The Flora of Wilden Marsh
It can be a mistake for people with or without historical knowledge of a site’s uses to assume too much about its current value. The number of people living around Wilden Marsh that think the area is an under managed industrial wasteland surprises me. People have long memories and will often recall the dark days of industrial dereliction and misappropriation of lands along the Lower Stour Valley. Thankfully, the days of heavy industry being able to dispose of its troublesome waste legally on the Wilden wetlands have passed. The marsh still suffers from treated sewage effluent inflow, land drainage runoff, and all manner of rubbish floating down the River Stour to the River Severn, but at least things are being done to minimise the effects of these types of pollution; although, well meaning efforts do tend to progress slowly. It can be a mistake rushing towards decisions without proper consideration of their likely positive and negative effects.
Many times I have stood on surrounding hills, inspecting the marsh through binoculars, when people have approached me with their views of what is happening down there on the marsh. The majority of these people were not aware of my connection to the marsh, so our conversations gave me an interesting insight into people’s perceptions of the Reserve; these range from: they ought to to do something with that unused land – build houses on it, perhaps; someone is making a packet from all the trees that are being felled; I’m going to complain to the council about the horrible flies breeding in that fetid wasteland; those poor cows have been abandoned – and it goes on and on a similar vein. Wilden Marsh is a highly and expertly managed site, and the fact that some people can’t see this, I think, is a credit to our comprehensive and well researched management plan.
The reserve’s most important habitats for botanical and nature conservation exist within a complex matrix of floodplain wetlands – ie. marshy grassland and mire, mesotrophic fen/ swamp, wet woodland (alder and willow carr) and open water (ditches, pools, scrapes). Other habitats such as dry broadleaf woodland, dry mesotrophic/acidic grassland and scrub are considered to be of secondary importance.
The important vegetation types are mesotrophic fens and damp neutral grassland, along with transitions between these and areas of carr. The flora includes many species which are rare or uncommon in Worcestershire, notably Marsh Cinquefoil, Marsh Pennywort (Hydrocotyle vulgaris), Fen Bedstraw (Galium uliginosum), Marsh Valerian (Valeriana dioica), Marsh Arrowgrass (Triglochin palustris), Lesser Reedmace, Sea Club-rush (Scirpus maritimus), Star Sedge (Carex echinata) and Lesser Tussock Sedge. Tall fen vegetation in the centre of the site has an especially rich flora with an abundance of Lesser Water Parsnip, Great Water Dock and commoner tall helophytes. Parts of the neutral grassland have flourishing colonies of Southern Marsh Orchids progressing further along the northern marsh each year; these have now reached the swamp at the far north of the site. Pollarded Crack Willow (Salix fragilis) and White Willow (S.alba) line some of the ditches. The two main areas of carr woodland are dominated by Alder (Alnus glutinosa) and Crack Willow. Scrub, mainly of Grey Sallow (Salix cinerea), invades the marshy grassland near some of the carr.
The highest quality marshy pastures occur in the northern compartment. These tend to be complex mosaics of rush pasture with localized transitions to acidic mire communities. The dominant vegetation is a tussocky mix of soft and sharp-flowered rush (Juncus acutiflorus) interspersed with grass sward of Yorkshire fog (Holcus lanatus) and bent grasses (Agrostis sp.).
Sedge or reed-dominated vegetation is dispersed throughout the reserve, but is prominent along the margins of drainage ditches or where these have become partially blocked – particularly to the south in wood pasture compartment and northern section bordering the settlement lagoon, where there is deep (and dangerous) silt. Though not as rich in plant species as the marshy grasslands, this habitat supports a range of emergent and semi-aquatic plants, the dominant species of which include lesser pond sedge (Carex acutiformis), reed sweet-grass (Glyceria maxima), reed canary grass (Phalaris arundinacea) and, locally, common reed (Phragmites australis), reed mace (Typha latifolia) and lesser reed mace (Typha angustifolia). Characteristic broad-leaved herbs are water mint (Mentha aquatica), tufted forget-me-not (Myosotis laxa), common skullcap (Scutellaria galericulata), lesser water parsnip (Berula erecta), marsh speedwell (Veronica scutellata), marsh marigold (Caltha palustris). Among the scarcer plants are: wood club-rush (Scirpus sylvaticus) and bladder sedge (Carex vesicaria) – both uncommon in Worcestershire; and the local marsh willow-herb (Epilobium palustre). Tall fen/swamp vegetation on this site is prime habitat for wetland birds such as sedge warbler (Acrocephalus schoenobanus) and water rail (Rallus aquaticus) and excellent for dragonfly species.
Wet Woodland – Alder Carr, Willow Carr and Sallow Scrub
There are areas of wet woodland where alder forms the dominant canopy tree. Mostly in the form of coppice woodland, the ground flora here comprises shade tolerant species including ferns and mosses, but also tracts of lesser pond-sedge swamp. Characteristic plants occurring include: creeping jenny (Lysimachia nummularia), yellow loose-strife (L. vulgaris), black-currant (Ribes nigrum), red-currant (Ribes rubrum), and gypsywort (Lycopus europaeus). Unfortunately, however, much of the field layer has been overrun by invasive Himalayan balsam (Impatiens glandulifera) and nettle (Urtica dioica), due to drying out of the peripheral parts of the reserve, as a result of a reduced ground-water table over recent years. Though it contains similar field-layer flora, willow carr is of generally lesser botanical importance, and sallow is invasive on the sedge-swamp at the southern end of the reserve.