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Flashcards in Lecture 7 Notes Deck (25):
1

What are 4 examples of natural disturbances?

1. Climate change
2. Fire
3. Storms/wind/flooding
4. Insects/pathogen outbreaks

2

What is disturbance essential for?

Natural part of ecosystems
- some species are particularly adapted to and rely on disturbances

3

What does diversity depend on?

Disturbances

4

What do paleo-records allow us to study? (example)

Long term scales
- example = we can use lake sediments to find out past forest and fire regimes

5

What are 3 factors that control fire regimes on long term scales? (decades to millennia)

1. Type
2. Frequency
3. Severity of fire

6

What 3 things effect fire regimes?

1. Climate --> hot and dry
2. Vegetation --> composition, density, species
3. Ignition --> sparks, volcanic eruptions, cigarettes

7

What are 2 examples of taphonomic filters?

1. Dispersal
2. Deposition

8

What are 2 examples of data collection?

1. Sampling
2. Quantification

9

What does is mean when charcoal is high in the lakes?

There is large accumulation

10

What kinda of change happens with charcoal?

Natural

11

What do fossil charcoal records help us to understand/manage?

Help us to understand/manage ecosystems by providing records of natural variability

12

What is the size of macroscopic charcoals?

> 150 um

13

How do you calculate charcoal accumulation rate?

Use sedimentation rate from 14C dating (number of particles/ cm^2 yr)

14

CHAR

Charcoal Accumulation Rate

15

What does fire history or periods of increasing fire not tell us about?

Individual fires

16

What are 4 fire characteristics?

1. Charcoal production
2. Vegetation type
3. fuel load
4. Fire intensity

17

Does grass lands produce more or less charcoal compared to a more dense forest area? Why?

Less
- because in a more dense forest there is more vegetation to burn

18

What type of particles travel further?

Smaller particles travel farther (regional fires) vs. secondary charcoal introduced during non fire years

19

What happens to secondary charcoal?

It sits on the land for a while and will eventually get deposited into the lakes

20

What 2 things influence source area?

1. Lake size
2. Catchment size

21

What happens with lodgepole is replaced with Douglas fir?

The fire return decreases

22

What does lodgepole rely on?

Fire
- open cones from spreading

23

What happens when fire return is less frequent?

Fire occurs more
- even dispute it is colder and wetter

24

What do people use fires for?

To modify their land

25

What are 4 lessons from paleo-fire records?

1. Forest fires frequency has varied continually over the holocene
2. Linked to climate is clear, but paleo-fire records are nor synchronous across space
3. Changing forest composition affects susceptibility to fire, sometimes over riding the roles of climate
4. Recent humans activity had radically altered fire regimes on all spatial scales