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Flashcards in Succession Deck (68)
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1

What is succession central to

Ecology as evolution is to biology

2

What is succession

Species change over time (turnover)

3

What effect does disturbance have on succession

It is started directed and redirected by it. Climate events, landuse change, conversion of rainforests etc

4

What is the incorrect thought about succession

It is thought to progress towards climax but in reality it is complex and multidirectional

5

What are the types of succession

Primary succession
Secondary succession

6

What is primary succession

From sterile beginnings with no existing communities

7

Example of primary succession

Volcanoes
Glaciers

8

Facts about volcanoes

3000 active ones.
60-70 erupt annually affecting 500 million people.

9

Facts about glaciers

10% earths surface
90% of that in Greenland and Antarctica.
75% of glaciers in retreat - get primary terrain left to look at succession over time

10

How do glaciers create disturbance

As they move through landscapes they peel vegetation away, grinding it up and creating a less biodiversity environment but there are microbes under them.

11

How much are glaciers retreating

20m per year

12

What is secondary succession

On previously colonised land after major disturbance

13

Examples of secondary succession

Landslides
Fires
Cultivation
Land abandonment
Wind throw

14

What are the source of new colonisers in secondary succession

Propagules (seeds) organism in the soil, bacteria, fungi, plants that can recover

15

What are the two types of succession processes

Autogenic
Allogenic

16

What is autogenic process

Species change due to activities organisms themselves - biotic. Competitive and interactions for niches and water

17

What is allogenic process

Species change due to external, non biological factors - abiotic. Like climate change and silting of waters

18

What are the two general trends for plant community succession

Early successional species
Late successional species

19

Characteristics of early successional species

Colonisers ‘ruderals’.
Small and fast growing.
Produce many small seeds for dispersal.
No dormancy requirement.
Often N fixers.
Allocate more energy to reproduction than biomass.

20

Example of N fixers

Lichens
Cyanobacteria
Dryas

21

What can colonisers ‘ruderals’ cope with

Desecration
Drought
Warm and cold conditions

22

Examples of dormancy periods

Some seeds have to be eaten by animals, some have to be frozen to be colonisers

23

What is an advantage in a nutrient limited enivonrkwbt

Ability to fix atmospheric nitrogen and turn it to an amino acid

24

Why do early successional species allocate energy to reproduction not biomass

To increase chances they have successful next generations

25

What are early successional species classed as

R-selected

26

What are late successional species classed as

Competitions ‘k-selected’

27

Characteristics of late successional species

Large, slow growing (trees)
Dormancy.
Dominate.
Late seeds, animal dispersal sometimes.
Competitive (canopy species)
Allocate energy to biomass not reproduction.

28

What are canopy species

Dominate and control light resource. Plants that dominate resources like light has impact on other plants - selection process goes on e.g plants that tolerate lower light.

29

Early advantage in late successional species

Big seeds. More energy for seed to produce energy and grow quickly

30

Model for r selected and k selected plants

R selected have fast growth rate, high investment in reproduction (Dispersor). High colonisation, low competitive ability.
K selected have slow growth rate, long lived, investment in biomass production (competitor). Low colonisation, high competive ability.