Transcript Poynton pool hydrosere

Succession
A Case Study – Poynton Park and Pool –
an arrested hydrosere
Some Definitions : Just to remind you!
 Sere: Another name for succession. A set of
stages of evolution of an ecosystem.
 Pioneer stage: First stage in a sere which is
dominated by opportunist species.
 Climax stage: Final stage in a sere where
all species are in balance.
Primary Succession
Priseres
Xerosere
(dry environment)
Lithosere
(bare rock)
Psammosere
(sand dunes)
Hydrosere
(wet environment)
Hydrosere
(fresh water)
i.e. Poynton Pool
Halosere
(salt water)
Glossary of Keywords : another reminder!!
Succession
The sequence of changes in a plant community as it moves towards a “seral
climax”
Sere
A stage in the development of plant communities towards climatic climax.
Climax
Community
The group of species that are at a dynamic equilibrium with the prevailing
environmental conditions – in the UK, under natural conditions, this would be oak
woodland.
Plagioclimax
When a plant community is permanently influenced by people – it cannot reach
climax because of burning, grazing, deforestation
Primary
succession or
priseres
Beginning on bare ground, or water
Secondary
succession or
subseres
Beginning after the destruction of existing vegetation
Pioneer species
The first plants to colonise an area
Sub climax
When vegetation is prevented from reaching its climax due to interruptions by local
factors (e.g. soils)
Arresting factors
The factors that cause succession to be interrupted
Hydrosere:
 Describe the
changes that you
see.
Hydrosere:
 The gradual conversion of ponds and
lakes to forest ecosystems.
 With time ponds and lakes are gradually
filled with eroded sediments.
 The sediments moves in the shorelines
and eventually fills in the lake.
 The plant sequence is as follows: lake
plants, reeds, grasses, shrubs, & trees.
Poynton Park : a hydrosere in
arrested succession.
Macclesfield Borough Council manage the
Park and the Pool which together cover an
area of 21 hectares.
Sluice gate on the west
bank allows water to leave
the Pool and succession is
therefore stopped as the
flow of water is too great.
Gardens of houses along
Anglesey Drive arrest the
natural succession by
cutting back vegetation in
their gardens.
Anglers (primarily) along the
west bank also limit the
growth of vegetation as
Stockport Angling Federation
cut back vegetation for pegs
while maintaining larger
trees as cover for fish.
Initial water source for the
Pool from the mining industry.
This area is now an example of
climax vegetation with oak
woodland, a shrub under layer.
It is protected from human
interference by being fenced
off allowing only grazing by
rabbits and other animals.
At the south end of the Pool
the flow of water is less and
therefore succession is more
advanced with a shallowing
of the water, increased
nutrient content and a
greater variety of
hydrophytic plants.
Large areas of the Park are
used as grazing for sheep by
local farmers. The sheep will
reduce the diversity of
naturally occurring vegetation
by grazing but will add
nutrients to the soil through
dung.
Poynton Pool looking south east – note the reeds at the
water’s edge and the willow trees in the water on the left.
What evidence of ecological
succession can you see in
this photo?
A clear photo ‘through’ succession –
what stages can you see?