BioExam 4 Review Modded Playthrough

Biome distribution is determined by what two factors

Biome distribution is determined by what two factors

Temperature, and Precipitation

What biome could you consider dry and polar?

Tundra

What are the characteristics of tropical rainforests?

• Annual rain >200cm

• Dominated by broadleaved evergreen trees.

• Almost no seasonal change

• Between 10 degrees N, and S

What are the limiting characteristics of tropical rainforests?

• Light and nutrients

• Soils are poor due to leeching by rain

What are some major causes of deforestation?

• Making room for cattle

• Lumber

• Cash crops

What are the characteristics of savannas, and dry forests?

• Between 10-25 degrees N/S

• Distinct dry and wet seasons

• Shorter/fewer trees

• more grasses/shrubs

• Wetter = Savannah

• Dry = dry forest

What are the limiting characteristics of savannas, and dry forests?

• Water

• Nutrients

• Disturbance

• Fire, and Herbivores

What is the main reason for the loss of dry forests, and savannas?

Cropland, and pastures

What are most crops grown for?

Animal feed

What are the four major climate biomes

• Tropical

• Temperate

• Polar

• Dry

What are the characteristics of temperate biomes?

• Warm and dry summers

• Cold and wet winters

• Occurs in temperate zone (30-50 degrees)

What are the characteristics of temperate grasslands?

• C4 plants

• 30-50 degrees

• Warm and dry summers

• Cold and wet winters

What are the limiting characteristics of temperate grasslands?

• Fire and grazing

What plant type dominates temperate deciduous forests?

• 30-50 degrees

• Occurs on continental edges

• stable precipitation

• Trees are deciduous

What are the limiting characteristics of temperate deciduous forests?

• Human impact

What plant type dominates temperate evergreen forests?

• 30-50 degrees

• Costal and maritime zones

• evergreen vegetation dominates

• Soils are acidic & nutrient poor

What are the limiting characteristics of temperate evergreen forests?

• High levels of leeching of neutrients

• light imitations due to dense canopy

• higher risks of fire

What is C4 photosynthesis?

Allows stockpiling of CO2

What is the US’s largest crop?

Corn

What are five major threats to biodiversity?

• Climate change

• Habitat loss

• Hunting/Fishing

• Pollution

• Invasive species

What are five major uses of land?

• Urbanization

• Fires, and other natural disasters

• Climate change

• Agriculture

• Mining operations

What are the characteristics of boreal forests?

• Occurs in polar zone (50-65 degrees)

• Long cold winters

• Short wet summers

• Evergreen trees (Conifers)

• Permafrost

What are the limiting characteristics of boreal forests?

Timber production creates habitat loss

What are the characteristics of tundra’s?

• >65 degrees

• dry

• long harsh winters

• Primarily grasses

• permafrost

What are the limiting characteristics of tundra’s?

• Human influence

• Warming of polls

What are the characteristics of chaparrals?

• Dry summers

• Wet winters

• Found on the west coasts of USA, Australia, and Chile

• Evergreen shrubs

• Fire dependent species

• 30-40 Degrees N/S

What are the limiting characteristics of chaparrals?

• Fire and water

• fire tolerance/dependance

What are the characteristics of deserts?

• Very low water availability

• Varied temperature extremes

• Spares flora and fauna

• Many plants with succulent stems

What are some plant adaptations to the desert?

• Small leaves

• Spines

• CAM Photosynthesis

• Spacing

What are the limiting characteristics of deserts?

Weather

Current conditions

Climate

Long term

Temperatures tend to be

cooler in the North, Warmer in the south

When Air rises

It forms a ploom

30* N and South of Equator

Hadley Cell, High Pressure

Equator

Low Pressure, Equatorial region

Atmosphereic Circulation and Wind direction

Easterlies

Westerlies
NE Trade Winds

Equator

SE Trade Winds

Westerlies

Easterlies

Effect of Summer on atmospheric circulation

Air over oceans is cooler
High pressures develop over the oceans

Winter

Air over continents is cooler
High pressures develop over continents

Great Ocean Conveyor Belt

• It is driven by differences in temperature and salinity of seawater.

• It begins in the North Atlantic Ocean, where cold, dense water sinks to the bottom of the ocean.

• This water then flows southward towards the Antarctic, where it becomes even denser and cooler.

• Eventually, this water upwells back to the surface near Antarctica, where it is warmed by the sun and becomes less dense.

• The less dense water then flows northward again, eventually returning to the North Atlantic Ocean.

How does the GOCB affect climate?

transports heat from the tropics to the poles, helping to keep the poles warm enough to support life. It also influences regional climates, such as the mild winters of Western Europe.

Sargasso Sea

Costal Upwelling

Brings nutrient rich cold water to surface, highly productive region

Air temperature on leads vs oceans

Tends to vary more. becuase of water’s higher heat capacity

Regional Climate Influences

Tapology → regional climate → vegetation

Elavation

Air pressure and density Decrease as elevation increase

Rain shadow effect

• occurs when a mountain range forces moist air to rise and cool.

• As the air rises, it expands and cools, which causes the moisture in the air to condense and form clouds.

• The clouds then release their precipitation on the windward side of the mountain range, leaving the leeward side dry.

• The rain shadow effect can create dramatic differences in climate between the two sides of a mountain range.

• creates deserts

Maritime effect

Results in narrower dialy and annual temperatures

Continental Effect

Results in more dramatic fluctuations in surface air temperatures

Vegetation increases rainfall

through evapotranspiration

Annual Climatic Variation

Tied to movement of inter tropical convergence zone

EL Nino

• Characterized by abnormally warm sea surface temperatures in the tropical Pacific Ocean

• Associated with increased rainfall in some regions and drought in others

La Nina

• Characterized by abnormally cool sea surface temperatures in the tropical Pacific Ocean

• Associated with increased drought in some regions and increased rainfall in others

Salininization of crop lands

occurs when excess salt accumulates in the soil, making it difficult for plants to absorb water and nutrients.

Soils

• Largely set by parent material

• Becomes more acidic over time

Major Climate types

• Tropical

• Temperatte

• Polar

• Dry

Tropical Biomes

• Rain furrest

• Dry Forest

• Savanna

Temperate Biomes

• Rain forest

• deciduous forest

• Grasslands

Polar Biomes

• Boreal Forest

• Tundra

Dry Biomes

• Chaparral

• Deserts

Distribution of biomes is largely deterimed by

Temperature & Precipitation

Temperature

influences distribution of plant growth directly through physiological effects

Precipitatiaon

Influences water availability and water loss by plants?

Climate

Average temperature + precipitation

Terrestrial biomes are characterized by

vegetation because plants are immobile and easily identifiable

Global Biome distribution

Human influence on biome vegetation

Conversion of land to agriculture, farmland, and,, urban development

Temperate zone

Latitudes between the tropics and arctic, distinctive cold/warm seasons.

Trophics=

• Latitudes between the tropic of cancer 23.5N and tropic of Capricorn 23.5S

• Chacterized by a lack of cold/warm seasonal variation

Tropical Rainforests (geographically)

• Between 10N and 10S

• Annual precipitation less >200cm

• Limited temperature change

• Dominated by broadleaved evergreen trees.

Tropical Rainfurests (tapologically)

Light and nutrients are limiting factors

Soils are very nutrient poor

Very high productivity

Tropical Dry forests and Savannas

• 10 - 25 N/s

• Distinct Wet and dry seasons

• Drought decidous

• Limited by water, nutrients and disturbance

Tropical Dry forests

Leaves drop during dry season

thorn woodland

Heavy thorns protect from herbivores

tropical savannas

grass intermixed w/ trees and shrubs

Temperate Grasslands

• 30 -50

• Seasonal temperature variation (Warm summers, cold winters)

• Low but stable precipitation

• Grasses dominate

Temperate Grasslands limiting factors

• Fire

• Grazing

• Results in high soil fertility

Impacts to temperate Grasslands

• Converted to agriculture

• Grasslands degradation, desertification

• salininization

• Habitat loss

Very good soil for crops

lots of soil water and low rainfall

Temperate deciduous Forests

• 30-50

• Moderate temperature

• Stable precipitation

• Deciduous trees

• Oak, maple, beeche forests

leaves changing color

occurs as a result of chlorophyll breakdown

Limiting factors for deciduous forests

• Timber, agriculture

• soil fertile and long growing seasons

• Very little Old-Grow

Timber

Major natural resource of the temperate forest biome

Temperate Evergreen Forests

• 30-50N

• Acidic soils & nutrient poor

• evergreen vegetation

• Low diversity

Limiting actors for Temperate Evergreen forests

• Limited Nutrients

• High Ranfall, High leaching

• light limiting

• Fire limited

Boreal Forests

• 50-65N

• Long, cold winters

• shirt, wet summers

• Permafrost

• Evergreen conifers

Impacts on boreal forests

• logging, oil, gas

• climate warming

Permafrost

thick subsurface layer of soil that remains frozen throughout the year, occurring chiefly in polar regions (arctic tundra and 80% of boreal forests).

Tundra

• >65N

• _{Alpine altitudes}

• _{Very long servere winters}

• _{dry conditions}

• _{short growing seasons}

• _{shrubs and mosses}

• _permafrost

Cold and biomes

cold temperatures can be due to either altitude or latitude

Impacts on Tundra

• Historically low impact from humans

• Warming is double global Average

Permafrost melting

currently melting all over the globe and releasing vast amounts of methane and CO₂ (greenhouse gases); this is predicted to accelerate warming

Hot and cold desets

• located ~30 N / S

• Extremes with variability

• sparse flora

• Succulent stems

Succulence

adaption to mimize water loss in deserts

reduced leaf area

short lived annual and lay dormant otherwise

Adaptions to the desert

• Small Leaves

• Spines

• Photosynthesis moved to stem

• Water storage

• CAM photosynthesis

CAM photosynthesis

involves opening stomata at night when evaporation is minimal, storing CO2 as malic acid, and then doing photosynthesis during the day with the malic acid and your stomata closed!