human impact on environment Flashcards

Question

what do PCBs and heavy metals do

Answer 1

egg shell thinning interference with mammalian reproduction damage to immune system carcinogenic

Answer 2

narrow belt of vegetation dominated by shrubs and occasional trees

Answer 3

barrier to movement of livestock | marking property boundaries

Answer 4

provide foraging and nesting sites for birds rich in plants and animals source of beneficial insects wildlife corridors through hostile landscapes

Answer 5

acts as refuge for weeds reduces loss of yield decreases land needed for turning machinery

Answer 6

increases soil erosion reduce crop yield through loss of beneficial insects species predators for pest control pollinators

Answer 7

removal of forests for timber agricultural use of land increasing housing development

Answer 8

loss of vegetation and roots lead to soil erosion water floods from higher to lower levels water runs off soil instead of being retained water evaporates more easily from soil leading to desertification

Answer 9

coppicing - tree trunk is cut , leaving a stool a few cm high. new shoots emerge from buds and from into poles which thicken they are cut on rotation to produce timbers. a long rotation increases sustainability which favours diversing wildlife selective cutting - steep slopes where total removal of trees would leave soil very vulnerable to erosion. also maintains nutrients in soil and minimises amount of soil washed away

Answer 10

nets with small mesh catch young fish that are sexually mature overtime there are fewer individuals left to reproduce so population size decreases

Answer 11

pelagic fish live in surface water. swim into a net suspended between two boats. but non target species are caught e.g. turtles and dolphins

Answer 12

fish living in deeper water. caught by a large net dragged through water. equipment damages the ocean bed which destroys habitats

Answer 13

trawlers catch capelin but important prey for cod fish (contributes to decline of cod stocks) harvesting antarctic krill - primary consumers main food of whales and seals, heavily fishing affects the food web

Answer 14

- mesh size but allow young fish to swim through - quotas to only allow a certain mass of fish - prohibit fishing in areas at certain times to allow reproduction - legislation controlling size of fishing nets - legislation controlling number of days at sea

Answer 15

bred and grown to maturity in ponds and lakes sometimes farmed in a pod (large steerable device) fish convert their food into protein more efficiently greater proportion of fish are edible lower carbon footprint

Answer 16

- diseased fish = densely stocked huge doses of antibiotics - pollution = ecological balance of waterways may be upset, eutrophication, fish excreta carried into water around pens - escaped fish = rapid growth of farm fish which out competes wild fish for food transmits parasites - resource use = farmed salmon are carnivorous and eat 3x their body weight in fish food - environmental toxins = more concentrated toxins than wild salmon although concentration so small that doesnt outweigh health benefits of eating fish

Answer 17

1) biosphere integrity boundary 2) land system change 3) biogeochemical flow 4) stratospheric ozone 5) ocean acidification 6) fresh water use 7) aerosols 8) introduction of novel entities 9) climate change

Answer 18

climate change biosphere integrity land system change biogeochemical flow

Answer 19

stratospheric ozone

Answer 20

ocean acidification | fresh water use

Answer 21

aerosols | novel entities

Answer 22

higher atmospheric c02 linked to higher global temp increases sea level by 7m combatting climate change --> - kyoto protocol signed by 84 countries - COP21 signed by 174 countries keep global temp well below 2 degree above pre industrial temp limit greenhouse gases to human activity to what can be naturally absorbed help poorer nations to adapt

Answer 23

``` habitat destruction leads to species becoming extinct 1 species lost per year in a million to natural selection boundary - 10 per million per year current rate - 100 per million per year must increase public awareness ```

Answer 24

problems - natural ecosystems used for urban development, raising livestock pollutants derived from agriculture and other human activity production of biofuel crops and crops grown for export means not enough food for local use solutions - no more than 15% ice free land should be used for crop growing and human habitation eat less meat

Answer 25

fertilisers use - atmospheric nitrogen is fixed in the haber process combustion of fossil fuels led to - - eutrophication - acidification (co2 forming carbonic acid in rivers) current - 150 million tonnes boundary - no more than 62 million

Answer 26

hole in ozone layer in 1970 measures taken - use of chlorinated hydrocarbons was banned boundary - 276 dobson units current - 300 dobson units

Answer 27

was pH 8.16 --> now pH 8.03 h+ ions are 30 times more complicated decreases internal pH of phytoplankton less o2 produced less co2 removed gas exchange in fish is less efficient calcium leaches out of the calcium carbonate skeletons od corals out of the shells of molluscs and arthropods current 2.9:1 boundary 2.7:1

Answer 28

``` 2.5% fresh water on earth 61% is frozen not all fresh water is drinkable human activity reduces water - - irrigation systems - polluting water - increased human population leads to - - desertification - rivers fail to reach seas - fisheries are destroyed boundary = 4000 km y-1 current = 2600 km y-1 solutions = stop irrigating non food crops drip irrigation for food crops reduce reuse recycle ```

Answer 29

``` atmosphere contains minute particles. some are natural consequences = 800,000 premature deaths soot absorbs heat sulphate reflects heat no boundary ```

Answer 30

``` synthetic organic pollutants radioactive materials genetically modified organisms nano materials no bigger than 100nm boundary = - ddt is banned - pcb controlled as its toxic and reports of it being carcinogenic few have been properly assessed ```

human impact on environment Flashcards

(54 cards)