Ecological Succession

Question 1

What are pioneer species?

Answer 1

First organisms to colonise a which are adapted to the abiotic conditions

Question 2

What do the new colonisers do?

Answer 2

Change the condition making the abiotic conditions less and less extreme
—> eventually survival adaptations
based on inter species
relationships and biotic factors

Question 3

What does the pioneer species do to the habitat?

Answer 3

They change the habitat, making it suitable for species that could not colonise it before
—> new colonisers may out compete
pioneer species

Question 4

What is the climax community?

Answer 4

The community of species that remain dominant as long as the climate does not change

Question 5

What is a sere?

Answer 5

Sequence of stages in ecological succession

Question 6

What is a Hydrosere?

Answer 6

1) area of freshwater colonised by algae; lake edges colonised by rooting plants

2) as plants grow and die lake fillls in w DOM, soil and sediments ; emergent plants thrive and submerged ones die out

3) as sediment fills lake aquatic species disappear

4) transpiration removes water and more sediments accumulates
—> trees colonise

5) eventually community dominated by trees

Question 7

What is a Lithosere?

Answer 7

1) Lichen colonise bare rock; as DOM accumulates conditions improve and mosses colonise

2) soil starts to form and grasses colonise ; plants get larger as more soil forms

3) pollinating insects arrive and flowering plants colonise

4) once soil is deep enough trees colonise from wind blown seeds

Question 8

What is a Psamosere?

Answer 8

1) as plants succeed in colonising, sand is stabilised; nutrient supply increases and organic matter builds up

2) eventually sequence of changes in community will establish same climax communities as hydro/lithosere

Question 9

What is a plagioclimax?

Answer 9

Area where human activity defers climax community

Question 10

What is secondary succession?

Answer 10

Species recolonise an area after it is left alone