Ch 56 Biodiversity and Global Change Flashcards
Conservation biology
Seeks to preserve life
Several fields that are integrated into several fields
1) Ecology
2) Physiology
3) Molecular biology
4) Genetics
5) Evolutionary biology
Three main components of biodiversity
1) Genetic diversity
2) Species diversity
3) Ecosystem diversity
1)___ ___ are concerned about 2)___ ___ because of alarming statistics regarding 3)___ and 4)___
1) Conservation biologists
2) Species lost
3) Extinction
4) Biodiversity
Global extinction rates of birds
12%
Global extinction rates of mammals
21%
Global extinction rates of amphibians
32%
Extinction may be 1)___ or 2)___
1) Local
2) Global
Species related to 1)___ ___ can have important 2)___ qualities
1) Agricultural crops
2) Genetic
Ecosystem services
Encompass all the processes through which natural ecosystems and their species help sustain human life
Examples of ecosystem services
1) Purification of air and water
2) Detoxification and decomposition of wastes
3) Cycling of nutrients
4) Moderation of weather extremes
Four major threats related to most species’ extinctions
1) Habitat destruction
2) Introduced species
3) Over-harvesting
4) Global change
What is the greatest threat to biodiversity throughout the biosphere?
Human alteration of habitat
In almost all cases, what leads to loss of biodiversity?
1) Habitat fragmentation
2) Habitat destruction
Without their native 1)___, 2)___, and 3)___, introduced species may spread rapidly
1) Predators
2) Parasites
3) Pathogens
What happens when introduced species gain a foothold in a new habitat?
They usually disrupt their adopted community
Over-harvesting
Human harvesting of wild plants and animals at rates exceeding the ability of populations of those species to rebound
What kind of organisms are especially vulnerable to over-harvesting?
Large organisms with low reproduction rates
Over-fishing
Occurs when fishing activities exceed the capacity of fish populations to maintain themselves
Over ___ of all fisheries are now fully exploited
Half
Fish and other marine organisms account for ___-___ of total global income of animal protein
13% to 17%
What occurred in the 1990’s in regard to global fishing harvests?
Global fish harvests reached a plateau
What was the maximum global fish harvest?
~86 million tons
During the 1990’s what fishery collapsed?
The cod fishery off of Newfoundland
Bycatch
Species of fish that are harvested, but are not of the targeted fishery
Bycatch includes:
1) Fish
2) Crustaceans
3) Birds
4) Sea turtles
5) Dolphins
6) Whales
___ of some fisheries is bycatch
80%
What is a common means of harvesting large predators?
Longlines
1)___ ___ such as sharks are directly targeted or depleted through 2)___ ___
1) Top predators
2) Bycatch mortality
Due to bycatch, what percentage of large, predatory fish stocks are gone?
90%
Many deep sea fish are at risk due to slow 1)___ and low 2)___ ___
1) Growth
2) Reproductive rates
Some deep sea fish that are at risk:
1) Orange roughy
2) Sablefish
3) Cods
How long does it take many deep sea fish to reach breeding maturity?
30 to 40 years
Individual Transferable quotas (ITQs)
Consists of limited access permits to harvest quantities of fish
Two methods of aquaculture (fish farming):
1) Closed inland enclosures in which foods and wastes do not immediately enter natural ecosystems
2) Open pens in which foods and wastes can enter natural ecosystems
On a 1)___ ___, aquaculture can be 2)___ damaging than fisheries based on catch from wild populations
1) Local scale
2) More
Human-caused environmental changes include:
1) Nutrient enrichment
2) Toxin accumulations
3) Climate change
4) Ozone depletion
What do ocean currents transport?
1) Nutrients
2) Wastes
3) Heat
The 1)___ ___ keeps 2)___ much 3)___ than other regions at the same latitude
1) Gulf Stream
2) Europe
3) Warmer
In the 1)___ ___, warm surface waters are normally pushed 2)___ by 3)___ ___ ___
1) Pacific Ocean
2) West
3) Equatorial trade winds
What does the movement of warm surface waters of the Pacific Ocean to the west cause?
1) Heavy precipitation in southeast Asia
2) Upwelling of nutrient waters along the Americas
El Nino
Occurs when the rising air currents weaken, and westward wind and ocean currents fail
How often does an El Nino occur?
Every 3 to 5 years
Two common characteristics of El Nino years:
1) Intense storms in the Americas
2) Droughts in the west Pacific
What occurs in Hawaii during an El Nino year?
Drought during Hawaii’s rainy season is more common
When is Hawaii’s rainy season?
October to March
What appears to be worsening El Nino?
Global warming
Greenhouse effect
CO2, water vapor, and other greenhouse gases reflect infrared radiation back toward Earth
What is important for keeping Earth’s surface at a habitable temperature?
The greenhouse effect
Increasing concentrations of atmospheric 1)___ is linked to increasing 2)___ ___
1) CO2
2) Global temperature
When was the greenhouse effect first recognized?
1827
From what can climatologists make inferences about the past?
1) Pollen and fossil plant records
2) CO2 levels (inferred from bubbles trapped in glacial ice)
3) Analysis of past temperatures (inferred from chemical isotope analysis)
With what does CO2 fluctuate?
Seasonal changes in photosynthesis and respiration
How much does CO2 usually change?
5 to 7 ppm
B 2009, atmospheric 1)___ levels had reached 2)___
1) CO2
2) 338 ppm
Atmospheric CO2 levels n 2009 were higher than what? By how much?
1) 39% higher than before the Industrial Revolution
2) Higher than the past 800,000 years
Burning fossil fuels release 1)___ ___ ___ of 2)___ to the air
1) 8 billion tons
2) C/year
Oceans and forests act as 1)___ ___ and absorb 2)___
1) Carbon sinks
2) 4.7 GtC/year
Where are the lowest emissions in the world?
In Chad
Per capita production is one-thousandth that of the US
Global warming projections vary between 1)___-___ within the 2)___
1) 2C to 4C
2) Century
What could stop circulation of deep seas?
Dilution of salt water by melting polar caps
Heinrich events
Slowing or ceasing of the circulation of the deep seas
If a Heinrich event occurs, what might the results be?
1) The ocean’s thermal conveyor system will shift south
2) Climate will cool in a few decades
What can slow global warming?
1) International reduction in energy need
2) Conversion to renewable energy sources
3) Reduced deforestation
What protects life on Earth from the damaging effects of UV radiation?
A protective layers of ozone molecules (O3)
Since when may the ozone layer have been gradually thinning?
The mid-1970s
What is the main cause of the destruction of atmospheric ozone?
Chlorofluorocarbons (CFCs) produced by human activity
What reaction decreases the amount of ozone in the atmosphere?
Chlorine (contained in CFCs) and ozone’s reaction, which produces O2
What is linked to increased UV radiation (due to ozone depletion)?
1) DNA damage
2) Poorer phytoplankton growth
Ozone levels have decreased 1)___-___ at 2)___ during the past 20 years
1) 2% to 10%
3) Mid-latitudes
Where is the ozone layer thinnest?
Over Antarctica
What has decreased ozone deplection?
An international agreement signed in 1987 to halt CFC emissions
