human impact Flashcards
what % is the human population growing per year
1.1% (135 million births and 55 million deaths)
what is the most invasive form of habitat loss
deforestation
how to limit effects of deforestation
- variable retention: leave representative old growth in each block (doesn’t work always)
- selective cutting - removal of single trees by helicopter (best but costly)
how big defines clear cutting
12ha to 2000ha
soil and lemur population
- in madagascar forests were comprised for profit
- lateritic soils (leached of silica after deforestation)
- concentration of iron, manganese, aluminum, nickle
- leaked into the ocean and killed coral reefs
- lemurs still exist but will go extinct
amazon deforestation
- deforestation for cattle export
- burned/slashed agriculture
- larges cattle farm in the world, sent cattle to 170 countries (3x export in the past 3 years)
what country has the highest rate of deforestation per year?
Brazil
- protest by indigenous ppl
- little response by the educated class
Brazil’s new laws about deforestation
- remission of penalties in landowners who illegally remove native vegetation
- reduce the areas classified as “requiring restoration”
- injustice in the population
- means that insect collectors are charged with high fines but landowners receive no punishment for illegal reforestation
amazon sugar cane article
- can’t cultivate sugar cane
- # of sugar canes have increased
- cane has been shown to decrease biodiversity
- Brazil wants to open the amazon region to sugar cane (in biodiversity hot spots)
Why shouldn’t they plant sugar cane in the amazon
- amazon plays important role in rainfall
- will harm Brazil itself (agriculture and biofuel production)
What did the Ecuadorian government announce
- recent signings of 2 new oil concessions in Yasuni National park
- piplines, wells, drilling platforms etc.
what percentage of worlds temperate rainforest have been cut
55% forest due to deforestation
what ecosystem has the greatest biomass/ha
coastal temperate rainforests
which countries have the highest percentage of deforestation?
nigeria and viet nam
55%
washington, oregon, california (how much of their ancient forest is gone)
95%
what is remaining of BC’s coastal temperate rainforest?
1/4
Gribbrell Island
- government clearcut river
- this was main source of salmon for bears
- 80% reduction of their major protein source for bears (4300kg/y to 300 kg/y)
Haida Gwaii logging
70% of the best forest gone
- spokes person said there is more old-growth forest now than 100 years ago… not true??
- 1967 = first clear cutting. all large trees are now gone except in protected areas
what are grasslands used for
- they all differ from their original state
- used for crops that increases population growth
where are the only natural grasslands left
alberta and saskatchewan
where is the highest species diversity and of vertebrates and richness
coral reef
what are coral reefs impacted by (7)
- warming of oceans
- cyclones
- ocean acidity
- coliform bacteria
- artisinal fishing
- commercial fishing
- aquaria trade
what % of coral reefs have degraded and declined?
75%
how much has the great barrier reef declined since 1980?
50% reduction in corals
- 90% reduction of northern GBR
how much reduction of carribean coral reefs
80%
in the study, what species experienced a larger reduction in suitable habitat
smaller-bodied amphibians, larger reptiles and medium-sized mammals
what are atmospheric substances that lead to global warming?
- carbon dioxide
- water vapour
- black carbon
- methane
- nitrous oxide
- nitrogen trifluoride
- chlorofluorocarbons
- (radioactivity leads to habitat loss, not GW)
what substance leads to increased smog but reduces global warming
sulphur dioxide
Jasper road thru parks and grizzly bear population
- grizzly’s won’t cross the road so their habitat decreased (less gene flow, smaller pop etc)
Carbon dioxide concentration over time
increasing exponentially
- the past 600,000 years it went from 180-300
- in the last 50 years it has increased to 380
how can you detect the change in CO2
- isotope in the ground
how are temperature and CO2 concentration related
as CO2 concentration increases so does temperature
how many isotopes to atmospheric CO2 have?
3 isotopes
- C12 (99%), C13 (1%), C14 (0.000000001%)
- living plants absorb all three of these carbon dioxides
- C14 is unstable (50% decays to N14 every 5730 years)
what is the main contributor the the rise of CO2
fossil fuels
- fossil fuels have no C14
- burning fossil fuels releases CO2 without C14
- MAJOR MAJOR rise after 2000
Suess effect
burning fossil fuels releases CO2 into air without C14
where are the highest levels of C14
arctic
- USA etc have virtually no C14… all CO2 in atmosphere because of fossil fuels
Black carbon
- coming out of industrial smoke stacks
- tiny particles that make atmosphere a little darker
- can also get these particles from burning forests
- absorbers of visible solar radiation
what is responsible for 50% of the increase of temp in arctic
black carbon particles
- contributes to melting of ice in arctic
- increase in 1.9 degrees Celsius since 1980
what rank (contributor to global warming) are black carbon particles
2nd strongest contributor beside carbon dioxide emissions
where is methane found
in the core
how does the methane levels vary with time
- increases and decreases in 50,000 year cycles (natural)
- in the last 50 years there has been a large increase in methane (not natural)
- disproportionate effect on global warming (higher capacity to maintain heat)
where do you find nitrous oxide
- cultivated soils, transportation
- also find when forest burning
where do you find nitrogen trifluoride
- used in computer industries for semiconductors
what does the impact of one molecule of nitrogen trifluoride have
effect on global warming is 17200 times that of a single molecule of CO2
how is the concentration of NF3 raising in the atmosphere
- quasi-exponentially
what industries use chlorofluorocarbons
- used to make refrigerator units
what do chlorofluorocarbons do
- destroy the ozone
- every year there is a part of ozone that disappears naturally
- CFC’s are making the hole bigger
- the UV radiation under this hole is intense (ozone absorbs UVA, UVB, UVC)
- 99% of UVA and 50% of UVB
why did they think the ozone stopped deteriorating
stopped using CFC’s
- turns out some unexpected countries still using CFC’s
how many molecules of CO2 would one methane molecule be
32
what are the effects of CFC’s on the ocean
- gap in ozone
- winds
- impact on ocean circulation and ventilation in these oceans
what are CFC’s effect on whales
- increased UV exposure
- lesions in skin
- pathways used to limit UV radiation damage in humans are shared by whales
- darker pigmentation is advantageous
what percentage of the ozone depletion is due to Cl in the atmosphere
1/4
how many molecules of CO2 is one molecule of chlorofluerocarbon?
> 10,000
how many molecules of CO2 is one molecule of N2O
150
what of % the total contribution of global warming does black carbon have?
20%
what % of overall greenhouse gases is because of natural causes vs. anthropogenic causes
75% anthropogenic
25% natural
3 other biophysical consequences of global warming
- loss of ice cover and sea level rise
- extremes in weather systems
- coral reef bleaching
how did the paper measure ocean temperature
measured it for the last 2000 years by using marine sediments
- another study measured atmospheric O2 and CO2 that are released when the ocean temperature rises
Threshold paper
- there is a threshold that if crossed, could prevent stabilization of the climate at intermediate temps even if human emissions are reduced
what does the paper say the temperature increase will be in 2100
3 degrees celsius
what happened to species richness during warm ‘greenhouse’ phases
- lower species richness
- high extinction
what is a useful approach to counteract global warming and how does it work
sulphur dioxide
- burning fossil fues rich in sulfur results in increased acidity of precipitation
what is acid rain composed of
HNO3 (25%) and H2SO4 (75%)
what is the difference in pH of acid rain and natural rain
natural rain: 5.8
acid rain: 3.2-5.0
consequences of acid rain
- loss of forest
- death of aquatic ecosystems of lakes in northern hemisphere
- costs a lot of $$!!! $13 billion in forest damage and crop loss in the US, $7 billion/y from reduced agriculture production
What has the world health organization set healthy level, bad level, and hazardous level air at?
healthy: 25 micrograms
bad: 300 micrograms
hazardous: 500 micrograms
dirty air shortens life
what do nuclear power plants use for fuel
uranium or plutonium
pros and cons of nuclear power plants
+ high efficiency, require little fuel
+ few greenhouse gases
- high environmental, human and financial costs with failure
what is nuclear power plants global electrical production
~11% in 2018
what was the cost of construction and clean up of fukushima
cost of construction: $10 billion
clean up: $180 billion
cost of construction and clean up of chernobyl
construction: $6 billion
current economic costs: $250 billion
how long has birth defects risen in belarus since chernobyl
83%
what cancers have increased due to radiation exposure
200% increase in breast cancer, 10% increase incidence of cancer and leukemia, 2400% increase of thyroid cancer
environmental impacts of chernobyl
- 99% of the Belarius is contaminated to degrees above internationally accepted levels
- 2,000 towns and villages were evacuated
- more than 400,000 thousand have been relocated and 70,000 ppl are still waiting to evacuate
- 30-70 squred km will nver be able to be liveable again
- half life of 24,400 years
controversial studies in the chernobyl exclusion zone
- some studies say that wildlife is affected in this 4,200 km2 zone
- another study shows no impact on the abundances in wildlife
what is more effected by radiation, plants or animals?
plants
how many people died from radiation exposure in chernobyl
1 million
- another study says that there is no scientific evidence of any significant radiation-health effects to most ppl
what is the open ocean saturated with that is necessary for plankton and corals. What is happening
calcium carbonate
(CO2 + H2O (seawater) –> HCO3 –> CaCO3)
–> CO2 is causing a reduced pH and lower levels of CaCO3!!!
pH is decreasing
CO2 is increasing
4 aquatic pollutants
- ocean acidification
- oil spills
- industrial chemicals and biocides
- plastics
what important molecule decreases in the ocean with increased CO2?
Iron
- limiting nutrient in large ocean acidification
what is the result of increased CO2 for marine life
- corals will be more rare and less diverse
- some corals appear to be adapting to acidic conditions
what did Hazelwood do?
- drunk and drove a boat into rocks
- 250, 000 barrels of oil discharged (10 million gallons)
- polluted 2100 km of coastline
- killed 250, 000 seabirds, 2800 sea otters, 300 harbour seals, 250 bald eagles, 22 whales
what molecule experiences biomagnification
DDT
What concentration does DDT increas
10 MILLION - starts of at 0.000003 ppm in water - 0.04 in zooplankton - 0.5 ppm in small fish - 2 ppm in large fish - 25 ppm in fish-eating birds > 80% mortality of eggs and chicks
what did the increased DDT concentration do to birds
- the amplified DDT in these birds interfered with shell producing glands so they could not produce eggs
when was there a ban of DDT in US and a world ban of DDT?
- ban in US: 1972
- world ban 2002
- some countries still use DDT to kill mosquitoes because malaria is such an issue
polychlorinated biphenyl study
Fish travelling to Alaska are carrying PCB with them
- may be harmful for the regions top carnivores
- [PCB] 7x higher here
- comparable to lake superior (highly populated)
St. lawrence beluga population
- high levels of intestinal cancers
- sterility near 20 years of age
- highly contaminated with polycyclic aromic hydrocarbons! (found in all fossil fuels, cooked meats)
what animal is the most contaminated from polychlorinated biphenyl?
- orcas
- PCB mediated effects ofn reproduction and immune function threated long-term viability of >50% of killer whale populations (in high industrial populations and feeding at high trophic levels)
Ivory gull populations
mercury pollution has risen nearly 50-fold in the feathers over the past 130 years
groundwater in the US study
- what is in the water
- what is the health effects
- high levels of chlorinated solvents
- mutagen (causes DNA mutation)
- carcinogen
- teratogen (causes birth defects)
what happened with the cattle in india
Diclofenac - anti-inflammatory drug given to cattle to reduce suffuring
- caused dehydration and kidney failure in vultures
- vulture population decline majorly
- increase in carcasses and increase in human diseases (rabies)
Neonicotinoids
- used as a natural pesticide to stop the collapse of bird species
- greatly toxic to insects
- by early 2000, negative impact on bees, other insects and their predators (birds, bats)
- loss of bee populations… widespread collapse of crops etc.
- increase of fungicide
Antibiotic that harms bee survival
- tetracycline
- used to prevent infections
- decreases bacteria in bee gut
- more sensitive to pathogens
neonicitinoids north american songbirds
- use of neonicotinoids = decrease in insect population
- depleting birds food supply; dec in bird pop
- more prevalent in NE of NA
- more prevalent in birds that migrate short distances
plastic and marine birds
- plastic smells good to these birds because when plastic is exposed to seawater it releases DMS
- birds prey releases DMS and birds smell this out
ocean pollution study
1) entanglements: affect northern right whales and green, loggerhead and hawkbill sea turtles the most, fur seals
2) 95% of dead northern fulmar birds had platic in their stomach. 35% of plankton eating fish had injested plastic
3) out of 693 marine species and manmade debris, 92% of involved plastic
how many species are affected by entanglement and ingestion of pollution
1300
whaling: canada and coal harbour
- coal harbour closed 1967
- canada pulled out commision 1982
- no whaling apart from first nations
what countries continue to have commercial whaling
Japan, Norway, Iceland
ecological role of whales
- nutrient cycling: ate a lot of plankton, cycled nutrients back into environment to be used
- increase primary productivity
most important fish in north atlantic
atlantic cod
- this fish is depleting and catch per unit effort is rising
if the primary production is 5.5x10^13 kg/y then what is the 2nd, 3rd, and 4th trophic level?
2nd: 5.5 x 10^12
3rd: 5.5 x 10 ^11
4th: 5.5 x 10 ^10
what is the expected fish biomass vs. actual fish biomass (3rd and 4th trophic level)
605 x 10^9 kg/y
240 x 10^9 kg/y
about 1/3 of expected
what is the current oceanic fish biomass and what is the capture production
current oceanic fish biomass: 240 x billion kg/y
capture production: 94 billion kg/y
commercial fishing is trying to catch more but cant
What does Daniel Pauly mean by ‘fishing down marine webs?”
- recorded the trophic levels (related to body size) of fish being caught
- over time, the fish caught gets smaller and smaller
difference in table fish in 1900 and 2000
- in 2000 the ocean basically empty
- table fish = fish we eat??
- fishery science began in 1930
where is fishing the highest
- alongside continents
- this effects coastal areas and many parts of the high seas
what terrestrial animals have been affected by a dramatic loss of habitat by hunting
- bison
- grizzly bear
difference between legal trade in 1990-1994 and 2012
- # ’s of legal trade increased (except parrots)
- live primates went from 35,000 to 70,000 - 15,000,000 furs/y and 350,000,000 coral fish/y
monkeys in research Grimm
- Grimm says that monkeys used in the laboratory may become extinct with the partnerships between sanctuaries and research centres
- but we need conservation of this species and many others
What is getting through the busiest airport in Europe
- illegal bush meat
- France
- primates, crocodiles, pangolins
how far in the forest was bird and mammal populations affected from hunting points
- 7 - 40 km
- bird pop declined by 58% and mammal pop by 83%
what is the problem with the protected tropical rainforests
- more than 18% protected
- of this protected area, poachers can enter and leave without punishment
- many of these areas are already considered empty forests
why were people poaching rhino’s
- horn was thought to have medicinal properties
- horn worth millions
how many elephants are poached each year
35,000 - 50,000
how has the rhino poaching numbers changed from 2007 to 2013
2007: 13/y
2013: 1004/y
how many dolphins caught in Japan (2004) commercial hunt
2012: 30,000 per year
additional 200 captured yearly
how many dolphins caught in peru and what were they caught for
- shark bait
- 15, 000 dolphins/y
how many black bears/y killed legally and illegally
10,000 legally
6000 illegally
how many grizzly bears/y killed and is this legal or illegal
300-400 grizzly bears/y
- 2017 there was a ban
how many legal seals killed/y and what is the revenue
100,000 - 400,000 legal seals killed/y ($30 million revenue)
what country has a lot of alien species
New Zealand
- almost as many alien species as their own
- bring their own pathogens, viruses etc.
- native species have no defense against non-native exotic pathogens
what country is the biggest importer
European Union, then UK then US
what was the revenue for legal trading in wildlife for 2000 and 2017
2000: $10 billion/y revenue
2017: $320 billion/y revenue
what animals were introduced that caused a negative impact on native species
- pigs, goats for human consumption
- rats colonized with humans (predation on native birds)
- mongooses introduced to control rats (predation on native species)
- cats to kill rats and mice (neg impact on birds)
What book did Charles Elton write
the ecology of invasions by animals and plants
- 50 years
biggest and second biggest reason for mortality in birds
- cats
- windows
3, communication towers
how many birds do domestic cats kill annually
1.4-3.7 billion birds, 6.9 - 20.7 billion mammals
every day in Australia: 75 million animals fall prey to roughly 15 million cats
what kind of diseases do domestic animals cause impacting wildlife
- canine distemper virus
- rabies
- feline infectious peritonitis
- mange
what is a major cause of bat mortality
bat white-nose syndrome (fungal growth)
what is a major cause of amphibian mortality
chitrid amphibian disease
what is a major accidental hawaiian introduction and high mortality rate of birds
- what birds survived this
avian malaria
- birds that survived this were living higher than 600 m
what is the average species persistance (in years) observed in fossil record
1 million years
- usually: one deer species will replace another deer species etc (NO OVERALL TROPHIC CHANGE IN THE COMMUNITY)
- occasional large turnover
different features of likelihood of extinction
1) rarity
2) dispersal ability - not good will not be able to reach new fragments
3) degree of specialization - more specialized = more prone to extinction
4) population variability (high vs. low)
5) trophic status: top vs. low
6) reproductive ability
population variability… is high or low more prone to extinction
high
- sudden population decline can lead to extinction
trophic status… what are more prone to extinction top or bottom
here the top is (top carnivores)
- small in terms of numbers
what happened to the bird species in the philippines
- 10 endemic bird species
- 9 extinct in the last 50 years from deforestation
hawaiian endemic plants
1126 species, 90 species extinct
of the 91 hawaiian honey creeper species how many extinct and how many endangered
51 species extinct
40 endangered
if there is an island 25km squared and 1 km squared what is the extinction rate in 100 years
1 km squared: 50% extinction rate in 100 years
25 km squared: 10% extinction rate in 100 years
what percentage of extinctions due to exotic mammalian predators (rats and cats)
58%
what is happening to the north atlantic right whale
- facing extincting
- have been on earth 40 million years and could be extinct in 20 years
- even losing a couple a year is enough for extinction
- live on most industrialized stretches of ocean in the world
what are 5 drivers of extinction
- habitat loss
- exotic species
- pollution
- exploitation
- disease
what is the main cause of extinction
habitat loss
stephem M meyer… what was the difference between extinction rates in the past versus now?
past: several species per year
today: 3000 species per year
what is the guiding head of evolution
humans
