APES Unit 5 Review (Land + Water use)

5.1 - 5.17

Tragedy of the Commons

Individuals will use shared/ public resources in their own self interest, degrading them.

• Must be a public resource

• Must be degraded

Examples of Tragedy of the Commons

• Overgrazing

• Overfishing

• Water and Air pollution

• Deforestation

• Overuse of groundwater

Solutions Tragedy of the Commons

• Private land ownership

• Fees or taxes for use of a resource

• Taxes, fines, or criminal charges on polluters

Clearcutting

Cutting down all the trees in a given area at once

Benefits of Clearcutting

• Economically advantageous

• Efficient source for timber and other wood products

Cons of Clearcutting

• Soil erosion - Clearcutting removes stable root structure, removes organic matter and nutrients from the forest’s soil, and deposits sediments into local streams

• Increased soil and stream temperature - Loss of tree shade, deposits sediments that increases temperature and turbidity

• Flooding and landslides - Logging machinery compacts soil, increased sunlight dries out soil (making it not absorb water as well)

• lowered biodiversity (less tree species = less resilience of an ecosystem)

Benefits of forests

• filters Air pollutants (VOCs, NO2, PM)

• Removes and stores CO2 from the atmosphere

• Provides a habitat for organisms

• Regulates water cycles and absorbs water, preventing floods

Consequences of deforestation

• reduces air filtering and carbon storing devices (VOCs, CO2, NO2, PM)

• Actively releases CO2 from decomposition of organic material

• Slash-and-burn method of clear-cutting releases CO2, N2O, and water vapor into the atmosphere (All GHGs)

• Increases the chance of flooding through the erosion of soil and the decrease in plant life absorbing water

GHGs

Greenhouse Gases

The Green Revolution

Shift in agriculture to large, industrial-scale businesses that mass-produce crops

Effects of Green revolution

• Increased use of mechanization, GMOs, irrigation, fertilizers, and pesticides

• Greatly increased efficiency of lands, short-term profitability, and food supply

• Decreased world hunger, increased Earth’s carrying capacity for humans

• Soil erosion, biodiversity loss, runoff, surface water contamination, leaching

Effects of Mechanization

• Increased reliance of fossil fuels and GHGs

• Heavy machinery compacts soil, decreasing water holding capacity (causing floods)

• makes topsoil prone to erosion

GMOs

Genetically Modified Organisms (Crops with new genes meant to produce high yields)

Effects of GMOs

• leads to desirable traits in crops and therefore higher profits (pest-resistant, disease resistant, higher yield, faster growth)

• GMO crops are genetically identical, decreasing genetic diversity and making it susceptible to other diseases or pests

Synthetic fertilizers

• shifts from organic fertilizers (manure, compost) to synthetic fertilizers (ammonium, nitrate, phosphate)

  • increases yield and profits

  • Excess nitrate, phosphate are washed off fields and into nearby waters where they cause eutrophication

  • Requires fossil fuels for production, releasing CO2

Cons of irrigation

• can deplete groundwater sources, especially aquifers

• over watering can drown roots and cause soil salinization or suffocate plants (lack of oxygen)

Effects of pesticides

• can wash off crops in runoff and kill or harm non-target species in local soil or waters (Example: DDT)

Monocropping

Growing one single species of crop (Corn, wheat, soy)

• highly efficient, all crops are harvested at the same time and pesticides can be applied non-discriminatorily

  • decreases biodiversity (more prone to pests, diseases)

  • Increases soil erosion (crops harvested all at once and soil left bare)

  • decreases habitat diversity for species living in the area

Tilling + effects

Mixing and breaking up soil to make planting easier

• also loosens soil for roots

  • Increases erosion by loosening topsoil, breaking up leftover root structure from harvest

  • Loss of organic matter and topsoil nutrients over time

  • Increased PM in the air and sediments in nearby water

Slash & Burn

• cutting down vegetation and burning it to clear land for agriculture and return nutrients in plants to the soil

  • leads to deforestation, loss of habitat and biodiversity, CO2 is released into the atmosphere, air filtration effect is gone

  • CO2, NO2, N2O are released (GHGs leading to global warming)

  • Increased PM causing respiratory issues

  • Lowers albedo, making area warmer

Leaching

Water carries excess nutrients (Nitrates, Phosphates) into groundwater or into surface waters through runoff

• Causes eutrophication, contaminates water

Methods for irrigation

Drip, Furrow, Spray, Flood irrigation

Furrow irrigation

• digging a trench along crop rows, filling it with water

  • Pros = Cheap and easy; water seeps into soil slowly

  • Cons = least efficient

Flood irrigation

Floods entire field

• Pros = cheap and easy

• Cons = Disruptive to plants, waterlogging of soil

Spray irrigation

Ground or surface water pumped into spray nozzles

• Pros = efficient than flood or furrow

• Cons = more expensive (installing equipment, getting energy)

Drip irrigatino

Uses pipes and tubes to direct water straight to plants’ routes.

• Pros = most efficient (over 95% efficient), avoids waterlogging and conserves water

• Cons = most expensive, cannot be used wide scale

Waterlogging

Oversatures the soil, filling all soil pore space with water

• Doesn’t allow oxygen access for the roots, stunting or killing plants

  • Solutions = drip irrigation, soil aeration

Soil salinization

Salt building up in a soil overtime

• groundwater used for irrigation has small amounts of salt

• water evaporates, and salt is left behind in soil. Over time, it can become toxic and dehydrate plant roots

  • Solution = drip irrigation, soil aeration, flushing with fresh water, switch to freshwater source

Groundwater recharge

Rain water percolates down through soil into aquifers

• unconfined aquifers recharge quickly

• confined aquifers are long term water deposits, and charge more slowly”

Types of Pesticides

Rodenticides = kills rodents

Fungicides = kills fungi

Insecticides = kills insects

Herbicides = kills plants

CAFOs

Massive feedlots meant to raise livestock as quickly as possible, fed grain

• Pros =

  • Cheapens cost for consumers, maximizes land use and profit

• Cons =

  • animals are given antibiotics and growth hormones to speed up growth and prevent disease

  • animals produce lots of waste which can contaminates nearby surface or groundwater

  • produces lots of methane, carbon dioxide, and Nitrous oxide

Manure lagoons

large pits for animal waste

• waste contains ammonia, hormones, antibiotics, fecal coliform bacteria (can cause e.coli_

• heavy rain can flood lagoons and contaminate nearby surface and ground water with runoff (causes e.coli, eutrophication, endocrine disruptions)

• Denitrification of ammonia in manure produces nitrous oxide

  • Solution = can be emptied and buried in landfills or turned into fertilizer

Free range grazing

Animals graze in a large pasture or greenlands

Fisheries

Populations of fish used for commercial fishing

Fishery Collapse

when overfishing causes 90% population decline in a fishery

• Population may never recover due to:

  • Environmental impact: decreases genetic biodiversity, species biodiversity, causes inability to find mates, and inbreeding depression

  • Economic consequences: lost income for fisherman, lost tourism money for communities

Bottom Trawling

Dragging a net along the bottom of the ocean to catch large amounts of fish

• Catches unintended species like dolphins, whales, turtles, etc.

• Stores up ocean sediment (creating turbidity) and destroys coral reef structure

Overburden

Soil, vegetation, and rocks that are removed to get ore deposits below

Tailings and slag

Leftover waste material separated from the valuable metals or minerals inside the ore

Surface Mining

Removal of overburden to access ore near the surface. Types of surface mining include:

• Open pit

• strip

• mountaintop removal (most damaging to landscape & habitats)

• placer

  • Negative consequences = topsoil erosion, habitat loss, increased stream turbulence, increased PM in the air

Subsurface mining

• more expensive because higher insurance and healthcare costs for workers

• Risks = toxic gas exposure, mine shaft collapse, falling rocks, lung cancer, asbestos, fires, explosions

Environmental impacts of mining

• rainwater carrier sulfuric acid into nearby streams or groundwater, lowering pH of water, making toxic metals (mercury and aluminum) more soluble in water sources

• Methane release, causing climate change

• PM Release, releases soot and other particulates, hurting human and animal lungs

Mine reclamation

Restoring land to original state after mining is finished

• Filling empty shafts/ holes

• Restoring original contours of land

• Returning topsoil, with acids, metals, and tailings removed

• replanting native plants to restore community

Urbanization

Removing of vegetation to convert natural landscape to urban landscape

• replaces soil, vegetation, and wetlands with Impervious surfaces that don’t allow water to infiltrate into the ground

  • Consequences = runoff, flood risks, prevents groundwater recharge, CO2 emissions from construction, deforestation

Saltwater intrusion

Caused by excessive groundwater withdrawal (over pumping) of aquifers or sea level rises

Population trends

Rural →Suburban or Urban

Urban sprawl

Population movement out of dense urban centers into suburban areas

• Causes=

  • Cheaper property

  • Development of cars

  • Lower taxes

• Solutions =

  • Urban growth boundaries (zoning laws)

  • Mixed land use (residential, business, entertainment)

  • Improve walkability of Urban areas

Ecological footprint factors

• Food production

• raw materials required

• housing

• Electricity production (coal, natural gas, etc.)

• Disposing waste

Ecological footprint vs. Carbon footprint

• Ecological footprint = measured of individual impact on the earth

• Carbon footprint = measure of CO2 produced per year by an individual

Sustainability

Consuming a resource or using a space that doesn’t degrade or deplete it for future generations

food production

• yields imply amount of water, good soil, and climate to support growth

• threats to food production = Climate change, soil degradation, groundwater depletion

• Increased meat consumption = further strain on food production than grains/ crops

Environmental impact of Urban Runoff

• decreased infiltration (groundwater recharge)

• rain washes pollutants into storm drains and local surface waters

• Pollutes water areas with salt, sediment, pesticides, oil, and fertilizers

  • eutrophication, turbidity, plant/ insect death, suffocation

Solutions for urban runoff

• permeable pavement

  • allows groundwater recharge/ infiltration

  • decreased pollutants carries into water areas

  • decreased likelihood of flooding

• Rain gardens

  • habitat for pollinators, stores CO2

  • Holds rain

• Public transit

  • Reduces the amount of cars on the road (decreases # of pollutants and CO2 emissions)

  • fewer lanes, decreasing impervious surface area

• Building up, not out

  • Building vertically decreases impervious surfaces

  • can use rooftop gardens (holds CO2, absorbs water, and pollutants inside soil)

Integrated Pest Management (IPM)

Using a variety of pest control methods that minimize environmental disruption and pesticide use

• Researching and monitoring pests and targeting methods to specific pest life cycles

• Biocontrol (Bringing in a natural predator)

• Crop rotation

• Intercropping

Biocontrol

introducing a predator of the parasite

Crop rotation

Many pests prefer one specific crop, and lay their eggs in the soil. By changing the crop, you take away their source of energy/ food.

Intercropping

Uses two plants that deter or attract the pest from crops. Uses “push” and “pull” plants.

• Push plants = emit volatile chemicals that repel pests

• Pull plants = emit chemicals that attract the pest to those plants instead of your crops

Pros/ Cons of IPM

Pros =

• Reduces death and mutation from pesticides

• reduces effects of pesticides when humans consume it

• reduces contamination of surface and groundwater with pollutants

Cons =

• Can be more expensive and time consuming

• Biocontrol can lead to the spread of an invasive species

soil convservation

• Benefits = adds nutrients, soil moisture, decomposers, and organic matter in topsoil

• Methods = Contour Plowing, terracing, perennial crops, Windbreaks, no till, strip cropping

Contour plowing

• Plowing parallel to natural slopes of land. Forms mini terraces that catch water running off

  • Benefits = catches lots of runoff and prevents soil erosion, conserves soil and water

Terracing

• cutting flat platforms of soil into a steep slope. Flatness ot terraces catches water.

  • Prevents runoff and eroding soil

Perennial Crops

Crops that live year round and are harvested numerous times

• Longer, more established roots

  • prevents bare soil between harvests

Windbreaks

Using trees or other plants to block the force of the wind, preventing topsoil erosion

• Prevents soil erosion, can be used as a source of firewood/ fruit, provides habitat for pollinators and biodiversity

No Till

Leaving leftover crop remains in soil instead of tilling

• Adds organic matter to soil (giving nutrients, soil cover, and moisture)

• Prevents erosion from loosened soil

Methods to improve soil fertility

Crop rotation, green manure (dead plants, organic matter), limestone (reduces acidity), rotational grazing (prevents overgrazing)

Pros/ Cons of aquaculture

Pros =

• Minimal land space usage compared to other livestock

• Reduces risk of fishery collapse

• Little water, space, and fuel usage

Cons =

• Risk of diseases like e.coli through high population densities and waste production

• may introduce non-native species or GMOs to a local ecosystem if captive fish escape

Methods of ecologically sustainable forestry

• selective cutting/ strip cutting

• Using human and animal labor to minimize soil compaction from machinery

• Replanting same species being logged

• Using recycled wood

• Reforestation (replanting forests that have been deforested)

• wood can be chipped and used as mulch for gardens/ agriculture

Selective cutting/ strip cutting

only cuts some of the trees in an area to preserve habitat and prevents soil erosion

• Cut down:

  • Biggest trees, oldest trees, diseased trees

fire-suppressed forests

• Characteristics:

  • Large biomass buildup, leading to worse fires over time

  • Dead trees hosting disease and pests

• Solution:

  • Controlled fires burn dead matter & break down biomass