Introduction

Moorland is the predominant land-use of the North Pennines Natural Area. Moorland contains a mosaic of semi-natural habitats including dry heath, wet heath, blanket bog, flushes and acid grassland.

Blanket bogs are the most common of any semi-natural vegetation type in the North Pennines, estimated to cover over 58,000 ha (if modified bogs are included, 46,000ha if not). As a proportion of the figure Durham holds 39% and 33% respectively. Wet heath is a much scarcer habitat in the North Pennines due to unsuitable climatic conditions and management which has pushed the habitat towards dry heath. Most wet upland heath is found in the west of the pennines.

Blanket bog and upland wet heath share many floristic characteristics which can make them difficult to differentiate, but which separates them both from upland dry heath. All three habitats contain dwarf shrubs (especially heather and cross-leaved heath), but bog mosses (Sphagnum) are rare or absent on dry heath. The main difference between active blanket bog and wet heath is whether peat-formation is taking place. This is due to three main species � Sphagnum capillifolium, S. papillosum and Erioporum vaginatum.

The difficulty in separating these habitats on the ground is exacerbated by the deterioration of habitats through inappropriate management. Degraded wet heaths may well appear as dry heaths as they loose their Sphagnum, and the flora of blanket bog which has been modified through burning, grazing or drainage, may take on the characteristics of wet or dry heath. The peat-forming Sphagnum species disappear and the wet heath species like Sphagnum compactum can become very abundant.

The least modified areas of blanket bog display vegetation that can be similar to that of the raised mires that may once have occurred in the lowlands. Because their development requires rain, they are found on plateaux and gently convex summits all over the wetter parts of the Natural Area.

In terms of the National Vegetation Classification, the main blanket bog communities in the North Pennines typically, include M18, M19, M20, and bog pool communities M2 and M3.

The majority of wet heath in the North Pennines is the M16 community, although very little wet heath is found in Durham.

Active blanket bogs are those still accumulating peat beneath a relatively pristine vegetation. These are a priority habitat within the Habitats Directive and the UK BAP. Some of the best examples of active blanket bog in the world are found in the UK, although many of those in the North Pennines are highly modified by man's impact.

Active bogs are not only an extremely important resource for biodiversity, but the accumulation of peat is also a way of sequestrating carbon. The modification of bogs through drainage, burning and grazing not only impacts on biodiversity, but may also cause the release of large quantities of carbon into water courses and the atmosphere. Restoration of modified bogs, therefore, by blocking drainage grips, introducing sustainable burning and grazing practices has the potential not only to restore biodiversity, but to enhance the bog as a valuable carbon reservoir.

Blanket bogs, and the drier upland heaths into which they grade further east, are often a crucial part of the upland farming system. The heather which dominates most of their area is very important fodder for sheep, especially in winter when more nutritious grasses are largely unavailable. It is also the major foodplant and nesting cover for red grouse, which in turn support the large Pennine sporting estates. Intensive management, especially for sheep, usually leads to ecological degradation of blanket bog.

Moorland drainage, or gripping, largely undertaken between the 1950s and 1970s with the intention of improving grazing has had a number of environmental consequences. Whilst there is no direct evidence that grazing improved as a result of this practice, there is much evidence of the environmental damage caused either directly or indirectly by gripping. This includes the following: disruption to natural hydrological processes, changes to bog vegetation, increased run-off and hence erosion of soils, increased sedimentation in water courses, increased water colour, loss of stock and young birds in overdeepened grips.

Burning can also contribute to bog degradation by reducing Sphagnum mosses. This is carried out principally to optimize food availability and habitat quality for red grouse. In some cases burning is also undertaken to improve agricultural grazings.

Although much of our blanket bog and wet heath is encompassed by designated sites in the North Pennines, and therefore subject to ongoing management agreements between landowners and Natural England, there are some areas of this habitat outside these designations. These potentially are at greater risk of degradation but can be targeted for positive land management schemes such as Environmental Stewardship. The North Pennines AONB Partnership project, Peatscapes, has identifies such areas.

The round-mouthed whorl snail (Vertigo genesii) English population was thought to be restricted to wet flushes on Widdybank Fell in upper Teesdale. The snail has been found every time the site has been revisited since its discovery in 1979. The population appears to be healthy with juveniles found on recent surveys. A single snail has also been found in flushes of a different type, suggesting that it is not restricted to these flushes as previously thought. A recent discovery near Malham Tarn, North Yorkshire by Adrian Norris (British Wildlife, June 2006 edition) means there are now two distinct populations within England . In Scotland it is frequently recorded around the Blair Atholl area in Perthshire and has also been recorded farther north on the Black Isle at the lower altitude of 90 m.

Current or recent activity

Project work

The Peatscapes Project, managed by the North Pennines AONB Partnership, started in 2006 and has completed a scoping study of peat extent and grip blocking in the north pennines. Work is now starting on pilot grip blocking schemes and a number of research programmes.

Natural England and its predecessor English Nature, has been working with land managers for over 15 years to encourage sustainable land management of the peatland resource. This has included schemes that reduce grazing intensity and block grips. Much of this work was developed in Teesdale. More recently it has developed in conjunction with the Moorland Association an agreed template for the management of burning on moorland. It is currently working with the Peatscapes project to maximise the potential of the resource available for blocking grips.

Research

Vertigo genesii survey at Widdybank

Threats

•  Continued gripping of wet moorland for drainage. Although this is illegal without consent on SSSIs, some gripping still takes place today, although most of this is confined to opening up existing drains.

•  Existing grips continue to drain formerly wet moorland, halting the formation of peat, and damaging the ecosystem.

•  Overgrazing is a problem on former wet moorland which has been gripped, leading to formation of species poor acid grassland.

•  Badly managed or too intensive heather burning can reduce biodiversity resulting in a monoculture of heather. It may also lead to an imbalance of age classes within the heather, favouring younger growth forms and reducing the extent of mature or degenerate stands. Combined with over-grazing this treatment can lead to domination by bracken or purple moor-grass.

•  Burning is always damaging to unmodified blanket bog regardless of whether or not it is well managed. Burning damages the peat-forming species, which are replaced by other species.

•  Recreation pressure - peat is a sensitive substrate. It is unable to withstand excessive use, and can erode severely as a result.

•  The impact of climate change is potentially a major threat to peatlands and some of the species it supports, particularly those at the southern or lower altitudinal edges of their range, including the round-mouthed whorl snail, an isolated ice age relict.

Objectives Restore all SSSIs and Local Sites designated for blanket bog or upland wet heath to favourable condition through appropriate management. Improve knowledge of the extent and status of blanket bog and upland wet heath through survey, research and monitoring. Maintain the current extent and distribution of blanket bog and upland wet heath ensuring no further loss or degradation. Raise public awareness and understanding of the biodiversity value and importance of blanket bog and upland wet heath habitats. Increase the extent of blanket bog and upland wet heath through restoration or habitat creation. Protect and maintain the existing populations of round-mouthed whorl snail on all known sites.