APES Unit 5 Review Part 2

Semester 2

Soil Erosion

Result of Clear-cutting

-Caused by loss of stabilizing root structure

• Removes soil organic matter & nutrients from forest

• Deposits sediments in local streams

  • Warms water & makes it more turbid (cloudy)

  • -decrease H₂O holding

Increased Soil and Stream Tempatures

Result of Clear-cutting

• Loss of tree shade increases soil temperature

  • Soil has lower albedo than leaves of trees

• Loss of tree shade along rivers & streams warms them

  • Erosion of sediments into rivers also warms them

  • -decrease H₂O holding

Flooding and Landslides

Result of Clear-cutting

• Logging machinery compacts soil

• Increased sunlight dries out soil

• Loss of root structure = erosion of topsoil & O horizon

• -decrease H₂O holding

Tree Plantations

Areas where the same tree species are repeatedly planted, grown, and harvested

-lowers biodiversity

-all trees planted at the same time

What happens when there is a lower species diversity?

lower resilence

Examples of soil benefits

1. Filtering of Air pollutants

2. Removal & storage of CO2 from atm

3. Habitats for organisms

Slash and Burn

method of clearing land for agriculture by cutting trees & burning them releases CO₂, N₂O and water vapor into the atmosphere (all GHGs)

Deforestation Consequences

• Reduces air filtering and carbon storing services

• Cutting trees down releases CO₂ from decomposition of leftover organic material

• Slash & burn method of clearing land for agriculture by cutting trees & burning them releases CO₂, N₂O and water vapor into the atmosphere (all GHGs)

Ecologically Sustainable Forestry

a holistic management approach that balances timber harvesting with preserving forest health, biodiversity, and ecosystem functions for current and future generations
-Using human & pack animal labor to minimize soil compaction from machinery
-Maximizes long-term productivity of land & preserves forest for future generations

Sustainable Forestry Practices

methods for managing forests to provide timber, wildlife habitat, clean water, and recreational opportunities today, without compromising their health, biodiversity, or ability to provide those benefits for future generations

-Using recycled wood, or simply reusing without recycling (furniture, decoration)

-Wood can be chipped and used as mulch for gardens or agricultural fields

Fire Suppression

1. Stopping Natural Fires
   

2. Problem-Leads to more biomass buildup

3. Solution- Monitoring instead

(an automatic or manual setup designed to detect and extinguish fires using agents like gas, foam, or chemicals (instead of just water) to cool, smother, or interrupt the chemical reaction of flames)

Prescribed Buring

an automatic or manual setup designed to detect and extinguish fires using agents like gas, foam, or chemicals (instead of just water) to cool, smother, or interrupt the chemical reaction of flames

1. problem-dead biomass builds up

2. solution- small, controlled fires burn lots of dead biomass

3. solution-promotes nutrients recycling

Urbanization

Removing of vegetation to convert natural landscape to CITY (urban)

soil, vegetation, wetlands»»»»» concrete,cement, asphalt

-prevents groundwater recharge

Urban Heat Islands

occur when cities replace natural land cover with dense concentrations of pavement, buildings, and other surfaces that absorb and retain heat.

Urbanization in Coastal Cities

Population growth in coastal cities can lead to  saltwater intrusion due to:

-seal level rise

-excessive groundwater withdrawal

Why do sea levels rise?

due to warming of ocean (thermal expansion) and melting of ice caps (increasing ocean volume) can contaminate fresh groundwater with salt

What can excessive groundwater with drawl do?

the water table to drop, leading to dried-up wells, streamflow depletion, land subsidence (sinking ground), sinkhole formation, and saltwater intrusion (near coasts)

Where do people tend to move from?

People move from rural → urban areas for jobs, entertainment, cultural attractions

Urban Sprawl

Pop. movement out of dense, urban centers to less dense suburban areas surrounding the city (Atlanta → Metro ATL)

Urban Sprawl Causes

• Expanded highway system makes travel easier and increases driving

• Increase in driving increases fuel tax revenue, which is used to build more highways

• Highway expansion makes it easier and easier to commute from suburbs into urban areas

Urban Sprawl Solutions

• Urban growth boundaries: zoning laws set by cities preventing development beyond a certain boundary

• Public transport & walkable city design that attract residents to stay

• Mixed land use: residential, business, and entertainment buildings all located in the same area of a city

  • Enables walkability & sense of place

Urban Footprint

the total land area and resources (food, water, energy) required to support a city's population and activities

What are some consequences to Urban Footprint?

-decreased infiltration (groundwater recharge)

-rain washed pollutants into storm drains

What are some solutions that can help reduce urban runoff?

1. Permeable Pavement

2. Rain Gardens

3. Public Trait

4. Building up, Not out

Permeable Pavement

SOLUTION TO URBAN RUNOFF

a specialized surface that allows rainwater to filter through its structure easily to the ground below.

+Decreases runoff, decreasing pollutants carried into storm drains & into local surface water

+Decreases likelihood of flooding during heavy rainfall

-More costly than traditional pavement

Rain Gardens

SOLUTION TO URBAN RUNOFF

Gardens planted in urban areas, especially surrounding a storm drain

+Decreases runoff by allowing it to soak into garden soil surrounding storm drain

+Decreases likelihood of flooding during heavy rainfall

+Redirected water to recharge groundwater.

Public Transit

SOLUTION TO URBAN RUNOFF

shared transportation like buses, trains, and subways

+Public transit decreases urban runoff, pollutants on road, CO₂ emissions & even traffic!

-More cars = more lanes & parking lots (impervious surfaces) & more stormwater runoff

-More cars on the road = more pollutants on streets to runoff into storm drains & local waters

Building Up, Not Out

SOLUTION TO URBAN RUNOFF

Building vertically decreases impervious surfaces (decreasing urban runoff)

Can be combined with “green roof” or rooftop gardens to further decrease runoff

Green roof also sequesters CO₂ and filters air pollutants out

Clearcutting

a logging method where nearly all trees in a specific area are harvested at once, maximizing short-term timber yield but causing significant environmental damage like erosion, habitat loss, increased water temperature, and reduced biodiversity

Bottom Trawling

Especially harmful fishing method that involves dragging a large net along ocean floor

-Bycatch: unintended species like dolphins, whales, turtles caught in nets 
-Stirs up ocean sediment (turbidity) & destroys coral reef structure

-decreases biodiversty

Bycatch

Unintended species like dolphins, whales, turtles caught in nets 

What happens when we fish down the tropic Cascade/ Food web?

• As we deplete large, predatory fisheries, we move down to smaller fish species

• Depletion of smaller fish pop. limits fishery recovery and decreases food supply of marine mammals & seabirds

Over-fishing-example of TOC

Overharvesting of a species or several species from a body of water at such a rate that they cannot replace themselves.

-Leads to instability in aquatic ecosystems

Maximum Sustainable Yield

the highest possible annual catch that can be sustained over time, by keeping the stock at the level producing maximum growth 

Fisheries

Populations of fish used for commercial fishing

Fishery collapse

When overfishing causes 90% population decline in a fishery

ITQs (Individual transferable quotas)

 fishing limits calculated using maximum sustainable yield.  If they can’t catch enough to remain economically viable, quotas can be sold to another fisher.

Magnuson-Stevens Fishery Conservation and Management Act

annual catch limits and accountability measures (ie fishing equipment) in federal fisheries.

Aquaculture

Raising fish, or other aquatic species in cages/enclosures underwater

Tragedy of the Commons

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

Ore

commercially valuable deposits of concentrated minerals that can be harvested and used as raw materials

Metals

elements that conduct electricity, heat, and have structural properties for building (found within ores)

Reserve

The known amount of a resource left that can be mined.

Usually measured in years left of extraction.

Overburden

Soil, vegetation, & rocks that are removed to get to an ore deposit below

TailingsZ&Slag

leftover waste material separated from the valuable metal or mineral within ore (often stored in ponds @ mine site)

Surface Mining:

Removal of overburden to access ore near surface

Open Pit Mining

Digging of large pits in the ground to extract valuable minerals

Mountaintop Removal

Explosives blast off mountain summits to access coal seams

Strip Mining

Removal of long strips of overlying soil and rock to expose mineral deposits

Subsurface Mining

underground mining, extracts minerals and ores located deep below the Earth's surface by digging tunnels or shafts to reach the deposits

Acid mine drainage

rainwater leaks into abandoned mine tunnels & mixes with pyrite, forming sulfuric acid

Methane Release

• coal mining releases methane gas (CH₄) from rock around coal

  • Vented out of mine to prevent explosion & continues seeping out after mine closes

  • Environmental impact of mining

PM Release

coal mining especially, releases lots of soot and other particulates that can irritate human & animal lungs

-environmental impact of mining

Smelting

roasting ore to release metals

-major source of air pollution

Heap-Leach Extraction

crushed ore piled in large heaps and sprayed with a dilute alkaline cyanide solution which percolates through the pile to dissolve the impurities.

Mine Reclamation

Process of restoring land to original state after mining has finished

-Includes:

1. Riling of empty mine shafts

2. Restoring original contours of land

3. returning topsoil, with acids, metals, and tailing removed

4. replanting of NATIVE plants to restore community to as close to originals state as possible

Surface Mining Control & Reclamation Act of 1977

Federal law that regulates the environmental effects of strip mining in the U.S.

Ecological Footprint

Measured in land (gha - global hectare) which is a biologically productive hectare (2.47 acres)

Carbon Footprint

Measured in tonnes of CO₂ produced per year

Sustainability

Consuming a resource or using a space in a way that does not deplete or degrade it for future generations

-EX: sing compost (renewable) over synthetic fertilizer (fossil fuel dependent)

Maximum Sustainable Yield

The maximum amount of a renewable resource that can be harvested without reducing or depleting the resource for future use

ENV. indications of sustainability

Factors that help us determine the health of the environment and guide us towards sustainable use of earth’s resources

Human POP & Resource Depletion

As human population grows, resource depletion grows