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Ecology Unit. REVIEW – What we’ve covered so far…. What is the organization of ecological study? Organism → Population→Community→Ecosystem→Biome Biosphere Abiotic vs. biotic factors What are they? What’s the difference? What is the difference between “habitat” and “niche”?
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REVIEW – What we’ve covered so far… • What is the organization of ecological study? Organism →Population→Community→Ecosystem→BiomeBiosphere • Abiotic vs. biotic factors • What are they? What’s the difference? • What is the difference between “habitat” and “niche”? • What is symbiosis? • What are the different types?
REVIEW – What we’ve covered so far… • What is succession? • a series of ecological changes in an ecosystem over time • What are the 2 types of succession? • Primary & Secondary • From Pioneer Stage Climax Community
Primary Succession No previous ecosystem (uninhabited) Soil must be created Pioneer species are the 1st to colonize areas – bacteria, algae, moss, lichen
Secondary Succession An existing ecosystem is disturbed Soil and some organisms may remain Remaining species such as small grasses repopulate first
Climax Community Ecological succession will occur until a climax community is reached. A climax community is when the plant life has reached a stable state
What would this be? • A volcano erupts in the ocean. When the lava cools, a barren rock is made. The rock becomes inhabited by mosses and lichen which over time will produce soil. This is an example of ______________ succession. • PRIMARY • WHY?
Atmosphere: the air blanketing Earth’s solid and liquid surfaces Hydrosphere: all Earth’s water, ice, and water vapor Geosphere: Earth’s surface (continents, rocks, and sea floor) and everything below Earth’s surface Biota: collection of LIVING things in the biosphere (biotic factors) Biosphere: includes biotic and abiotic factors on Earth Biota Geosphere
Biomes • Large regions of ecosystems characterized by similar abiotic conditions and climax communities • Distinctive biomes prevail at certain latitudes and elevations
Plants grow in layers (canopy receives most light) • Soil is so thin and poor in nutrients • high biodiversity and biomass • Found near equator…little variation in temperatures. No distinct seasonal changes. http://www.blueplanetbiomes.org/rnfrst_animal_page.htm
Much of the human population lives in this biome • Characterized by an abundance of leaf bearing trees • Distinctive seasons • Trees adapt to varied climate by becoming dormant in winter • Deep soil layers, rich in nutrients
Winters are long and cold • Soil poor in nutrients and very acidic • Growing season is very short • Animals burrow, hibernate, warm coat, insulation, etc
Contain the greatest number of grazing animals on Earth. • Found in the tropics…near equator
High winds • Because of the dry climate, trees are found only near water sources such as streams
Little to no topsoil due to high winds. • Minerals not deep in soil. • Too dry for decay • Plants have spines
Located North of the Arctic Circle • Coldest biome • Permafrost • Plants grow close to the ground • Few predators • Little Competition http://www.runet.edu/~swoodwar/CLASSES/GEOG235/biomes/tundra/tundra.html
Marine or Freshwater?? • Salinity <0.5 ppt. • Sun can reach bottom • Fed by rainfall • Plants are floating algae and plants along shoreline • Animals live in or near water
Let’s take a closer look at climate • There is a difference between climate and weather. • Weather consist of conditions of the atmosphere from the day-to-day • Climate consist of the weather patterns in a region, averaged over a long period of time (Typically 30 years or more)
Climate is affected by… • Amount of incoming solar radiation • Prevailing winds • Ocean currents/circulation • Proximity to oceans and mountains • Elevation
What causes the seasons to change? • Northern end of Earth’s axis tilts toward sun in June and away in December • Difference in tilt causes differences in sunlight intensity and day length • The greater the distance from the equator, the more pronounced the seasonal changes
Human Population Growth and Natural Resources • Approximately how big is the Earth’s population?? • Over 6 BILLION… • Technology has helped to increase Earth’s carrying capacity. • gas-powered farm equipment • medical advancements
Human Population Growth and Natural Resources • The growing human population exerts pressure on Earth’s natural resources. • Nonrenewable resources are used faster than they form. • coal • oil • Renewable resources cannot be used up or can replenish themselves over time. • wind • water • sunlight
Apply the Concept… • Out of the following list of resources, label them as renewable or nonrenewable: • Soil • Coal • Trees • Sun • Water • Natural gas • Wind
Human Population Growth and Natural Resources • 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
Human Impact How are humans affecting ecosystems all over the Earth?
Threats to Biodiversity • Introduced Species • is one that is brought to an ecosystem by humans whether accidentally or purposefully. • Habitat Destruction • Habitat Fragmentation • prevents an organism from accessing its entire home range • Habitat Degradation • Air, Water, and Soil Pollution
Invasive Species • Non-native organisms that “move-in” to a particular area • There can be a lack of competitors which leads to exponential growth • Out-compete natives for resources
Loss of Diversity • Threatened Species • Endangered Species • Extinction of Species • Believe it or not….99.9% of all once living species are now extinct! • How big is the problem?
Chemical Pollution Cycle • Pollution added to the environment will cycle & ultimately reach humans: • EX: Chemicals are: • Dumped – land/water river/lake/ocean • Enter the food chain • Harm the aquatic & terrestrial life • Threaten humans
BIOMAGNIFICATION • A concentration INCREASE in a chemical as it moves up the trophic levels
Let’s talk about 3 other HUGE human impact global problems… • Ozone Layer Depletion • Acid Rain • Global Warming
Humans & The Environment • Ozone (O3) Depletion • O3 forms a “good layer” around the Earth • CFC release is breaking down the protective ozone layer • CFC’s are used in refrigeration equipment • UV rays increase skin cancers & other cell mutations to plants & animals! ●
Humans & The Environment • Acid Precipitation • rain, snow, dew or fog • Created when gases such as nitrogen oxide (NO2) and sulfur oxide (SO2), come from the burning of fossil fuels (coal and oil) • They react in the atmosphere with sunlight to produce acids… • These acids dissolve in water to become acid precipitation
How is Acidity Measured? • Acidity is measured in units called pH. • The pH scale = 0 to 14 • pH 7 indicates neutral • higher pH numbers = base • smaller numbers = acid
carbon dioxide(CO2) methane (CH4) water (H2O) Global Warming = Climate Change • Global warming refers to the trend of increasing global temperatures. • “The Greenhouse Effect” • Greenhouse gases slows the escape of heat from Earth’s surface • Fossil fuels give off lots of CO2 • This builds a blanket around the earth
Conservation • Conservation methods can help protect and restore ecosystems • The Environmental Protection Agency (EPA) develops policies and regulations to protect the environment. • Clean Air Act • Clean Water Act • US Endangered Species Act • Made it illegal to harm any species on the endangered OR threatened list • Including changing an ecosystem where the species lived
Conservation • Nature preserves • Protects entire communities/ecosystems