity, vegetation of BOREAL FORESTS?

Temp = VERY low

Seasonality = STRONG (mild summers + VERY COLD winters)

Precipitation = Low to moderate

Soil = low

Vegetation = Coniferous

• extensive WETLAND + PEATLAND vegetation

Diversity = LOW

***Why is the SOIL FERTILITY LOW for BOREAL FORESTS?

Low temps + precipitation = low biomass + vegetation

• Mainly coniferous trees = low diversity

TRUE or FALSE: Boreal means NORTH therefore boreal forests are only found in the north?

TRUE

****Around what latitudes do TUNDRAS normally exist?

66 and above

*****What is the Temp, Seasonality, Precipitation, Soil, biomass/productivity, and diversity, vegetation of TUNDRAS?

Temp = VERY LOW

Seasonality = STRONG (cool summers + VERY COLD winters)

Precipitation = Low

Soil = low fertility + acidic

Vegetation = low shrub + grass vegetation (due to short growing seasons + treeless

Diversity = LOW

TRUE OR FALSE: TUNDRAS exist in both the arctic circle and the Antarctic circle?

FALSE

****Which biome(s) has/have permafrost + short growing seasons?

Boreal forests aka. taiga

Tundra

*****What do Whittaker Diagrams display?

Biomes as a function of MAP + MAT (mean annual temp + precipitation)

• shows the range at which each biome occurs

****What is the main Diff between TEMPERATE GRASSLANDS vs. FORESTS + TROPICAL RAIN FORESTS + DRY FORESTS? What is the key thing that distinguishes these biomes?

Amount of precipitation

****Why are Hot deserts hot and Cold deserts cold? Why is there such VARIETY?

Hot deserts = Hadley cells at 30

• warm dry air

Cold deserts = RAIN SHADOW

• only dry because of rain shadow effect

***What is an ecozone?

Subdivision of a biome

****How many ecozones do we have in Canada?

15

Arrange: Biome, ecodistrict, ecozone + ecoregion from biggest to smallest

1. Biome

2. Ecozone

3. Ecoregion

4. Ecodistrict

Soil = rich in biodiversity: What are 6 FUNCTIONS of organic life in soil (eg. bacteria, fungi, lichen, insects etc.)

1. Nutrient cycling

2. Decomposition

3. Control plant growth

4. Form soil structure

5. Gas exchange + Carbon sequestration

6. Regulate soil moisture