Brandon Marsh nature reserve

View of Grebe Pool, with the LaFarge aggregate processing centre in the background. The wind pump for irrigation of the reedbeds can also be seen.

There are eight main pools in the reserve, some of which are maintained to support specific flora or fauna. At the centre of the reserve is East Marsh Pool, the largest of the pools, which contains two islands. Tern Island is composed of gravel and pebbles which attracts certain species to breed here, notably common tern and little ringed plover. There are also a number of artificial rafts on the pool, again to induce common tern to breed; eight pairs did so in 2008.[13] Willow Island is much larger and more grassy, providing suitable areas for lapwing, common redshank and green sandpiper.[7] The existence of the islands helps to prevent the nests of species such as these being predated by foxes. There are three hides overlooking the pool. An artificial structure alongside the pool is designed to attract sand martins to breed, as they did when the gravel quarry was operational; this was successful for the first time in 2009, with eight nestholes occupied and over 40 young fledged.[10]

To the south lie Teal Pool and River Pool, created in 1983 when an earth dam was constructed between the two in order that Teal Pool retained water to provide habitat for dabbling duck species, which generally include common teal and mallard.[7] River Pool is a larger expanse of water popular with wading birds, especially redshank and greenshank.

Central Marsh and Pool is a diverse area where the main flora is common reed, reed sweetgrass, sedges, bulrushes and teasel. Willow trees are particularly important in this habitat as they have over 250 species of insect associated with them.[7] Alder trees support birds such as redpoll, siskin and various tit species.[8] Beyond Central Marsh lies West Marsh Pool, a small area of water surrounded by reedbed, where a number of dragonfly pools have been dug. Plants which thrive in damp areas, such as marsh marigold and meadowsweet, flourish here.

Adjacent to the visitor centre are three further pools. Grebe Pool is named for the great crested grebes which regularly breed there, whereas Goose Pool was used by the aggregate company for water storage, and as such the water level is very variable due to its unstable base. Swallow Pool was so named because it was formerly a favourite roosting area for swallows, although this is no longer the case.[7]

The main reedbed on the site is known as Newlands, an extensive area forming the eastern end of the reserve. Together with other areas in the West Marsh, the total area of reedbed is now around 25 hectares (62 acres).[14] A wind-powered water pump is currently installed to lift water from the flood plain to irrigate a further 9 hectares (22 acres) area near the Visitor Centre. This project is part of the UK Biodiversity Action Plan which has targeted the creation of 1,200 hectares (3,000 acres) of reedbed nationwide.[15] The reedbeds support a number of acrocephalid warblers such as the reed warbler, sedge warbler and marsh warbler as well as others such as grasshopper warbler, and it was the first recorded breeding site in the region for Cetti's warbler.[16] There is a long-term plan to have an endangered species, the Eurasian bittern, breeding here by 2014[17] and regular sightings of the species have already occurred, with up to three individual birds being sighted during late 2009.[10] A new hide overlooking Newlands, named after Brandon volunteer Ted Jury who died in 2009, was opened in 2014.[18]

New Hare Covert is woodland, mainly composed of oak, ash, larch and Scots pine. The area is managed for biodiversity purposes and provides habitat for numerous mammals, including muntjac, as well as woodland bird species. Between New Hare Covert and Swallow Pool there is also an area of grassland, which attracts numerous species of butterfly. The area also has a large population of small mammals such as common shrew, field vole and bank vole, which in turn attract birds of prey such as the common kestrel and short-eared owl.[7]

Horsetail Glade, as the name suggests, is home to a large area of giant horsetails. There are numerous willow species, and common spotted orchid grows here in the summer.[7]

Brandon Marsh has a very low risk of pollution[19] and as such the main threat from man has been from vandalism; in 2007, a fire started by youths destroyed a third of the Newlands reedbed.[20] This was the second time the reed bed had been targeted, the previous attack seven years earlier having occurred shortly after threats were made by animal rights activists protesting against a cull of ruddy duck.[21]

Most of the current threats to the biodiversity of the site are natural in origin. A perennial problem is the invasive Japanese knotweed, which shades out local plant species with its dense growth. Removing it is time-consuming as the herbicide used to control it has to be injected straight into the root system, to prevent it reaching other flora.[13] Alder trees are also at risk at the reserve, this time from a fungal disease caused by Phytophthora alni. Being water-borne, this infection could spread to all the alders on the site.[7] Another natural threat is that of the introduced Harlequin ladybird which was first identified at the site in June 2008 and is a severe threat to the native seven-spot ladybird population as it is such an effective aphid predator.[13] Mink are occasional visitors to the reserve, although humane traps are used in an attempt to control them. Mink are a serious threat to ground-nesting birds, and since they are strong swimmers, the nests on the East Marsh islands are vulnerable to them.[7]