Life processes in the biosphere

Question 1

What is the range of tolerance?

Answer 1

The range of a factor in which a species can survive

Question 2

What abiotic factors affect species survival?

Answer 2

Light
Water
Nutrients
pH
Habitat provision

Question 3

What biotic factors affect species survival?

Answer 3

Food supply
Disease
Pollination
seed dispersal
Competition
Predation

Question 4

What does species mean?

Answer 4

A group of closely related organisms that can inter-breed to produce fertile offspring

Question 5

What does taxonmy mean?

Answer 5

The science of grouping organisms based on their characteristics.
Any taxonomic group is a taxon

Question 6

What does ecological niche mean?

Answer 6

The role an individual has in its habitat

Question 7

What does population mean?

Answer 7

All the individuals of a single species in a certain area.

Question 8

What does community mean?

Answer 8

All the members of all the species that live in an area

Question 9

What does ecosystem mean?

Answer 9

The combination of abiotic and biotic factors, including the community of species, their inter-relations with each other and the environment

Question 10

What does biome mean?

Answer 10

A large geographical region with particular climatic features, in which a community of unique species live.

Question 11

What are the first species to colonise?

Answer 11

Pioneer species

Question 12

What is a sere?

Answer 12

The sequence of stages in ecological succession

Question 13

Describe how a hydrosere is formed

Answer 13

Seed dispersal brings seeds to a body of water.
The lake edges become colonised by plants so provides habitats for animals.
As plants grow and die the body of water will fill with DOM and soil, this makes the water shallower so rooted plants can survive in the open water.
As the body of water fills with soil aquatic organisms die out, much bigger plants colonise the waterlogged soils.
More water is removed by transpiration, more trees like oak colonise they form a canopy which changes the abiotic factors.
Climax community is reached

Question 14

Describe how a lithosere is formed

Answer 14

Development on bare rock.
Algae first colonise then mosses, a thin layer of soil builds up.
As soil builds up bigger plants colonise, abiotic factors become less extreme.
Flowering plants colonise when insects become established.
Eventually trees colonise, a climax community is reached

Question 15

Describe how a psammosere is formed

Answer 15

Starts on sand.
Drainage is rapid, low in nutrients so plants find it hard to establish themselves.
Eventually they will succeed, their roots stabilise the sand, nutrients build and more plants colonise.
Eventually a climax community will be reached

Question 16

What is a plagioclimax community?

Answer 16

A climax community which is prevented from reaching its natural state due to human intervention

Question 17

How are hay meadows managed?

Answer 17

Mowing

Question 18

How are wild flower meadows managed?

Answer 18

Grazing of animals and mowing

Question 19

What is secondary succession?

Answer 19

Succession on land that has previously been colonised but damaged by floods, fires, earthquakes etc

Question 20

How is burning used to manage habitats?

Answer 20

Burning of heather is used to prevent oak woodlands establishing themselves.
The older heather is also less nutritious, burning allows younger heather to grow which is food for grouse.

Question 21

What are density independent factor?

Answer 21

Factors that do not change their impact based on the density of a population, e.g. flood, drought

Question 22

What are density dependent factors?

Answer 22

Factors that change their impact based on the density of a population, e.g. disease, competition, predation, food supply

Question 23

How do predator-prey relationships work?

Answer 23

When the prey population rises there is alot of food for predators, so their population rises.
The prey population then decreases, there is now less food for predators so their population declines.
The prey populations recover and it happens again.

Question 24

When might a population need to be controlled artificially by culling or intervention?

Answer 24

Breeding rate of endangered species is low so CBR programme is used.
A non-indigenous species introduced is a pathogen, predator or competitor.
An indigenous predator being removed so its prey species becomes over populated and is causing ecological damage

Question 25

What is the biosphere?

Answer 25

All of plant earth that is inhabited by living organisms

Question 26

How can the conservation of biodiversity be achived?

Answer 26

Legal protection, SAC, SPA, RAMSAR, countryside and wildlife act, european common fisheries
CBR
Management of habitats
Creation of new habitats