Topic 33

Question 1

Internal cycling of nutrients

Answer 1

primarily concerned with the flow of nutrients through the ecosystem dominated by the biological processes of primary production and decomposition

Question 2

Many transformations take place in the..

Answer 2

non living (abiotic) component- atmosphere, water, soil.

Question 3

Weathering of rocks and minerals releases..

Answer 3

inorganic nutrients into soil and water thins available for plant uptake

Question 4

Biogeochemical cycle

Answer 4

flow of all nutrients from the nonliving to the living and back to the nonliving components of the ecosystem in a more or less cyclic path

Question 5

2 major types of cycles (based on primary source of nutrient input)

Answer 5

-gaseous cycles

sedimentary cycles

Question 6

Gaseous cycles

Answer 6

main pool of nutrients: atmosphere and ocean. ex: nitrogen, oxygen, CO2, dominant components of atmosphere

Question 7

Sedimentary

Answer 7

main pool of nutrients: soil, socks, minerals. nutrients required by organisms come initially from inorganic source via weathering

Question 8

All cycles involve..

Answer 8

biological and non biological processes, both driven by flow of energy through the ecosystem

Question 9

Water is the..

Answer 9

medium in which inorganic nutrient travel through the ecosystem

Question 10

Without water..

Answer 10

biochemical cycles would stop

Question 11

Inputs of nutrients into the ecosystem depend on

Answer 11

the type of ecosystem

Question 12

Terrestrial input

Answer 12

nutrient inputs are supplemented by rain, snow, air currents and animals

Question 13

Wetfall

Answer 13

precipitation inputs nutrients

Question 14

Dryfall

Answer 14

airborne particles with associated nutrients fall from the atmosphere

Question 15

Aquatic input

Answer 15

major source of nutrients are from the surround land in the form of drainage, water, detritus and sediment (also wet and dry fall)

Question 16

Input of organic carbon from terrestrial ecosystems constitutes the..

Answer 16

majority of energy input into stream and river ecosystem

Question 17

Output step 1

Answer 17

release into atmosphere

Question 18

Output step 2

Answer 18

inorganic nutrients released via leaching (dissolved and washed) out of the soil in underground water –> streams

Question 19

Output step 3

Answer 19

organic matter exported from forest ecosystems by streams and rivers –> lakes

Question 20

Output step 4

Answer 20

organic matters transferred between ecosystems in form of faces and other rates via movement patterns of consumers

Question 21

Output step 5

Answer 21

harvesting- nutrients stored in organisms are directly lost during removal from the system but balanced by adding fertilizers because nutrients become limited

Question 22

Processes of inputs and outputs of nutrients during biochemical cycles link

Answer 22

different ecosystems

Question 23

The output from one ecosystem represents ..

Answer 23

inputs to another (terrestrial –> aquatic system)

Question 24

Processes of nutrient exchange among ecosystems requires..

Answer 24

examining biogeochemical cycles from much broader view than single ecosystem. (true of those nutrients w gaseous cycle)

Question 25

Main pools are the atmosphere and ocean which have..

Answer 25

local circulation patterns because carbon is the basic nutrient in all organic compounds

Question 26

Terrestrial carbon cycle

Answer 26

photosynthesis: CO2 – organic form – herbivores – carnivores – organic matter – decomposers – plant tissue. CO2 released back into atmosphere via respiration

Question 27

Swamps and Marshes

Answer 27

dead organic matter falls into water doesn’t completely decompose, carbon stored as humus or peat. buildup of partially decomposed organic mater forms fossil fuels – long terms.

Question 28

Freshwater and marine ecosystem

Answer 28

CO2 diffuses into the surface water form atmosphere –> carbonates. Phytoplankton uses carbonates – plant tissue – herbivores – carnivores –organic matter – decomposers – plant tissue. CO2 releases via respiration is either reused or released into atmosphere (diffusion)

Question 29

Diffusion

Answer 29

movement of substance from area of higher to lower concentration

Question 30

Earths C budget (100,000,000 Gt) most..

Answer 30

buried in sedimentary rocks (not involved in cycle) = 99%

Question 31

Global cycle is = 55,000 Gt and divided into..

Answer 31

• oceans (major) 38,000 Gt
• fossil fuels (decomposed matter) 10,00 Gt
• atmosphere 750 Gt
• terrestrial 2000 Gt

Question 32

Oceans Carbon

Answer 32

surface water to atmosphere is main exchange site. exchange rate governed by diffusion gradient between surface waters and atmosphere

Question 33

Terrestrial Carbon

Answer 33

includes soil and organisms, exchange rate governed by diffusion gradient between plant leaf and atmosphere (photosynthesis) historically exchanges of CO2 between terrestrial environments and the atmosphere were thought t be in equilibrium (has increased)

Question 34

Atmospheric Carbon

Answer 34

CO2 in atmosphere have increase 25% in last 100 years. industrial revolution CO2 increase steadily by mid 1900s increased exponentially

Question 35

Historically CO2 is ..

Answer 35

280-290 ppm.

Question 36

Burning fossil fuels in industrialized nations

Answer 36

adding 6.4 Gt/year in 1990s

Question 37

Deforestation

Answer 37

forested lands are typically clearly and burned for farming. adding 2.2 Gt / year in 1990s.

Question 38

Also issues with increased levels of…

Answer 38

methane which is 25x more effective as greenhouse gas

Question 39

Predictions of global warming

Answer 39

• increases average global temps and precipitation (increase 2-6 C in 100 years)
• changes will not be evenly disturbed over Earths surface (warming is expected to be greater during winter months)
• increased variability in climate (more sever storms and hurricanes, great snowfall increasing variability in rainfall)