Transcript File

Effect of Wildfires on ALL
Geochemical Cycles: Summary
Water
water vapour is produced
in a combustion reaction:
C6H12O6(s) + 6 O2(g) 
6 CO2(g)+ 6 H2O(g)
less tree roots &
vegetation means less
retention of water in the
soil
Carbon
Oxygen
heat breaks nitrogen
compounds down into
nitrates & ammonia;
same effect as nitrogen
fixation
dramatic increase in
nitrogen levels in soil: more
viable for bacteria
combustion produces CO2
(carbon source): C6H12O6(s) +
6 O2(g) 
6 CO2(g) + 6 H2O(g)
loss of green plants to
undergo photosynthesis
(loss of a carbon sink)
Nitrogen
loss of plants to undergo
photosynthesis (loss of an
oxygen source)
AND combustion reactions
uses O2 from the
atmosphere
C6H12O6(s) + 6 O2(g)  6
CO2(g) + 6 H2O(g)
The Recycling of Matter: Water and
Biogeochemical Cycles
Practice Questions
Answer Key
( / 18)
Question 1:
Use the information below to answer question 1
Prescribed burning is a practice in which forestry personnel deliberately set
small, controlled fires under ideal weather conditions — low winds and
reasonably high moisture content. This strategy attempts to mimic the
historical pattern of more frequent, low-intensity burns that are an integral
part of the forest ecology.
1.Explain how this practice may actually enhance public safety and
ensure the long-term health of the forest. (2 marks)
 A prescribed burn mimics a natural wildfire, but b/c they occur MORE
frequently, they burn with LESS intensity, than be SMALLER .
 Another advantage of is that it reduces the accumulation of “fuel”
, (old dry branches and pine needles), so that a large catastrophic
fire is less likely.
 AND helps maintain the long-term health and diversity of the
forest habitat, since fires ARE needed for conifers to reproduce.
Question 2:
1.
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2. For organisms that live in the forest floor’s soil, identify at least two
abiotic factors significantly affected by wildfires. (2 marks)
 Wildfires remove the surface vegetation
 Abiotic factor affected: shade
 Wildfires are an exothermic combustion reaction
 Abiotic factor affected: temperature (experienced by organisms living
within the soil).
 Wildfires are an exothermic combustion reaction, which break
down nitrogen molecules
 Abiotic factor affected: nitrogen (availability for plants in ashy soil left
after fire is extinguished).
 Wildfires REMOVE atmospheric oxygen and ADDS carbon
dioxide.
 Abiotic factor affected: O2 and CO2 levels
 Wildfires REMOVE water from the ecosystem (b/c vegetation is
removed).
 Abiotic factor affected: water levels
Question 3:
1.
2.
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3. What is a biogeochemical cycle? (1 mark)
 A series of reactions that move elements and compounds between
the living and non-living components of an ecosystem.
 Ex. carbon cycle, oxygen cycle, and the nitrogen cycle
Question 4:
1.
2.
3.
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4. Water is often applied to lawns and gardens to keep plants
healthy and green.
a) Use your knowledge of the water cycle to explain why it is more
effective to water lawns in the early morning rather than the
middle of the afternoon. (1 mark)
 because LESS water will be is lost to evaporation b/c the Sun’s
rays are less intense, in the morning than at mid-day AND the air is
cooler.
b) Use your knowledge of the water cycle to explain why it is
better to use a soaker hose instead of a sprinkler to water trees
and shrubs. (1 mark)
 A soaker hose is more effective than a sprinkler, b/c a sprinkler
shoots water into the air—(increasing the surface area of water
exposed to the air, which leads to greater losses due to evaporation)
 AND the soaker hose directs water directly to the root of the plant
where it can be effectively absorbed.
1.
2.
3.
4.
Aa
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5. Explain the following statement. “There is no need to memorize a
Question
5 & 6:
separate chemical equation for photosynthesis and another one
for cellular respiration. One equation can describe both.” (1 mark)

There is no need to memorize both equations because the reactants
of one equation are simply the products of the other-and vice versa.
 Photosynthesis: 6 CO2(g) + 6 H2O(g)  C6H12O6(s) + 6 O2(g)

Cellular Respiration: C6H12O6(s) + 6 O2(g)  6 CO2(g) + 6 H2O(g)
6. Decomposition, combustion of fossil fuels, cellular respiration,
volcanic activity, and wildfires all have something in common
when it comes to the carbon cycle. Identify the common feature.
(1 mark)

all of these activities RELEASE carbon dioxide into the atmosphere.
1.
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2.
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3.
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Question 7 & 8:
1.
2.
3.
4.
5.
6.
4.
7.
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bhfsdf
Bfsbs
Ndndsn
Fgmndgmng
Mfhmf
Ndndsn
vvasd
5.
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8.
Cellular respiration is said to be an
energy
is and oxygen will occur within both
7. exothermic
Identify the reaction
key formsbecause
in which
carbon
released.
If cycle
photosynthesis
is an cycle. (1 mark)
the oxygen
and the carbon
endothermic reaction because energy is
 Carbon and oxygen both occur in glucose (C6H12O6(aq)) and carbon dioxide
required,
(CO2(g)).identify the source of the
energy for photosynthesis. (1 mark)
6.
Mfhmf

The source of energy for photosynthesis is
solar (or radiant) energy from the Sun.
9. Concisely explain why plants cannot use
the air as a source of nitrogen. (2 marks)
 because nitrogen
in
the10:
air is N , which is VERY stable.
Question
9
&
 Plants don’t have the structures required to break the bonds, into
2
nitrogen's more usable forms.
10.Explain why many plants thrive in a
post-fire habitat (2 marks)


The soil in a post-fire habitat
tends to have LOTS of nitrogen.
Soil is warmer and less acidic,
which increases the number of
nitrogen fixing bacteria, which
plants need to grow..

nitrogen is a critical element in
biological structures of protein.
We meet our nitrogen needs, by
eating foods high in protein, like:
8.
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Question
11 & 12:


9.
Bsbsbs
10.
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11.
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Meats, eggs, nuts and beans/
12.
soybeans, and dark green vegetables,
like kale, spinach and Swiss chard.
Sewage often contains high
concentrations of nitrates that could
be harmful if released directly into
the environment. Explain the role
that denitrifying bacteria could play in
sewage treatment plants. (2 marks)
 Denitrifying bacteria are used b/c they
convert nitrates BACK into nitrogen
gas.

Harmless, pure N2 is released into the
atmosphere and harmful nitrates are
removed from the aquatic
environments.
The Biosphere
of Life
Section 1.6
Human impact on ecosystems
Human Activities
• Human activities have a significant effect
on the cycling of matter
– deforestation
– forest fires
– burning of fossil fuels
– industry
– fertilizer use
– irrigation
The Result?
• Polluting of water sources ( in H2O
quality & quanity)
• Over-reliance on fertilizers ( Ncompounds)
• Clear-cutting ( O2,  CO2)
• Burning of fossil fuels ( O2,  CO2)
• Use of CFCs ( O3,  UV radiation)
Human Impacts on Ecosystems
• Now you will examine the human impact
on biotic factors
 Read Ch 1.6: Biodiversity and the
Heritage of Our Lands (pg’s 454462) in your Textbook
 Complete the “Biodiversity
Worksheet” in your note package.
Biodiversity Worksheet
Answer Key
( /24 )
Question 1:
In the definition of lichen, it was
stated that lichen is formed by the
symbiotic association of a fungus
and a photosynthetic algae.
a. Explain what a “symbiotic
association” is…(1 mark)
b. The fungus in the lichen
contains microscopic fibres that
provide the alga with a place to
grow. The fungus also supplies
the alga with water and minerals
that these fibres filter from dust
particles and moisture in the air.
Identify the contribution that the
alga makes to this association.
(1 mark)
a. A symbiotic association is a
long-term relationship
between two species where
one and/or both benefit.
b. The alga is a photosynthetic
organism, so it converts CO2
& H2O into glucose (aka
nutrients) for the fungus to
ingest.
The following illustrates the sequence
of events that led to a decline in the
caribou population due to habitat
fragmentation.
I. Cleared forest areas attract caribou
to live in the area.
II. Human activities create open areas
and cut lines throughout a habitat.
III. The caribou population declines
due to increased predation.
IV. More wolves move into the area.
V. Cutline and open areas allow wolves
to spot and capture prey more easily.
Question 2:
2. The order of events beginning with
habitat fragmentation and resulting in
a decline in the caribou population is:
(1 mark)
A. I, II, III, IV, V
B. V, I, II, IV, III
C. II, I, V, IV, III
D. II, III, I, IV, V
Question 3:
3. Match each description with the appropriate term listed. Place
your answer in the blank space given. (2 marks)
i. biodiversity
ii. habitat destruction
iii. invasive species iv. habitat fragmentation
•_______ a. a species introduced to an area by human action that
expands to threaten the area’s variety of life
• _______
b. the conversion of formerly continuous habitat into
iii
patches separated by non-habitat areas
• _______ c. the variety of life in all its forms
iv
• _______
d. the permanent alteration of vital characteristics in an
organism’s habitat
i
ii
Question 4:
4. Suggest one reason why an invasive species is able
to establish itself in a new area. (1 mark)
• An invasive species is able to establish itself in a new area
because it has no natural predators in the new location to
reduce its numbers.
Question 5:
5. Decide whether each statement is true (T) or false (F). Place your answer in the
blank space given. CORRECT ANY FALSE STATEMENTS (3 marks)
 _______ a. Only an animal can be an invasive species. (1
mark)
F
 _______ b.Plants
Clearcutting
an area
of forest
results
in habitat
AND Animals
can both
be invasive
species
T
destruction.
(0.5 mark)
 _______ c. The elimination of one key species can affect
theT health of an entire ecosystem. (0.5 mark)
 _______ d. You should Rethink your basic assumptions
about
your lifestyle after you Reduce, Re-use, and Recycle
F
materials you require for your lifestyle.
“rethinking” should occur BEFORE, then changes can be made to your
lifestyle.
Question 6:
6. Your ecological footprint is affected
by
(1 mark)
A. the type of food you consume
B. the type of transportation you use
C. the type of housing you maintain
D. all of the above
Question 7:
In the middle of the nineteenth century, it was
estimated that the population of prairie dogs in
North America was about four billion animals.
When the prairie grassland was converted into
farmland, farmers dramatically reduced the prairie
dog numbers; prairie dogs were thought to eat too
much vegetation that farmers wanted to save for
cattle AND the entrance-holes to the prairie dogs
burrows were considered a tripping hazard for
livestock. To reduce their numbers, prairie dogs
were poisoned.
7. The swift fox and the
black-footed ferret are two
species that feed on prairie
dogs, what effect would the
mass poisoning of prairie
dogs would have on each of
these animals. (2 marks)
• Mass poisoning of the
prairie dogs would
remove the main food
source for both the foxes
& the ferrets.
• Both predators
populations would go
Question 8:
In the middle of the nineteenth century, it was
estimated that the population of prairie dogs in
North America was about four billion animals.
When the prairie grassland was converted into
farmland, farmers dramatically reduced the prairie
dog numbers; prairie dogs were thought to eat too
much vegetation that farmers wanted to save for
cattle AND the entrance-holes to the prairie dogs
burrows were considered a tripping hazard for
livestock. To reduce their numbers, prairie dogs
were poisoned.
8. Prairie dogs require a
habitat of low grasses for
good visibility and hardpacked soil to prevent
their burrows from
collapsing. In much of
southern Alberta, the
original prairie grassland
ecosystem was
converted into farmland
to grow tall grain crops.
Explain why habitat
destruction is listed as
the key reason why the
burrowing owl is on the
list of species at risk. (2
marks)
Question 9:
In the middle of the nineteenth century, it was
estimated that the population of prairie dogs in
North America was about four billion animals.
When the prairie grassland was converted into
farmland, farmers dramatically reduced the prairie
dog numbers; prairie dogs were thought to eat too
much vegetation that farmers wanted to save for
cattle AND the entrance-holes to the prairie dogs
burrows were considered a tripping hazard for
livestock. To reduce their numbers, prairie dogs
were poisoned.
9. A keystone species is
a type of organism whose
disappearance will be
followed by a decrease in
many other community
species. Explain why the
black-tailed prairie dog is
considered to be a
keystone species in
prairie grassland
ecosystems. (2 marks)
•Since so many other
species cannot survive
without prairie dog, it
would be the keystone
Question 10:
10. Three things that the boreal forest provides are:
(1 mark)
A. carbon dioxide, oxygen, and a reservoir for fresh water
B. oxygen, a sink for carbon, and a reservoir for fresh water
C. oxygen, nitrates, and carbon dioxide
D. oxygen, nitrogen, and a sink for carbon
Question 11:
11. a. Why are the Earth’s
boreal forest important to
a. Since the boreal forest covers the entire biosphere? (1 mark)
most of the Northern
b. Explain how biodiversity
Hemisphere, it provides
is linked to the health of
Earth’s biosphere with most
boreal forest ecosystems. (1
of its oxygen AND acts as a
mark)
carbon sink (absorbing CO2
from the atmosphere) AND is
a huge reservoir of fresh
water.
b. The more healthy organisms
there are, the greater the
quantity of organisms that
can be sustained by the
ecosystem there are.
Question 12: (5 marks)
b. species no longer exists
anywhere on Earth
iii. Banff longnose dace
ii.
e. species no longer exists in a
region, but lives elsewhere in the
world
a. species numbers becoming
v.
dangerously low. Will soon become
extinct or extirpated, if conditions do
not change to improve their survival
c.
species faces endangerment in
the near future, unless the
circumstances threatening its survival
and reproduction improve.
d. species are monitored closely to
try to prevent them from becoming
“threatened”.
i. anatum peregrine falcon
iv. Wolverine
Submit your MARKED assignment
now.
Tally up the marks /24
If you wish to hand in question 13 (a,b & c)
for BONUS MARKS, please include it with
your MARKED Ch 1.6 Biodiversity
Assignment.
12. Some ecologists are suggesting that
a dollar value be assigned to the
ecological services that a forest
provides. Services like carbon storage,
soil formation, and the maintenance of
biodiversity would each be appraised as
being worth so many dollars for an area
of forest.
a.Explain how this idea attempts to
address one of the fundamental
differences between the ecological
system and the economic system.
a.This proposal attempts to use money -an understandable unit of measurement in
both systems.
•
This idea addresses how each system
views “value” and tries to quantify the
ecological system in an economic way,
so decision can be made using one
common denominator: net worth.
12. Some ecologists are suggesting that a
dollar value be assigned to the ecological
services that a forest provides. Services
like carbon storage, soil formation, and the
maintenance of biodiversity would each be
appraised as being worth so many dollars
for an area of forest.
b.Explain how this system could
promote a new style of decision
making when it comes to economic
development in the boreal forest.
b. If a decision is being debated that might
lessens the ability of the boreal forest to
provide its ecological “service”, then the
“cost” associated with that decision
will be able to be weighted out with other
financial decisions, like profits, cost of
labor/transportation, etc.
12. Some ecologists are suggesting that
a dollar value be assigned to the
ecological services that a forest
provides. Services like carbon storage,
soil formation, and the maintenance of
biodiversity would each be appraised as
being worth so many dollars for an area
of forest.
c. Identify some of the challenges of
implementing this approach.
c. Difficult to:
 agree on the dollar value of each
environmental service.
 determine a dollar value to carbon
storage, oxygen production,
biodiversity maintenance, personal
enjoyment.
 monitor and enforce
 implement world wide