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”?

What is symbiosis?– What are the different types?

What is succession?• a series of ecological changes in

an ecosystem over timeWhat are the 2 types of succession?

• Primary & SecondaryFrom Pioneer Stage Climax Community

REVIEW – What we’ve covered so far…

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?

Geosphere

Biota

Atmosphere: the air blanketing Earth’s solid and liquid surfacesHydrosphere: all Earth’s water, ice, and water vaporGeosphere: Earth’s surface (continents, rocks, and sea floor) and everything below Earth’s surfaceBiota: collection of LIVING things in the biosphere (biotic factors)Biosphere: includes biotic and abiotic factors on Earth

BiomesLarge regions of ecosystems characterized by similar abiotic conditions and climax communities

–Distinctive biomes prevail at certain latitudes and elevations

http://www.blueplanetbiomes.org/rnfrst_animal_page.htm

• 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.

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

http://www.runet.edu/~swoodwar/CLASSES/GEOG235/biomes/tundra/tundra.html

• Located North of the Arctic Circle• Coldest biome• Permafrost• Plants grow close to the ground• Few predators• Little Competition

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

Fresh and salt water meet…

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:

1. Dumped – land/water river/lake/ocean

2. Enter the food chain

3. Harm the aquatic & terrestrial life

4. 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

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

methane (CH4) water (H2O)

carbon dioxide(CO2)

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