Wildlife | wetlands in berkshire
Water moving through ecosystems forms part of the hydrological cycle, one of the most important natural cycles and is fundamental to life. Through this cycle, rivers, lakes, marshes and other wetlands are integrally linked to each other. Any changes to one part of the cycle may have a major consequence to another.
Wetlands are defined by the as areas of "marsh, peatland and water, whether natural or artificial, permanent or temporary, with water that is static or flowing, fresh or brackish". It is the predominance of water in these habitats which characterise wetlands. Wetlands vary widely due to differences in climate, geology, topography, hydrology, water chemistry and vegetation. Other factors such as human disturbance can also influence the type and the extent of wetlands.
Rivers are drainage systems through which water flows from the catchment to the sea. Their nature reflects the climate and the effects of geology on the catchment. Riverine habitats are affected by human activities which degrade the ecological value of the habitat. Within England and Wales there is approximately 40,000km of running water.
The Thames Path follows England's best known river for 294 km. On its way the Path passes peaceful water meadows rich in wildlife, historic towns and many lovely villages, including those in Berkshire.
Lakes occur in depressions in the landscape. Natural lakes are more commonly found in north Wales, and the north and west of England. Lakes are generally classified according to their nutrient status. There are five main types of lake found in England and Wales:
- Dystrophic - very poor in nutrients, especially nitrogen;
- Oligotrophic - poor in nutrients;
- Mesotrophic - intermediate level of nitrogen;
- Eutrophic - nutrient rich;
- Marl - rich in calcium.
Each type of lake supports its own characteristic community of plants and animals. The communities found in these lakes are generally more diverse than similar habitats in recently constructed gravel pits and reservoirs.
There is evidence that acidification from the deposition of sulphur dioxide (produced from the combustion of fossil fuels) was beginning to affect the quality of some lakes in England and Wales in the 19th century. The nutrient state of some lakes was affected by forest clearance in the Bronze Age (approximately 3,000 to 5,000 years ago). Studies have shown however, that the quality of standing waters have deteriorated at a greater rate in the 20th century than ever before.
Ponds are small water bodies both natural and man-made. About 95% of all standing waters in Britain are less than one hectare in size. Over the last century there has been a decrease of about 75% in the number of ponds in Britain. Part of this loss can be attributed to natural succession, but other major causes include infilling, land drainage and changes brought about by pollution.
All lakes, ponds and reservoirs are temporary features in the landscape. Eventually, the lake will fill with sediment and become swamp, and over time this itself will become woodland. This process may take many thousands of years for large lakes or only a couple of years for small ponds.
Reedbeds are peatlands which receive their nutrients by a combination of rainfall and inputs from soil water and groundwater's. Currently there are 750 Sites of Special Scientific Interest (SSSI's) in England which contain fen vegetation with Norfolk containing the largest number (80).
Reedbeds are a type of fen vegetation which has very few plant species. They are however, one of the most important wetland habitats for birds in England and Wales. One such project has been successful on Berkshire at Maiden Erleigh lake.
Wetlands are vulnerable to change from a variety of sources. The principal problem facing wetlands is from drying out. There are many causes for wetlands to dry out. Changes in climate is one long-term consideration. Drier conditions cause the peat to dry out and it then becomes susceptible to wind erosion. As the water levels drop, the species that are associated with wet habitats are replaced by ones which prefer drier conditions. More direct impacts come from human activity. These include drainage for agriculture and forestry, the construction of flood defences and excessive abstraction of groundwater and surface water. Nutrient enrichment leads to a change in water chemistry and this can directly affect the species of plants that grow in an area.
The decline in the number of ponds and wetlands has to some extent been offset by an increase in the number of flooded gravel pits and reservoirs, which provide open water and marginal wetland habitats.
Wildberks Wetland Management link to learn about conservation management of wetland habitats, such as ponds, rivers and ditches for wildlife.
Marsh Plants found in Berkshire.
Water Plants found in Berkshire.
summary of wildlife you may see in and around Berkshires wetland
Wildfowl & Wetlands Trust Working to save wetlands for wildlife and people
The Environment agency Government agency monitors and legislates water and environmental issues across England and Wales.