The Tragedy of the Commons: When a common resource is utilized, eventually it will be destroyed by overuse.

Overuse: is usually driven by population growth

Technology cannot solve the problem, so the solution is to change human behavior

Requirements to be a Common Resource: Must be a shared resource available to a variety of individuals. Must NOT be privately owned.

Examples of TOC Areas: Oceans, the air, rangeland, groundwater

Solutions to TOC: Provide an incentive for people to think about long-term sustainability; Educate people abt sustainable yields, tax a good that includes negative externalities/reduce demand, Use full-cost pricing, set up community management protocols.

Regulate the resource by restricting access to certain times, requiring permits, setting harvesting limits, determining the maximum sustainable yield, and selling it to private owners.

Habitat Corridors: Protected areas must be connected in order to be effective.

Isolation leads to inbreeding, speciation, and reduced options for escaping undesirable conditions (fires, droughts, etc).

Habitat Corridors connect protected lands to allow species to migrate and increase habitat

Cons can include migration of diseases, pests, or invasive species

Rangeland: Important ecological services of grasslands: Soil formation, Erosion control

Nutrient cycling, Storage of atmospheric carbon dioxide in biomass, and Maintenance of diversity

How Should We Manage and Sustain Grasslands? We can sustain rangeland productivity by controlling the number and distribution of livestock and by restoring degraded rangeland. Almost half of the world’s livestock graze on natural grasslands (Rangelands) and managed grasslands

Overgrazing occurs when too many animals graze for too long and exceed the carrying capacity of a grassland area. Examples: Grass/shrubs are damaged beyond repair, Reduces grass cover

This leads to the erosion of soil by water and wind

Desertification - The degradation of land that results in a desert. Caused by overgrazing, deforestation, or overuse The world's deserts are getting bigger. Some Rangelands Are Overgrazed

Prevention of overgrazing: Rotational grazing, Replant barren areas, Apply fertilizer, and Reduce soil erosion

Forests: Old-growth forest: Original forests that have not been disturbed for logging, road building, or development. Sometimes called primary, ancient, virgin, or primeval forests 36% of world’s forest, High biodiversity because of many specialized niches

Second-growth forest: The area which has re-grown after a major disturbance such as fire, insect, or timber harvest. 60% of world’s forest. The area is reclaimed by the natural process of secondary succession. Small shrubs and trees followed by the larger trees

Tree plantation (tree farm): Planted stands of a particular tree species that are maintained, harvested and replanted. Typically used for paper or particle board.

Economic and Ecological Services: annual value: $1.8 trillion. Ecological services: $4.7 trillion

Tropical Deforestation: Slash and burn agriculture

Why? Poverty. Short term survival is more important than long term consequences.

Problem: Tropical rainforests store most of their nutrients in the plants, so the soil is very poor and new areas must be slashed and burned every few years. Once an area is cut, the microclimate changes and the area will likely never be a TRF again (evaporation lower, more sunlight = different plants). Tropical Forest: Top soil layer is extremely thin. Great Plains: Top soil layer is much thicker

Unsustainable Logging is a Major Threat to Forest Ecosystems: Building roads into previously inaccessible forests paves the way for increased erosion, habitat fragmentation, loss of biodiversity, and invasion by non-native species. For this reason, many federal wilderness areas do not allow the construction of roads.

Three major tree harvesting methods: Selective cutting, Clear-cutting, and Strip cutting

Selective Cutting: Mature trees are harvested individually from diverse forests, Younger trees left to harvest later, Reduces crowding, Removes diseased trees, and Encourages growth of younger trees

Clear-cutting: Removing all trees in a single pass.

Strip-cutting: A type of clear cutting that involves clear trees along the contours of the land. Less erosion

Tropical Forests Are Disappearing Rapidly: Large areas of tropical forest are burned to make way for cattle ranches and crops. The soil in the rainforest is very poor. Farmers burn the trees down to provide nutrients for the soil. Heavy rain leaches away the nutrients so they move to another area and burn again. At least half of the world’s terrestrial plants and animals live in tropical rain forests. About 2,100 of the 3,000 plants identified by the National Cancer Institute as sources of cancer-fighting chemicals come from tropical rain forests.

Logging roads give access to once isolated ecosystems

We Can Improve the Management of Forest Fires: Fire prevention programs have been very effective…too effective. Large amounts of highly flammable underbrush have accumulated

Leads to larger, more destructive crown fires, To reduce fire damage: Set controlled surface fires (Prescribed Fires). Allow fires to burn on public lands if they don’t threaten life and property.

Clear small areas around property subject to fire.

Threats

Logging interests cut down rain forest trees for timber used in flooring, furniture, and other items.

Power plants and other industries cut and burn trees to generate electricity.

The paper industry turns huge tracts of rain forest trees into pulp.

The cattle industry uses slash-and-burn techniques to clear ranch land.

Agricultural interests, particularly the soy industry, clear forests for cropland.

Subsistence farmers slash-and-burn rain forest for firewood and to make room for crops and grazing lands.

Mining operations clear forest to build roads and dig mines.

Governments and industry clear-cut forests to make way for service and transit roads.

Hydroelectric projects flood acres of rain forest.

Threats: Sustainable-logging regimes that selectively cull trees rather than clear-cut them would save millions of acres of rain forest every year. Campaigns that educate people about the destruction caused by rain forest timber and encourage purchasing of sustainable rain forest products could drive demand down enough to slow deforestation. Encouraging people who live near rain forests to harvest its bounty (nuts, fruits, medicines) rather than clear-cutting it for farmland would save million of acres. Government moratoriums on road building and large infrastructure projects in the rain forest would save many acres. From National geographic

Clear Cutting

Consequences include

Increased erosion due to loss of roots, more wind exposure, and faster water flow

Results in loss of top soil, runoff that threatens aquatic ecosystems, and loss of soil nutrients, and can cause mudslides

Changes local climate due to less transpiration, loss of shade, and global climate by the loss of CO2 absorbing plants (although new plants may absorb more CO2 if they grow rapidly)

Slash left behind provides fuel for fires

Loss of habitat, biodiversity and natural beauty

Benefits include

cost effective if enough trees are valuable

creates direct sunlight for some fast growing species

Types of Fires

Surface Fires – fires that burn on the surface of the forest

Burn understory, but most trees survive; provide all the ecological benefits of fires

Ground Fires – fires that slowly burn under the leaf litter layer

Burn underground leaving most plants unharmed, but can spread

Crown Fires – very hot, dangerous fires that burn the middle and top of trees

Spread quickly, especially on slopes; hard to manage; may be too hot to provide ecological benefits

Fire Management

Many ecosystems are fire maintained and are expected to burn at regular intervals (chaparral, grasslands, etc)

Fires provide many ecological benefits:

seed germination, removal of old/diseased/non-native species, renewal of soil nutrients, opening of space/light for seedling all of which can improve an ecosystem

As long as humans live in fire prone areas, fires will continue to damage property, but good management can reduce the risks

Under-management can result in loss of human lives and loss of property from uncontrolled fires

Over-management results in the build-up of fuel and can cause larger, more destructive fires due to fire suppression.

Prescribed Burn

A fire set intentionally for one of the following purposes:

Fuel reduction to prevent the spread of an existing fire or the threat of a large fire

Expose mineral soil for seedbeds for regeneration of wind-disseminated species

Control of insects, diseases, and competing vegetation (invasive species, non-fire resistant species)

Improvement of natural ecosystems, wildlife habitat, and range forest

Prescribed burns

Pros

Forest fires are a natural part of many ecosystems.

Years of fire prevention lead to a build up of fuel and can result in much larger, hotter and more damaging fires

Fire suppression stops important ecological functions such as

nutrient cycling

seed germination

removal of non-native

removal diseased species

Cons

All forest fires produce air pollution including particulates, dioxins and carbon dioxide

Can aggravate asthma and reduce visibility

Require a lot of fire fighters to effective manage = expensive

Can get out of control and cause an uncontrolled wildfire

Healthy Forest Initiative (HFI) (also called the Healthy Forest Restoration Act)

Enacted by President Bush in 2001 to reduce fuel loads and reduce the number of large, dangerous forest fires

History of over-suppression of fires resulted in an increase in tree density and understory growth creating unsafe conditions

Makes it easier to clear unsafe growth by not requiring a NEPA study (EIS document) for

Prescribed burns on sites under 4500 acres

Mechanically clearing sites under 100 acres

Restoring habitat after a fire for sites under 4200 acres

Allows the sale of “vegetative material” as long as the purpose of the cutting was fire reduction

Reduces the length and complexity of environmental reports for other fire reducing projects

FYI: 1000 acres = ~760 football fields = ~800 soccer fields

HFI

PROS

Should reduce the build up of dangerous fuels due to fire suppression and thus risk of large, dangerous fires

Act does specify focusing on the removal of small trees and leaving larger trees in place

Expedited NEPA process should allow these projects to occur faster

Review of projects is done by a collaborative group composed of local interests

CONS

Forest fires are a natural part of ecosystems and previous human intervention caused the current problem

Reduces public review and oversight of projects

Allows logging without a thorough environmental review

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

Light Pollution

Pollution created by artificial lighting at night.

Creates a variety of health and environmental concerns including:

Loss of sleep

Interferes with animal navigation

Interferes with the feeding patterns and behavior of nocturnal animals

Changes circadian rhythms in humans, animals and plants that dictate sleep, growth, reproduction and development

Noise Pollution

Unwanted, disturbing, or harmful sound that impairs or interferes with hearing, causes stress, hampers concentration and work efficiency or causes accidents.

Noise is measured in decibel-A (dbA), which is a measure of sound pressure.

85 dbA can be damaging

120 dbA is painful

180 dbA can kill

Noise Pollution

dbA scale is logarithmic, so 60 dbA is 10x louder than 50 dbA

The recommended maximum volume for an mp3 player is 85 dbA. Many teens regularly listen to their mp3 players at 125 dbA or higher.

Effects of Noise Pollution

Hearing loss

Hypertension

Muscle tension

Migraines

Headaches

Higher cholesterol levels

Gastric ulcers

Lowers memory

Insomnia

Psychological disorders

Aggression

Heart attack

Stroke

Solutions to Noise Pollution

Personal

Wear ear plugs when participating in a loud activity (concerts, using power tools, fireworks, etc)

Use listening devices with built in volume control and/or noise cancelling capabilities

Urban areas

Set and enforce noise ordinances

Move noisy activities away from residential areas

Modify noise producing sources to make less noise

Limit the size and speed of cars and trucks

Install sound barriers/noise proofing

Set flight paths to avoid neighborhoods

Use anti-noise to cancel noises out

Urban Heat Island

Urban areas can be 6-8 F hotter than the surrounding area

More man-made surfaces = more heat absorbed

Less trees and vegetation = less evapotranspiration, less shade

Impact is much great at NIGHT because surfaces absorb and store heat all day, then release it at night

Albedo Effect

Albedo effect is a measure of reflectivity of surfaces.

Dark and non-reflective surfaces (like asphalt) tend to absorb more light and store it as heat.

Light and highly-reflective surfaces (like snow) tend to reflect light and do not store as much heat.

Vegetation tends to absorb sunlight, but uses it for photosynthesis.

City planners can use the albedo effect to counter the urban heat island effect by painting surfaces lighter colors or using concrete instead of asphalt.

Pavement

Pavement also impacts the water cycle:

Impervious surface do not absorb water meaning less infiltration and more runoff

Reduces groundwater recharge and increases flooding

Pavement = no/less vegetation, so less evapotranspiration

Zoning

Urban Planning is the process of deciding how urban land will be used. Zoning is a tool for urban planning

Traditional zoning separates uses that are considered incompatible.

Zoning also regulates things like maximum housing density, number of parking spaces, minimum distances between building, requires set-backs from the street all of which can contribute to sprawl

Alhambra Zoning Maps

Mixed-use zoning can cluster housing, stores, and offices in the same area to decrease sprawl and encourage walking, public transit, etc

Housing Development

TRADITIONAL

Bulldoze the entire area

Build row houses on a grid

Rename streets after trees that used to be there

CLUSTER

High-density residential clusters in a compact area

Trees, streams, and animals stay put

Connected habitat wraps around housing clusters