Aims
- To improve the condition of the floodplain grassland and marsh
- To promote the value of the habitats and secure the involvement of local people in their conservation
Introduction
Floodplain grassland is typically found in river valleys and represents those low-lying grasslands which are flooded by a river in periods of high rain or high tides, and where the drainage is impeded. Traditionally these grasslands were managed by grazing, mowing, or both.
Marsh is a less specific term which generally refers to taller, infrequently managed vegetation, also occurring in areas with impeded drainage, such that the water table is at or above the ground surface for much of the year. It may include ditches and ditch side vegetation.
Reed beds are wetlands dominated by stands of Common Reed, where the water table is at or above ground level for most of the year.
These three habitats have been included within one Action Plan in Waltham Forest. This is because floodplain grassland, marsh and reed bed in the borough are rare, closely related and face similar issues.
Nearly all of this habitat is found on Walthamstow Marsh, with smaller areas on the nearby Essex Filter Beds. Prior to the 20th century Walthamstow Marsh was all floodplain grassland with a hay crop being taken on about 1st August after which the land was grazed until April. Over the years since it has suffered from the cessation of grazing and development of a coarser vegetation. River 'improvements' and urbanisation of the area have brought about changes to water levels which have contributed to a drying out of Walthamstow Marsh.
Following the decommissioning of the filter beds a diverse range of habitats has developed whose maintenance requires constant management.
It is currently difficult to define and apportion the extent of the different habitats on the marsh as they are drier than they should be. This plan therefore relates to what is considered desirable, the present condition of the habitats being a transitional (sub-optimal) phase.
Nationally and locally there has been a very severe decline in the amount of floodplain grassland over the last 100 years. There are approximately 432 hectares in London, 8.9 ha of which are in Waltham Forest.
Marshland within London is now relatively rare and fragmented, a picture mirrored nationally and throughout Europe. There are approximately 273 hectares of marshland in London with an estimated 16.5 ha in Waltham Forest.
There are approximately 43.5 hectares of reed bed in London, 7 ha are reported to be in Waltham Forest. Reed is common throughout much of London but is rare in stands of more than half a hectare. It is the larger stands which are most valuable as they support correspondingly greater numbers of birds and invertebrates.
Both Walthamstow Marsh and Essex Filter Beds present excellent educational opportunities about these habitats, because of their location and the range of habitats and issues present.
Current Status
These habitats are almost wholly restricted to Walthamstow Marsh in the West of the Borough, which is a nature reserve and a Site of Special Scientific Interest. A small amount also exists on the nearby Essex Filter Beds. Smaller areas of reed can be found at Banbury Reservoir and some of the larger ponds within Epping Forest.
Much of the boroughs floodplain grassland is currently too dry and resembles damp neutral grassland, having a damp but quite well drained meadow flora, which results from higher winter water levels which drop rapidly in early summer. The habitat is currently species-rich meadow with Black knapweed, Agrimony and a rich array of grassland species including Yellow oat-grass (Trisetum flavescens). Parts of the marsh habitat intergrade in to it and contain species more typical of the floodplain grassland as it should be e.g. Ragged-robin (Lychis flos-cuculi) and Cuckoo-flower (Cardamine pratensis). A special feature of the damper areas is the Adder's-tongue Fern (Ophioglossum vulgatum). The grassland is also rich in invertebrates such as the Common Blue butterfly (Polyommatus icarus), Roesel's Bush-cricket (Metrioptera roeselii) and the Long-winged conehead (Conocephalus discolor).
Marsh comprises a rather diverse range of vegetation communities. Common constituents of the vegetation are Common Comfrey (Symphytum officinale), Meadowsweet (Filipendula ulmaria) and various sedges. Other plants form small stands within this. Adder's-tongue Fern is widespread but inconspicuous. Yellow Loosestrife (Lysimachia vulgaris), Marsh dock (Rumex palustris) and Meadow-rue (Thalictrum flavum) are locally rare plants. Low summer water levels have assisted the invasion of plants such as Michaelmas-daisy (Aster spp.) and Bramble (Rubus fruticosus) in to marshland areas.
Sedge warbler and Reed bunting are common and Snipe are present in winter on floodplain grassland and marshland. The marsh areas are good for dragonflies and Soldier-flies, which frequent ditch sides. This is also where the very rare Creeping Marshwort (Apium repens) is found. Grass snake and Water vole are present along ditch sides together with Common Frog, Common Toad and Smooth Newt.
The filter beds are being used as a place to conserve rarer elements of the marsh's flora. Intensive moth-trapping here has revealed a very diverse range of species, many nationally or locally scarce.
The reed beds are slowly expanding in size on Walthamstow Marsh, and declining on Essex Filter Beds where management has favoured aquatic and marsh habitats. The quality of the reed beds is variable, depending on how wet the spring and summer months are. They provide the main habitat for the Reed Warbler and a number of uncommon moths. The Fen Wainscot occurs at the Essex Filter Beds and is likely to occur on the marsh as well.
Specific Factors Affecting The Habitat
Cessation of cattle grazing on Walthamstow Marsh
Cattle grazing ceased in the early years of the 20th century and in the absence of other management coarser species began to take over. Apart from keeping the coarser species at bay, grazing disturbs the ground and helps to open up seeding opportunities and to distribute seeds around the marsh. Without grazing the vegetation tends to develop in uniform patches and less competitive species are lost.
Walthamstow Marsh is no longer part of a rural scene and so no local cattle herds are present. However cattle grazing is being re-instituted in Epping Forest and it occurs further up the Lea Valley in the Waltham Abbey area. Bringing grazing back to the marsh is therefore a feasible option. A carefully planned approach is being taken before re-introducing cattle, balancing issues of public perception, animal welfare, access and amenity.
Low water levels
Changes to river management over the last 50 years means that the river rarely floods nowadays and that ground water levels are lower than they would have been in the past, particularly in the spring and summer. To attain higher water levels an extra source of water needs to be found. Discussions about this are ongoing. At Essex Filter beds water levels are controlled by a pump but have to be carefully managed.
Natural Succession
With all three habitats succession to coarser vegetation and scrub is an issue. However current management is tackling this problem successfully, if slowly. Succession in the ditches is being managed by rotational clearance.
Invasive species
The wildlife of the ditches is threatened by aggressive introduced species such as Water Fern (Azolla filiculoides), Floating Water-pennywort (Hydrocotyle ranunculoides), Parrott's-feather (Myriophyllum aquatica) & Swamp Stonecrop (Crassula helmsii).
Amenity Use
Use of the marsh by pedestrians, cyclists and dogs has increased considerably over the last 15 years. It is speculative as to whether or not this has had a detrimental effect on the wildlife. Yellow Wagtail and Skylark have ceased to breed but this may be due to the increasing isolation of these species from other populations in the area. Trampling and dog faeces/urination causes negative but localised changes to the vegetation. Disturbance to wildlife is caused where people let their dogs in to the ditches. The new visitor centre and hide by the filter beds "The Waterworks" should increase visitor awareness and enjoyment of these habitats.
Current Action
Legal Status
Most of Walthamstow Marsh is owned by the Lee Valley Regional Park Authority with a small section (the triangle) owned by the London Borough of Hackney. The site was declared a Site of Special Scientific Interest in 1983 and is also a Lee Valley Park Nature Reserve. Creeping Marshwort (Apium repens) has recently been found on Walthamstow Marsh. This is protected by the European Union Habitats Directive and the Countryside and Rights of Way Act 2000.
The Essex Filter Beds are owned by the Lee Valley Regional Park Authority.
Management and restoration
These habitats owe their diversity to continued management. Whilst mowing is restoring much of the wildlife interest it will take the restoration of grazing to maximise the marsh's potential.
Mowing is currently undertaken on various areas of the marsh in order to maintain the species richness of the drier areas and to restore the flora of some of the wetter areas. Once an area is restored mowing can be switched to other, ranker areas of marsh. The triangle is not managed at the moment and succession to bramble and scrub is taking place. Mowing is an expensive option which also presents a problem of 'green waste' disposal.
Proposals to re-introduce grazing to the marsh are currently being explored by the Authority. A trial is being planned for 2003. A revised management plan is also being drawn up.
At the Essex Filter Beds scrub clearance and restoration of water level control is helping to restore the habitats.
Groups from the Lea Bridge Conservation Volunteers and the British Trust for Conservation Volunteers help to maintain the beds.
Research
An NVC survey of the marsh was carried out for English Nature in 2001. An Invertebrate Survey was carried out over 2000/2001 and revealed the presence of a varied and rich fauna, fully supporting the site's conservation status. The main gaps in knowledge of the site are for bats and fungi. Moths and Hymenoptera are also poorly recorded.
The flora of the Essex Filter Beds was surveyed in 1985 but a lot has changed since then although casual records have been kept. The fauna is less well recorded with the exception of Moths and Butterflies which were well recorded between 1994 and 2001.
Mechanisms targeting the habitat
Lee Valley Regional Park Biodiversity Action Plan
Walthamstow Marsh Management Plan
Waltham Forest Unitary Development Plan
Countryside Stewardship
Key species
Plants - creeping marshwort, adder's-tongue fern, ragged-robin, cuckoo-flower, yellow loos
Birds - reed bunting, sedge warbler, snipe, reed warbler
Mammals - water vole, bats
Invertebrates - dragonflies, soldier-flies, a picture-winged fly (Ancinia corniculata)
Reptiles - grass snake
Objectives, Actions and Targets
| Action | Target Date | Lead | Other Partners |
|---|---|---|---|
| Produce and implement a new management plan for WM | 2003 | LVRPA | *LBCV - re implementation |
| Produce and implement a new management plan for EFB | 2003 | LVRPA | *LBCV - re implementation |
| Produce and implement a Water Level Management Plan for WM | 2004/2005 | LVRPA | EA, TW, EN |
| Produce proposals for the re-introduction of grazing to WM | 2003 | LVRPA | DEFRA, EN, WM, LUF |
| Action | Target Date | Lead | Other Partners |
|---|---|---|---|
| Monitor favourable condition status (quadrats) | 2003/4 | LVRPA | |
| Monitor population of Creeping Marshwort | 2003 | LVRPA | EN |
| Other species monitoring | 2003 | LVRPA | Volunteers |
| Monitor water levels | 2003 | LVRPA |
| Action | Target Date | Lead | Other Partners |
|---|---|---|---|
| Visitor surveys to gather opinion on cattle grazing | 2003 | LVRPA | EN |
| Interpretation boards or leaflets | 2005 | LVRPA | LBWF, LRT, GH |
| Public awareness event | Annual | LVRPA | TW, WFBAPP |
| Promote use of Marsh as place of study for schools | Ongoing | LVRPA LRT | Lea Rowing Club & Leaside Canoeing Centre as bases. |
| Promote use of EFB (Waterworks) as place of study for schools | 2003 | LVRPA | |
| Put HAP on website | 2003 | LBWF |
