Unit 5: Land and Water Use

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Tragedy of the Commons

when individuals act in their own self-interest & deplete a shared source

Result of Tragedy of the Commons

overconsumption, underinvestment, and depletion of resources

Concerns of Clearcutting

severe soil erosion, diffuse pollution and sediment delivery, removes carbon sinks, addts to golobal warming & climate change

why are forests beneficial?

regulate the climate by absorbing carbon dioxide

Consequences of deforestation?

biodiversity loss, increased greenhouse gas emissions

The green revolution

the increase in agriculture production that has been made possible by new crops & farming methods

Pros and Cons of Mechanization

Pro: Increased Farm Income

Con: High Costs

Pros and Cons of High Yield Variety Crops

Pro: Increases food production

Con: Frequent weeding

Pros and Cons of GMOs (Genetically Modified Organisms)

Pro: more crops

Con: allergic reactions

Pros and Cons of Synthetic Fertilizer

Pro: quick results

Con: pollution

Pros and Cons of Irrigation

Pro: save water

Con: Waterlogging

Pros and Cons of Pesticides

Pro: enhanced food production

Con: Decline in population of birds and insects

Monocropping

Description: Growing a single crop year after year on the same land

Impact: upsets the natural balance of soils

Tilling

Description: aerating the soil to permit moisture and air to permeate

Impact: disrupts soil structure

Slash & Burn

Description: cut down trees, let it dry, burn area to clear area for planting crops

Impact: deforestation and loss of habitat and species

Synthetic Fertilizers

Description: quick burst of nutrients to the soil can cause rapid growth

Impact: contaminate soil, water, and air

Waterlogging

saturation of soil with water

solutions for waterlogging

drip irrigation, soil aeration

Soil Salinization

salt that builds up in soil overtime

Solutions for soil salinization

flushing with freshwater

Global human water use

primarily use water for agriculture, freshwater withdrawals, followed by industrial uses, and domestic needs

Importance of clean freshwater

results in healthy ecosystems and provides wildlife habitat and places to fish

Furrow Irrigation

Trench dug along crops and filled with water. It is easy and inexpensive however there is an increased risk of salt buildup on beds

Flood Irrigation

floods the entire field and is easier however it is disruptive to plants and can waterlog the soil

Drip Irrigation

holes in the hose allows water to slowly drip out, however, it is more costly

Spray Irrigation

Ground or surface water is pumped into spray nozzles. It is more efficient and will lose less water than flood or furrow. However, it needs more energy for pumps & movement

Pros and Cons of Pesticides

Pro: controls various pests and disease carriers

Cons: cancers, birth defects, reproductive harm

Pros and Cons of herbicides

Pro: controls weeds and reduces the number of tillage operations

Con: decreased photosynthesis, cell divisions

Pros and Cons of Rodenticides

Pro: quick and easy rodent solutions

Con: toxicity, neurological damage, death

Pros and Cons of Insecticides

Pro: mitigate insects of one or more species

Con: stinging eyes, rashes, blisters

Pros and Cons of Fungicides

Pro: Kills or prevents the growth of fungi and their spores

Con: runoff can affect freshwater environment and can cause infections to humans

GMOs

organisms that have their DNA altered using genetic engineering

Benefits: fewer pesticides

Consequences: genes pass into wild plants and other crops

CAFOs

animals are fed grains to raise them as fast as possible

Benefits: maximizes land use and profit

Consequences: animals produce large amount of waste which can contaminate nearby surface or groundwater

Free Range Grazing

animals graze on grass and grow at a natural rate

benefits: no need for antibiotics

consequences: requires more land use

Overgrazing

too many animals grazing on an area of land

Causes: Desertification - plants are killed by overgrazing, Soil Erosion - animals compact soil, decreasing H2O holding capacity → more erosion

Why is meat production inefficient

all the energy needed to plant, grow, and harvest plants to feed the animals, PLUS:

• energy needed to bring water to animals

• energy needed to house animals

  • energy needed to slaughter and package

Fisheries and Fishery Collapse

Cause: overfishing, climate change

Problems: reducing food supply to larger fish

Economic Impact

Cause: lower income for fishermen

Problems: increased food prices for consumers

Bottom Trawling

Cause: the gear is not selective & discards lots of dead fish

Problem: damages the seafloor and catches juvenile fish

Food Webs and Trophic Cascade

Cause: top predators are heavily fished & their prey population explode

Problem: leads to imbalances to the food chain

How does mining impact resources, waste, and pollution

abondoned mining operations can lead to leaching iron and other chemicals into nearby waterbodes. Active mining operations are considered point sources of pollution

Benefits and Consequences of Strip Mining

Benefits: faster, cost-effectice, and less safety precautions needed

Consequences: erosion, destruction of ecosystems

Subsurface Mining and how it relates to coal

a method of extracting minerals like coal from deep beneath the earths surface by digging tunnels and shafts to acces the coal seam

Environmental Impacts of Mining

deforestation, erosion, contamination or local streams

Mine Reclamation

process of modifying land that has been mined to restore it to an ecologically functional or economically unstable state

Urban Sprawl

an uncontrolled expansion of urban areas

How urbanization affects the water cycle

greater frequency and severity of flooding, channel erosion, and destruction of aquatic habitat

How urbanization affects the atmosphere

increase anthropogenic emissions and affect concentrations of air pollutants

How urbanization affects Flooding

the concrete and asphalt will not allow rainwater to be absorbed into the ground, leading to increased surface runoff

Ecological Footprint

the impact of a person or a community on the environment, expresses as the amound of land required to sustain their use of natural resources

How ecological footprint compares to carbon footprint

one is a broader measure of human impact on the environment and one only focuses on greenhouse gas emissions

Factors that affect footprint

consumption patterns, resource use, and population size

Sustainability

living on eath in a way that allows humans to use its resources without depriving future generations of those resources

Indicators of sustainability

environmental, social, economic, institutional

Methods to reduce urban runoff

Erosion Controls, sediment controls, green roofs, permeable pavements, rain gardens

Benefits of IMP (integrated pest management)

• minimize risk to people and property

• prevents levels of pest damage

• reduce evolution of pest resistance

Drawbacks of IMP (integrated pest management)

• price

• starts slow

• shortage of the training

Biocontrol

a method of controlling pests by using other organisms

Crop Rotation

practice growing a series of different types of crop in the same area across a sequence of growing seasons

Intercropping

a multiple cropping practice that involves the cultivation of two or mor ecrops simultaneously on the same field

Conservation

prevention of wasteful use of a resource

Contour Plowing

plowing around the curves of the land in order to minimize soil erosion

Terracing

a flat surface that has been cut into hills or mountains to provide areas for the cultivation for crops

Perennial Crops

plant species that are cultivated and live longer without the need to be replanted more often

Windbreaks

Rows of trees or shrubs planted to protect soil from wind and erosion

No till

growing crops and pasture without disturbing the soil through tillage

Strip Cropping

different crops are sown in alternate strips to prevent soil erosion

How crop rotation improves soil fertility

helps return nutrients to the soil without synthetic inputs

how green manure improves soil fertility

releases nutrients slowly which supports microbial activity and benefits plant growth

how limestone improves soil fertility

conditions soil by raising pH levels. It controls natural nutrients to promote healthy plant growth

how rotational grazing improves soil fertility

the roots boost soil biomass and fertilize the ground by isolating carbon from the atmosphere

Benefits of Aquaculture

• improved food security

• increased amount of seafood available

• fish for consumption without overfishing

Drawbacks of Aquaculture

• transmission of disease between farmed and wild fish

• introduction of pathogens and parasites

methods for mitigating deforestation

protected areas such as national parks, wilderness preserves, and other places set aside to conserve nature

Sustainable forestry practices

• Timber Harvesting: removing trees to generate revenue

• Biodiversity Conservation: establish protected areas to enhance biodiversity