Lecture 4-Biogeochemical Cycles

Question 1

what takes place in a biogeochemical cycles

Answer 1

The recycling of nutrients between the abiotic environment and living organisms

Question 2

what are in Gaseous cycles

Answer 2

oxygen, carbon, nitrogen, sulphur

Question 3

what are in Sedimentary cycles

Answer 3

phosphorus, calcium, potassium, carbon

Question 4

what % of Methane emissions from cattle account for Ireland’s greenhouse gas total

Answer 4

almost 20%

Question 5

what % of agricultural methane is emitted
through eructation (burping)

Answer 5

95%

Question 6

what % of agricultural methane is emitted
through flatulence and slurry storage.

Answer 6

only 5-10%

Question 7

how many litres of methane per day can a fully grown cow release

Answer 7

500 litres

Question 8

with 1.4 billion cows on the planet what % does cows account for all global greenhouse gas emissions

Answer 8

3.7 %

Question 9

usally fires decrease nutrient for soils but soil fertility can temporally increase after low intensity fires. why is this?

Answer 9

since fire converts
organic nutrients in dead plant tissue to inorganic readily available nutrients

Question 10

what does Net ecosystem productivity mean

Answer 10

difference between rate of
carbon uptake in photosynthesis and the rate of carbon loss due to autotrophic and heterotrophic respiration

Question 11

how much is predicated of greenhouse gases trapped in frozen ground to leech into the air by 2040 as permafrost continues to melt.

Answer 11

45 billion tonnes

Question 12

define methane hydrates

Answer 12

is a crystalline solid that consists of a methane molecule surrounded by a cage of interlocking water molecules.

Question 13

what is the The phosphorus cycle

Answer 13

No gaseous component
Natural scarcity (limiting nutrient in aquatic environments)
Main reservoirs: rocks and minerals
Released by weathering, erosion, runoff (fertilizers)
Only a small fraction available to plants in natural soils

Question 14

where is the highest phosphate rock reserves (85%)

Answer 14

Morocco and Western Sahara

Question 15

what are the causes of acid rain

Answer 15

burning coal, oil and petrol they mix with water vapour and rainwater in the atmosphere, producing weak carbonoic acid- acid rain

Question 16

what are Man’s impact on biogeochemical cycle

Answer 16

Carbon cycle: Excessive production of CO2 by fossil fuel burning –global warming
Nitrogen cycle: Deforestation, fertilisation - eutrophication and
acidification
Phosphorus cycle: Critically limiting phosphate supplies,
eutrophication
Sulphate cycle: Production in fossil fuel burning – acid rain