Ecosystems In The British Isle Flashcards
1
Q
What does the composition of vegetation depend on
A
- interaction between all components that make up the environment
- include natural factors like climate relief and soil
- also includes human influence through clearance fires and livestock grazing
2
Q
What is species diversity
A
When plant populations become more complex over time
3
Q
What is a succession
A
The change in in a plant community through time
4
Q
How does an ecosystem reach climatic climax and what is it
A
- if allowed to continue undid turned succession will reach climatic climax
- where plant species live in perfect balance with the current environmental conditions
5
Q
What can affect an ecosystem from reaching their climatic climax
A
Drainage
Geology
Relief
6
Q
What happens at the
Beginning of a succession
A
- plants will invade where the conditions are suitable and die off when the succession leads to unfavourable local conditions
- change in dominant plant species with time
7
Q
What are the two basic types of succession
A
- primary and secondary
8
Q
What happens in a primary succession
A
- occurs on the surface that have had no previous vegetation by the gradual colonisation of a lifeless abiotic surface
- includes lava flows, bare rock and sand dunes
9
Q
What are the two main types of primary succession and where do they form
A
- xeroseres (formed on dry land) lithoseres on bare rock
- hydroseres (formed in water)
10
Q
What are the entire sequence of stages known as
A
Sere
Stages are sera
Stages
11
Q
What is secondary succession
A
- follows the destruction of modification of an existing plant community.
- can occur naturally - after a landslide or a fire caused by lightning
- can also occur unnaturally- human activity such as deforestation to provide farmland
12
Q
Development of a succession
A
- processes are invasion, colonisation, competition, domination and decline
- as a succession develops it passes through a series of stages called seres
13
Q
Development of a succession
What happens In Stage one and what is it called
A
- colonisation
- begin to colonise for available space light and water
- as they die they modify the environment
- develop the soil
- roots help to break up and weather the surface and so aid soil formation
14
Q
Development of a succession
What happens at stage two and what is it called
A
- establishment
- soil develops further
- species diversity increases
- other plants colonise their
- better conditions for plant growth
15
Q
Development of succession
What is stage 3 and what happens
A
- competition
- larger plants begging to establish themselves
- use us a lot of the available resources
- some of the earlier colonisers begin to die out
16
Q
Development of succession
Stage 4 what is it and what happens
A
- stablilzation
- fewer new species colonise
- complex food webs begin to develop
- stage is dominated by taller plants/ trees
17
Q
Development of succession
What is stage 5 and what happens
A
- climatic climax
- slow growing trees begin to grow
- it when vegetation has reached its climax
18
Q
Give one example of a succession
A
Lithosere
Raised beach
- Begins on newly exposed rock surface
- which may have been created by a volcanic eruption
19
Q
Seral stage one for a lithosere
A
- colonisation
- pioneers begin to colonise beginning with lichens
- they adapt to the harsh climate
- as they die they add dead organic matter to weathered Rock
- creates a simple soil
- then allows other plants to grow there
20
Q
Seral stage two for a lithosere
A
- establishment
- soil develops further
- ferns and small herbaceous plants and grasses begin to grow
- species diversity increases
- die back, bacteria convert their remains into humus
- helps recycle nutrients and improve soil fertility
21
Q
Seral stage three of a lithosere
A
- competition
- larger plants begin to establish themselves
- shrubs and small trees
- use up a lot of available space and water
- some of the earlier colonisers begin to die out
22
Q
Seral stage four of a lithosere
A
- stablilzation
- fewer new species colonise
- complex food web develops
- dominated by larger pioneer trees
- fast growing such as willow and birch
23
Q
What is stage five in a lithosere
A
- seral climax
- slow growing trees begin to develop
- ask and oak
- initially in the shade of shrubs so only appear in later stages
- dominants on the climax community
- temperate deciduous woodlands
24
Q
What is a biome
A
- a global scale ecosystem and its naturally occurring organic community of plants and animals in the climatic climax stages of succession
25
What are the three main components of an ecosystem
- climate
- vegetation
- soils
- all closely linked in equilibrium
26
What is an example of high-energy biomes
- tropical rainforest
| - temperate deciduous woodlands
27
Give the characteristics of a high-energy biome
- shows similarities in climate, soil, plants and animal life
- has own distinctive vegetation
28
Examples of a low-energy biome
- tundra
| - dessert
29
Characteristics of a low-energy biome
- high latitudes
- vegetation is scant
- net primary productivity is low
30
What happens to a biome in its natural state
- dynamic equilibrium with its environment
- vegetation exists in perfect balance with the climate and soils
- any change would alter the balance
31
Describe plant succession in the uk
- reached climatic climax around 8000 years ago
| - 5000 years ago the effects of forest clearing by the bronze aged people created a plagioclimax
32
Describe the temperature deciduous woodland as a high energy biome
- high productivity
- mid-latitudes
- adequate Moisture
- not found in the interiors of continents where patterns are more clear
33
What was the most common species found in the British isle
- the dominant one is the oak in the lowlands
| - although as was common in some areas
34
Describe the climate in the temperate deciduous woodland
- four distinctive seasons
- average winter is 2-7
- average summers 13-17
- total precipitation is 500-2000 mm a year
- westerly winds are predominate
- moist air
- low pressure weather systems dominate
35
Describe the vegetation in a temperate deciduous woodland
- seasonal colour change- autumn leaf fall
- broadleaf deciduous woodlands (oak and ash) shed their leaves in Autumn before the cold winters
- soil temperatures fall so tree roots can only absorb a small amount of water- growth is stopped
- heat loss reduces transpiration
36
Describe the soil in a temperate deciduous woodland
- brown earth, 1.5m deep which is deep and well drained
- leaf litter, accumulates during autumn, quickly decomposed during the following year, supports large amount of fauna
- well mixed by earthworms and other soil organisms
- layers are not clear
- mild leaching occurs during autumn and winter
- makes soil slightly acidic p= ideal for plant growth
37
What are the four layers in a oak woodland
- tall tree canopy
- shrub layer
- field layer
- ground layer
38
What is the tall tree layer and what trees are there
- oak, and ash
- shed there leaves in winter
A reduce transpiration be chase water is les available
- light is prevented from reaching lower levels
- reduces number of species
39
What is in the shrub layer
- small trees such as hazel and rowan
40
What is in the field layer
- woodland flowers such as bluebells and primroses
41
What is in the ground layer
- mosses and tree seedlings
| - leaf layer
42
What might effect the layering of a woodland
- soil type
- age
- climate
- landform
43
What has happened to our woodlands
- human activity- deforestation
- been coppiced to provide wood for charcoal burning
- can't recognise ancient woodlands from a oak forest since the last ice age
- trying to compromise for the growing population so we destroy the woodland for agriculture, industrial and residential purposes
44
What are upland British forests
- afforestation programs
| - composed of conifers because they mature in only 30 years compared to 200 years
45
How and when we're British ancient forests cleared
- cleared by felling
- new growth grazed by livestock and wild animals until the tree dies
- began in 4000BC
- occurred slowly until the Iron Age
46
What happened in 500BC
- over half of Britain's woodland had been cleared
| - remaining woodlands being managed and used for timber and wood for fuel
47
What happened in 1086
- small area of wildwood remained within the Forest of Dean
- all others had been owned or managed by individuals or communities
- everyone was heavily wood dependent
48
What happened during the 13th century
- woodland plantations were introduced
| - trees were cut at ground level
49
What happened during the 18th century
- extensive woodland clearance by wealthy landowners
| - replaced this by open space landscape parkland
50
What happened during the 19th century
- practice of coppicing died out
| - industrial revolution lead to timber and wood being replaced as major resources and fuel
51
What happened during the First World War
- national change
- Britishs sources of imported wood pulp were lost
- lead to creation of forestry commission in 1919
- most conifer plants were in areas of moorland and heatherland
- some ancient woodlands were part of the afforestation
52
What happened in the post war period
- the most ancient woodland was lost
| - over 1/3 of remaining were cleared in less than 25 years
53
What would happen if the trend (deforestation) continued
- there would be no native woodland
- very little has been lost since 1975
- threats are now challenged by conservation groups
54
Example and description of a plagioclimax
- Heather Moorland
- people interfere with plant succession and stop a plant community from reaching climatic climax
- human activity can do this
- reduces the total number of species and the biodiversity
- so a plagioclimax develops where there are breaks in succession
55
What is a secondary succession
- one that restarts on the land that has been previously vegetated
- can occur after a natural event (volcanic eruption) or after human interference
56
Description of how the Heather moorland came about
- many of the uplands in Britain were once covered by deciduous woodland
- Heather would have featured a small part
- gradually the forests were removed
- hardy plants like Heather dominated the upland
- sheep grazing became the form which prevented the regeneration of the forest which once was
57
How is the heather moorland managed
- managed by burning to encourage new Heather shoots
- bringing eliminates the less fire resistant plants just leaving the Heather
- it is burnt every 15 years
- if the burning did not continue then the Heather moorland would deteriorate
- eventually allowing trees to grow back and overtake
