Case studies Flashcards
Chernoybl
- nuclear reactor exploded
- radioactive fallout
- 336k evacuated
- cancer increase in surronding area
- reinforced negative perceptions around nuclear
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 caused shells to crack
- 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 and Capricorn)
Temperature: Constant high (26 degrees Celsius)
Precipitation: High (over 2500mm annually)
Productivity: High
Species Diversity: High
Example: Amazon, South America
Tundra
Location: Places with high latitudes and low insolation
Temperature: Extremely low (often snowing, can reach -50 degrees Celcius)
Precipitation: Low
Productivity: Low
Example: Iceland, Europe
Reindeer moss, thick shrub absorbs moisture
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
Primary succesion
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
Mass Extinction - The End Triassic extinction
About 199-214 million years ago. Massive amounts of lava erupted from the mid atlantic rift which led to the break up of Pangea. It killed 80% of all species.
The Ordovician-Silurian extinction
About 439 million years ago. Caused by a drop in sea levels as glaciers formed, then by rising sea levels as glaciers melted. 86% of all species died.
American bald eagle’s (Improved by intervention)
American bald eagle. It only lived in North America and, therefore, became the USA’s symbol. These birds can live up to 40 years in the wild. They live near large bodies of water and nest in trees. They primarily feed on fish but also eat smaller animals like rabbits.
In the 1700s, there were 300,000 - 500,000 birds, and their population size declined to fewer than 500 pairs by the early 1960s. This was mainly due to shooting them, using pesticides on crops, destroying their habitats, etc. DDT caused their eggshells to become thinner.
The population size was restored by banning DDT and having laws protecting them. In 2007, there were 10,000 pairs of them, and they were removed from the list of endangered animals.
Tigers
- The bengal tiger, found in parts of india, sub and tropical rainforests
- indochinese, parts of thailand and neighbouring regions hilly and mountanious
- siberian found in eastern russia and northern china, temperate forests and sikhote alin mountain range
- Habitat loss due to deforestation as a result of ubranisation causing decrease in movment corridors
- poaching and illegal trade driven by medicine
- genetic isolation auses inbreeding causing reduced genetic diversity
Red squirrel
- effective seed disperers help regeneration conferious forest
- forgetting seeds they collect
- middens create micro habitats supporting higher abundance
- found in woodland habitats
- invasive grey squirrel is competiton
- habitat loss and fragmentation as a result of climate change causing drier and warmer climates
