The study area covers the extent of Northumberland National Park, ca. 1049km2 (NNPA, no datea), within northern England (Figure 2.1). NNP was designated as a national park in 1956 (NNPA, 2009). The climate in general terms is temperate maritime. However, there is a reasonably strong altitudinal gradient within the Park, with upland areas such as the Cheviot Hills reaching an
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altitude of over 488m (NNPA, no dateb). The highest point is the Cheviot itself at 815m (NNPA, no dateb). The lowest elevations (ca. 50m) are associated with the river valleys o the pa k s o th and north-eastern borders (NE, 2013b 2013c). In general, NNP experiences low mean temperatures and relatively high rainfall (>1100mm annual rainfall at the Cheviot) due to its altitudinal and latitudinal characteristics (NNPA, no dateb). However its easterly position and the location of the higher ground mean a fairly significant rain-shadow effect influences the lower hills (<900mm annual rainfall) (NNPA, no dateb). NNP has a history of extensive management.
About 70% of the Park is moorland, much of which is used for low input livestock farming (NNPA, 2009; no datec). In addition, about 20% of the Park is managed as commercial forestry plantations. Notable semi-natural vegetation communities within the Park include blanket and raised bogs (5%), dwarf shrub heath (7%) and unimproved acid grassland (20%) (NNPA, no datec).
The land covers within the Park are largely determined by the complex interaction of climate, topography, altitudinal gradient, soil type and human management (NNPA, 2009; no dateb; no datec).
The park also partially covers five National Character Areas (NCAs) (Figure 2.2). Each NCA is a distinct natural area …. defi ed a u i ue o i atio of la ds ape, iodi e sit , geodi e sit and cultural and economic activity (NE, 2013a). Such designations are useful in providing a deeper context to investigations, allowing more comprehensive, holistic conclusions and recommendations to be made (NE, 2013a). Some results and analysis in subsequent chapters are provided for these NCAs, specifically, their extents within the borders of NNP (areas of darker colour in Figure 2.2). The sections below provide a brief summary of the characteristics of each of the five NCAs.
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Figure 2.1: Land use/landcover of Northumberland National Park, UK Figure 2.2: National Character Areas Associated with NNP.
41 Cheviots
NNP covers 99% (361km2) of the NCA (NE, 2013b). The top of the Cheviot in the centre west of the NCA is the highest point (815m). Lower elevations are found in the deep narrow valleys that radiate from the central igneous cluster of the Cheviots (NE, 2013b). The minimum elevation is 50m in the College Valley to the north of the Cheviot Hills. The NCA is mainly upland. Mean elevation is 360m.
Because of its upland characteristics, the soils comprising the NCA are generally poor with a dominance of acidic peaty types (NE, 2013b). Better-draining acid soils occur on the steeper slopes of river valleys. Moorland (including heath and bog) dominates the area, much of which is grazed (NE, 2013b). The relatively small amount of enclosed farmland is mainly confined to the lower ground of the valley bottoms. The small amount of arable land that occurs within the NCA is confined to lower ground at its far northern tip. Large blocks of coniferous woodland occur on moorland to the south and east of the Cheviot Hills. However, smaller more scattered extents of more natural woodland types (e.g. oak, birch and alder) are found on the valley bottoms (NE, 2013b).
Cheviot Fringe
NNP covers only 3% (15km2) of the NCA (NE, 2013c). The maximum elevation of the NCA within NNP is 320m in the lower reaches of the Cheviot foothills which border its far western edge (NE, 2013c). Lower elevations of 50m are observed within the NCA along the far north-eastern border of NNP, where elevation drops to form the undulating to flat lowland farmland landscape that typically dominates the NCA to the east (NE, 2013c, pp. 5). Mean elevation is 189m. Although extents of semi-natural habitat types occur within the NCA, their distribution is limited. They include small, diffuse, patches of grazing marsh and semi-natural woodland types (NE, 2013c).
Much of the NCA within NNP is dominated by enclosed, relatively intensive agriculture, including quite a high proportion of arable land (NE, 2013c).
Northumberland Sandstone Hills (NSH)
NNP covers 15% (105km2) of the NCA (NE, no datea). The lowest elevations within NNP are 91m.
The highest point (443m) is Simonside to the east. Simonside is surrounded by the Simonside Hills (ca. >250m). Mean elevation is 246m. Weathering of the underlying sandstone bedrock creates thin, acidic, nutrient-poor sandy soils, particularly above 250m. These soils are associated with the
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moorland (particularly dry heath), which covers about 50% of the NCA within NNP (NE, no datea &
Figure 2.1). Grazing occurs on much of this moorland (NE, no datea). However, relatively productive soils supporting more intensive agriculture (including arable) in lowland areas also comprise quite a high proportion of the NCA within NNP (Figure 2.1). Fairly extensive conifer plantations occur within the area.
Border Moors and Forests (BMF)
NNP covers 39% (499km2) of the NCA (NE, 2013d). BMF essentially encompasses an upland plateau dissected by wide shallow valleys (NE, 2013d). The elevation of the NCA within NNP ranges from 101m in the valleys up to 524m in north-western areas next to the border of the Cheviots NCA. Mean elevation is 264m.
The wet upland characteristics of the area mean that approximately 70% of soils are comprised of poorly draining wet very acid types with peaty top layers (NE, 2013d). These support the moorland (including bogs and heaths) that dominates much of the NCA (NE, 2013d). Extensive grazing occurs on much of this moorland. More productive soils are found at lower concentrations in the lower valleys, such as the North Tyne valley, which runs approximately west to east across the centre of the NCA. This is evidenced by the relatively high concentration of enclosed farm land that occurs in the area (Figure 2.1). The small extents of arable land that occur within the NCA are concentrated within this area (NE, 2013d). Extensive conifer plantations also lie within the NCA, particularly to the south (Figure 2.1). Smaller, more diffuse distributions of more natural woodland types also occur (NE, 2013d).
T e Gap a d Had ia s Wall TG
NNP covers 16% (70km2) of the NCA (NE, no dateb). The elevation of the NCA within NNP ranges from 139m to approximately 300-350m on the outcrops of the Whin Sill, which generally runs east to west across the north of the area. The NCA is generally lowland. Mean elevation is 223m and the NCA becomes increasing low and flat to the south, where more productive soils occur and more intensive farming dominates (including quite a high proportion of arable land) (NE, no dateb). Moorland largely occurs in the more upland north, associated with the less fertile, more acidic soils that are present. Patches of conifer plantation and more natural woodland types are scattered throughout the NCA.
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