Ecological succesion

Question 1

What is a sere

Answer 1

The sequence of stages in ecological succession during which an uncolonised habitat develops into the climax community

Question 2

What is secondary succession

Answer 2

Ecological succession that takes place in an area where the existing climax community has been disturbed or destroyed.

Question 3

What is primary succession

Answer 3

Changes in an ecosystem over time when the starting point was nothing (no soil just bare rock, sand or water)

Question 4

What are the three types of seres

Answer 4

• Hydrosere
• Lithosere
• Psammosere

Question 5

What are pioneer species

Answer 5

One of the first species to colonise an area at the start of ecological succession. They are usually well adapted to extreme abiotic factors.

Question 6

What is a hydrosere

Answer 6

Succession where the first stage or sere is freshwater

Question 7

What is a lithosere

Answer 7

Succession where the first stage or sere is bare rock

Question 8

What is a psammosere

Answer 8

Succession where the first stage or sere is on sand

Question 9

What is a plagioclimax

Answer 9

Community maintained by human activity where succession/ the climax community was deflected or stopped

Question 10

What is deflected succession

Answer 10

Natural ecological succession is stopped by human actions. Long-term continuation of the actions that deflect succession will create a plagioclimax.

Question 11

What is a climax community

Answer 11

The relatively stable community of species present at the end of ecological succession.
The species that make up the community are controlled by the climate, so it is often called the climatic climax community

Question 12

What is the main difference between primary and secondary succession

Answer 12

Primary succession occurs in an environment without previous life. Secondary succession occurs in an area that had previously been inhabited but experienced a disturbance, such as a wildfire or human activities such as grazing livestock or coppicing

Question 13

During the succession process what increases over time

Answer 13

• Biodiversity
• Soil depth
• Complexity (plants develop)
• Plants become taller (supported by deeper soil = deeper roots)
• Shade
• Decay and decomposition

Question 14

What are 6 plagioclimaxes in the UK

Answer 14

• Lowland heath
• Upland moor
• Chalk grassland
• Hay meadows
• Water meadows
• Coppiced woodland

Question 15

What is the management practice in lowland heath

Answer 15

• Burn it (controlled burning)
• Grazing

Question 16

What is the management practice in upland moor

Answer 16

• Burn it (controlled burning)
• Grazing

Question 17

What is the management practice in chalk grassland

Answer 17

Grazing

Question 18

What is the management practice in hay meadows

Answer 18

Mowing / harvesting the hay

Question 19

What is the management practice in water meadows

Answer 19

Grazing

Question 20

What is the management practice in coppiced woodland

Answer 20

Coppicing (cut trees down to a stump at intervals every 10 years)

Question 21

How do early colonisers change abiotic conditions to enable more and more species to thrive

Answer 21

Early colonisers (pioneer species) go through the cycle of death and decay which helps with the production of soil and makes the habitat suitable for new species to thrive

Question 22

How does lithosere develop

Answer 22

Developed by a cliff fall, glacier retreat or a volcanic eruption

Question 23

What are the abiotic conditions usually like before succession of a lithosere

Answer 23

Abiotic conditions are usually harsh and unsuitable.
- Extreme temperatures
- Limited water availability
- No soil

Question 24

What happens in stage 1 of primary succession of a lithosere

Answer 24

The ground surface consists of ash and bare rock and pioneer species usually lichen and moss colonise.

Question 25

What happens in stage 2 of primary succession in a lithosere

Answer 25

Conditions improve as DOM and rock fragments accumulate which allows mosses to colonise and a thin layer of soil to build up

Question 26

What happens in stage 3 of primary succession in a lithosere

Answer 26

Grasses and ferns colonise and the layer of soil increases which allows for larger plants to grow. Development of soil makes plant nutrients more available

Question 27

What happens in stage 4 of primary succession in a lithosere

Answer 27

Once pollinating insects are established flowering plants are able to grow. The soil is deep enough for trees to colonise usually by wind blown seeds e.g. birch trees

Question 28

What are the abiotic conditions usually like after succession of a lithosere

Answer 28

The conditions are less extreme and more stable

Question 29

What is a sand dune

Answer 29

Sand dunes are depositional landforms that form on coastal environments

Question 30

What are the abiotic conditions usually like before succession of a psammosere

Answer 30

• Plant nutrients are not readily available
• Drainage is rapid = poor water supply

Question 31

What happens in stage 1 of primary succession of a Psammosere

Answer 31

Pioneer species such as sea rocket colonise an area of sand and helps to create the structure of embryonic sand dunes and couch grass grows

Question 32

What happens in stage 2 of primary succession of a Psammosere

Answer 32

Marram grass begins to grow which helps stabilise the sand dunes creating yellow dunes allowing the sand dunes to grow and become colonised by other species.

Question 33

What happens in stage 3 of primary succession of a Psammosere

Answer 33

Fixed dunes have more vegetation grow such as red fescue

Question 34

What happens in stage 4 of primary succession of a Psammosere

Answer 34

Scrub stage brambles start to grow

Question 35

What happens in stage 5 of primary succession of a Psammosere

Answer 35

Oak trees start to grow creating woodlands

Question 36

What are the abiotic conditions usually like after succession of a psammosere

Answer 36

• Nutrient supplies increase
• Organic matter builds up
• Water availability increases