Unit 6: Land and Water Use

Forests cover 32% of Earth’s land surface

• Types of forest: \n • Boreal forest (evergreen)

• Canada, Scandinavia, Russia

• Tropical rainforest

• Central and South America, Africa, Indonesia, SE Asia

• Temperate deciduous forest

• Temperate rainforests \n • Tropical dry forests \n • Woodlands

• Ecosystems with lower density of trees (usually secondary growth)

Land Use & Resources

What are some ecosystem services provided by forests?

Cultural \n • Camping and recreation \n • Aesthetic and health benefits

Supporting \n • Biogeochemical cycles

• Carbon sink

Regulating \n • Erosion control

• Slow runoff/flood control

• Purify water

Provisioning \n • Paper, fuel, timber

Deforestation

• Deforestation = the clearing and loss of forests \n • Mostly caused by clearing land for farming and livestock rearing, and mining. \n • Urbanization, forestry practices (clearing forests for timber products) and forest fires account for the rest.

Types of forestry practices

• Clearcutting

• Selective harvesting

• Sustainable forestry

Timber Management

Clear Cutting

Method of harvesting and regenerating trees in which ALL trees are cleared from a site, and new even aged timber is grown.
Benefits: \n • Economically advantageous ()

• High yield

Drawbacks: \n • Increased soil erosion \n • Increased soil and stream temperatures

• Potential flooding

Maximum sustainable yield – the amount of a renewable resource that can be taken without reducing the available supply

Selective Harvesting

A tree harvesting method in which certain trees are selected and others are left on site for ecosystem services.
Benefits: \n • Sustain ecosystem services
Drawbacks: \n • Lower yield

• Time consuming

• Adaptive Management: monitoring results and adjusting methods as needed.

Sustainable Forestry

• Sustainable forestry practices include: \n • Harvest lumber in a manner that leaves forests for many future generations.

• How can we mitigate human impacts on forests?

• Reuse wood

• Reforestation

Ecosystem Based Management –

Restore ecologically important habitats
Consider patterns at the landscape level
Preserve the forest’s functional integrity

• Purchase sustainably harvested wood \n • IPM – protect from pathogens and insects

Prescribed (controlled) burns = burning areas of forests under carefully controlled conditions

Clears away fuel loads
nourish soil
encourage growth of new vegetation
reduces the occurrence of natural fires

Primary vs Secondary Forest

Primary Forest- Natural forest, uncut by people
Secondary Forest– contains second-growth trees (trees that have grown

back after humans cut them down.)

Tragedy of the Commons

• Explain how the deforestation of the Amazon rainforest is an example of the tragedy of the commons?

• Include:

• 1. What is the TOC?

• 2. How does deforestation fit into this?

Ecological Issue: Loss of Biodiversity

Extirpation vs. extinction
Extinction is a natural process

• 99% of all species that ever lived are now extinct

Background rate of extinction = natural extinctions

• For mammal or marine species: each year 1 species out of every 1–10 million goes extinct

Extirpation is the disappearance of a population from a given area, but not the entire species globally.

• Deforestation and HABITAT LOSS/ HABITAT FRAGMENTATION is one of the leading causes of loss of biodiversity.

Current extinction rates are higher than normal

• The current extinction rate is 100 to 1,000 times greater than the background rate

• This rate will increase tenfold in future decades \n • Human population growth and resource consumption

Example: The Green Tree Frog

• Frogs in the rainforest are a great example of a species that is being lost.

EVERYTHING is linked.

• Deforestation aides in climate change –> climate change increases growth of fungus –> fungus causes extinctions of frog species –> frogs provide the ecosystem service of catching disease-ridden insects –> loss of ecosystem services

Islands warn us of habitat fragmentation

\n •Island biogeography theory = explains how species come to be distributed among oceanic islands$$

• The number of island species results from a balance between species added (immigration) versus lost (extirpation)

@@• Predicted by the island’s size and distance from the mainland@@

• Two factors effect this theory: Area and Distance

• Habitat fragmentation is very similar.

The theory of island biogeography

Distance effect: the farther an island is from the continent, the fewer species find and colonize it
Area effect = large islands have more species. They have more habitats, environments, and variety
Larger islands have higher immigration rates – they are fatter targets, and lower emigration rates

Effects of habitat fragmentation

• Edge effects = conditions along a fragment’s edge are different than conditions in the interior

• Interior bird species can’t reproduce when forced near the edge of a fragment

Parasites and predators attack nests

Speciation? \n • Allopatric? Sympatric?

Set aside land with protections:

National Park - public lands protected from resource extraction and development of infrastructure
Wilderness areas – the land is considered a natural state; allows hunting, minimal impact development (no logging, mining, etc), NO MOTOR VEHICLES
Wildlife refuge – designated for the protection of wild animals, within which fishing and hunting are either prohibited or extremely controlled; NO CAMPING
Biosphere reserves - areas of land with exceptional biodiversity that couple preservation and sustainable development to benefit local people

Federal parks and reserves began in the U.S.

• National Parks = public lands protected from resource extraction and development.

• Open to nature appreciation and recreation. • No hunting

Yellowstone National Park Act 1872

• Organic Act 1916

• Highest level of restriction

• Essentially created the National Park Service (NPS)

Wilderness Areas

Wilderness areas = off-limit to development
Located on federal lands
For hiking, nature study, etc \n • Must have minimal impact \n • No real roads or infrastructure of any kind
Established in federal lands or public domain
Allow hunting, but prohibit motorized vehicles, any other
The Wilderness Act of 1964. Established National Wilderness Preservation System.

National Wildlife Refuges

• Begun in 1903 by President Theodore Roosevelt

39millionha(96millionacres)in550sites
The Pacific Remote Islands Marine National Monument added 22 million

ha (55 million acres)

• U.S. Fish and Wildlife Service (USFWS) \n • Administers wildlife refuges, serving as havens \n • But allows hunting, fishing, wildlife observation, photography, education • Doesnotallowcamping \n • Managed for waterfowl and non-game species \n • Restores marshes and grasslands

Biosphere reserves have several zones

• Biosphere reserves - areas of land with exceptional biodiversity that couple preservation and sustainable development to benefit local people

Administration of Federal Land

BLM land - for grazing, mining, timber, and rec. \n USFS land - for timber, grazing, and rec.

NPS land - for rec. and conservation \n FWS land - for wildlife, hunting, and rec.

SLOSS: Single Large or Several Small?

• With habitat fragmentation, the size and placement of protected areas are key to protecting biodiversity

• Which is better, a single large preserve, or several smaller ones? • Why?

• Species Richness vs Species Evenness

Urbanization

• The creation and growth of urban areas

• Roughly 52% of the world’s population live in urban areas, and this growth has increased sharply in recent years

• First, people migrated from rural to urban cities

• Second, many people migrated from large central cities to smaller cities or suburbs

• Thisiscalledurbansprawl,astheymove away from city centers and take up more land surrounding it.

Ecosystem Impacts of Urbanization

Water problems: as cities grow, their water demands increase \n • Depletes the resource, but also can pollute the resource (saltwater intrusion)
Lack vegetation: increase air pollutants, temperature, urban noise, while decreasing wildlife habitat
Impervious Surfaces: increase flooding risks and/or runoff, as water cannot reach the soil

• Urban Heat Islands \n All of this leads to a high ecological

footprint

Solutions to urbanization

Smart Growth: recognizes that urban growth will occur, but uses tools to make the growth less harmful

Tools:

1.Limits and Regulations

• Limit Building Permits

• Draw Urban Growth Boundaries

• Create greenbelts around cities

Zoning

• Promote mixed use of housing and small business

• Concentrate development along mass transportation routes

• Walkable neighborhoods

• Growth boundaries

3. Planning

• Ecological land use planning

• Environmental impact analysis

4. Protection

• Preserve open space/buy new open space

• Prohibit certain types of development

5. Taxes

6. Tax Breaks

7. Revitalize and New Growth

Types of waste management

• Waste = any unwanted material or substance that results from human activity or process

Types of waste:

• Municipal solid waste:

non-liquid waste that comes from homes, institutions, and small businesses

• Industrial solid waste:

waste from production of consumer goods, mining, agriculture, and petroleum extraction and refining

• Hazardous Waste:

solid or liquid waste that is toxic, chemically reactive, flammable, or corrosive

• Wastewater:

water used in a household, business, or industry, as well as polluted runoff from our streets and storm drains

Goals of managing waste

Three main components of waste management:

• Minimizing the amount of waste we generate (source reduction)

• Recovering waste materials and finding ways to recycle them

• Disposing of waste safely and effectively

• Source reduction is the preferred approach

Patterns in the municipal solid waste stream vary

Municipal solid waste is also referred to as trash or garbage
In the U.S., paper, yard debris, food scraps, and plastics are the principal components of municipal solid waste
In developing countries, food scraps are the primary contributor

Sanitary landfills are regulated

Sanitary landfills = waste buried in the ground or piled in large, engineered mounds
Must meet national standards set by the EPA and RCRA
Waste is partially decomposed by bacteria and compressed under its own weight to make more space.
Layered with soil to reduce odor, speed up decomposition, and reduce pest infestations.
When the landfill is closed, it must be capped and maintained.

A typical sanitary landfill

• To protect against environmental contamination, landfills must be located away from wetlands, earthquake-prone faults, and 20 ft above water table

Environmental Hazards of Sanitary Landfills

• Leachate \n • Landfill shave liners to contain liquids in the landfill. If the liner is punctured the liquids (leachate) will escape. Leachate includes everything from decomposing organic matter, improperly disposed of chemicals, paints, and hazardous waste.

Methane

Decomposing organic matter produces methane, which is
flammable. If it builds up it could cause a fire or explosion.
Landfills are undesirable and nobody wants them: NIMBY Not-In-My-Backyard syndrome
Case Study: The Garbage Barge Case
1987: Islip New York.
Landfills were full so a barge transported waste to NC landfill. They were rejected and had to return to NY to incinerate the waste. 6,000 mile journey.

Incinerating trash reduces landfill pressure

Incineration = a controlled process in which mixed garbage is burned at very high temperatures
Incineration in specially constructed faculties can be an improvement over open-air burning of trash
But, the remaining ash must be disposed of in a hazardous waste landfill Hazardous chemicals are created and released during burning
Scrubbers = chemically treat the gases produced in combustion to remove hazardous components and neutralize acidic gases

Waste Laws

• Resource Conservation Recovery Act (RCRA) - Requires that any hazardous waste be taken to facilities in which they can either be stored, treated, or disposed of in permanent containers.

• Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA)

• Also known as Superfund. \n • It was passed in 1980 in response to some alarming and decidedly

unacceptable hazardous waste practices and management going on in the 1970s.

example: Love Canal

How do we use water?

Irrigation – 70% of water use
Industry – 20% of water use

• Factory use

Domestic and Municipal – 10% of water use

• Water for consumption and household needs

Surface Water \n

Types of Freshwater systems – RIVERS/Lakes

Floodplain – area nearest river’s course that are flooded periodically (riparian)
Lakes/ponds – bodies of open standing water

Irrigation

• Furrow – least efficient \n Easy and cheap but only 65% of water goes to the crops, the rest is lost to

evaporation or runoff.

• Flood \n • About 70%-80% of water goes to the crops but its hard on the plants

• Waterlogging and drowning roots

• Conventional (spray irrigation) \n • 75%-95% of water goes to the crops, but it requires energy from a water

pump \n •Drip – most efficient

• Uses buried hoses to get over 95% of water to the plants. This reduces weed

growth because the surface soil remains dry. Expensive to establish but cheap

to run and maintain.

Current Irrigation Use is Unsustainable

• What happens when the demand for water is higher than the system can naturally replenish?

• Water mining \n • Example: The Ogallala Aquifer in the Midwest, where majority of agriculture in the United States takes place, is severely overused

Water Pollution

• Water pollution- the contamination of streams, rivers, lakes, oceans, or groundwater with substances produced through human activities and that negatively affect organisms. • Point sources- distinct locations that pump waste into a waterway. • Nonpoint sources- diffuse areas such as an entire farming region that pollutes a waterway.

Human Wastewater

• Human Wastewater - Water produced by human activities such as human sewage from toilets and gray water from bathing and washing clothes or dishes. Why are scientists concerned with this?

Oxygen-demanding wastes like bacteria that put a large demand for oxygen in the water. • BOD–(biological oxygen demand) the amount of oxygen a quantity of water uses overall period of time at a specific temperature. Lower BOD values indicate the water is less polluted and higher BOD values indicate it is more polluted by wastewater.
Nutrients that are released from wastewater decomposition can make the water more fertile causing eutrophication.
Wastewater can carry a wide variety of disease-causing organisms.

Common Diseases from Human Wastewater

Cholera -Transmitted as fecal matter enters water and is consumed. Vibro Cholera is the bacteria responsible. GI infection. Causes diarrhea, vomiting, leg cramps, etc.
Typhoid fever - Caused by salmonella bacteria. Causes high fevers, weakness, abdominal pain, constipation, headaches, vomiting. Rash. Takes 6-30 days to present symptoms after exposure.
Stomach flu -Bacteria or virus present in fecal matter that contaminates water supply.
Diarrhea - Caused by any number of bacteria present in water contaminated by fecal matter.
Hepatitis A -Transmitted as fecal matter from a contaminated person is ingested,

usually by being present in drinking water. Caused by a virus. Symptoms include

fatigue, nausea and vomiting, loss of appetite, joint pain, etc.

Wastewater Treatment: Septic Systems

Septic systems- a large container that receives wastewater from the house. * Solid waste settles to the bottom of the tank (removed every few years).
Liquid waste flows through an outlet pipe into a drainage field where it is naturally filtered through the earth.
Sewage Treatment Plants- centralized plants in areas with large populations that receive wastewater via a network of underground pipes.

Heavy metals and other substances that can threaten human health and the environment

Lead \n • Ex. Flint Water Crisis

Arsenic

Mercury

• Ex. Minamata Disease

Acids

• Synthetic compounds (pesticides, pharmaceuticals, and hormones)

Other water pollutants

• Solid waste pollution (garbage) \n • Sediment pollution (sand, silt and clay) • Thermal pollution \n • Noise pollution

Water Laws

• Clean Water Act- (1972) supports the “protection and propagation of fish, shellfish, and wildlife and recreation in and on the water”.

• Issued water quality standards that defined acceptable limits of various pollutants in U.S. waterways.

• Safe Drinking Water Act- (1974, 1986, 1996) sets the national standards for safe drinking water.

• It is responsible for establishing maximum contaminant levels (MCL) for 77 different elements or substances in both surface water and groundwater.