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Chemical CyclesEarth is always receiving energy from the sun. Is this an open or closed system?

Is Earth also receiving new matter? Is this an open or closed system?

Major Environmental CyclesWater, carbon, nitrogen, phosphorus

Biogeochemical Cycles• Chemical elements available only in limited

amounts• Movement of essential elements between

the biotic and abiotic environment – Decomposition allows these cycles to occur!

• Carbon Cycle• Nitrogen Cycle• Phosphorus Cycle• Water Cycle (Hydrological cycle)

Hydrologic /Water Cycle

• The Water Cycle - the cycling of water through the earth system. – The hydrologic cycle

is a cycle of water AND energy

• Evaporation, Condensation, Precipitation, Transpiration, Infiltration, Interception

What is the Carbon Cycle?• The Carbon Cycle – the continual cycle created as

plants/ photosynthetic organisms use carbon dioxide and release oxygen, while other organisms use oxygen and release carbon dioxide

What is the Carbon Cycle?– In addition when organisms die their carbon becomes

part of the soil and over time can be converted to oil and gas

What is the Oxygen Cycle?• The Oxygen Cycle –

balance of oxygen/ carbon dioxide on Earth– Water can dissolve

oxygen– Oxygen is needed for

the decomposition of dead organisms

**NOTE: ENERGY FLOW IS NOT CYCLICAL, BUT NUTRIENTS DO CYCLE!**

What is the Nitrogen Cycle?• Nitrogen comprises 78.08 % of the

atmosphere

• Nitrogen is important in the make up of organic molecules like proteins.

• Unfortunately, nitrogen gas is inaccessible to most living organisms.

• Nitrogen must be “fixed” by soil bacteria, by chemically combining nitrogen in the air to form nitrates (NO3) and ammonia (NH3) making it available to plants.

• Organisms that feed on the plants ingest the nitrogen and release it in organic wastes.

• Bacteria frees the nitrogen from the wastes returning it to the atmosphere.

What is the Phosphorus Cycle?• Phosphate salts that are released

from rocks through weathering usually dissolve in soil water and will be absorbed by plants.

• Because the quantities of phosphorus in soil are generally small, it is often the limiting factor for plant growth. That is why humans often apply phosphate fertilizers on farmland.

• Do you know of any issues associated with fertilizers/excess phosphorus?

Phosphorus can be found on earth in water, soil and sediments.

Unlike the compounds of other matter cycles phosphorus cannot be found in air in the gaseous state.

Eutrophication: nutrient enrichment of lakes mostly from runoff of plant nutrients (nitrates & phosphates)

Eutrophication of Lakes

Eutrophication

Dead Zones• Dead zones are hypoxic (low-oxygen)

areas in the world's oceans and large lakes, caused by "excessive nutrient pollution from human activities coupled with other factors that deplete the oxygen required to support most marine life in bottom and near-bottom water

• Less oxygen dissolved in the water is often referred to as a “dead zone” because most marine life either dies, or, if they are mobile such as fish, leave the area.

• Over the past five years, dead zones have averaged about 6,000 square miles.

• Last year, smallest in 18 year history 1,580 square miles of hypoxia due to historical drought

Human activity

How do and can humans bring change to a community?

Human Impact

EFFECT ON NATURAL PROCESSES– Erosion of Soils

• Agricultural practices have exposed soil to the weather resulting in great loss of topsoil.

– Control of the Water Cycle• The cutting of forests and

other human activities have allowed increased uncontrolled runoff leading to increased erosion and flooding.

Think of humans as a non-native species to many habitats. Due to humans many natural processes are drastically changing in a harmful manner.

Removal of wastes• Untreated sewage wastes and

runoff from farms and feedlots have led to increased water pollution.

Nutrient Recycling• The use of packaging material

which does not break down, burning of refuse, and the placing of materials in landfills prevents the return of some useful materials to the environment.

Effect on natural processesEnergy Flow

Some industries and nuclear plants have added thermal pollution to the environment. The release of some gases from the burning of fossil fuels may be slowly increasing the Earth's temperature. (Greenhouse Effect).

What are the Effects of Human Activities?

• Population Growth – our increasing population limits resources

• Overconsumption – factories are able to mass produce products, thus utilizing natural resources

• Technology – often introduced without knowing the effect on the environment

• Pollution – factories, companies and individuals contaminate air, land and water

• Logging and Deforestation – forests are cut to make way for expansion and trees cut for wood, paper, etc. ruining entire habitats

• Hunting – humans hunt for food, sport, clothes, etc. often in excess and using little or no parts of the animal

What are the Strategies for Prevention? • Social Awareness• Wildlife refuges and national

parks• Wildlife management laws,

such as game laws and catch restrictions

• Reducing pollution• Increased use of

biodegradable packaging materials will breakdown quickly in landfills

• Use fuels/energy that contain less pollutants

• Eating less red meat!

Climate changes

Tsunamis, hurricanes, global warming, green house effect, and acid rain

How does Climate Changes affect Ecosystems?

• Climate variability and change has broad effects on physical and ecological attributes of ecosystem composition, structure, and function

• Vegetation and Animal response to climate changes varies, yet vegetation often shows first signs of effect

• Some changes are more “natural” than others; such as thunderstorms, hurricanes, tsunamis, however many of these weather conditions are becoming intensified largely due to human activity.

• The Greenhouse gases will accumulate resulting in warmer temperatures and changes in ecosystems.

What is the Greenhouse Effect?

• The greenhouse effect is the rise in temperature that the Earth experiences because certain gases in the atmosphere (carbon dioxide, methane) trap energy from the sun

• Without these gases, heat would escape back into space and Earth’s average temperature would be about 60ºF colder.

• Caused as a result of household cleaners, forest destruction, and pollution

Why is there Global Climate Change?Reasons

• Naturally the earth goes through cycles of warmer and cooler weather, however this warming is becoming intensified due to humans– Power plant emissions – heat

trapping gases– Vehicle emissions – heat

trapping gases– Forest Destruction – forests

naturally absorb CO2, but we are cutting forests thus losing their absorbing abilities

– Household products

Global Warming

Effects• Heat Waves• Disease• Severe Storms• Water Shortages• Rising Sea Levels• Reduction of biodiversity• Receding glaciers

Effects of Climate Change On Plants:• Slower growth, less crops• Abnormal rainfall (too much/too little) prevents normal plant growth • Increased CO2 plants are unable to use it fast enough, stays in atmosphere

On Animals: • Decrease in animal population/endangerment/extinction as a result of

changing biomes, environments, food sources, etc.

ON a separate sheet of paper- will be cover sheet of your stamped sheet (Bellringer):

1) Title it stamped sheets2) Draw the Hydrologic cycle, Carbon cycle, and the Nitrogen

cycle.3) Write down how you know the difference between the

three: (DO NOT SAY: Carbon, Nitrogen, and Water)