Topic 10

Question 1

What is succession?

Answer 1

Process by which communities or organisms colonising an area change over time

Question 2

Where does primary succession occur?

Answer 2

With an empty inorganic surface such as bare rock or sand dune.

Question 3

What are the first organism on primary succession?

Answer 3

Opportunists or pioneer species, such as algae or mosses.

Question 4

What doe pioneer species do the start primary succession?

Answer 4

Can penetrate the rock surface, helping to break it into small grains, and trap organic material that willl break down to form hummus.

Question 5

What starts the formation of the soil?

Answer 5

The inorganic rock grans and organic humus.

Question 6

What occurs after there is soil in primary succession?

Answer 6

Species such as grass and ferns can establish a root system.

Question 7

What does the grass and ferns do to the soil?

Answer 7

The action of their roots and the humus they form, when they die, decay and add to the soil.

Question 8

What happens as the soil layer develops in primary succession?

Answer 8

More water and nutrients are retained and become available for plant roots, and so less hardy species can survive

Question 9

How does the biodiversity increase in primary succession?

Answer 9

The soil becomes stronger, so more species can grow their. Larger plants can be supported.

Question 10

What happens as plant diverts increases during primary succession?

Answer 10

The biodiversity of animals can also be supported and increase

Question 11

What is a climax community?

Answer 11

Self sustaining community with relatively constant biodiversity. It is the most productive group of organisms that a given environment can support long term.

Question 12

What is a climatic climax community?

Answer 12

Is the only climax community possible in a given climate. One that generally remains constant over time.

Question 13

What is a plagioclimax?

Answer 13

Climax community that is at least in part the rule of human intervention

Question 14

Example of a plagioclimax?

Answer 14

Chalk grassland, clearing woodland, eg

Question 15

What is secondary succession?

Answer 15

development of an ecosystem from existing soil that is clear of vegetation.

Question 16

What occurs to produce secondary succession?

Answer 16

As rivers shift their courses, after fires, floods, after disturbances abused by humans etc.

Question 17

How similar is primary and secondary succession?

Answer 17

Very, but soil is already produced and formed with seeds, roots and soil organisms. The number of plants and animal present right form the beginning of succession are much higher.

Question 18

What does secondary succession depend on?

Answer 18

Temperature, rainfall, underlying soil fertility.

Question 19

What can show a whole record of stages of succession?

Answer 19

Sand dunes.
The area of sand closest to the sea is primary succession, with loose sands. It gradually increases in structure and plants and organisms as you increase across the beach

Question 20

What is Surtsey?

Answer 20

A volcanic eruption burst through the seas off the coast of Iceland. The hot magma cooled rapidly and produced to form a new island. When they stopped, there was a huge 2.7 km area of volcanic rock.

Question 21

What were the earliest colonisers on Surtsey?

Answer 21

Mounds, bacteria, fungi, followed by flowering plants.

Question 22

What caused more fertility to the soil at Surtsey?

Answer 22

Bird droppings, fell after gulls colonised to the island.

Question 23

What is microclimate?

Answer 23

Small area with a distinct climate that is different to the surrounding areas.

Question 24

How is light an abiotic factor on populations?

Answer 24

Non living therefore abiotic. The amount of light in a habitat gas direct effect on number of organisms.

Question 25

Why do plants need light?

Answer 25

Photosynthesis, therefore wont thrive in places with low light. Some plants reproduce early to avoid the shade from other plants ,
Other plant with a lot of chlorophyll are sensitive to Lower level, therefore niche is found.

Question 26

Why do animals need light?

Answer 26

As a real of food plants. Seasonal light changes also affect reproductive patterns in animals.

Question 27

Why is temperature an abiotic factor?

Answer 27

Every organism needs a range f temperatures with without W the able to reproduce or grow.
Extreme temperatures determine if the organism survives, not the average.

Question 28

What’s most important about temperature?

Answer 28

Enzymes controlled reactions. In plants and ectotherms, day time temperature exceeds body temperature, and many animals have evolved behavioural or physiological adaptations to prevent damage.

Question 29

Why is wind and current an abiotic factor?

Answer 29

Wind has direct effect on organisms in a habitat.

Wind increases water loss form the body and cooling, and so adds to the environmental stress of an organism

Question 30

What does wind cause?

Answer 30

Fewer species can survive, woodlands may be destroyed and the communities of plants and animals may be destroyed.

Question 31

Why are water currents important?

Answer 31

Organisms may have to flow with the current, e stronger swimmer or be able to attach to a surface and resist the force of the water.

Question 32

Why is water availability an abiotic effect?

Answer 32

Availability of water is affected by general factors including amount of precipitation, rate of evaporation, edaphic factors in the soil, etc. Water is vital for living things

Question 33

What happens of there is water stress?

Answer 33

Organisms will die, unless, like camels, kangaroo rats and cacti, they have special adaptations.
An increase in the availability of water can lead to huge change in habitat and to a massive increase in population size of some organisms.

Question 34

Why os oxygen availability a abiotic factor?

Answer 34

Can be in short supply in water and soil

When water is fast flowing or old, sufficient oxygen dissolves. If water becomes warm and sill, less oxygen in it

Question 35

Why is oxygen in soil important?

Answer 35

Soil has spaces which oxygen is trapped. Plenty of oxygen for respiration of plant roots.
If no air spaces, plants may die
Some plants such as mangroves have special adaptations in aerial roots

Question 36

Why are edaphic factors an abiotic factor?

Answer 36

Structure of soil.
Sand has loose structure, and allows very little to grow.
Plant populations are linked to massive roots and rhizome networks
Soils tha contain a high proportion of sand are light, easily worked, but also very easily drained.

Question 37

Why is sans soil bad?

Answer 37

easily drained. Water passes through them rapidly, carrying minerals that may be needed by plants. This is LEACHING.

Question 38

What does leaching result in?

Answer 38

Reduces the population density of plants, difficult for water to drain through the soil that mare made up of clay.