Section 6-2: Renewable & Nonrenewable Resources

Overgrazing Grazing on commons 100 yrs ago in England Land became overused No longer able to support cattle AKA “Tragedy of the Commons”

Tragedy of the Commons Refers to the idea that any resource can be destroyed through overuse Groundwater Fish populations Whales: Some whales were hunted to near extinction Who is responsible for protecting a resource?

6–2 Renewable and Nonrenewable Resources A. Classifying Resources B. Sustainable Development C. Land Resources D. Forest Resources E. Fishery Resources 1. Overfishing 2. Sustainable Development 3. Aquaculture F. Air Resources G. Freshwater Resources Section 6-2 Section Outline

A. Classifying Resources Renewable or Nonrenewable Resources

Renewable or Nonrenewable Can regenerate or be replenished Example: A tree can grow in place of an old tree Not necessarily an unlimited resource - example water! One that cannot be replenished (by natural processes) Fossil fuels, oil, natural gas When depleted, they are gone forever

B. Sustainable Development Meeting our needs while maintaining the ecosystem.

Sustainable Development This is one possible answer to how we can meet our needs. Using natural resources without: *depleting them *causing long term ecological damage

Sustainable Development & Human Activities Our activities affect the quality & supply of renewable resources Air Land Forests Fisheries Freshwater

Sustainable development Must keep in mind: Function of the ecosystem How human economics work What humans need to live

C. Land Resources

Land Resources Space for human communities and cities Raw materials for industry Soils for farming Soil fences like these limit soil erosion during development or building homes

Soils If managed properly, soils can be a renewable resource Here is a form of erosion control If it is not managed properly, it can be lost

Topsoil Good topsoil is maintained by the interaction of plants and the soil Deep rooted plants help retain soil in wind and rain Good topsoil is able to retain moisture and nutrient

Topsoil Plowing (tilling) removes the roots that help hold the soil in place This increase soil erosion (desertification) Some farmers now practice contour farming and no-tilling farming

Erosion Erosion can be due to Climate changes Overgrazing Drought Farming practices

Desertification This process has led to severe erosion of many soils It may be due to drought, farming practices, or both

D. Forest Resources Ecology and Products

Forests Wood is used for homes and for paper Wood is used as a fuel for cooking or heating The forest is the “lungs of the Earth” - CO2 & O2 Forests also store nutrient

Forests * Store nutrients *Provide habitat & food *Moderate climate *Limit soil erosion *Protect Freshwater supplies

Forests Renewable: Nonrenewable: Temperate deciduous forests They grow back Nonrenewable: Old growth forests Many centuries to “re- grow” so in effect nonrenewable Hartwick Pines is considered an “old growth” forest Forests

Forests Deforestation - loss of forests Can lead to erosion Grazing or plowing after deforestation can permanently damage the ecosystem

Forest Sustainable Development Strategies Selective harvesting Plant, manage, harvest, and then replant Tree farming Genetic breeding of plants

Managing fish & other organism that live in water E. Fishery Resources Managing fish & other organism that live in water

Fishery Resources Effectively managing fresh, salt water Recent collapses in the fishery industry illustrates the “tragedy of the commons”.

Harvesting fish faster than they can be replaced E-1. Overfishing Harvesting fish faster than they can be replaced

Overfishing Between 1950 - 1990 the world fish catch grew from 19 to 90 million tons Many fish populations began to decrease Cod and haddock had dropped Another example of the “tragedy of the commons” - no one country would take responsibility

Amount of Fish per Person Growth of Fish Catch Section 6-2 World Fish Catch World Fish Catch per Person (million tons) Total Catch Year Year Amount of Fish per Person (kilograms)

E-2: Sustainable Development Fishery Resources

Sustainable Development of Fisheries? Ecologists collect data on fish Size Growth Rate Populations This created guidelines for the fishing industry How many? What size? Where caught?

E-3: Aquaculture Fish farming.

Aquaculture Raising of aquatic animals for human consumption Helps sustain fish resources Must be properly managed to prevent pollution

A challenge for society is to maintain air quality. F. Air Resources A challenge for society is to maintain air quality.

Air Resources Smog is a growing problem Mixture of chemicals that creates a “haze” Due to automobile exhaust & industrial emissions L.A. Smog

Smog Threatens those with asthma & other respiratory diseases Considered a pollutant: a harmful material in the biosphere Pollutant: present in land, air, or water Smog

Fossil Fuels Nitates Sulfates Particulates - ash, dust Fossil fuels release pollutants into the atmosphere Nitates Sulfates Particulates - ash, dust Cause health problems

Control of fuel emissions Factories (some) use technology to reduce emissions Automobiles have emission controls (catalytic converters) Air quality legislation

Fossil Fuels & Emissions Burning fossil fuels releases nitrogen & sulfur compounds When they combine with water vapor they produce nitric & sulfuric acid One product is acid rain

Acid Rain Acid rain can kill plants and trees by changing the water chemistry It may dissolve or release other toxic elements (mercury)

Chemical Transformation Emissions to Atmosphere Figure 6-12 The Formation of Acid Rain Section 6-2 Chemical Transformation Nitric acid Sulfuric acid Condensation Emissions to Atmosphere Nitrogen oxides Sulfur dioxide Dry Fallout Precipitation Acid rain, fog, snow, and mist particulates, gases Industry Transportation Ore smelting Power generation

G. Freshwater Resources Although a renewable resource, the total supply is limited.

Freshwater We use billions of water daily ! Drinking Washing Watering crops Making steel

Maintaining our fresh water supply is a high priority in society Water pollution threatens water supplies in many ways Freshwater

Sources of Water Pollution Improperly discarded chemicals Waste discharge into ground water Domestic sewage from sinks, toilets contain Nitrogen that affects algae

Water More than 3/4 of all water is consumed in agriculture Drip irrigation is one way to conserve water

Water Cycle Protection of the water cycle Reduce the loss of wetlands that purify water Restore forests that also help purify water

Water The demand for water continues to grow In what ways can you conserve water? Water conservation Homes Agriculture Industry