Transcript Ecology Chp 15-16 2015

15.3 KEY CONCEPT
Biomes are land-based, global communities of
organisms.
Earth has six major biomes.
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Rainforest
Grassland (tropical and temperate)
Desert
Temperate Forest (deciduous and rain)
Taiga
Tundra
• There are a variety of ecosystems in each biome.
• The biomes are characterized by abiotic factors
• The same biomes in different areas of earth have similar plant and
animal species. Ex: tropical rainforest (Brazil and Madagascar)
• Tropical rain forest
biomes produce lush
forests.
– warm temperature
– abundant precipitation all year
The tropical rain forest can be found in three major
geographical areas around the world.
- Central America in the Amazon river basin.
- Africa - Zaire basin, with a small area in West Africa;
also eastern Madagascar.
- Indo-Malaysia - west coast of India, Assam, Southeast
Asia, New Guinea and Queensland, Australia.
Source: World Meteorological Organization
• Grassland biomes are where the primary plant life is
grass.
– Temperate grasslands are dry and warm during the summer; most
precipitation falls as snow.
– Tropical grasslands are warm through the year,
with definite dry and rainy seasons.
Rapid City, South Dakota
• Desert biomes are
characterized by a very arid
climate.
– very low amount of
precipitation
– four types: hot, semiarid, coastal, and cold
Tucson, Arizona
Source: National Oceanic Atmospheric Administration
• Temperate forest biomes include deciduous forests and
rain forests.
– Temperate deciduous forests have hot summers and
cold winters.
– Deciduous trees are the dominant plant species.
– The temperate rain forests have a long wet season
and relatively dry summer.
– Ferns and moss
cover the forest floor.
• The taiga biome is located
in cooler northern climates.
– boreal forest
– long winters and short
summers
– small amount of
precipitation
Banff, Canada
Source: Environment Canada
• The tundra biome is found
in the far northern latitudes
with long winters.
– winter lasts 10 months
– limited precipitation
– permafrost
Barrow, Alaska
Source: National Oceanic Atmospheric Administration
Polar ice caps and mountains are not considered biomes.
• Polar ice caps have no soil, therefore no plant community.
• The climate and organisms found on mountains change as
the elevation changes.
Marine Ecosystems
• A. Ocean Zones
• 1. Intertidal zone:
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Area of beach that you walk on.
2. Neritic Zone:
Coral Reefs and Kelp Forests. A few cm – 200
meters deep; intertidal zone out to
continental shelf
3. Bathyal Zone:
200 – 2000 meters; turbid murky water due
to silt; includes mostly burrowing animals.
4. Abyssal Zone:
Below 2000 meters, complete darkness,
deep sea vents and chemosynthetic organisms.
Estuaries and Freshwater Ecosystems
• Estuary: A partially enclosed body of water formed where a river flows into an
ocean. Ex: San Francisco and Chesapeake Bays, Everglades. Includes harbors,
sounds, and inlets. Mixture of freshwater and salt water. High level of nutrients, life
thrives here. Lots of biodiversity
Freshwater Ecosystems
• River, streams, lakes, ponds, wetlands (bogs, swamps,
marshes): all originate from watersheds.
• Watershed: a region of land that drains into a river, river
system, or another body of water.
16.1 KEY CONCEPT
As the human population grows, the demand for
Earth’s resources increases.
Earth’s human population continues to grow.
• Earth’s human carrying capacity is unknown. J or S?
• Technology has helped to increase Earth’s carrying
capacity.
– gas-powered farm
equipment
– medical
advancements
The growing human population exerts pressure on
Earth’s natural resources.
• Nonrenewable resources are used faster than they form.
– Coal
– Oil
– Natural Gas
• 77 million barrels per day are used (2006)
• Our dependency on these resources is depleting them.
• Renewable resources cannot be used up or can replenish
themselves over time.
– wind
– water
– sunlight
Effective management of Earth’s resources will help meet
the needs of the future.
• Earth’s resources must be used responsibly.
• Careless use of resources makes them unavailable to
future generations.
• Easter Island is
an example of
irresponsible
resource use.
• An ecological footprint is the amount of land needed to
support a person.
• The land must produce and maintain enough
– food and water
– shelter
– energy
– Waste
• Several factors affect the size of the ecological footprint.
– amount and efficiency of resource use
– amount and toxicity of waste produced
• Ecological Footprint 9.7 hectares = 24 football fields
• Hectare = 10,000 square meters
16.2 KEY CONCEPT
Fossil fuel emissions affect the biosphere.
Pollutants accumulate in the air.
• Pollution is any undesirable
factor added to the air, water, or
soil.
• Smog is one type of air pollution.
– sunlight interacts with
pollutants in the air
– pollutants produced by fossil
fuel emissions
– made of particulates and
ground-level ozone
– Smog can be harmful to
human health.
• Acid rain is caused by fossil fuel emissions.
– produced when pollutants in the water cycle cause rain
pH to drop
– can lower the pH of a lake or stream
– can harm trees
Air pollution is changing Earth’s biosphere.
• The levels of atmospheric carbon dioxide rise and fall over
time.
• High levels of carbon dioxide are typical of Earth’s warmer
periods.
• The greenhouse effect slows the release of energy from
Earth’s atmosphere.
– sunlight penetrates Earth’s atmosphere
– energy is absorbed and reradiated as heat
– greenhouse gases absorb longer wavelengths
– Greenhouse
carbon dioxide
(CO )
gas molecules
methane (CH )
water (H O)
rerelease
infrared
radiation
2
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• Global warming refers to the trend of increasing global
temperatures.
North Pole
16.4 KEY CONCEPT
The impact of a growing human population threatens
biodiversity.
Preserving biodiversity is important to the future of the
biosphere.
• The loss of biodiversity has long-term effects.
– loss of medical and technological advances
– extinction of species
– loss of ecosystem stability
Loss of habitat eliminates species.
• Habitat fragmentation prevents an organism from
accessing its entire home range.
– occurs when a barrier forms within the habitat
– often caused by human development
– Habitat corridors are a solution to the problem.
– allow species to move between different areas of
habitat
Introduced species can disrupt stable relationships in an
ecosystem.
• An introduced species is one that is brought to an
ecosystem by humans.
– accidental
– purposeful
• Invasive species
can have an
environmental
and economic
impact.
• Invasive species often
push out native species.
16.5 KEY CONCEPT
Conservation methods can help protect and
restore ecosystems.
Sustainable development manages resources for present
and future generations.
• Sustainable development meets needs without hurting
future generations.
– resources meet current needs
– resources will still be available for future use
Conservation practices focus on a few species but benefit
entire ecosystems.
• The Environmental Protection Agency
(EPA) was created in 1970.
• The EPA develops policies and
regulations to protect the environment.
• Legislation helps to protect the
environment and endangered species.
– Clean Air Act
– Clean Water Act
– Endangered Species Act
• The National Park Service helps
manage public lands.
• There are several ways that people can help protect the
environment.
– control population growth
– develop sustainable technology and practices
– protect and maintain ecosystems