Unit 5 I wanna die. I wanna decompose, but not help the plants, I want to be turned into fossil fuel to help burn the planet to the ground because I'm so sick of this class.

Tragedy of the commons defintion

The tendency of a shared, limited PUBLIC NOT PRIVATE resource to become depleted if it is not regulated in some way

The Tragedy of the Commons examples

• Overgrazing

• Overfishing

• Water and air pollution

• Overuse of groundwater

Externality

The cost or benefit of a good or service that is not included in the purchase price of that good or service

The Tragedy of the Commons persectives

Although no one is directly wounded from the depleted resouceses, everyone suffers since they now have to go somewhere else to do their work and may even need to have privately owned land, which isn’t as cost-effective

The Tragedy of the Commons Fixes

• How to solve

• Private land ownership

• Fees for use

• Taxes or fines or criminal charges for polluters

• Protected land and marine areas of the world

More than 95 percent of all federal lands are managed by four federal agencies. Which federal agencies are these?

• Bureau of Land Management (BLM)

• U.S. Forest Service (USFS)

• National Park Service (NPS)

• Fish and Wildlife Service (FWS)

Bureau of Land Management (BLM):

grazing, mining, timber harvesting and recreation

U.S. Forest Service (USFS):

timber harvesting, grazing, and recreation

National Park Service (NPS)

recreation and conservation.

Fish and Wildlife Service (FWS):

conservation, hunting, and recreation

Forests are some of the richest ecosystems for biodiversity

• structurally complex, with many niches

• provide food and shelter for multitudes of species

• Fungi and microbes have parasitic and mutualistic relationships with plants

Forests also provide vital ecosystem services

• Stabilize soil and prevent erosion

• Slow runoff, prevent flooding, purify water

• Store carbon, release oxygen, influence weather patterns, and moderate climate

Tree roots draw minerals to surface soil layers

Plants return organic material to the topsoil as litter

Deforestation definition

the clearing and loss of forests

Deforestation bad effects

• Changes landscapes and ecosystems

• Reduces biodiversity

• Worsens climate change

• Disrupts ecosystem services

• Ruins civilizations

Clearcutting def

All trees in an area are cut

Clearcutting effects

• Most cost-efficient

• Greatest ecological impact

• May mimic some natural disturbance (e.g., storms)

• Leads to soil erosion

• Public outrage caused companies to use other harvesting methods

Clearcutting impacts

• Soil erosion due to loss of roots which hold soil together

• Sediment is deposited into local streams and causes water to become cloudy (turbidity)

• Increase of soil and water temperature – trees provide shade

• Flooding and landslides – machinery compacts soil, increased sunlight and

loss of roots cause soil to not be able to hold as much water

Tree plantation def

A large area typically planted with a single rapidly growing tree species.

Tree plantation attributes

• Less biodiversity

• Less species diversity

• All trees are the same age

Selective cutting

removes single trees or relatively small number of trees from an area

Selective cutting benefits

• Provides area for seeds to be planted or reseeded

• Good for shade tolerant trees since young trees will have sunlight blocked by older, mature trees

• Less impact than clearcutting

Ecologically sustainable forestry

removes trees from the forest in ways that do not cause a large impact on other trees. Tries to keep plants and animals in as natural a state as possible

Sustainable Forestry uses

• Using recycled wood or reusing

• Wood can be chipped and used for mulch

• Reforestation – replanting trees in an area that has been logge

• Removing diseased trees to prevent spread of infection

• Selective cutting

Fire Suppression

• Stopping natural fires by putting out forest fires as soon as they start

• Adds biomass buildup which can lead to bigger fires

• Better to monitor to prevent damage and worse fires in future

• Prescribed Burns

• Dead biomass builds up and provides fuel for fires

• Small controlled fires will burn up the extra fuel load (dead biomass)

• Helps to promote nutrient cycling

The Green Revolution

Shift from small family farms (subsistence) to large industrialized farms

The Green Revolution depended on

• Synthetic fertilizers

• Chemical pesticides

• Irrigation

• Machinery

• Genetically modified organisms (GMO)

• Fossil fuel use for machinery

The green revolution spread to the developing world in the 1940s in the form of

Wheat, rice, corn

Mechanization

can increase profits and efficiency of farms but

also reliance on fossil fuels

Positive effects of Green Revolution on the environment

• Prevented some deforestation and land conversion

• Preserved biodiversity and ecosystems

Negative effects of Green Revolution on the environment

• Pollution, erosion

• Salinization, desertification

Transgenic organism

an organism that contains DNA from another species

Genetically modified (GM) organisms

organisms that have been genetically engineered by recombinant DNA

-New genes spliced into their geno

Environmental benefits of genetic engineering:

• Reduced use of chemical insecticides

• Increased no-till farming

• Decreased irrigation, deforestation, land conversion

Negatives of genetic engineering

• Increased herbicide use affects health and habitats

• Some GM fields support less biodiversity

GMO crops have genes for

• Drought resistance

• Pest resistance

• Faster growth

• Larger fruit/grain

Monocropping def

growing one species (wheat, corn, soy)

Monocropping is

• Highly efficient

• Little/no biodiversity

• More prone to pests

Tilling def

mixing and breaking up soil to make it easier to plant

Tilling is

• More erosion since soil is loosened

• Less organic matter and nutrients

• More particulate matter in the air and sediment in nearby water

Slash and burn agriculture

cutting down vegetation and burning it to clear land for agriculture. Returns nutrients in plants to soil

Deforestation

loss of biodiversity, forest ecosystem services, loss of habitat

Impacts of Agricultural Practices

• Air and water warmer – no shade from trees

• More sediment in water and particulate matter in air

Synthetic (inorganic) fertilizers

• Do not return organic matter to the soil

• Do not help soil to hold more water

• Do not add soil decomposers

Leaching def

water carries excess nitrates and phosphates

Leaching causes

Causes groundwater contamination and eutrophication of surface waters

Groundwater storage

in pore spaces of permeable rocks and sediment called aquifers

Unconfined aquifer

water can flow easily in and out

Confined aquifer

surrounded by impermeable rock and clay, slows down water flow

Water table

uppermost level the groundwater fully saturates the rock or soil

Groundwater recharge

how precipitation moves (percolates) through soil and goes into groundwater

Water cannot go into a

confined aquifer

A spring

where water naturally flows to the surface

An artesian well

hole is drilled into a confined aquifer and the pressure is used to move the water to the surface

Aquifer

can be depleted if overused by agricultural irrigation

Ogallala Aquifer

in central United States has been overused for irrigation

Cone of depression

when water is quickly withdrawn from a well and there is no groundwater around it

Irrigation

artificially providing water to support agriculture

Largest use of freshwater

Irrigation 70%

Waterlogging

overirrigated soils

Why is waterlogging bad

Too much water in soil which raises the water table and inhibits plants’ ability to absorb oxygen through their roots

Salinization

• the buildup of salts in surface soil layers

• Worse in arid areas

• Can make soil toxic to plants

There are four types of irrigation

Furrow, Flood, Spray, Drip

Furrow

a trench along crop rows that is flooded with water

• inexpensive but about 1/3 of water is lost to evaporation and runoff

Flood

the entire field is flooded with water

• about 20% of water is lost to evaporation and runoff, and can also lead to waterlogging

Spray

an apparatus sprays water across a field

• more efficient, only ¼ of water is lost to evaporation or runoff – more expensive and requires energy to run

Drip

a slow dripping hose is laid on or buried beneath the soil

• most efficient

• only 5% of water is lost to evaporation or runoff, expensive so often not used

Agriculture allowed people to…

to settle in one place

• Populations increased

• Leading to more intensive agriculture

Traditional agriculture

biologically powered, Subsistence agriculture, Uses human and animal muscle power, hand tools, simple machines, Polyculture

Subsistence agriculture

families produce only enough food for themselves

Polyculture

different crops are planted in one field

Industrialized agriculture

uses large-scale mechanization and fossil fuels to boost yields

Industrialized agriculture

uses large-scale mechanization and fossil fuels to boost yields. Also uses pesticides, irrigation, and fertilizers. monoculture

Sustainable agriculture

does not deplete soil, pollute water, or decrease genetic diversity

Low-input agriculture

uses smaller amounts of pesticide, fertilizers, growth hormones, water, and fossil fuels than industrial agriculture

Organic agriculture

uses no synthetic fertilizers, insecticides, fungicides, or herbicides

• Relies on biological approaches (e.g., composting and

biocontrol)

Delaney Clause of the Food, Drug and Cosmetic Act (1958)

To prevent any potentially harmful cancer-causing food ingredients ( there are naturally occurring compounds that can cause and prevent cancer)

Contour farming

plowing perpendicular across a hill

- Prevents rills and gullies

Terracing

level platforms cut into steep hillsides

• This “staircase” contains water

Perennial Crops

Crops that live year round, Harvested multiple times, Longer and more established roots, Prevents bare soil after harvest

Shelterbelts (windbreaks)

rows of trees planted along edges of fields

• Slows the wind

• Can be combined with intercropping

Conservation tillage

reduces the amount of tilling

- Leaves at least 30% of crop residues in the field

- No-till farming disturbs the soil even less

Crop rotation

growing different crops from one year to the next

Why crop rotation is the GOAT

• Returns nutrients to soil

• Prevents erosion, reduces pests

• Wheat or corn and soybeans

• Pests usually prefer one crop

Intercropping (strip cropping)

planting different crops in alternating bands

- Increases ground cover

- Replenishes soil

- Decreases pests and disease

Ways to improve soil fertility

crop rotation and using green manure and limestone

Limestone

base will neutralize acids in soil, raises pH so soil is more basic than acidic

Rotational grazing

regular rotation of livestock between different pastures in order to avoid overgrazing in a particular area

Green manure

Leftover plant matter from a cover crop

Seed banks

institutions that preserve seed types as living museums of genetic diversity

• Seeds are collected, stored, and periodically planted

Pest

any organism that damages valuable crops

Weed

any plant that competes with crops

Pesticides

poisons that target pest organisms

Insecticides

kill insects

Herbicides

kill plants

Fungicides

kill fungi

Rodenticide

kills rodents

Pesticide immunity in individuals

pass these genes to their offspring

Pesticides stop being effective

Pesticide treadmill

Pesticide treadmill

chemists increase chemical toxicity to compete with resistant pests