Case studies Flashcards
Chernoybl
- nuclear reactor exploded
- radioactive fallout
- 336k evacuated
- cancer increase in surronding area
- reinforced negative perceptions around nuclear
- forests surrounding the nuclear plant died (Red Forest)
- Fauna inhabited abandoned cities and villages
- Mutations and malformations in the offsprings.
Minamata disease
- 1956
- chemcial factories released toxic mecurury into water
- fish gained through biomagnifcation,then cats, then humans
- caused paralysis
- raised awarness of risks from factories and enviormental regulations
Silent spring
- DDT used as pesticide to control malaria (1940s-1970s)
- banned due to env. & health impacts (Stockholm Convention on Persistent Organic Pollutants)
- DDT caused eagles to lay thin-shelled eggs (biomagnification) and lead to reproductive failure
- published into a book by Rachel carlson
- 1962
- concern of dangers from pesticides
Millennium Ecosystem Assessment
- 2001 by the United Nations to assess ecosystem change for human well-being
- Over 1,300 experts from 95 countries
- The MA found that humans have degraded ecosystems more rapidly in the past 50 years than ever before
- While ecosystem degradation has contributed to economic development,
Tropical rainforest
Poison dart frog
Location: Near equator (tropics of Cancer (23.5°N) and Capricorn (23.5°S))
Temperature: Constant high (21-30°C)
Precipitation: High (2000-10000 mm annually)
Productivity: High
Species Diversity: High
Example: Amazon, South America
Human Impacts:
- 38% of the remaining Amazonian rainforest is suffering from degradation
- 20% of the Amazon rainforest has been destroyed since the 1970s
- 36% of Earth’s tropical rainforests remain intact
Temperate Rainforest
- Location: 40° and 60° in both the Northern and Southern hemispheres
- Temperature: Low ( 0-20°C)
- Precipitation: Heavy (840-5590 mm)
Human Impacts:
- Logging
- Cut and burn trees to generate electricity
- Paper industry
- Pollution (industrial activities, agricultural runoff, & urbanization)
- Lead to the decline of s sensitive species and disrupt ecological interactions.
Boreal Forest
- Location: Between 50-60 N & S of the equator
- Precipitation: Low (300-900mm/yr)
Temperature: Low (-30 to 20°C) - Biodiversity: Low
Tundra
Location: Places with high latitudes and low insolation (60°-75° North and South)
Temperature: Extremely low (often snowing, -40 to 18°C)
Precipitation: Low (150 to 250 mL/yr)
Productivity: Low
Example: Iceland, Europe
Reindeer moss, thick shrub absorbs moisture
Human Impacts:
Climate change and global warming, which are causing the permafrost to thaw and the tundra to shrink
Desert
Location: 30 degrees North and South of the equator.
Temperature: Extremely high (45-49 degrees Celcius)
Precipitation: Low (under 250mm annually)
Productivity: Very low
Species Diversity: Low
Example: Sahara, Africa
Scorpion
Tropical Coral Reef
- Location: Tropics & subtropics (35°N to 35°S)
- Temperature: 23°to 29°C
- Productivity: Very high
Human Impacts:
- Climate change
- Declining water quality
- Overfishing
- Pollution
- Unsustainable coastal development
- By 2050, 70-90% of coral will die (coral bleaching)
- Corals lose their symbiotic algae (zooxanthellae) which provide nutrients through photosynthesis. When they are released due to environmental stresses, corals lose their color and die.
Hydrothermal Vents
- Location: deep ocean along mid-ocean ridges (East Pacific and Mid-Atlantic Ridge)
- Temperature: Very hot (400+°C)
- Diversity: Very low (little to no sunlight)
Human Impacts:
- Deep-sea mining
- Climate change
- Pollution
- Affects organisms living around the vents (e.g. chemosynthetic bacteria which form the base of the food chain)
Savannah
- Location: 5-30° North and South of the equator (Central Africa)
- Precipitation: 800-900 mm/yr
- Temperature: 15°-35°C
Diversity: High
Temperate Grasslands
- Location: 40°-60° North and South of the equator
- Precipitation: 250-750 mm/yr
- Temperature: -40 to 40°C
Diversity: High
Tri-Cellular Atmospheric Wind Model
Made up of three air masses that influence atmospheric movement and heat energy redistribution
Hadley Cell
- Largest cell (0° to 40° N and S)
- Trade winds travel from the tropical region to the equator
- When trade winds meet, hot air rises, forming thunderstorms
- Air travels higher and becomes cooler (sinks to subtropical region)
- Dry, cloudless air is warmed by the sun (Hot Deserts)
Ferrel Cell
- Middle cell (edge of Hadley cell to 70° N and S)
- Moves in the opposite direction
- Air joins with Hadley and Polar Cell (unsettled weather)
Polar Cell
- smallest/weakest cell (edge of Ferrel cell to 90° N and S)
- Air is cold and sinks = high pressures
- Air is warmed and rises to return to the poles
Primary succession
Surtsey, Iceland
- Formed due to an undersea eruption in 1963
- 30 plant species had been established by 2008
- Forestation on the island may require 300-2000 years
Secondary Succession natrual
Mount St Helen, US
- Volcanic eruption in 1980 caused disturbance in meadows and forests. This destroyed the community
- Colonization
Pioneer species survived in burrows and ice-covered lakes colonize
Vine maple resprout in soil, logs held fungi and microbes - Competition
Diversity increase rapidly
In 20 years, plant growth grew 66%
Old climax species migrate back (Roosevelt Elk) - Stabilization
There is little additional increase in diversity
Secondary Succession Due to Human Impact
Heather Moorlands, Northern England
- Logging in the Middle Ages removed deciduous woodland
- Invasive species Heather reach the new equilibrium
Management strategies to burn and graze dominant heather in small patches
Promote the growth of birch, pine, oak trees
Zonation
- Spray zone (limpets)
- High tide (Barnacles & limpets)
- Mid tide (Hermit crabs & mussels)
- Low tide (kelp & benthic inverts)
- Faunal turf
Constructive/Divergent Plate Tectonics
Mid-Atlantic Ridge
1. Convection currents rise & spread outwards when they reach the top of the mantle
2. Plates are dragged apart
3. Magma from the mantle rises up through the opened cracks
4. Ocean ridges and volcanoes are formed
5. Magma cools, forming new ocean crust
Convergent Plate Tectonics
(Continental-Continental crust)
Himalayas
1. Mantle convection currents converge & sink
2. Plates are pushed together
3. Plates crumble up (forms mountains)
Conservative Plate Tectonics
San Andreas fault of California
- No crust is created or destroyed
- Plates move past each other
Convergent Plate Tectonics
(Oceanic-Continental crust)
Andes Mountains/Peru Trench
1. Plates move toward each other
2. Denser plate subducts (oceanic plate)
3. Causes earthquakes & volcanic eruptions
Convergent Plate Tectonics
(Oceanic-Oceanic crust)
Lemnos (Island of Hephaestus)
1. One plate sinks beneath the other
2. Subduction zone forms along the boundary where the denser plate sinks into the mantle
3. Plate is heated
4. Plumes of molten magma rise upward through the top plate
5. Volcanic island is formed
