Land and Water Use Part II. Unit 5

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Land and Water Use – Part II

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Topics – Part I

(on PowerPoint Land and Water Use Part II)

 5.1 – The Tragedy of the Commons

 (C. 1.3)

 5.2 – Clearcutting

 (C. 10.1)

 5.3 – The Green Revolution

 C. 12.2, 12.3  5.4 – Impacts of Agricultural Practices  C. 12.2, 12.3



5.5 – Irrigation Methods

 (C. 13.2, 13.5)

 5.6 – Pest Control Methods

 (C. 12.4)

 5.7 – Meat Production Methods

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5.11 – Ecological

Footprint

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Ecological Footprints

Ecological footprint – the amount of biological capacity

needed to support people in a given area

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5.12 – Introduction to

Sustainability

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Sustainability

 Sustainability refers to humans living on Earth and their use of resources without depletion of the resources for future

generations.

 Indicators of sustainability:

 Biological diversity

 Food production

 Global temperatures and CO2

 Human populations

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5.13 – Methods to

Reduce Urban

Runoff

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Methods to Reduce Urban Runoff

1. Mixed land uses (parks/housing)

2. Permeable pavement

3. Walkable neighborhoods

4. Variety of transportation options

5. Compact building design (build up not out)

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5.14 – Integrated Pest

Management

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Integrated Pest Management (IPM)

 IPM combines methods to

reduce pest populations while minimizing the disruption to the environment

 Pros: reduces exposure of wildlife and humans to pesticides

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Integrated Pest Management (IPM)

 Polyculture instead of monoculture

 Intercropping – alternate rows of crops that have different pests

 Planting pest-repellent crops  Mulch to control weeds

 Natural insect predators –

ladybugs, preying mantis, birds

 Rotating crops to disrupt insect cycles

 Using Pheromones to attract insects to traps

 Releasing sterilized insects

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5.15 – Sustainable

Agriculture

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Sustainable Techniques

 Sustains the need for food and fiber while enhancing the quality of the soil,

minimizing energy use and allowing economic viability for the farmer

 Soil Conservation Techniques:

 Contour plowing - Prevents erosion

 Windbreaks - Intercropping crops with trees to act as windbreaks

 Perennial crops – longer roots keep soil intact

 Terracing – reduces slopes on mountainside which reduces soil loss

 No-till agriculture -–leaves crop residues intact

 Intact roots keep soil in place

 Reduces wind and water erosion

 Increased use of herbicides

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Sustainable Techniques

 Sustains the need for food and fiber while enhancing the quality of the soil, minimizing energy use and allowing economic viability for the farmer

 Soil Fertility Techniques:

 Crop Rotation – plant legumes to return nutrients to soil

 Add manure – returns nutrients, conserves water and lessens soil

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5.16 – Aquaculture

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5.17 – Sustainable Forestry

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Methods for Harvesting Trees

 Pros

 Varying age stands

 Small openings

 Selective cuttings

 Cons

Increased wind → increased soil erosion Mudslides

Decreased water quality (increased nutrient runoff and turbidity)

Increased water

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How should Forests be Managed?



Timber Harvesting



Forest service keeps most

of the profit



Counties get 1/4 of profit



Mixed-use



Reduce timber demand



Ecology/Recreation only

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Sustainable Forestry

❖ Standards for sustainable forestry

 Longer rotations

 Selective or strip-cutting

 Minimize fragmentation

 Improved road building techniques

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Healthy Forest Initiative (HFI)

 Reduce fuel

 Leaves larger trees in place

 Forest fires are a natural part of ecosystems

 Reduces public review

 Allows logging without a thorough

environmental review

 Concerns that program might neglect the removal of ladder fuels that start crown fires

PROS

CONS

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Integrated Pest Management (IPM)

 Polyculture instead of monoculture

 Intercropping – alternate rows of crops that have different pests

 Planting pest-repellent crops  Mulch to control weeds

 Natural insect predators –

ladybugs, preying mantis, birds

 Rotating crops to disrupt insect cycles

 Using Pheromones to attract insects to traps

 Releasing sterilized insects

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Prescribed Burn

 A fire set intentionally for one of the following purposes:



Fuel reduction



Expose mineral soil



Control of insects, diseases, and competing

vegetation



Improvement of natural ecosystems, wildlife

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Prescribed burns

 Natural part of many ecosystems.

 Reduce fuel load

 Increase ecological functions such as

 nutrient cycling

 seed germination

 removal of non-native

 removal diseased species

 Produce air pollution

 Aggravate asthma and reduce visibility

 Manage & expensive

 Potential uncontrolled wildfire