1. Topic 2: Ecosystems
Energy Pathways in the Sub-arctic
(Tundra and a bit of Tiaga)

2. Topic 2: Ecosystems
2.4.2: What makes the Tundra biome
Limited Solar Energy

3. Topic 2: Ecosystems
2.4.2: What makes the Tundra biome
Limited Solar Energy
At higher latitudes light required for At the Poles the suns energy
photosynthesis is spread over a greater is spread over a large area
area
At the Equator
the suns energy
is spread over a
small area

4. Topic 2: Ecosystems
2.4.2: What makes the Tundra biome
Limited Solar Energy
At higher latitudes light required for At the Poles the suns energy
photosynthesis is spread over a greater is spread over a large area
area
This means the rate of photosynthesis At the Equator
is much lower than at the equator the suns energy
is spread over a
small area

5. Topic 2: Ecosystems
2.4.2: What makes the Tundra biome
Limited Solar Energy
At higher latitudes light required for At the Poles the suns energy
photosynthesis is spread over a greater is spread over a large area
area
This means the rate of photosynthesis At the Equator
is much lower than at the equator the suns energy
is spread over a
small area
Therefore GPP is also lower

6. Topic 2: Ecosystems
2.4.2: What makes the Tundra biome
Limited Solar Energy

7. Topic 2: Ecosystems
2.4.2: What makes the Tundra biome
Limited Solar Energy
The Earth also tilts at an angle of 23.5˚ Northern Hemisphere
Winter
Southern Hemisphere
Summer
23.5˚
Tilt

8. Topic 2: Ecosystems
2.4.2: What makes the Tundra biome
Limited Solar Energy
The Earth also tilts at an angle of 23.5˚ Northern Hemisphere
Winter
Creating summer and winter in each
hemisphere
Southern Hemisphere
Summer
23.5˚
Tilt

9. Topic 2: Ecosystems
2.4.2: What makes the Tundra biome
Limited Solar Energy
The Earth also tilts at an angle of 23.5˚ Northern Hemisphere
Winter
Creating summer and winter in each
hemisphere
During the Northern Winter almost no
solar energy reaches the high arctic
Southern Hemisphere
Summer
23.5˚
Tilt

10. Topic 2: Ecosystems
2.4.2: What makes the Tundra biome
Limited Solar Energy
The Earth also tilts at an angle of 23.5˚ Northern Hemisphere
Winter
Creating summer and winter in each
hemisphere
During the Northern Winter almost no
solar energy reaches the high arctic
This again reduces productivity at the
poles Southern Hemisphere
Summer
23.5˚
Tilt

11. Topic 2: Ecosystems
2.4.2: What makes the Tundra biome
Extreme seasonality

12. Topic 2: Ecosystems
2.4.2: What makes the Tundra biome
Extreme seasonality Temperature (˚c) Precipitation (mm)
Tundra experiences very little 30
“rainfall” - making it the driest
20
terrestrial biome
10
0
-10
-20
-30
-40
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec

13. Topic 2: Ecosystems
2.4.2: What makes the Tundra biome
Extreme seasonality Temperature (˚c) Precipitation (mm)
Tundra experiences very little 30
“rainfall” - making it the driest
20
terrestrial biome
10
Limited solar energy and
excessive albedo effect lead to 0
extreme winter temperatures
-10
-20
-30
-40
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec

14. Topic 2: Ecosystems
2.4.2: What makes the Tundra biome
Extreme seasonality Temperature (˚c) Precipitation (mm)
Tundra experiences very little 30
“rainfall” - making it the driest
20
terrestrial biome
10
Limited solar energy and
excessive albedo effect lead to 0
extreme winter temperatures
-10
Summers are short but long -20
hours of daylight help to
compensate and slightly extend -30
the “actual” growing season
-40
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec

15. Topic 2: Ecosystems
2.4.2: What makes the Tundra biome
Survival of the fittest!

16. Topic 2: Ecosystems
2.4.2: What makes the Tundra biome
Survival of the fittest!
Few plants can survive the extreme conditions found in
the tundra

17. Topic 2: Ecosystems
2.4.2: What makes the Tundra biome
Survival of the fittest!
Few plants can survive the extreme conditions found in
the tundra
All need adaptations to survive conditions that would
freeze the cells of most plants while managing with very
little moisture

18. Topic 2: Ecosystems
2.4.2: What makes the Tundra biome
Survival of the fittest!
Few plants can survive the extreme conditions found in
the tundra
All need adaptations to survive conditions that would
freeze the cells of most plants while managing with very
little moisture
Lichens - a symbiotic associating between a fungus and
a photosynthesising algae are the only available “plant”
biomass during the winter

19. Topic 2: Ecosystems
2.4.2: What makes the Tundra biome
Survival of the fittest!
Few plants can survive the extreme conditions found in
the tundra
All need adaptations to survive conditions that would
freeze the cells of most plants while managing with very
little moisture
Lichens - a symbiotic associating between a fungus and
a photosynthesising algae are the only available “plant”
biomass during the winter
Hard tough species like cotton grass manage to grow
during the summer

20. Topic 2: Ecosystems
2.5.5: Productivity
Tundra Productivity

21. Topic 2: Ecosystems
2.5.5: Productivity
Comparison of Net productivity in different Biomes
Tundra Productivity
2500
Plant biomass can the thought of as the
Biomass (g m-2 yr-1)
2000
energy store for the entire ecosystem
1500
1000
500
0
Tropical rain forest
Temperate deciduous forest
Boreal Forest
Savanna
Temperate grassland
Tundra
Based on a table from: Whittaker, R.H. and Likens, G.E. 1975. The biosphere and man. In: Leith, H. and Whittaker,
R.H. (Eds.), Primary Productivity and the Biosphere, Ecological Studies 14, Springer-Verlag, Berlin, Germany, pp. 305-328.

22. Topic 2: Ecosystems
2.5.5: Productivity
Comparison of Net productivity in different Biomes
Tundra Productivity
2500
Plant biomass can the thought of as the
Biomass (g m-2 yr-1)
2000
energy store for the entire ecosystem
1500
With the extreme climate and limited 1000
light Tundra biomass is very low
500
0
Tropical rain forest
Temperate deciduous forest
Boreal Forest
Savanna
Temperate grassland
Tundra
Based on a table from: Whittaker, R.H. and Likens, G.E. 1975. The biosphere and man. In: Leith, H. and Whittaker,
R.H. (Eds.), Primary Productivity and the Biosphere, Ecological Studies 14, Springer-Verlag, Berlin, Germany, pp. 305-328.

23. Topic 2: Ecosystems
2.1.3: Food chains - Tundra food system
Tundra Foodchain

24. Topic 2: Ecosystems
2.1.3: Food chains - Tundra food system
Tundra Foodchain
In winter reindeer survive eating lichen,
in particular Cadonia rangiferina (Reindeer
Winter Foodchain
moss) Solar energy
Primary Producer Primary Consumer Secondary Consumer
Reindeer moss Reindeer Grey Wolf

25. Topic 2: Ecosystems
2.1.3: Food chains - Tundra food system
Tundra Foodchain
In winter reindeer survive eating lichen,
in particular Cadonia rangiferina (Reindeer
Summer Foodchain
moss) Solar energy
In the summer there is a greater choice
of plants - though all with relatively low
NPP
Primary Producer Primary Consumer Secondary Consumer
Cotton grass Reindeer Grey Wolf

26. Topic 2: Ecosystems
2.6: Changes in Ecosystems - Tundra carrying capacity
Tundra Populations

27. Topic 2: Ecosystems
2.6: Changes in Ecosystems - Tundra carrying capacity
Tundra Populations Reindeer population - St Matthew Island,
Alaska
6000
Studies of Reindeer populations on islands show:
5000
4000
Population size
3000
2000
1000
1944 1950 1955 1960 1966
Year After Klein 1968

28. Topic 2: Ecosystems
2.6: Changes in Ecosystems - Tundra carrying capacity
Tundra Populations Reindeer population - St Matthew Island,
Alaska
6000
Studies of Reindeer populations on islands show:
5000
That the amount of winter food available sets the
carry capacity for that ecosystem 4000
Population size
3000
2000
1000
1944 1950 1955 1960 1966
Year After Klein 1968

29. Topic 2: Ecosystems
2.6: Changes in Ecosystems - Tundra carrying capacity
Tundra Populations Reindeer population - St Matthew Island,
Alaska
6000
Studies of Reindeer populations on islands show:
5000
That the amount of winter food available sets the
carry capacity for that ecosystem 4000
Population size
The carrying capacity of the herbivore 3000
population controls the size of any predator
population 2000
1000
1944 1950 1955 1960 1966
Year After Klein 1968

30. Topic 2: Ecosystems
2.6: Changes in Ecosystems - Tundra carrying capacity
Tundra Populations Reindeer population - St Matthew Island,
Alaska
6000
Studies of Reindeer populations on islands show:
5000
That the amount of winter food available sets the
carry capacity for that ecosystem 4000
Population size
The carrying capacity of the herbivore 3000
population controls the size of any predator
population 2000
1000
The studies also show that without predation to
control the population, reindeer numbers often
outstrip their food supply 1944 1950 1955 1960 1966
Year After Klein 1968

31. Topic 2: Ecosystems
1.1.6: Feedback in the Reindeer Wolf cycle
Negative Feedback - Wolf and Reindeer
Figures from: Kojola, I., Tuomivaara, J., Heikkinen, S., Heikura, K., Kilpeläinen, K., Keränen, J., Paasivaara, A. & Ruusila,V.
2009: European wild forest reindeer and wolves: endangered prey and predators. — Ann. Zool. Fennici 46: 416–422

32. Topic 2: Ecosystems
1.1.6: Feedback in the Reindeer Wolf cycle
Negative Feedback - Wolf and Reindeer
In parts of Finland Grey Wolf populations changes appear
to follow behind Reindeer population changes
Figures from: Kojola, I., Tuomivaara, J., Heikkinen, S., Heikura, K., Kilpeläinen, K., Keränen, J., Paasivaara, A. & Ruusila,V.
2009: European wild forest reindeer and wolves: endangered prey and predators. — Ann. Zool. Fennici 46: 416–422

33. Topic 2: Ecosystems
1.1.6: Feedback in the Reindeer Wolf cycle
Negative Feedback - Wolf and Reindeer
In parts of Finland Grey Wolf populations changes appear
to follow behind Reindeer population changes
Is this evidence of a Negative feedback - predator / prey
relationship?
Figures from: Kojola, I., Tuomivaara, J., Heikkinen, S., Heikura, K., Kilpeläinen, K., Keränen, J., Paasivaara, A. & Ruusila,V.
2009: European wild forest reindeer and wolves: endangered prey and predators. — Ann. Zool. Fennici 46: 416–422

34. Topic 2: Ecosystems
1.1.6: Feedback in the Reindeer Wolf cycle
Negative Feedback - Wolf and Reindeer
In parts of Finland Grey Wolf populations changes appear
to follow behind Reindeer population changes
Is this evidence of a Negative feedback - predator / prey
relationship?
While the actual answer is more complex - the population
numbers of all predator and prey systems do have an effect
on each other
Figures from: Kojola, I., Tuomivaara, J., Heikkinen, S., Heikura, K., Kilpeläinen, K., Keränen, J., Paasivaara, A. & Ruusila,V.
2009: European wild forest reindeer and wolves: endangered prey and predators. — Ann. Zool. Fennici 46: 416–422

35. Topic 2: Ecosystems
1.1.5: Equilibria - Tundra / Tiaga ecosystems
Ecosystem Stability

36. Topic 2: Ecosystems
1.1.5: Equilibria - Tundra / Tiaga ecosystems
Ecosystem Stability
Low productivity in the Tundra and Tiaga
leads to short food chains

37. Topic 2: Ecosystems
1.1.5: Equilibria - Tundra / Tiaga ecosystems
Ecosystem Stability
Low productivity in the Tundra and Tiaga
leads to short food chains
This leads to simple foodwebs which can be
prone to disturbance

38. Topic 2: Ecosystems
1.1.5: Equilibria - Tundra / Tiaga ecosystems
Ecosystem Stability
Low productivity in the Tundra and Tiaga
leads to short food chains
This leads to simple foodwebs which can be
prone to disturbance
The Grey Wolf is reliant on only a few prey
species

39. Topic 2: Ecosystems
2.1.5: Pyramid structure and Tundra / Tiaga ecosystem
function
Ecosystem Vulnerability - Bioaccumulation

40. Topic 2: Ecosystems
2.1.5: Pyramid structure and Tundra / Tiaga ecosystem
function
Ecosystem Vulnerability - Bioaccumulation
Canadian researchers have found that even
small quantities of POP’s (Persistent Organic
Pollutants) increase dramatically in
concentration up the Lichen - Caribou
(reindeer) - Wolf food chain