BIOL 350 Final Exam Question And
Answers.
1) The current state of civilization can be described in terms of
problems of 'input' or problems of 'output'. Describe the main
current concerns associated with 'forests' as a problem of
'input', and describe the main reasons why forests have
important value in terms of providing ecosystem services for
humans. - (correct answer) -Problems of input:
-Deforestation; clearing forests for agriculture, urban
expansion, mining, over-harvesting for timber and paper
production
-increased frequency of fire, drought, insect outbreaks
-clearing forests out faster than we can replace them
-world forest area shrunk by 80% per capita in past century
Value:
-"earth's lungs"; source of oxygen
-Earth's major source of water circulation; about 50% of the
water that ends up in the clouds for rain has been transpired by
forests
-forests build and protect top soil; without forests we lose soil
and minerals through erosion
,o ,o
,-major carbon sinks; capture, store, and decrease greenhouse
carbon dioxide levels (about 25% of carbon emitted by burning
fossil fuels each year are absorbed by forests)
-home to Earth's treasury of biodiversity
(2) World food production now appears to have peaked and
prices are rising. Describe the main reasons for this crisis that
we discussed in BIOL350. - (correct answer) -Today's food
shortages result from 4 critical long-term trends:
1) Rapid pop'n growth
-leads to over-plowing and over-grazing resulting in a loss of top
soil
-increased demand for energy therefore increasing energy from
fossil fuels which contributes to global warming
-higher demand for food...causing food shortages
2)Loss of top soil
-because of deforestation, global warming, over-plowing...etc
3)Spreading water shortages
4)Rising temperatures and Global warming
-leads to rising sea level causing coastal flooding, which leads to
loss of top soil
-higher temps also reduce crop yield
OTHER REASONS:
-arable land has peaked
-lost irrigation water from melting/dried up glaciers resulting
from global warming
,o ,o
,-rising energy prices
-more land being used to grow bio-fuels instead of crops
-falling pollinator (bee) pop'ns from pesticide use and pollution
-over exploitation of fish
(3) The current state of civilization can be described in terms of
problems of 'input' or problems of 'output'. Describe the main
current concerns associated with 'fossil fuels' as a problem of
'input'. - (correct answer) -problems of input:
-problem of supply and demand
-oil discoveries peaked in the 60s and since the 80s we have
used more oil yearly than we are discovering
-most things that we use require oil/natural gas to make
(includes everything plastic)
-rely on fossil fuels for transportation
-since the Great acceleration 5x more energy use (especially
fossil fuels)
-turn to renewable resources like solar and wind energy but
forget that a lot of these alternate solutions depend on petro
chemicals/fossil fuels to keep them running; not durable,
reliable, or completely safe
-2x more oil consumption in last 4 decades
-fossil fuels=non-renewable=definite supply
-contributes to global warming/climate change
4) The current state of civilization can be described in terms of
problems of 'input' or problems of 'output'. Describe the main
,o ,o
, current concerns associated with 'soil loss' as a problem of
'input' - (correct answer) -soil is one of the most precious and
threatened resources:
-arable land is disappearing...top soil is vital for maintaining the
world's food supply
-it takes centuries to generate an inch of top soil even in a
healthy ecosystem so essentially it is a non-renewable resource
-soil degradation is especially high in dry lands due to salination
from irrigation
-losing it from water erosion, wind, glacier melting (flooding) ,
deforestation
-loss of biodiversity from pesticide use; less biodiversity= more
susceptible to disease
MAIN PROBLEM OF OUTPUT= decreased capacity for food
production
(5) Forecasters worry that climate change may disrupt the so-
called 'global ocean conveyer'. Describe what this is, how it
might be disrupted, and what the main consequences would be.
- (correct answer) -Global conveyer belt= a constantly moving
system of deep ocean circulation driven by temp/salinity; warm
less salinated water from gulf stream travels upward towards
Europe in Atlantic and the wind over this current picks up heat
to warm Europe...this causes evaporation making the water
more salty which makes the water colder b/c it's more dense
and sinks...downdraft of heavy cold water generates south
,o ,o
Answers.
1) The current state of civilization can be described in terms of
problems of 'input' or problems of 'output'. Describe the main
current concerns associated with 'forests' as a problem of
'input', and describe the main reasons why forests have
important value in terms of providing ecosystem services for
humans. - (correct answer) -Problems of input:
-Deforestation; clearing forests for agriculture, urban
expansion, mining, over-harvesting for timber and paper
production
-increased frequency of fire, drought, insect outbreaks
-clearing forests out faster than we can replace them
-world forest area shrunk by 80% per capita in past century
Value:
-"earth's lungs"; source of oxygen
-Earth's major source of water circulation; about 50% of the
water that ends up in the clouds for rain has been transpired by
forests
-forests build and protect top soil; without forests we lose soil
and minerals through erosion
,o ,o
,-major carbon sinks; capture, store, and decrease greenhouse
carbon dioxide levels (about 25% of carbon emitted by burning
fossil fuels each year are absorbed by forests)
-home to Earth's treasury of biodiversity
(2) World food production now appears to have peaked and
prices are rising. Describe the main reasons for this crisis that
we discussed in BIOL350. - (correct answer) -Today's food
shortages result from 4 critical long-term trends:
1) Rapid pop'n growth
-leads to over-plowing and over-grazing resulting in a loss of top
soil
-increased demand for energy therefore increasing energy from
fossil fuels which contributes to global warming
-higher demand for food...causing food shortages
2)Loss of top soil
-because of deforestation, global warming, over-plowing...etc
3)Spreading water shortages
4)Rising temperatures and Global warming
-leads to rising sea level causing coastal flooding, which leads to
loss of top soil
-higher temps also reduce crop yield
OTHER REASONS:
-arable land has peaked
-lost irrigation water from melting/dried up glaciers resulting
from global warming
,o ,o
,-rising energy prices
-more land being used to grow bio-fuels instead of crops
-falling pollinator (bee) pop'ns from pesticide use and pollution
-over exploitation of fish
(3) The current state of civilization can be described in terms of
problems of 'input' or problems of 'output'. Describe the main
current concerns associated with 'fossil fuels' as a problem of
'input'. - (correct answer) -problems of input:
-problem of supply and demand
-oil discoveries peaked in the 60s and since the 80s we have
used more oil yearly than we are discovering
-most things that we use require oil/natural gas to make
(includes everything plastic)
-rely on fossil fuels for transportation
-since the Great acceleration 5x more energy use (especially
fossil fuels)
-turn to renewable resources like solar and wind energy but
forget that a lot of these alternate solutions depend on petro
chemicals/fossil fuels to keep them running; not durable,
reliable, or completely safe
-2x more oil consumption in last 4 decades
-fossil fuels=non-renewable=definite supply
-contributes to global warming/climate change
4) The current state of civilization can be described in terms of
problems of 'input' or problems of 'output'. Describe the main
,o ,o
, current concerns associated with 'soil loss' as a problem of
'input' - (correct answer) -soil is one of the most precious and
threatened resources:
-arable land is disappearing...top soil is vital for maintaining the
world's food supply
-it takes centuries to generate an inch of top soil even in a
healthy ecosystem so essentially it is a non-renewable resource
-soil degradation is especially high in dry lands due to salination
from irrigation
-losing it from water erosion, wind, glacier melting (flooding) ,
deforestation
-loss of biodiversity from pesticide use; less biodiversity= more
susceptible to disease
MAIN PROBLEM OF OUTPUT= decreased capacity for food
production
(5) Forecasters worry that climate change may disrupt the so-
called 'global ocean conveyer'. Describe what this is, how it
might be disrupted, and what the main consequences would be.
- (correct answer) -Global conveyer belt= a constantly moving
system of deep ocean circulation driven by temp/salinity; warm
less salinated water from gulf stream travels upward towards
Europe in Atlantic and the wind over this current picks up heat
to warm Europe...this causes evaporation making the water
more salty which makes the water colder b/c it's more dense
and sinks...downdraft of heavy cold water generates south
,o ,o
