Unit 5 - Land & Water Use

## 5.1 Tragedy of the Commons

* individuals will use shared resources in their own self-interest rather than maintaining the public good → %%resource depletion%%
* used by everyone, regulated by no one
* no presence of sustainability
* can be caused by ==overuse or degradation== of the resource
* ex. ocean, seafood, air pollution, etc.
* resolved by r%%egulations & replenish%% resources after use
* ex. fishing licenses, land use permits, careful cutting of trees, country quotas, rebuilding trees, etc.
* ensure %%compliance%% with laws through oversight (done by government agencies, fines, incentives, debt forgiveness, etc.)
* can also be resolved by %%privatization%% (ie. owning land and regulating use on its own)

## 5.2 Clearcutting

* forests provide many ecological services
* forests → %%water sink%% (holds water in tree trunks)
* improves @@air quality@@ by exchanging CO2 → O2 during photosynthesis
* improves @@water quality@@
* reduces water runoff by going into the topsoil and into groundwater reservoirs
* carbon sink (bring in Co2 and store it in tree structures; organic matter enters topsoil)
* %%economic significance%%: timber (trees before being cut down) → lumber (trees after being cut down), livestock, tourism, high property values, potential minerals for medicine and other uses
* ^^clearcutting^^: cutting all trees in a forest
* causes loss in biodiversity, aesthetics, food sources, materials, etc.
* ==ingress== → invasive species that couldn’t previously attack habitat
* ==engress== → organisms w various diseases & viruses emerging as a result of habitat loss
* carbon cycle → decreased soil carbon on topsoil due to less organic matter falling from trees
* topsoil blowing away & mudslides due to greater amounts of water entering the ground→ soil erosions
* decreased albedo → desertification
* decreased photosynthesis & increased decomposition, combustion, burning of fossil fuels → more CO2 in the air → climate change
* decreased transpiration → climate change
* soil erosion → decreased infiltration to groundwater → less water in aquatic bodies/more runoff in aquatic bodies
* increase in turbidity → decrease in primary productivity & albedo (heat up); increase nutrients → decreased O2 levels; algal booms
* loss of biodiversity/habitat

## 5.3 The Green Revolution

* small laborious farms → large industrialized highly productive farms (1960s) to maximize crop yield
* mechanization → always ready, specialized/updated, easy to use, high efficiency/profits; causes combustion and reliance upon fossil fuels (CO2 buildup in the atmosphere, soil erosion, interruption of biogeochemical cycles)
* monocultures → easy to plant harvest and maintain, specialized pests (easy to eradicate); loss of habitat/biodiversity/ancestral varieties, increased risk of catastrophe (vulnerable to fungal and insect attacks)
* artificial fertilizers/pesticides → max yield, mass production, can fit any plant, easy use, no smell; easily dissolve in the runoff, disruption in nitrogen cycle (atmosphere to pesticide), negative health effects, contamination of groundwater, antiresistant pests
* Haber-Bosch process: N2 + 3H2 → 2NH3
* irrigation → scaleable, maximizing yield to potential; freshwater depletion, waterlogging & salinization
* GMOs: genetically modified organisms
* artificial selection: evolution controlled by humans to yield beneficial and preferable traits based on genetic material → creation of GMOs (taking advantage of the genetic material of normally incompatible species, creating new traits)
* ex. self-producing pesticide
* creates crops on deserted land (drought, heat, salt tolerant conditions)
* crops can be herbicide resistant
* can be modified to fit habitat conditions
* self-producing insecticide → reducing artificial insecticide
* cons: low nutrient soil from unfavorable lands, herbicide-resistant, bt crops can kill nontarget crops → insecticide-resistant pests, economic/ethical/moral issues
* loss of genetic diversity due to monoculture
* loss of biodiversity as a result of killing nontarget species

\
## 5.4 Impacts of Agricultural Practices

* arable: usable for crop growth
* tilling: preparing soil for crops
* bare soil → soil erosion, increased evaporation of soil moisture → need for fertilizer
* changes soil structure & composition
* sequestration of CO2 released into the atmosphere
* use of mechanization → fossil fuel use, emissions (contributing to climate change), and soil change
* eutrophication → runoff of nutrients and pollution in the soil to aquatic bodies
* slash-and-burn agriculture: used in many developing countries for low-nutrient soil
* consists of cutting trees and burning them, using the ashes to grow better trees
* unsustainable → quick use of nutrients, CO2 in the air from combustion
* intensive agriculture: overuse of natural resources, pollution, loss of ancestral crop varieties
* synthetic fertilizer: a form of nitrogen ammonia (phosphorus + potassium)
* can cause runoff
* overused
* doesn’t improve soil structure
* organic fertilizer: horse manure, anything natural that can stimulate crop growth
* easy to transport, timed release, can be adjusted for further use, can be worked into the soil, digested vegetation = better soil structure
* must be gathered
* nutrient levels unknown
* harder to use
* pesticide overuse: max crop yield, hurts human health and causes resistance from weeds, kills nontarget species

\
## 5.5 Irrigation Methods

* 70% freshwater → irrigation use
* %%flood irrigation%%: diverting water from a lake or river to the field
* no mechanization, inexpensive, easily used in developing countries
* needs nearby water, not for all plant types, tilled land, @@20% water lost to evaporation@@
* %%furrow irrigation%%: building trenches near crops to divert water into
* low mechanization, high sediment water usable, some control over precision
* not efficient in sandy soil, difficult to apply in small amounts, @@33% water lost to evaporation (least efficient)@@, prone to soil erosion
* more mechanized methods → more prevalent in developed countries
* spray irrigation: lines of pumps are used to spray out water onto crops
* LEPA: low emission precision application
* allows for nutrient supplements to be sprayed into the water, => 25% of water lost to evaporation (efficient), easy to program
* costly compared to nonmechanized irrigation methods, uses fossil fuel/electricity for machinery, issues with nozzle (requires low to no sediment), can create ruts in soil → prone to soil erosion
* drip irrigation: water is directly given to roots through micropores in underground pumps
* low evaporation rate at 5% (most efficient), reduces nutrient loss (goes directly to roots), no land modification needed
* very expensive, require extensive mechanization, difficult to move, clogs easily
* waterlogging: air pockets in soil are completely filled with water → deprivation of cellular respiration → plant death
* salinization: salt buildup on soil caused by traces of freshwater entering soil and being evaporated over time
* inhibits plant growth → causing sandy deserted area
* solutions: flushing out water from soil, making plants salt-tolerant
* aquifers: infiltrated water is being used at a faster rate than replenishment → overuse
* ogallala aquifer: largest aquifer for crops in the united states
* spans from nebraska to texas
* pressure from freshwater pushes away saltwater from other bodies in coastal aquifers

## 5.6 Pest Control Methods

* pesticide treadmill: pests become resistant to a pesticide caused by genetic mutations & overuse → more pesticide is needed to have the same effect on pests over time (or a stronger type of pesticide)
* pesticide runoff → directly kills organisms/crops in its path unintentionally
* contaminates groundwater supply, evaporation to other areas
* becomes toxic in large amounts
* biomagnification: storing pesticide in low trophic organisms in apex predators

## 5.7 Meat Production Methods

* meat production: raising of livestock for human consumption
* overconsumption of meat: prevalent in developed countries
* extensive land use for grazing → 25% of the earth’s land is used for grazing
* lots of animal waste that is displaced (ex. cow waste → methane → greenhouse gas in the atmosphere)
* high in nitrates & phosphates → causing runoff
* carries dangerous viruses and diseases for humans through fecal coliforms
* more work to have the same amount of calories (10 percent trophic rule)
* antibiotics/hormones → makes prone for bacteria resistant animals
* soil compaction, erosion, damage, etc. → desertion & change to soil composition
* reduces CO2, methane, and N2O emissions
* water conservation → improves topsoil
* free-range grazing: allowing livestock to be raised in natural habitat (natural diet)
* eating vegetation, insects, other organisms, etc.
* no need for preventative antibiotics
* requires more land per unit of livestock (inefficient)
* must coexist with other organisms within an environment
* fewer heads of cow to control for production
* longer growth times
* prone to overgrazing → soil erosion & desertification → loss of biodiversity

concentrated animal feeding operation (CAFO): feedlots; raising any type of livestock for human consumption

* mass grazing of animals to meet economic standards
* easy to clean, maintain, efficient, and large
* usually fed grain to meet high caloric standards → makes meat less expensive for consumers (little labor to raise)
* crowded → creates mass waste → decrease of O2 levels in water that waste infiltrates
* fecal coliforms can carry various diseases and health risks for humans in the water
* extensive use of antibiotics and growth hormone use

## 5.8 Impacts of Overfishing

* commercial: large-scale fishing (fishing in mass quantities)
* left unregulated → endangerment of species → extinction of species
* long-line: a long line of rope w hooks held by buoys to catch fish w bait
* can be up to 28 miles long at any depth (pelagic: above the surface)
* very efficient → can catch much fish at once
* prone to overfishing and capturing bycatch species
* drift/gill net: a long net that catches fish gills
* also prone to capturing bycatch species
* have to untangle fish from the net to gain catch
* very long, can be placed at any depth
* purse seine: net with drawstrings (6.5k ft long & 650 ft deep)
* catches lots of fish at once (many schools of fish)
* can be tailored to species of any size
* trawling: cone-shaped net dragged across the bottom
* destructive to underwater benthic ecosystems
* sonar: strategic use of technology to see the seafloor to locate fish
* reduces fuel and carbon emissions; very profitable
* interferes with natural navigation systems (ie. dolphins)
* prone to overfishing
* tragedy of commons within the fishing industry → extinction of fish species and companies going out of business due to competition
* bycatch: nontarget species caught in fishing nets
* usually do not survive being caught, or tossed back into the water despite not being alive → prone to extinction due to unregulated fishing practices
* sustainable fishing: saving fish for future generations and allowing for replenishment of fish every cycle
* uses catch limits of max sustainable yield
* limit age/size of fish caught to minimize the amount of fish able to reproduce
* law/treaties that protect overfished species (gov regulations)
* ex. the convention on international trade in endangered species of wild flora and fauna (CITES) → places halts on fishing species that are endangered
* giving fines or denying trade with countries that breaks the regulation (consequences) OR subsidizing fishing operations for maintaining within MSY (incentivize)
* modify fishing techniques to minimize bycatch
* ex. turtle exclusion device (TED) (inserted in trawling nets with a net that allows turtles to exit from the lower large end of the net)

## 5.9 Impacts of Mining

* mining: obtaining materials from the ground
* ex. gold, diamonds, phosphorous rock, gravel, coal
* ore: materials that are just mined
* contains many impurities
* refining: removing impurities from a substance
* surface mining: mining materials starting from the ground down
* strip mining: harvesting material in strips
* requires a lot of equipment → increase in pollution and fossil fuels
* mountaintop removal: dig away from the top of the mountain to obtain materials (mainly coal)
* target material: material after impurities are removed
* tailings: impurities removed from the ore
* overburden: soil on top of the ore
* becomes spoil after soil is removed from on top of ore
* cyanide heap leaching: adding cyanide to a pile of ore to remove impurities
* prone to soil erosion → desertification in areas where surface/subsurface mining takes place
* invasive species to penetrate the Earth
* more use of fossil fuels to operate mining equipment
* soil runoff into bodies of water → decreased oxygen levels
* acid mining drainage: acid water in old mines collected underground sulfuric metals over time → lower pH, more acid in water
* remediation: to fix things back to what they were before
* allow land to serve a new purpose

## 5.10 Impacts of Urbanization

* urbanization: shifting from an agricultural lifestyle to a lifestyle with a large population density
* gone through the demographic transition (stages 2-3)
* mass transit: large populations of people traveling
* lowers the amount of fossil fuels per person, very efficient, lowers emissions
* more access to a variety of resources, minimizes land impact, and walkable
* cities can be small though (ie. NYC)
* negatively impacts the water cycle → disrupts the path of water flow through dams (increasing water for humans)
* upstream: flooding, runoff
* downstream: lowering the amount of water for organisms living in that area
* saltwater intrusion for coastal aquifers near the ocean as a result of depleting water from the reserve
* impermeable surfaces: water is unable to penetrate through them → decreased chance of replenishing groundwater reserves & increased runoff (in the remaining runoff many impurities are present → health issues for humans)
* carbon cycle: increased CO2 being spread to the atmosphere as a result of waste and fuel emissions → climate change (global warming)
* increases air pollution from fuel emissions in factories and machinery
* heat island effect: low albedo (absorb more sun) → higher temperatures
* remediation to urbanization: adding more vegetation → helps with runoff, replenishing groundwater, increasing albedo, increased CO2 intake into plants away from the atmosphere
* extending mass transit systems in suburban areas
* inventing permeable pavement
* repurposing brownfields (abandoned areas)

## 5.11 Ecological Footprints

* a measure of how much land is used to meet one’s needs (hectares/land required)
* carbon footprint: the amount of energy used (transportation, electricity, etc)
* built-up land: type of shelter living in (how big?)
* forests: how much of the forest do you use? (paper, shelter, etc.)
* cropland & pasture: food & nutrients
* fisheries: also for food (seafood)
* LDC → lower ecological footprints
* MDC → higher ecological footprints
* demographic transition → higher ecological footprints
* lower ecological footprint → more environmentally friendly

## 5.12 Introduction to Sustainability

* the ability to use and maintain a resource for the future
* use = replenishment or input = output → sustainable
* use < replenishment or input > output → wasteful
* use > replenishment or input < output → unsustainable
* biological diveristy: healthier ecosystems strong to change/invasion → preserve nature
* food production: poor practices lead to soil degradation and water pollution → sustainable food practices
* global surface temperature/co2 concentrations: excess CO2 → increase in temperature & climate change → decrease energy use
* human population: population growth stresses planet capacity → demographic transition
* resource depletion: how fast does a resource get used up (how much do we have of that resource before it runs out) → three Rs (reduce, reuse, recycle)
* sustainable yield: the max amount of resource that can be taken w/o reducing the availiable supply (50% of carrying capacity)
* must be below the rate of replenishment of that resource
* underuse: using * overuse: using >MSY of resource (>50%)
* population grows fastest with it at 50% carrying capacity
* research/planning → reproductive abilities of a resource
* setting quotas/limits
* requiring permits
* focus on long-term benefits
* reforest (replace harvested trees)

## 5.13 Methods to Reduce Urban Runoff

* water pollution → collecting sediment and matter in runoff
* the inability to recharge groundwater reserves → water not percolating into the ground
* solution for water infiltration: permeable pavement, planting trees, decreasing paved areas by using land efficiently, making land more permeable through small city design, public transportation

## 5.14 Integrated Pest Management

* combination of pest control methods that are meant to minimize environmental disruption and reduce pest species
* biological: natural pest predators
* ex. ladybugs, farm cat/dog, parasitic wasps, praying mantis, bacteria/fungi
* physical: crop barriers
* ex. traps, tilling, screens, weed blockers, fences
* chemical: pesticides (poisons)
* causes harm to the environment
* affects nontarget species
* increases water pollution
* brings risks to human health
* ex. DDT, atrazine, glyphosate
* crop rotation: changing the crop being planted in a field each time
* ex. corn one year, soy next year
* intercropping: planting two different crops on the same field
* ex. allows all pests to be naturally against competitive → minimizes damage from pests
* benefits: decreases chemical pesticide use, economic savings, sustainable, targeted, minimize health risk and loss
* drawbacks: complex, slow, expensive

## 5.15 Sustainable Agriculture

* preventing soil erosion → sustainable food practices
* contour plowing: maintain the shape of a mountain or hill by plowing on the slope (contour)
* allows water to slide down the hill/mountain to crops → preserving soil
* windbreaks: adding trees/breaks near crops
* slows down wind speed to allow soil to be blown away
* strip cropping: planting multiple types of crops, harvesting each type at differnet times
* roots that hold soil together reduce erosion from wind/water
* terracing: plowing steps in mountain
* decreases velocity of water → reducing soil erosion
* no till agriculture: no plowing at all
* leaves soil; keeps it natural
* perennial crops: harvesting crops year round
* roots are intact → do not loosen up soil when harvested
* maintaing soil fertility → sustainable food production
* crop rotation: changing the type of crops being planted on a field at a fixed interval
* replenishes soil of natural nutrients
* green manure: covers soil and decomposes in soil, providing nutrients for soil
* limestone: increases pH (alkaline) & calcium → favorable for many types of crops
* overgrazing: overuse of pasture leading to plant damage
* using it up faster than it can be replenished → soil erosion and plant damage
* rotational grazing: cycling livestock around different parts of pasture to not overgraze the whole area
* dividing up pasture land to preserve other parts and give time for grazed land to replenish itself

## 5.16 Aquaculture

* farming of seafood and aquatic plants by individual/corporation for business
* can occur in marine/freshwater environments
* china worldwide leader in aquaculture production
* pros: highly efficient, less costs economically
* allows meeting increasing protein source demands
* compensates for decreasing wildfish harvests
* opens more jobs and stable income for fisherfolk
* less time-consuming and resource-consuming, less dangerous (more efficient, fewer cons)
* less fossil fuel inputs
* cons: arise from a large population in small space
* organism waste → water pollution with excess nitrogen → algal bloom/hypoxia
* uneaten food pellets → water pollution
* risk of escape → interbreed or compete with wild organisms
* diseases/infections spread more easily → increased use of antibiotics → water pollution & spread to wild organisms

## 5.17 Sustainable Forestry

* forests are essential for many ecosystem services
* ex. food, fuel, co2, air, water, recreation, aesthetics, etc.
* collection of methods that attempt to mitigate the human impact of harvesting trees using forest resources
* mitigating deforestation: reforestation, consumption from providers that use sustainable forestry practices, and the 3Rs of wood products
* preserves biodiversity and ecosystem services
* supporting companies that use sustainable practices
* reduces the need to cut new timber
* mitigating pathogens: affects ecosystem health
* IPM → minimizing infestations sustainably
* ex. routine checks, underbrush thinning, common pest awareness, pest threshold, removing pests, using natural predators, chemical control (last resort), selective removal of diseased trees
* reduce the impact of pesticide
* reduced chance of disrupting the trophic structure
* prescribed burns → removes excess understory plants and dead matter
* reduces forest fire severity by reducing dry matter
* encourages new growth

\
\