AP Environmental Science Unit 7

why will the oceans continue to be overfished?

human population increases, money, tragedy of the commons

what type of solution needs to be implemented into the fishing industry?

regulation on how much fish should be caught

what are some problems with atlantic salmon fish farms?

transfers disease to wild stock, some may escape and become non-native species, pollution in ocean habitats, sea lice

why is fish farmed tilapia better than fish farmed salmon?

tilapia is lower on the tropic pyramid so you get more energy

what is the intention of the magnussen-stevens fisheries conservation and management act?

to prevent overfishing, rebuilding overfished stocks, increasing long term economic and social benefits, ensuring a safe and sustainable supply of seafood, and protecting habitat by setting regulations

as human populations grow and tools and methods of use become more advanced…

the impact of a single human could have on the surroundings can increase

what did environmental modifications allow to rise?

larger, dense human populations

how much of the earth’s surface has been affected in some way by human activity?

83%

three primary factors that affect the population of damage (impact) done by pollution

size of consumption, affluence (consumption), level of technological development

in many industries, the cost of purchasing recycled raw materials is…

higher than the cost of purchasing virgin materials

which is more costly to produce products from? recycled or virgin materials?

recycled materials

as energy prices increase…

incentive to recycle will increase

how much of the world was originally forested?

½ of US, ¾ of canada, and almost all of europe

why were forested areas under increasing pressure due to population growth?

in order to provide wood products, paper and agricultural land

what do we have efficient methods of today?

harvest and transportation

what problems do harvesting trees cause?

loss of soil (nutrients) and reduces soil fertility

what does road building in forests cause?

increase in erosion

more erosion increases water turbidity =

increase in water temp = decrease in dissolved oxygen

what does a standing forest do?

reduce erosion and can lead to a cleaner watershed (less need to clean water downstream for municipal water)

clear cutting

removal of all trees in an area. economical but increases erosion, especially on steep stopes. greatly reduces biodiversity

patch-work clear cutting

clear cutting in small, unconnected patches - preserves biodiversity and most costly

selective harvesting

single tree harvesting - not as economical but reduces economical damage, best method for maintaining an ecosystem and obtaining wood

explain the three E’s costs associated with resource exploitation?

economics, environment, energy

which of the three costs do we often not consider?

environment

why was the forest stewardship council formed?

to develop a list of primarily sound practices for use in certifying timber and products made for such timber

what are 3 advantages of using kenaf?

less herbicide and insecticide use, does not deplete nitrogen in soil, and produces less toxic wastewater

what did national city lines accomplish?

disassembled light rail so that we can buy more cars

what is a problem associated with purse seining?

catching juvenile fish, sharks, and other vulnerable marine life

what is a benefit of fish farming tilapia on land compared to fish farming salmon in the ocean?

we can filter water pollution in tanks on land

how do lumber companies manage plantation forestry?

plant single species and even-aged forests of fast growing hybrid trees & competing species are controlled by herbicides and insects controlled by insecticides

plantation forestry

mature rate is as low as 20 yrs, low species diversity and wildlife value

what country has the largest area of forest?

russia (taiga)

why is it important to have trees of all stages of age?

many different species rely on a certain age of forest for their habitat

what two species need old growth of trees?

red cockaded woodpecker and spotted owl

US forestry service - department of agriculture

subsidizes the logging industry by building roads and selling trees at a loss. biggest problem - often doesn’t replant trees quick enough and there is soil erosion leading back to primary succession

how are national forests supposed to be managed?

for sustainable yield and multiple use basis

what two tree species need prescribed burns for seed germination?

giant sequoia and jack pine

what type of forest has the greatest species diversity?

tropical rainforest (50% of organisms on planet)

why are tropical rainforest difficult to regenerate after logging?

poor soil characteristics

concerns of deforestation

-significantly reduces species diversity - creates fragmented habitats

-impacts climate via lowered transpiration

-decreases our CO2 sink within the trees - increases global warming

-human population pressure is greatest in the tropics and still increasing. great need to cut down trees for wood and also create agricultural land

why are birds important?

they are found in every biome and are indicators of health

what is a problem with managing birds?

they are migratory

benefits of birds

pollinators, seed dispersal, controls insects and rodent populations

what are the 4 categories of the ecosystem service?

provisioning (direct) - products, regulating (indirect) - CO2 sequestration and O2 production, cultural - asthetic benefits, supporting - habitat for species

desertification

process of converting arid and semi-arid land to desert

how is desertification caused in rangelands?

overgrazing, firewood cutting, bad farming practices

wilderness act (1964)

preserves areas of land from human use (no roads and defined wilderness)

wilderness

“an area where the earth and its community of life are un-trampled by man, where man himself is a visitor who does not remain”

what are some problems with tree plantations?

can deplete soil of important nutrients like calcium, less biodiversity, herbicide/insecticide use

list one regulatory service that forests provide

carbon sequestration 

list one supporting service that forests provide

provides habitat for pollinating animals

list one provisioning service that forests provide

lumber

list one cultural service that forests provide

scientists are willing to pay for research

convention on international trade in endangered species (CITES)

ensures that international wildlife trade in specimens of wild animals and plants does not threaten the survival of the species (exotic leather goods)

marine mammal act of 1972

prevents marine mammal species and stocks from diminishing to the point that they are no longer a significant functioning part of their ecosystems & restore diminished species and stocks to their optimum sustainable populations

purse seining

surrounds fish with a large wall of netting

longlining

mainline can be more than a mile long and have baited hooks at every meter (placed near the surface)

midwater trawl (trawling)

pulled through the water above the ocean bottom where fish are herded into the net

bottom trawl (dragging)

cone-shaped nets that run along the ocean bottom

what percentage of the ocean is overfished?

90%

overfishing harm to ecosystems

removing fish that play key or outsized roles in food webs also alters the larger dynamics of ocean ecosystems

overfishing economic and social costs

thousands of workers can lose their jobs when fish are overfished

two aquaculture farming methods

-pens: structures that hold farmed fish in open water as they grow

-ponds: enclose fish and crustaceans in a relatively shallow and usually small body of freshwater or saltwater where farmers have significant control over the rearing process and pond conditions and production per hectare is very high