Succession

Question 1

Outline the 3 main stages of the nutrient cycle

Answer 1

Biomass, litter, soil

Question 2

What is the humus layer?

Answer 2

Weathered rock that supplies nutrients to the soil

Question 3

Define succession

Answer 3

A series of changes that take place in a plant community over time

Question 4

Define vegetation succession

Answer 4

Composition of vegetation in an ecosystem depending on natural and human factors

Question 5

Define ecological succession

Answer 5

Vegetation at a certain site changes over time and because more diverse

Question 6

Define primary succession

Answer 6

A species will colonise a previously in-colonised site

Question 7

Define secondary succession

Answer 7

Changes in vegetation occur due to the original being destroyed

Question 8

What is the climatic climax theory?

Answer 8

After initial colonisation, they provide nutrients in the soil after decomposing, allowing more complex species to grow

Question 9

In order, what are the stages of ecological succession?

Answer 9

Sere, pioneer species, establishment and climatic climax

Question 10

What is the pioneer species for psammosere succession?

Answer 10

Lyme grass (halophytic)

Question 11

What is Lyme grass resistant to? (Psammosere)

Answer 11

Salty conditions

Question 12

Outline the main stages of psammosere succession

Answer 12

Embryo dune, fore dune, main dune, gray dune and climatic climax

Question 13

Was flora is found on the fore dune? (Psammosere)

Answer 13

Marram grass

Question 14

What adaptations are in the flora of the fore dune? (Psammosere)

Answer 14

Extensive rhizome system, lateral roots, xerophytes, waxy cuticles

Question 15

What happens to the soil at the main dune? (Psammosere)

Answer 15

Marram grass has binded the soil so and humus increases through decay

Question 16

Why is the gray dune coloured that way? (Psammosere)

Answer 16

Nutrient content is so high

Question 17

What is the pioneer species in halosere succession?

Answer 17

Blue green algae

Question 18

What adaptations do pioneer species have in halosere succession?

Answer 18

Resistant to salty conditions

Question 19

When is a plagioclimax reached?

Answer 19

When human interruption causes succession to be maintained at a subclimax

Question 20

Outline the process of halosere succession

Answer 20

Colonisation bind mud to the surface, pioneer plants grow, lavender will take over, climatic climax

Question 21

Pioneer species for lithosere succession?

Answer 21

Moses and lichens

Question 22

Outline the process of lithosere succession?

Answer 22

Organic acids corrode the bare rock releasing minerals for growth, growth of moss, germination of seeds, climatic climax

Question 23

What is the pioneer species for hydrosere succession?

Answer 23

Algae e.g elodea

Question 24

Outline the process of hydrosere succession

Answer 24

Phytoplankton on surface of water that settles at the bottom to decay, submerged stage, plants with rhizomes, marsh meadow and climatic climax