Whitton Bridge Pasture
Encyclopedia
Whitton Bridge Pasture is a Site of Special Scientific Interest
(SSSI) in the unitary authority of Stockton-on-Tees
, England
. At 3.18 hectares (7.9 acres) it lies to the south of Whitton
village and north west of Stockton-on-Tees
. SSSIs are chosen by Natural England
, and Whitton Bridge Pasture was designated in 2004 because of its biological interest. It is one of 18 SSSIs in the Cleveland area of search.
The biological interest is focused on the species-rich
mesotrophic grassland
found across the site, which is actively maintained by grazing
. The species present are predominantly grasses, although herbs and orchids are also found. The area has been classified as MG5
under the British National Vegetation Classification
because of the species composition. The site is small and isolated, and therefore requires careful management to avoid damage caused by activity on neighbouring land.
, previously English Nature
, which uses the 1974-1996 county system
. This means there is no grouping of SSSIs by Stockton-on-Tees
unitary authority, or County Durham
which is the relevant ceremonial county
. As such Whitton Bridge Pasture is one of 18 SSSIs in the Cleveland area of search.
Whitton Bridge Pasture is nationally important for its species-rich
grassland
which is unimproved by fertilisers. This type of grassland—once common in the Tees lowland—is becoming increasingly rare with its associated species also becoming scarce. Whitton Bridge Pasture is one of only two remaining examples of this habitat in the Tees lowland area. The other example is Briarcroft Pasture
, an SSSI about 3 kilometres (1.9 mi) to the south, which was designated at the same time but is significantly smaller.
Under the British National Vegetation Classification
(NVC) Whitton Bridge Pasture is considered as mesotrophic grassland
because it represents well-drained and permanent pasture. In particular it is considered to be an MG5 community
because of the species present. MG5 is widespread in many lowland areas in England, Wales, and Scotland, particularly in the Midlands
. Whitton Bridge Pasture is predominantly subcommunity MG5c (Danthonia decumbens), however subcommunity MG5a (Lathyrus pratensis) is present with a substantially different species composition.
Located north-west of Stockton-on-Tees
and 500 metres (546.8 yd) south of the village of Whitton
, it is a small site of 3.18 hectares (7.9 acre) between a sewage works and Whitton Beck
. Topographically the site slopes north towards the stream from a height of 40 metres (131.2 ft) to less than 30 metres (98.4 ft). The underlying geology
of Whitton Bridge Pasture is responsible for shaping the species-rich community found on the surface. Glacial tills
and sands
are the prominent geological features resulting in a relatively base-poor soil, characteristic of glacial drift geology. The soils of MG5c (Danthonia decumbens) subcommunity are typically acidic.
Because Whitton Bridge Pasture is located in North East England
it experiences a climate that is different from the UK average. The North East receives on average 370 millimetres (14.6 in) less rainfall than the UK over a year. Similarly the North East has roughly 129 days each year with more than 1 millimetre (0.0393700787401575 in) of rainfall, more than 25 days fewer than UK average. Despite these differences the temperature is similar for both the North East and the UK, although the North East does have fewer days with air frost and more hours of sunshine per year.
and several other grass species at lower abundances. The dominant species are Red Fescue (Festuca rubra), Common Bent
(Agrostis capillaris) and Yorkshire Fog
(Holcus lanatus). The less abundant species of grass include, Crested Dog’s-tail (Cynosurus cristatus), Heath-grass
(Danthonia decumbens) and Cocksfoot (Dactylis glomerata). The subcommunity also has many broad-leaved herbs including Common Knapweed
(Centaurea nigra), Tormentil
(Potentilla erecta), Devils-bit scabious
(Succisa pratensis) and Betony (Stachys officinalis).
A second subcommunity (MG5a) is present and is characterised by the legume Meadow vetchling
(Lathyrus pratensis). Other species present in this subcommunity include Salad burnet
(Sanguisorba minor), Quaking grass (Briza media), Pignut
(Conopodium majus) and the Orchid species: Common Twayblade (Listera ovata) and Early Purple Orchid
(Orchis mascula). The subcommunity also contains Meadow barley
(Hordeum secalinum), a perennial
grass, which is a characteristic species of the Tees Lowland.
The two subcommunities of MG5, characterised by species rich grassland form a belt across the site, but they do not cover the whole site. Towards the north there is a community dominated by False oat-grass (Arrhenatherum elatius), a constant species in the MG1
and MG2
communities of the British NVC and therefore not typical of an MG5 community. At Whitton Bridge Pasture it is growing on alluvial soils located at the northern edge of the site, which have most likely been formed by Whitton Beck just to the north. A number of springs
at the site are associated with flushes of the Pale sedge
(Carex pallescens), which form small populations.
Natural England's role is to advise and help the owners manage Whitton Bridge Pasture effectively. To achieve this Natural England provides guidelines for each SSSI. Species-rich grassland, such as that found at Whitton Bridge, requires careful management for it to retain its high species diversity
. This means many activities are not allowed at the site including: ploughing, drainage
and the use of fertilisers, pesticides or herbicides.
Management of the site requires moderate grazing during the summer and autumn to help maintain the species diversity. This is because grazing removes each year's new growth which helps stop the site becoming dominated by vigorously growing
grasses. Such grasses would allow a build up of dead organic matter
, which together with the increased growth, would reduce the growth of less vigorous species. The overall effect would be a reduction in species diversity, which was one of the reasons for the SSSI designation. Trampling can be of benefit because it breaks up accumulated dead organic matter.
The small and isolated nature of the site makes it susceptible to damage from the surrounding area. For example herbicides, thought to be generally damaging for the species richness, could get onto the site from the drift of spray from surrounding fields. To help combat this the maintenance of mature hedgerows around the perimeter is encouraged. As of 2006 the condition of Whitton Bridge Pasture is described as favourable, which means that the land is being adequately conserved and any conservation objectives are being met, but that there is scope for enhancement of the site. The condition of the site was also described as favourable in 2004 and 2005 assessments. In the future it is hoped that the grazing regime will become more regularised and will be of high priority.
Site of Special Scientific Interest
A Site of Special Scientific Interest is a conservation designation denoting a protected area in the United Kingdom. SSSIs are the basic building block of site-based nature conservation legislation and most other legal nature/geological conservation designations in Great Britain are based upon...
(SSSI) in the unitary authority of Stockton-on-Tees
Stockton-on-Tees (borough)
Stockton-on-Tees is a unitary authority area and borough in the Tees Valley area of north east England, with a population in 2001 of 178,408, rising to 185,880 in 2005 estimates....
, England
England
England is a country that is part of the United Kingdom. It shares land borders with Scotland to the north and Wales to the west; the Irish Sea is to the north west, the Celtic Sea to the south west, with the North Sea to the east and the English Channel to the south separating it from continental...
. At 3.18 hectares (7.9 acres) it lies to the south of Whitton
Whitton, County Durham
Whitton is a village within the borough of Stockton-on-Tees and the ceremonial county of County Durham, England. It is situated to the north west of Stockton-on-Tees, near Stillington and Thorpe Thewles.-Landmarks:...
village and north west of Stockton-on-Tees
Stockton-on-Tees
Stockton-on-Tees is a market town in north east England. It is the major settlement in the unitary authority and borough of Stockton-on-Tees. For ceremonial purposes, the borough is split between County Durham and North Yorkshire as it also incorporates a number of smaller towns including...
. SSSIs are chosen by Natural England
Natural England
Natural England is the non-departmental public body of the UK government responsible for ensuring that England's natural environment, including its land, flora and fauna, freshwater and marine environments, geology and soils, are protected and improved...
, and Whitton Bridge Pasture was designated in 2004 because of its biological interest. It is one of 18 SSSIs in the Cleveland area of search.
The biological interest is focused on the species-rich
Species diversity
Species diversity is an index that incorporates the number of species in an area and also their relative abundance. It is a more comprehensive value than species richness....
mesotrophic grassland
Mesotrophic grasslands in the British National Vegetation Classification system
This article gives an overview of the mesotrophic grassland communities in the British National Vegetation Classification system.-Introduction:The mesotrophic grassland communities of the NVC were described in Volume 3 of British Plant Communities, first published in 1992, along with the...
found across the site, which is actively maintained by grazing
Grazing
Grazing generally describes a type of feeding, in which a herbivore feeds on plants , and also on other multicellular autotrophs...
. The species present are predominantly grasses, although herbs and orchids are also found. The area has been classified as MG5
British NVC community MG5
British NVC community MG5 is one of the mesotrophic grassland communities in the British National Vegetation Classification system. It is one of four such communities associated with well-drained permanent pastures and meadows.This community is widely distributed community though common only in...
under the British National Vegetation Classification
British National Vegetation Classification
The British National Vegetation Classification or NVC is a system of classifying natural habitat types in Great Britain according to the vegetation they contain....
because of the species composition. The site is small and isolated, and therefore requires careful management to avoid damage caused by activity on neighbouring land.
Reason for notification
SSSIs are designated by Natural EnglandNatural England
Natural England is the non-departmental public body of the UK government responsible for ensuring that England's natural environment, including its land, flora and fauna, freshwater and marine environments, geology and soils, are protected and improved...
, previously English Nature
English Nature
English Nature was the United Kingdom government agency that promoted the conservation of wildlife, geology and wild places throughout England between 1990 and 2006...
, which uses the 1974-1996 county system
Metropolitan and non-metropolitan counties of England
Metropolitan and non-metropolitan counties are one of the four levels of subdivisions of England used for the purposes of local government outside Greater London. As originally constituted, the metropolitan and non-metropolitan counties each consisted of multiple districts, had a county council and...
. This means there is no grouping of SSSIs by Stockton-on-Tees
Stockton-on-Tees (borough)
Stockton-on-Tees is a unitary authority area and borough in the Tees Valley area of north east England, with a population in 2001 of 178,408, rising to 185,880 in 2005 estimates....
unitary authority, or County Durham
County Durham
County Durham is a ceremonial county and unitary district in north east England. The county town is Durham. The largest settlement in the ceremonial county is the town of Darlington...
which is the relevant ceremonial county
Ceremonial counties of England
The ceremonial counties are areas of England to which are appointed a Lord Lieutenant, and are defined by the government as counties and areas for the purposes of the Lieutenancies Act 1997 with reference to the metropolitan and non-metropolitan counties of England and Lieutenancies Act 1997...
. As such Whitton Bridge Pasture is one of 18 SSSIs in the Cleveland area of search.
Whitton Bridge Pasture is nationally important for its species-rich
Species richness
Species richness is the number of different species in a given area. It is represented in equation form as S.Species richness is the fundamental unit in which to assess the homogeneity of an environment. Typically, species richness is used in conservation studies to determine the sensitivity of...
grassland
Grassland
Grasslands are areas where the vegetation is dominated by grasses and other herbaceous plants . However, sedge and rush families can also be found. Grasslands occur naturally on all continents except Antarctica...
which is unimproved by fertilisers. This type of grassland—once common in the Tees lowland—is becoming increasingly rare with its associated species also becoming scarce. Whitton Bridge Pasture is one of only two remaining examples of this habitat in the Tees lowland area. The other example is Briarcroft Pasture
Briarcroft Pasture
Briarcroft Pasture is a 1.76 hectare biological Site of Special Scientific Interest in Cleveland, England notified in 2004.-Reason for Notification:SSSIs are designated by Natural England, formally English Nature, which uses the 1974-1996 county system...
, an SSSI about 3 kilometres (1.9 mi) to the south, which was designated at the same time but is significantly smaller.
Under the British National Vegetation Classification
British National Vegetation Classification
The British National Vegetation Classification or NVC is a system of classifying natural habitat types in Great Britain according to the vegetation they contain....
(NVC) Whitton Bridge Pasture is considered as mesotrophic grassland
Mesotrophic grasslands in the British National Vegetation Classification system
This article gives an overview of the mesotrophic grassland communities in the British National Vegetation Classification system.-Introduction:The mesotrophic grassland communities of the NVC were described in Volume 3 of British Plant Communities, first published in 1992, along with the...
because it represents well-drained and permanent pasture. In particular it is considered to be an MG5 community
British NVC community MG5
British NVC community MG5 is one of the mesotrophic grassland communities in the British National Vegetation Classification system. It is one of four such communities associated with well-drained permanent pastures and meadows.This community is widely distributed community though common only in...
because of the species present. MG5 is widespread in many lowland areas in England, Wales, and Scotland, particularly in the Midlands
English Midlands
The Midlands, or the English Midlands, is the traditional name for the area comprising central England that broadly corresponds to the early medieval Kingdom of Mercia. It borders Southern England, Northern England, East Anglia and Wales. Its largest city is Birmingham, and it was an important...
. Whitton Bridge Pasture is predominantly subcommunity MG5c (Danthonia decumbens), however subcommunity MG5a (Lathyrus pratensis) is present with a substantially different species composition.
Abiotic
Stockton-on-Tees
Stockton-on-Tees is a market town in north east England. It is the major settlement in the unitary authority and borough of Stockton-on-Tees. For ceremonial purposes, the borough is split between County Durham and North Yorkshire as it also incorporates a number of smaller towns including...
and 500 metres (546.8 yd) south of the village of Whitton
Whitton, County Durham
Whitton is a village within the borough of Stockton-on-Tees and the ceremonial county of County Durham, England. It is situated to the north west of Stockton-on-Tees, near Stillington and Thorpe Thewles.-Landmarks:...
, it is a small site of 3.18 hectares (7.9 acre) between a sewage works and Whitton Beck
Stream
A stream is a body of water with a current, confined within a bed and stream banks. Depending on its locale or certain characteristics, a stream may be referred to as a branch, brook, beck, burn, creek, "crick", gill , kill, lick, rill, river, syke, bayou, rivulet, streamage, wash, run or...
. Topographically the site slopes north towards the stream from a height of 40 metres (131.2 ft) to less than 30 metres (98.4 ft). The underlying geology
Geology
Geology is the science comprising the study of solid Earth, the rocks of which it is composed, and the processes by which it evolves. Geology gives insight into the history of the Earth, as it provides the primary evidence for plate tectonics, the evolutionary history of life, and past climates...
of Whitton Bridge Pasture is responsible for shaping the species-rich community found on the surface. Glacial tills
Till
thumb|right|Closeup of glacial till. Note that the larger grains in the till are completely surrounded by the matrix of finer material , and this characteristic, known as matrix support, is diagnostic of till....
and sands
Sands
-Buildings:*Sands Casino Resort Bethlehem, a newly-opened casino resort in Bethlehem, Pennsylvania*Sands Hotel, a closed hotel/casino in Las Vegas, Nevada**Sands Atlantic City, a closed hotel/casino in Atlantic City, New Jersey...
are the prominent geological features resulting in a relatively base-poor soil, characteristic of glacial drift geology. The soils of MG5c (Danthonia decumbens) subcommunity are typically acidic.
Because Whitton Bridge Pasture is located in North East England
North East England
North East England is one of the nine official regions of England. It covers Northumberland, County Durham, Tyne and Wear, and Teesside . The only cities in the region are Durham, Newcastle upon Tyne and Sunderland...
it experiences a climate that is different from the UK average. The North East receives on average 370 millimetres (14.6 in) less rainfall than the UK over a year. Similarly the North East has roughly 129 days each year with more than 1 millimetre (0.0393700787401575 in) of rainfall, more than 25 days fewer than UK average. Despite these differences the temperature is similar for both the North East and the UK, although the North East does have fewer days with air frost and more hours of sunshine per year.
Biotic
The majority of the site is made up of species-rich grassland (subcommunity MG5c), which comprises three dominant species of grassGrass
Grasses, or more technically graminoids, are monocotyledonous, usually herbaceous plants with narrow leaves growing from the base. They include the "true grasses", of the Poaceae family, as well as the sedges and the rushes . The true grasses include cereals, bamboo and the grasses of lawns ...
and several other grass species at lower abundances. The dominant species are Red Fescue (Festuca rubra), Common Bent
Agrostis
Agrostis is a genus of over 100 species belonging to the grass family Poaceae, commonly referred to as the bent grasses...
(Agrostis capillaris) and Yorkshire Fog
Yorkshire Fog
Yorkshire Fog or Velvet Grass, Holcus lanatus, is a perennial grass in the Poaceae Family. 'Lanatus' is latin for 'wooly' which describes the plant's hairy texture....
(Holcus lanatus). The less abundant species of grass include, Crested Dog’s-tail (Cynosurus cristatus), Heath-grass
Danthonia
Danthonia is a genus of grass species. Grasses of this genus are sometimes referred to as oatgrass, but that common name is not restricted to this genus.Species include:*Danthonia alpina Vest*Danthonia cachemyriana Jaub. & Spach...
(Danthonia decumbens) and Cocksfoot (Dactylis glomerata). The subcommunity also has many broad-leaved herbs including Common Knapweed
Centaurea
Centaurea is a genus of between 350 and 600 species of herbaceous thistle-like flowering plants in the family Asteraceae. Members of the genus are found only north of the equator, mostly in the Eastern Hemisphere; the Middle East and surrounding regions are particularly species-rich...
(Centaurea nigra), Tormentil
Tormentil
Common Tormentil is a herbaceous perennial belonging to the rose family , also known as Septfoil or simply as "tormentil" .-Characteristics:It is a low, clumb-forming plant with slender, procumbent...
(Potentilla erecta), Devils-bit scabious
Succisa
Succisa is a genus of flowering plants in the Dipsacaceae family.Species include the Devil's bit scabious, Succisa pratensis....
(Succisa pratensis) and Betony (Stachys officinalis).
A second subcommunity (MG5a) is present and is characterised by the legume Meadow vetchling
Meadow vetchling
Lathyrus pratensis or Meadow vetchling, also known as the Meadow Pea and Meadow pea-vine, is a perennial legume that grows to 1.2 m in height....
(Lathyrus pratensis). Other species present in this subcommunity include Salad burnet
Salad Burnet
Sanguisorba minor is a plant in the family Rosaceae that is native to western, central and southern Europe; northwest Africa and southwest Western Asia; and which has naturalized in most of North America...
(Sanguisorba minor), Quaking grass (Briza media), Pignut
Conopodium majus
Conopodium majus is a small perennial herb, whose underground part resembles a chestnut and is sometimes eaten as a wild or cultivated root vegetable....
(Conopodium majus) and the Orchid species: Common Twayblade (Listera ovata) and Early Purple Orchid
Early Purple Orchid
Orchis mascula, the Early Purple Orchid, is a species of orchid in the genus Orchis.-Etymology:The specific name is derived from the Latin "masculus", meaning "male" or "virile" and it should refer to the robust aspect of this species or to the shape of the tubers, similar to a pair of...
(Orchis mascula). The subcommunity also contains Meadow barley
Hordeum
Hordeum is a genus of about 30 species of annual and perennial grasses, native throughout the temperate Northern Hemisphere, temperate South America, and also South Africa....
(Hordeum secalinum), a perennial
Perennial plant
A perennial plant or simply perennial is a plant that lives for more than two years. The term is often used to differentiate a plant from shorter lived annuals and biennials. The term is sometimes misused by commercial gardeners or horticulturalists to describe only herbaceous perennials...
grass, which is a characteristic species of the Tees Lowland.
The two subcommunities of MG5, characterised by species rich grassland form a belt across the site, but they do not cover the whole site. Towards the north there is a community dominated by False oat-grass (Arrhenatherum elatius), a constant species in the MG1
British NVC community MG1
British NVC community MG1 is one of the mesotrophic grassland communities in the British National Vegetation Classification system.It is a very widespread community throughout the British lowlands...
and MG2
British NVC community MG2
British NVC community MG2 is one of the mesotrophic grassland communities in the British National Vegetation Classification system.It is a localised community found only in northern England...
communities of the British NVC and therefore not typical of an MG5 community. At Whitton Bridge Pasture it is growing on alluvial soils located at the northern edge of the site, which have most likely been formed by Whitton Beck just to the north. A number of springs
Spring (hydrosphere)
A spring—also known as a rising or resurgence—is a component of the hydrosphere. Specifically, it is any natural situation where water flows to the surface of the earth from underground...
at the site are associated with flushes of the Pale sedge
Carex
Carex is a genus of plants in the family Cyperaceae, commonly known as sedges. Other members of the Cyperaceae family are also called sedges, however those of genus Carex may be called "true" sedges, and it is the most species-rich genus in the family. The study of Carex is known as...
(Carex pallescens), which form small populations.
Management
Species diversity
Species diversity is an index that incorporates the number of species in an area and also their relative abundance. It is a more comprehensive value than species richness....
. This means many activities are not allowed at the site including: ploughing, drainage
Drainage
Drainage is the natural or artificial removal of surface and sub-surface water from an area. Many agricultural soils need drainage to improve production or to manage water supplies.-Early history:...
and the use of fertilisers, pesticides or herbicides.
Management of the site requires moderate grazing during the summer and autumn to help maintain the species diversity. This is because grazing removes each year's new growth which helps stop the site becoming dominated by vigorously growing
R/K selection theory
In ecology, r/K selection theory relates to the selection of combinations of traits in an organism that trade off between quantity or quality of offspring...
grasses. Such grasses would allow a build up of dead organic matter
Plant litter
Plant litter, leaf litter or tree litter is dead plant material, such as leaves, bark, needles, and twigs, that has fallen to the ground. Litter provides habitat for small animals, fungi, and plants, and the material may be used to construct nests. As litter decomposes, nutrients are released to...
, which together with the increased growth, would reduce the growth of less vigorous species. The overall effect would be a reduction in species diversity, which was one of the reasons for the SSSI designation. Trampling can be of benefit because it breaks up accumulated dead organic matter.
The small and isolated nature of the site makes it susceptible to damage from the surrounding area. For example herbicides, thought to be generally damaging for the species richness, could get onto the site from the drift of spray from surrounding fields. To help combat this the maintenance of mature hedgerows around the perimeter is encouraged. As of 2006 the condition of Whitton Bridge Pasture is described as favourable, which means that the land is being adequately conserved and any conservation objectives are being met, but that there is scope for enhancement of the site. The condition of the site was also described as favourable in 2004 and 2005 assessments. In the future it is hoped that the grazing regime will become more regularised and will be of high priority.