Climatic Events in High Latitude Ecosystems

Question 1

What is happening to the frequency and intensity of fires in high latitudes?

Answer 1

Increasing.
Throws off carbon neutral fire systems, struggling to sequester enough carbon.

Question 2

What is NBP?
What is it made of and how have these changed since the 1950s?

Answer 2

Net biome production
C = CO2 influenced NBP. Small increase
D = Disturbance influenced NBP. Large decrease
M = Met (climate) influences NBP. Small decrease

Question 3

What happened in the Anaktuvuk River fire in 2007?

Answer 3

Tundra fire, 60% of carbon lost from the soil.
All plants and top 4cm of soil was burned. More carbon was lost from this soil than the vegetation.

Question 4

What is an example of a herbivore outbreak caused by climate change?

Answer 4

Epirrita (insect)
Usually, eggs are killed by extreme cold, but because of warming, less eggs are being killed.
Results in defoliation of trees and understorey
Natural 10 year cycle.

Question 5

What is an example of how pathogen outbreaks are caused by climate change?

Answer 5

Fungus: Arwidssonia empetri
Targets Empetrum.
Deeper snow lay promotes outbreaks.

Question 6

What are some winter extreme climatic events?

Answer 6

WARMING:
Causes mid winter bud burst, lost freeze tolerance due to warmth
FROST DROUGHT:
Desiccation damage, plants transpire but soil is frozen so roots get no water. Reduces C sink strength.
ICING:
Rain on snow, partially melts snow then refreezes around vegetation. Causes a loss of insulation, high CO2, hypoxia