Conservation Management Of Water In Raised Mires

And Lowland Wet Grasslands Essay, Research Paper

Introduction Wetlands make up 6% of the earth¹s land surface and in the past, people had misconceptions about them. The only policy for management was to drain them, but nowadays, the emphasis is on protection. A wetland has a water level high enough to force vegetation to survive for a significant time in anaerobic conditions. Britain has relied on land drainage to become agriculturally productive and habitable; 61% of its agricultural land has been drained. Wetlands though are amongst the most fertile ecosystems on the planet, providing numerous advantages to humans, such as the ability to cleanse water, remove pollutants, and provide peat, an organic fuel. They also provide fish, food, and stores for floodwater. This report aims to concentrate on the water requirements of two wetlands, lowland wet grasslands and the raised mire. Lowland wet grasslands, such as the Somerset Levels, include wet meadows, a traditional farming system from the 16th century. Their decline began with the quickening of the pace of conversion to arable land coupled with intensified land management. Britain originally had 1,200,000 hectares of wet grassland, but this is now only 220,000, of which only 20,000 is agriculturally unimproved of a high conservation value. To save this ecosystem, a positive and sympathetic water and land management plan is needed (RSPB). Undisturbed raised mires are ombotrophic peats fed by precipitation and the mire surface is isolated from the regional water table. Western Europe has very few undisturbed mires left; in Britain, 98% have been transformed and utilised leaving only 1170hectares remaining. Positive action is needed to save them. Water requirements to conserve the wetlands Certain water requirements need to be met to conserve these ecosystems. Most wetlands have been lost through drainage, and one being drained is unhealthy and in decline, and can only be restored by restoring its original water regime. In the case of wet grasslands, drainage, intensified land use, conversion to arable land and river engineering have all led to their decline. Wet meadows are traditional Œflowing¹ systems with an intentionally high winter water table so they could be used in early spring for grazing. They were then drained before being Œdrowned¹ again later. Wet grasslands need the water table near the surface for a significant period of the year. The major threat facing them is the dropping water table in surrounding land, making it hard to keep the necessary high water levels in the wet grassland. Raised mires face threats from agricultural reclamation, afforestation, drainage and especially peat extraction. The latter is the most serious, as peat mining can irreversibly damage the underlying substrate below the mire. To conserve a raised mire, a high water level at all times is of paramount importance. In conclusion, a high water level is needed to conserve these ecosystems, but this is exactly what other parties with interests in wetlands don¹t want.Water requirements of competing land users Farming is the biggest threat to wetlands in this country, through conversion of land and land intensification. When drained, wetland soils are amongst the most fertile in the country, comparable with fen soils. Those in the Somerset Levels would be Grade One soils if not for the late frost. Farmers who have not drained their land feel they are being deprived of an opportunity that others have already taken advantage of to appease conservationists. Farmers need low water levels so crop roots don¹t have to endure unnecessary anaerobic conditions, and often to achieve this land has to be protected by levees and pumped dry. Intensive crops need a water level up to 1.5metres below that found in wet grasslands. In the case of raised mires particularly, the extraction of minerals such as phosphorus, along with gravel, coal and peat is the biggest threat. Peat is a very valuable commodity, not only as a fuel but as a raw material for waxes, cellulose and tar, but when this is mined, the wetland is often damaged irreversibly. Like other competing land uses such as industry, timber production and highway building, the major requirement is for the land to be dry. Every land user surrounding a wetland wants a drop in water levels so that the land can be used for something else, in their opinion more valuable. Wetland management The losses to wetlands through human exploitation are not necessarily going to be replaced by processes of natural recovery, and if peat is mined or dries out, recovery may not be possible. To combat the multitude of problems, some sort of management is needed to protect our wetlands, especially those of national importance. Making people aware of the losses is one thing, but there has been an unfavourable view of wetlands as places where diseases and evil exist. The population needs to be persuaded that wetlands are beneficial and need conserving, as public pressure is a strong ally to have on the side of conservationists. Another requirement is for sensitively directed active management to halt or reverse declines already taking place. The ideal of a conservationist would be to control all hydrological influences over the site so it could be properly managed, but this is almost impossible to achieve. Before this though, each individual site needs to be appraised, and all existing wetland characteristics should be understood. To sum up, the general awareness that a problem exists with our wetlands needs to be translated into management and conservation strategies that actually work. Certain management schemes can be applied to both wet grasslands and raised mires to protect them. The main problem is drainage, so all existing drainage ditches, etc. should be prohibited, blocked and infilled. If sites have already lost water, one solution is to use drainage water from other areas, such as urban run-off, water being used to replenish the wetland if it is of the right quality. The problem of surrounding land users draining their land is more difficult to solve, but hydrological buffer zones could be used to keep wetland water levels high. Industrial and urban development should also be excluded from wetland sites, and the government should introduce legislation to enforce this so only projects in the national interest get the go ahead. The government could become a major player in conservation. A scheme similar to that governing the pollution of rivers by industry could be rigorously enforced so as to stop people draining and damaging the wetlands. This means that the government also needs to be convinced that the sustainable development of wetlands is a good thing. They could then set up bodies of control to influence management and development of sites. In Northwest Germany, many raised mires now have legal protection to prevent their loss. To be conserved, they must be protected in their entirety and desiccation avoided at all costs. For this, there needs to be sufficient flow of water to keep a high water level all year round. One possible way to do this is to use dams to keep the water in. The exploitation of peat for fuel must also be stopped. A growing trend recently has been the planting of trees on mires, but this is very harmful as they intercept a lot of rainfall. The planting of trees on wetlands should be halted if conservation is desired. Compared to raised mires, wet grasslands are more difficult to manage, and

they are very costly to do so due to their complexity. Water availability and absence of drainage is crucial. From October to March, water levels should be near the surface leading to shallow flooding, and a traditional management system is also needed, such as extensive grazing. The RSPB is the main conservationist for wet grasslands. They have purchased numerous sites throughout the UK at a great cost to be protected. Sites should be at least 200 hectares, but this can cost £1,000,000 to acquire and £200,000 to manage each year. In total, they now manage 3025 hectares bought at a cost of £3,880,000. This ecosystem is difficult to manage. Existing schemes of management and their success The international Ramsar Convention meant that the British government had to protect its prime wetlands, and they hoped to achieve this through introducing legislation to implement management strategies. The basic scheme was for the Nature Conservancy Council to introduce Sites of Special Scientific Interest (SSSI¹s), acknowledging particular wetlands as too important to be lost. For example, the Somerset Levels contains 10 grassland SSSI¹s covering 6100 hectares. In 1981, the Wildlife and Countryside Act was passed, later updated, to implement policies for SSSI¹s. But this legislation has come in for heavy criticism, as Lord Mustill said when relating to problems with drainage occurring on an SSSI: “It needs only a moment to see that this regime is toothless for it demands no more from the owner or occupier of an SSSI than a little patience. Unless the NCC can convince the Secretary of State that the site is of sufficient national importance to justify an order under section 29 – as we have seen, a task rarely accomplished – the owner will within months be free to disregard the notification and carry out the prescribed operations no matter what the cost to the flora etc. on the site. In truth, the Act does no more in the great majority of cases than give the NCC a breathing space within which to apply moral pressure, with a view to persuading the owner or occupier to make a voluntary agreement.” (Wet Grasslands: What Future? Page 22). The 1981 Act was totally inadequate in conserving wetlands. Firstly, it gave no law to protecting SSSI¹s, simply guidance, and damage continued. The whole Act relied entirely on voluntary co-operation of farmers in order to protect the countryside, no proposals could be enforced. In fact, the NCC had to pay farmers compensation for not draining land. This Act was not very successful. In 1987, the Ministry of Agriculture, Fisheries and Food introduced the Environmentally Sensitive Areas scheme to halt wetland loss. Areas classed as ESA¹s have a one or two tier protection system with various requirements that farmers must meet, the farmers being paid for sticking to them. A third tier was added in 1992. Despite all Maff¹s efforts at a comprehensive scheme, it is still totally voluntary and can be terminated after five years. An improvement on the 1981 Act, it still has only had limited success. There is still no long-term security and effectiveness, and it¹s difficult to isolate small areas of land with a high water table while surrounding land is being drained. The cost effectiveness of the scheme is also being questioned, the uptake of tiers two and three appears discouraging, and damage is still occurring. From 1987-90, government grants helped to protect 45,000 hectares of agricultural land. This is a good idea, and although grants are increasing, infrastructure such as pumps, banks and sluices has seen no reduction in funds. So although more is now spent on conserving wetlands, even more is being spent on draining them. Other methods of management include countryside stewardship and even set-aside can possibly create new wet grasslands. In 1992, English Nature set up a programme to protect raised mires, but it mainly involved implementing measures for the effective after-use of mires after peat mining. It in no way tackled the original problem, only helped in regeneration. In Britain, there appears to be more efforts taking place to conserve wet grasslands than raised mires, so a wider participation in mire conservation is needed throughout the country. The US has a Œno net loss¹ policy, which works up to a point, but Germany has a more thorough policy, giving wetlands legal protection, such as the raised mires in Lower Saxony, making damage illegal. Britain still has a long way to go to reach this standard of conservation, and while legislation continues to be only in the form of guidelines, wetlands will still suffer losses.Conclusions for future policy If the British government is serious about conservation, policies must have the power to enforce what it recommends, and SSSI¹s need to have a legal standing meaning all damage is unlawful. The main aim for the future is to establish a way to relax drainage standards without putting human lives at risk. Farmers must also be made to manage wetlands positively. The framework in place from current schemes is a useful base to build on, an example being that 50% of the Somerset Levels is already managed by people with a definite conservation interest. If this can be increased and replicated elsewhere, and farmers¹ attitudes changed, there is no reason why wetlands cannot only be conserved, but flourish. There are a few recent developments which may affect wetlands. Profit orientated privatised water companies may lead to damage in the long-term, but this may be balanced by the increasing importance of the EC in British affairs. On the whole, Europe is more of a conservationist than Britain, and EC grants and legislation can help with the management of our wetlands. Finally, recent climate patterns have meant dryer summers in Britain, particularly bad for wetlands. Not only will they naturally dry up through falling water levels, but the need for water for agriculture to feed everyone may be so great that water is drained straight from the wetland to water the crops. These are all possibilities though, and at present, wet grasslands and raised mires are in a bad situation, and they need near total protection to prevent them disappearing.BibliographyDennison, M S & Berry, J F, 1993. Wetlands: Guide to science, law & technology. Noyes Publications; Park Ridge, N.J. Enact, Vol. 3 No. 1. Spring 1995 Gilman, K, 1994. 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