Climate and Terrestrial Biodiversity
Chapter 6
(Biomes: Sections 3-7)
Key Concept 1: How Does Climate Affect
the Nature and Locations of Biomes?
 Differences in average annual precipitation and
temperature lead to the formation of tropical,
temperate, and cold deserts, grasslands, and
forests, and largely determine their locations.
Climate Affects Where Organisms
Can Live
 Major biomes
• Similar climate, soil, plants, animals throughout
world
• Ecotone
 Latitude and elevation
 Annual precipitation
• Deserts, grasslands, forests
 Temperature
• Tropical, temperate, polar
The Earth’s Major Biomes
Generalized Effects of Elevation and
Latitude on Climate and Biomes
Polar
Tundra
Subpolar
Coniferous forest
Temperate
Desert
Deciduous
forest
Grassland
Chaparral
Tropical
Desert
Savanna
Rain forest
Tropical
seasonal
forest
Scrubland
Fig. 7-10, p. 147
There Are Three Major Types of Deserts
 Tropical deserts
 Temperate deserts
 Cold deserts
 Fragile ecosystems
• Hundreds of years for soil to recover from
disturbances
• Slow plant growth
• Low species diversity
• Slow nutrient recycling (Why?)
• Lack of water
Climatographs
of 3 Types of
Deserts
Staying Alive in the Desert
 Plant adaptations
•
•
•
•
•
Drop leaves or no leaves
Storage of water and food in fleshy tissue
Take in CO2 only at night
Deep roots to tap into ground water
Waxy coating on leaves
 Animal strategies and adaptations
•
•
•
•
•
•
Small, hide during the day
Dormant
Camel – stores massive amounts of water, doesn’t sweat
Don’t drink – water from break down of fats in seeds
Think coverings
Dry feces and urine
There Are Three Major Types of
Grasslands
 Tropical
• Savanna
• Grazing animals
• Browsing animals
 Temperate
• Tall-grass prairies
• Short-grass prairies
There Are Three Major Types of
Grasslands
 Cold (arctic tundra) – treeless plains
• Can be referred to as desert
• Fragile biome
• Nutrient poor soil
• Melting of permafrost
• Release CH4 and CO2 into the atmosphere
 Adaptations of plants and animals
• Thick fur or feathers
• Living underground
• Low growing plants
 Alpine tundra – below permafrost snow line on
mountains, more sunlight, more flowers
Climatographs
of Tropical,
Temperate,
and Cold
Grasslands
Temperate Shrubland: Nice Climate,
Risky Place to Live
 Chaparral
 Near the sea: nice climate
• Significant human impact
 Prone to fires in the dry season
 Maintained by fire, plants adapt with fire-resistant
roots, produce seeds that sprout after fire, use
nutrients released by the fire
 Soil thin and not very fertile
Chaparral Vegetation in Utah, U.S.
There Are Three Major Types of
Forests (Dominated by Trees)
 TROPICAL
 Tropical rain forests
• Warm temperatures, high humidity, heavy rainfall
• Dominated by broadleaf evergreen plants
• Stratification of specialized plant and animal
niches
• Emergent layer, canopy (most life forms),
understory, shrub layer, ground level
• Little wind to spread seeds, depend on pollinators
• Rapid recycling of scarce soil nutrients due to
warm, moist conditions
• Immediately taken up by trees, poor soil
• Impact of human activities?
There Are Three Major Types of
Forests
 TEMPERATE
 Temperate deciduous forests
•
•
•
•
Moderate temperatures, abundant precipitation
Dominated by few species of broad-leaf trees
Drop leaves and become dormant in winter
Slow rate of decomposition: storehouse of
nutrients
• Impact of human activities more than any other
biome
There Are Three Major Types of
Forests
 COLD
 Evergreen/Northern coniferous forests: boreal
and taigas
•
•
•
•
Long extremely cold and dry winters
Few species of cone-bearing evergreen trees
Low plant diversity
Slow decomposition: waxy coating on needles,
acidic soil, nutrient poor
 Coastal coniferous forest/Temperate rain forests
• Ample rainfall or moisture from dense ocean fog
Climatographs
of Tropical,
Temperate, and
Cold Forests
Stratification of Specialized Plant and
Animal Niches in a Tropical Rain Forest
Mountains Play Important
Ecological Roles
 Dramatic changes in altitude, slope, climate, soil, and
vegetation
 Majority of the world’s forests
• Majority of world’s terrestrial biodiversity
 Habitats for endemic species
 Sanctuaries for migrating animals (low to high)
 Help regulate the earth’s climate
• Ice and snow reflect solar radiation back into space
• Opposite – dark exposed rock absorbs energy?
 Can affect sea levels
 Major storehouses of water - role in hydrologic cycle
Key Concept 2: How Have We Affected
the Word’s Terrestrial Ecosystems?
 In many areas, human activities are impairing
ecological and economic services provided by
the earth’s deserts, grasslands, forests, and
mountains.
NATURAL CAPITAL
DEGRADATION
Major Human Impacts on Terrestrial Ecosystems
Deserts
Grasslands
Forests
Large desert cities
Conversion
to cropland
Release of CO2
to atmosphere
from burning
grassland
Clearing for
agriculture,
livestock grazing,
timber, and urban
development
Soil destruction by
off-road vehicles
Soil salinization
from irrigation
Depletion of
groundwater
Overgrazing
by livestock
Land disturbance
and pollution from
mineral extraction
Oil production
and off-road
vehicles in
arctic tundra
Conversion of
diverse forests to
tree plantations
Damage from offroad vehicles
Pollution of
forest streams
Mountains
Agriculture
Timber extraction
Mineral extraction
Hydroelectric dams
and reservoirs
Increasing tourism
Urban air pollution
Increased ultraviolet
radiation from ozone
depletion
Soil damage from off-road
vehicles
Fig. 7-20, p. 158