Transcript Terrestrial Biomes

Terrestrial Biomes
IB Syllabus: 2.4.1-2.4.2
AP Syllabus
Ch 6
Video – planet Earth – pole to pole
Syllabus Statements
• 2.4.1: Define the term Biome
• 2.4.2: Explain the distribution, structure and
relative productivity of tropical rainforests,
deserts, tundra and any other biome
vocabulary
• Biome
• Latitude
What is a biome?
• World climate is variable
– Differences in temperature and precipitation
– Different climates  Different communities
• Biomes = Regions of the earth characterized by
specific climates and community types
• Remember they cross national boundaries
• Real biomes do not have sharply defined
boundaries. Ecotones = Transitional zones
• Biomes not uniform, instead a mosiac of
patches
– Vary in microclimate, soil types, disturbances
Tropic of
Cancer
Equator
Tropic of
Capricorn
Arctic tundra (polar grasslands)
Desert
Boreal forest (taiga), evergreen coniferous
forest (e.g., montane coniferous forest)
Tropical rain forest,
tropical evergreen forest
Semidesert,
arid grassland
Mountains
(complex zonation)
Temperate deciduous forest
Tropical deciduous forest
Ice
Temperate grassland
Tropical scrub forest
Dry woodlands and
shrublands (chaparral)
Tropical savanna,
thorn forest
Major Terrestrial Biomes
1. Desert
2. Tundra
3. Forests
1. Tropical Rainforest, Tropical deciduous forest
2. Temperate Rainforest, Temperate deciduous
3. Tiaga (Boreal)
4. Grasslands
5. Scrublands
6. Mountains
For each Biome you should comment in
the distribution, climate (read
climatograms), structure, relative
productivity and limiting factors
Main Biome Effects
Altitude
Mountain
Ice and snow
Tundra (herbs,
lichens,
mosses)
Coniferous
Forest
Latitude
Deciduous
Forest
Tropical
Forest
Tropical
Forest
Deciduous
Forest
Coniferous
Forest
Tundra (herbs,
lichens, mosses)
Climate and vegetation vary in a predictable
fashion with changes in Altitude and Latitude
Polar ice
and snow
Vegetation changes
• Plants in cold regions have traits to limit heat
& water loss
– Winter dormancy (drop leaves), smaller size,
evergreens have needles
• Plants in dry areas must lose heat and
conserve water
– No leaves, water storage, nocturnal activity
• Plants in rainforests must get light and
remove water
– Broad leaves, drip tips, radiate heat
100
30
20
50
10
ft
m
Tropical
rain forest
Coniferous
forest
Deciduous
forest
Thorn
forest
Thorn
scrub
Tall-grass
prairie
Short-grass
prairie
Comparison of types, sizes and stratification of species
in different terrestrial biomes (structure)
Desert
scrub
Deserts
1. Climate
•
•
•
Precipitation < 25 cm / yr – scattered unevenly through
year Arid
May be Tropical, Temperate and Cold types – always
extremes
High to moderate insolation
2. Distribution
•
30% of earth surface  between 30 degrees north and
south of the equator – Major ones Saraha (Africa), Gobi
(Asia), Mojave (N. america)
3. Structure
•
•
Simple – very little vegetation
Most complex is temperate desert which has largest cacti
4. Relative Productivity
•
Low – limited by water availability
World Distribution of Deserts
Desert Types
• Tropical Deserts
• High temp. year round
• Little rain, only 1-2
months
• Driest places on earth
• Few plants
• Hard windblown
surface: sand & rock
• Middle East areas
Tropical desert
(Saudi Arabia)
Desert Types
• Temperate Deserts
• Day temp. high in
summer, low in winter
• More precipitation
• Sparse vegetation –
suculents, cacti,
animals
• Southern CA (Mojave)
Temperate desert
(Reno, Nevada)
Desert Types
•
•
•
•
•
Cold deserts
Winters cold
Summers warm to hot
Precipitation low
Gobi desert, China
Polar desert
(northwest China)
Plant Adaptations
Every drop of water counts
1. Wax coated leaves
limit transpiration
2. Deep roots tap
underground water
3. Wide spread shallow
roots gather falling
water
4. Drop leaves &
dormancy in heat & dry
periods
5. Store biomass in
seeds
Animal Adaptations
• Hiding in cool areas
during day
• Thick skin
• Dry feces,
concentrated urine
• Water from dew & food
• Dormancy in heat &
drought
Red-tailed hawk
Producer
to primary
consumer
Gambel's
quail
Primary
to secondary
consumer
Yucca
Jack
rabbit
Agave
Collared
lizard
Prickly
pear
cactus
Secondary to
higher-level
consumer
All producers and
consumers to
decomposers
Roadrunner
Diamondback rattlesnake
Darkling
beetle
Bacteria
Fungi
Kangaroo rat
Human Impacts on Deserts
Large desert cities
Soil destruction by vehicles
and urban development
Soil salinization from irrigation
Depletion of underground
water supplies
Land disturbance and pollution
from mineral extraction
Storage of toxic and radioactive
Wastes
Large arrays of solar cells and
solar collectors used to produce
electricity
Temperate Grasslands
1.
Climate
•
•
•
•
2.
Precipitation 25-45 cm / yr – enough to grow grass, erratic Semiarid
fire, drought, animals prevent tree growth
May be Tropical, Temperate
Moderate insolation
Distribution
•
•
3.
9% of earth surface  Temperate Latitudes – Major onesNA tall grass
prairie, steppes, pampas, veldt
Grasslands overall up to 40% of earth’s surface
Structure
•
4.
Simple – grasses and herbaceous plants
Relative Productivity
•
Medium to high – high turnover of grasses, rich soils
World Distribution of Grasslands
Polar Tundra
Alpine Tundra
Temperate Grassland
Tropical Savanna
Grassland Types
• Temperate grasslands
• Vast plains and rolling
hills
• Summer hot & dry
• Winter cold
• Sparse, uneven
precipitation
• Thick fertile soils
Temperate grassland
(Lawrence, Kansas)
Golden eagle
Pronghorn antelope
Producer
to primary
consumer
Primary
to secondary
consumer
Coyote
Grasshopper
sparrow
Grasshopper
Blue stem
grass
Prairie
dog
Bacteria
Fungi
Prairie
coneflower
Secondary to
higher-level
consumer
All producers and
consumers to
decomposers
Grassland Types
•
•
•
•
•
•
Tropical Grasslands
Savannas
High average temp
Moderate rainfall
Prolonged drought
Herds of herbivores
– Grazing & Browsing
• Africa, SA, Australia
• Migrations in dry
season
Tropical grassland (savanna)
(Harare, Zimbabwe)
Herbivore coexistence
•
•
Minimize competition by resource
partitioning
African animals differ by region & niche
1. Giraffes eat leaves from tree tops
2. Elephants eat leaves and branches further
down
3. Gazelles & Wildebeasts eat short grasses
4. Zebras eat longer grass & stems
Cape buffalo
Wildebeest
Beisa oryx
Topi
Warthog
Thompson's
gazelle
Dry Grassland
Waterbuck
Grant's zebra
Moist Grassland
Giraffe
African elephant
Gerenuk
Black rhino
Dik-dik
East African
eland
Dry Thorn Scrub
Blue duiker
Greater
kudu
Bushbuck
Riverine Forest
Human effects on Grasslands
Conversion of savanna and temperate
grassland to cropland
Release of CO2 to atmosphere from
burning and conversion of grassland
to cropland
Overgrazing of tropical and temperate
grasslands by livestock
Damage to fragile arctic tundra
by oil production, air and water pollution,
and vehicles
Tundra
1. Climate
•
•
•
Precipitation < 15 cm / yr – mostly snow & summer rain
Arid
Bitter cold  -57 – 50 °C - permafrost
low insolation gives short growing season
2. Distribution
•
•
60 – 75 °N latitude – northern North America, Asia,
Greenland
About 20% of the earth’s surface
3. Structure
•
•
Simple – low spongy mat of vegetation, lichens, mosses
Even trees are less than knee high
4. Relative Productivity
•
Low – limited by temperature and insolation
Tundra Distribution
Tundra
• Treeless spongy mat of
low growing plants
• Common breeding area
b/c predators visible
• Organisms migratory
• Cold & Windy & Dark
• Ice & snow cover
• Low precipitation but
poor drainage b/c
Permafrost
Polar grassland (arctic tundra)
(Fort Yukon, Alaska)
Long-tailed jaeger
Grizzly bear
Producer to
primary
consumer
Caribou
Primary to
secondary
consumer
Mosquito
Snowy owl
Arctic
fox
Horned lark
All consumers
and producers
to decomposers
Willow ptarmigan
Dwarf
Dwarfwillow
willow
Lemming
Mountain
Mountaincranberry
cranberry
Moss campion
campion
Moss
Secondary to
higher-level
consumer
Forest Types
• Undisturbed areas with moderate to high
rainfall
• Dominated by various species of trees and
other vegetation
• 3 main types of forest – Tropical,
Temperate, Boreal
World Distribution of Forests
Temperate coniferous forests
Temperate deciduous forests
Tropical rain forests
Tropical Rainforest
1.
Climate
•
•
•
2.
Precipitation over 150 cm / yr – Wet – still rainy and dry seasons
Warm humid year round climate  80 °F
high insolation gives long growing season
Distribution
•
•
•
3.
23.5 °N to 23.5 °S latitude – Tropic of Capricorn to Cancer
About 2% of the earth’s surface
Three chunks – S. & C. America, C. Africa, SE Asia
Structure
•
•
4.
Complex – stratified layers
High diversity - 50-80% of terrestrial species
Relative Productivity
•
Highest in terrestrial system – unlimited by temperature and insolation
• Tropical Rainforest
• Broadleaved evergreen trees
• High biological diversity,
Specialized niches,
• Much of animal life found in
canopy layer
• Stratification of life in different
tree layers increases niche
partitioning
• Paradox  high diversity but
very poor soils
• Rapid recycling of nutrients
• Little nutrients stay in soil
most taken back into plants
• Dense forest limits wind 
animal pollinators
Tropical
Rainforest
Tropical rain forest
(Manaus, Brazil)
45
Harpy
eagle
40
35
Height (meters)
Emergent
layer
Toco
toucan
Canopy
30
25
20
Understory
Wooly
opossum
15
10
Brazilian
tapir
5
Black-crowned
antpitta
0
Shrub
layer
Ground
layer
Harpy
eagle
Blue and
gold macaw
Ocelot
Producer
to primary
consumer
Primary
to secondary
consumer
Squirrel
monkeys
Climbing
monstera palm
Secondary to
higher-level
consumer
Katydid
Slaty-tailed
trogon
Green tree snake
Tree frog
Ants
Bromeliad
Fungi
Bacteria
All producers and
consumers to
decomposers
Diverse forests cleared
Replaced with monospecific
stands – tree plantations
Songbird species often
spend time in these areas
Top predators hunted out
and displaced
Fragmentation of habitats
Forests
Temperate deciduous forest
(Nashville, Tennessee)
• Temperate Forests
• Significant seasonal
changes
• Abundant precipitation
throughout year
• Dominated by a few
broadleaved deciduous
trees
• Simple structure
• Thick layer of leaf litter
• Once diverse, now
predators gone
Broad-winged
hawk
Producer
to primary
consumer
Hairy
woodpecker
Primary
to secondary
consumer
Gray
squirrel
White oak
White-footed
mouse
White-tailed
deer
Metallic
Metallic woodboring
beetle
wood-boring
and
larvae
beetle
and
Mountain
winterberry
Shagbark hickory
May beetle
Fungi
Bacteria
Long-tailed
weasel
Racer
Wood frog
Secondary to
higher-level
consumer
All producers and
consumers to
decomposers
Forests
• Boreal Forests (Tiaga)
• Just below tundra
• Dominated by coniferous
tree species
– Withstand cold, rapid
growth in summer
• Low temperature
– Low decomposition, high
soil acidity
• In summer soil is
waterlogged = muskegs
Polar evergreen coniferous forest
(boreal forest, taiga)
(Moscow, Russia)
Blue jay
Great
horned
owl
Marten
Balsam fir
Moose
White
spruce
Producer
to primary
consumer
Primary
to secondary
consumer
Secondary to
higher-level
consumer
Wolf
Bebb
willow
Pine sawyer
beetle and larvae
Snowshoe
hare
Fungi
Starflower
Bacteria
Bunchberry
All producers and
consumers to
decomposers
Human Effects on Forests
Clearing and degradation of tropical
forests for agriculture, livestock grazing,
and timber harvesting
Clearing of temperate deciduous
forests in Europe, Asia, and
North America for timber, agriculture,
and urban development
Clearing of evergreen coniferous
forests in North America, Finland,
Sweden, Canada, Siberia,
and Russia
Conversion of diverse forests to less
biodiverse tree plantations
Climatograms Review