Presentation on theme: "Some Definitions : Just to remind you!"— Presentation transcript:
1 Succession A Case Study – Poynton Park and Pool – an arrested hydrosere
2 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.
4 Glossary of Keywords : another reminder!! SuccessionThe sequence of changes in a plant community as it moves towards a “seral climax”SereA stage in the development of plant communities towards climatic climax.Climax CommunityThe 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.PlagioclimaxWhen a plant community is permanently influenced by people – it cannot reach climax because of burning, grazing, deforestationPrimary succession or priseresBeginning on bare ground, or waterSecondary succession or subseresBeginning after the destruction of existing vegetationPioneer speciesThe first plants to colonise an areaSub climaxWhen vegetation is prevented from reaching its climax due to interruptions by local factors (e.g. soils)Arresting factorsThe factors that cause succession to be interrupted
6 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.
7 Poynton Park : a hydrosere in arrested succession. Image courtesy of Ordnance SurveyMacclesfield Borough Council manage the Park and the Pool which together cover an area of 21 hectares.Image from Google maps
8 Gardens of houses along Anglesey Drive arrest the natural succession by cutting back vegetation in their gardens.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.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.
10 Poynton Pool looking south east – note the reeds at the water’s edge and the willow trees in the water on the left.
11 What evidence of ecological succession can you see in this photo? A clear photo ‘through’ succession – what stages can you see?
12 Account for the characteristics of a chosen vegetation succession you have studied. (20 marks) Use these notes to help you ;What is succession?Which case study are you using? – Poynton pool – simple sketch to show the main features.Describe how Poynton pool differs from one area to another – how the succession is evident? – be logical go from stage 1 to stage4/5What affects the succession i.e what gives the pool its characteristics – grazing, human trampling, anglers, houses backing onto the lake.