Transcript Biomes and Ecosystems

Biomes and Ecosystems
Human Impact and Earth Systems
Review
• We have studied how the main elements of
life (C, N, O, H2O, P) cycle through ecosystems.
• We have studied how energy moves through
ecosystems.
• Now it is time to study ecosystems
themselves.
This Unit – Biomes and Ecosystems
Systems thinking:
• Earth systems (atmosphere, biosphere,
geosphere, hydrosphere, cryosphere)
• Biomes – Regions where non-living Earth
systems interact to form unique conditions
that foster the growth of a unique
combination of organisms in the biosphere
• Ecosystems – can range from macro (biome)
to micro (fish bowl, under log, under arm)
VOCAB
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Species
Individual
Population
Community
Ecosystem
Biome
TERRESTRIAL BIOMES
Tundra
Taiga
Deciduous
Tropical rainforest
Desert
Savanna
Grasslands
Chaparral
Alpine
MARINE and AQUATIC BIOMES
Estuary
Wetland (temperate)
Swamp (tropical)
Reef
Riparian
Lake
Ocean
BIOME MAP
BIOMES
• Characterized by climate – temperature and
precipitation
• Each biome has a characteristic latitude 
amount of direct sunlight during specific months of the year
• Each biome is also determined by geographic
components--coastline vs inland, elevation 
proximity to water moderates temperatures
elevation moderates temperature
rainshadow effect affects moisture
Hypothesize:
Which city in Russia is
most inland?
Which city in Russia is
southernmost?
WHY do you think so?
Climate is represented graphically
Annual
temperature and
rainfall can be
broken down
into monthly
averages and
graphed into
what is called a
CLIMATOGRAM
Assignment 1
Given: a data table of monthly precipitation and
temperature* for a specific location:
1. Construct a climatogram
2. Hypothesize its geographic location
3. Hypothesize its biome
4. Justify your claims by considering slide 5
*open tempPrecipdata.docx
Website that contains many climatograms…
What about L.A.?
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Climatogram
Latitude, longitude, elevation, coastal/inland?
Name of Biome
Soil type – geologic history
Native plants (flora)
Native animals (fauna)
Human impact
LA Climatogram
Latitude, longitude, elevation
34° 3' 8" N / 118° 14' 34" W, 71 meters
Biome - Chaparral
• Very hot and dry -- winters are mild 10 °C,
summers are so hot and dry at 40 °C that fires
and droughts are very common.
• Plants are adapted to these conditions. Most
plants have small, hard leaves which hold
moisture. Examples: poison oak, scrub oak, Yucca
Wiple and other shrubs, trees and cacti.
• Animals are mainly grassland and desert types
adapted to hot, dry weather. Examples: coyotes,
jack rabbits, mule deer, alligator lizards, horned
toads, praying mantis, honey bee and ladybugs.
LA Geology / Soil
Los Angeles area is located over a
deep sedimentary basin with hills
composed of folded Miocene and
Pliocene sedimentary rocks
(suggesting it was once covered by
water).
The basin is rimmed by the
crystalline rocks of the Santa Monica
Mountains and the San Gabriel
Mountains (suggesting volcanic
origins).
Excavation shows mostly sand and
silt, not particularly fertile soil.
LA – Human Impact
• LA River – channeled to prevent flooding
• Water use – saltwater intrusion in groundwater
• Paved surfaces - watershed pollution carried by
runoff into ocean
• Oil and gas drilling, groundwater pollution
• Fossil fuels combustion – air pollution
– Smog
– Ground level ozone
• Invasive species
Summary of Biomes - Tropical
• Humid tropical regions are the most complex and
biologically rich
• Soil is nutrient -poor because decomposition and
photosynthesis occur at an accelerated rate
• Nutrients are contained in living organisms
• When living organisms are removed, the biome
cannot repopulate due to loss of nutrients
• Tropical rainforests (and their biodiversity) are
endangered due to human activity
Summary: Grasslands & Savannas
• Too little rainfall to support trees
• Have rich soils and are now used extensively
for agriculture and grazing
• Overgrazing livestock threatens native animals
and plants
• Monoculture threatens the multi-layered
ecosystems that re-enrich soil
• Human exploitation  soil erosion, loss of
habitat for animals
Deserts
• Less than 30 cm rain per year
• Plants and animals specially adapted to these
conditions
Deciduous forests
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Temperature ranges from -30°C to 30°C
Four seasons – lose leaves in autumn
75-150 cm rainfall/yr
Can regenerate since decomposition and
photosynthesis is slower than tropical
• Extensive human exploitation  loss of habitat
for animals
• Not ideal for agriculture, although some does
take place
Coniferous forests
• Boreal warmer than Taiga
• Forests are mostly cone-bearing (coniferous)
also called evergreens (do not lose leaves)
• Needles preserve moisture, cones protect
seeds
• Tolerant of cold temperatures
• Human exploitation has caused loss of habitat
for animals
Tundra
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Far northern latitudes
Cold temperatures
Short growing season
Permafrost
Migratory area for birds and sea mammals
Not threatened by human activity, but
impacted by climate change
Marine
• Photosynthetic organisms support the food
web (mostly algae)
• Vertical stratification is a key concept
• Temperature, light penetration, salinity vary at
different strata or Zones
• Cold water holds more oxygen than warm
water
Marine Ecosystems Biodiversity
• Kelp forests – temperate latitudes
• Coral Reefs – tropical latitudes, shallow water
• Mangroves – tropical latitudes, forests and
swamps growing in salt water along coastlines
that stabilize and protect shorelines
• Estuaries – nutrient rich bays where fresh and salt
water meet and mix
• Barrier islands – protect shorelines and bays
All are endangered due to human activity.
Freshwater Ecosystems
• Lakes also have strata or zones by light,
temperature, oxygen
• Centers of biodiversity because they are reliable
sources of water to land animals
• Aquatic ecosystems are highly impacted by
phosphorus and nitrogen nutrient excess
(eutrophication)
• Riparian – river and banks
• Wetlands – filtering system for runoff, high
concentration of nutrients, plants, “nursery” for
fish, amphibians, birds, etc.
Human impact
• Habitat disruption by humans’ creates the
most serious damage to ecosystems
• Temperature deciduous forests are the most
dominated by humans (lumber)
• Grassland and chaparral are highly impacted
(agriculture overuses soil)
• Tundra and arctic biomes are least disturbed
due to low productivity