Resources

What are Resources?

• Humans are most consistently impacting their environment through their quest for resources.– The types of resources are limitless, but can

basically be defined as an environmental factor that is desirable to somebody.

– Basically if there is somebody who wants something, we can consider it a resource

When resources are freely availableThe Tragedy of the Commons- Garrett Hardin (1968)1. “commons” – any freely available resource shared by a

group of people– Ex. Fish, forests, clean air, water, pasture land, etc.

2. Hardin believed that people are greedy and will act in their own short-sighted self-interest, depleting resources until the “commons” collapses

– Each person attempts to maximize their portion of the resource at the expense of others

3. As populations density increases, “commons tragedies” increase.

4. Take home message: Any resource openly shared will eventually be destroyed because everyone will use it and no one will be responsible for preserving it

Human Activities- Tragedy of the CommonsOverexploitation of cod fishery- grand banks. Fishery was found in international waters, so boats from many different countries were harvesting fish. Each group was racing to catch the fish before another ship. No one was concerned about the stability of the fish population, only their own profits.

Quick Activity

• Classify the following resources as renewable or nonrenewable with your seat partner:– Solar energy– Wind/air– Water – Fossil fuels– Metals – Soil – Plants – Animals

Types of Resources• Environmental resources can be classified into two categories:– Renewable =can regenerate and are replaceable (trees,

water), but not necessarily unlimited• The classification “renewable” depends upon the context in which you use

it. (For example, a forest is not renewable, because the climate would change if all trees were cut down, but individual trees are renewable)

• Think replenished in the short term 1-10 years…

– Nonrenewable = cannot be replenished by natural processes (fossil fuels, coal, oil, natural gas)

• Sustainable use = way of using natural resources at a rate that doesn’t deplete them to make sure renewable resources are available for future generations

Renewable resources

• Human activities affect the supply and the quality of renewable resources including:

– Land resources – Forest resources – Ocean resources – Air resources – Water resources

Changing landscape• Past and present humans have had a powerful influence on

the physical and living world by modifying their environment. • Our practices are changing the environment!

– From deforestation to fishing• We used the environment for food, medicine, wood, and fiber• We introduced new species, predators, agriculture, industry,

and disease• The world is very different from what it was long ago.• Think of Earth as an island – all of the organisms that live on

Earth share limited resources and increasing population sizes place greater demands on the biosphere

Land resources• Provide space for cities and suburbs, raw materials for

industry, and fertile soil with nutrients and moisture to grow plants with roots to hold soil against rain and wind– Negative activities:

• Soil erosion = wearing away of surface soil by water and wind (usually results from removing roots that hold soil through plowing, mowing, road building, etc.)– Typical midwest high plains field loses 47 tons of soil/year– Soil is the top pollutants in most aquatic systems

• Desertification = turning once productive areas into deserts (usually results from farming, overgrazing, and drought)

– Positive activities:• Sustainable agriculture = reduces soil erosion by conserving

soil’s properties

Cover CropsLegumes, grasses, and othercover crops recycle soil nutrients,reduce fertilizer need, andprevent weed growth.

Controlled GrazingBy managing graze periods and herddensities, farmers can improve nutrientcycling, increase the effectiveness ofprecipitation, and increase the carryingcapacity of pastures.

Biological Pest ControlThe use of predators and parasitesto control destructive insectsminimizes pesticide use as well ascrop damage

Contour PlowingContour plowing reduces soil erosion from land runoff. On hilly areas, plowing is done across the hill rather than straight up and down.

Crop RotationDifferent crops use and replenish different nutrients. By rotating crops, the loss of important plant nutrientsis decreased.

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Section 6-4

Sustainable Agriculture

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