6.3.1 (d) Successoon

Question 1

what is succession?

Answer 1

when ecosystems change over time

Question 2

what causes succession?

Answer 2

changes to abiotic factors which causes the animal and plant species to change

Question 3

what is primary succession?

Answer 3

occurs on newly formed land where there is not soil or organic matter at the start

Question 4

what is secondary succession?

Answer 4

occurs in land where soil is present but without any plant or animal species

Question 5

examples of primary succession

Answer 5

• volcanoes erupt and deposit lava which cools and solidifies into igneous rock
• sand is blown by wind to create sand dunes
• silt and mud deposited at river estuaries
• glaciers retreat and deposit rubble

Question 6

what is each stage in succession called?

Answer 6

seral stage

Question 7

what are pioneer species?

Answer 7

they carry spores and seeds carried by the wind from other organisms rubbish

Question 8

adaptations of pioneer species?

Answer 8

• the ability to produce large quantities of seeds or spores
• seeds which germinate rapidly
• ability to photosynthesise their own energy
• tolerance to extreme environments
• ability to fix nitrogen

Question 9

what happens when pioneer species die?

Answer 9

they decompose and their nutrients are released into the soil

soil now known as humous

the soil can now retain water and allow for growth of new species

Question 10

what come after pioneer species?

Answer 10

secondary colonisers which also arrive as spores/seeds

Question 11

what comes after secondary colonisers?

Answer 11

tertiary colonisers which have waxy cuticles which prevents water loss and allows for them to survive in extreme conditions

Question 12

how does the soil become more nutrient rich?

Answer 12

with more organisms decaying, more nutrients enter the soil which makes it more rich and allows for more species to grow

Question 13

what is a dominant species?

Answer 13

overtime, species will outcompete older species and will become the more dominant one in the ecosystem

Question 14

what is the climax community?

Answer 14

when the community is in a stable state

• a few dominant species
• depending on the climate, there will be different species growing

Question 15

where is biodiversity greatest during succession?

Answer 15

• mid succession

the more dominant a species is the less biodiverse the ecosystem is

Question 16

what is animal succession?

Answer 16

• insects are the primary consumers which colonise the area first
• once a suitable food source is established, secondary consumers move in and habitats are created due to plant cover
• once conditions are favourable then larger mammals and reptiles will move in

Question 17

what is deflected succession?

Answer 17

when human activity prevents succession from reaching climax

Question 18

what is the stage called when succession is stopped artificially?

Answer 18

plagioclimax

Question 19

how does agriculture cause deflected succession?

Answer 19

• grazing and trampling on vegetation
• removing existing vegetation and replacing with plant crops
• burning forests causes increase in nutrient rich ash for other species to grow