|
Environmental Change
Network
|
ECN SITE LINES: MOOR HOUSE AND UPPER TEESDALEJohn Adamson describes life as an upland site manager
The ECN Site The Moor House and Upper Teesdale ECN Terrestrial Site, which is situated in the northern Pennines, is the largest and highest site presently in the network. As the name suggests, the site comprises two separate areas, and both are National Nature Reserves (NNRs). Moor House NNR was designated in 1952, making it the first NNR in England. The reserve was not simply intended to protect rare or endangered communities of animals or plants but rather as a good example of an upland ecosystem to be used as an "open-air laboratory". Moor House NNR takes it name from the former shooting lodge which was used as a Nature Conservancy Field Station between 1952 and 1979. The reserve covers approximately 3500 ha and ranges in altitude from 290 to 848 m. It extends from the upper edge of enclosed land in the Eden Valley, over the Dun Fells, to the upper end of Cow Green Reservoir on the River Tees. The Tees rises on the edge of the reserve and forms its northern boundary. The geology is Carboniferous in age and consists of alternating strata of limestone, sandstone and shale into which has been intruded the dolerite of the Great Whin Sill. The eastern side of the reserve slopes gently and rocks are commonly masked in clayey glacial till making the drainage poor and resulting in the development of blanket bog with peat 2 to 3 m deep. The vegetation here is dominated by cotton grass, sphagnum moss and heather at lower altitudes with the heather absent at higher altitudes. The western side of the reserve slopes steeply and rocks are commonly exposed giving rise to a wider variety of soils and more diverse vegetation. The climate has been described as sub-arctic oceanic with the rainfall averaging 1900 mm per year and ground frost recorded in all months of the year. Although the land is owned by English Nature, the reserve is free range common grazing for villages in the Eden Valley. Upper Teesdale NNR was designated in 1963 and extended 1969, to protect the unique communities of Arctic-Alpine plants and other flora and fauna. This reserve covers some 3000 ha and ranges in altitude from 300 to 780 m. From Cow Green Reservoir it extends southwards to the summit of Mickle Fell and eastward, down the Tees, to High Force waterfall. At the lowest altitudes on the reserve there are deciduous woodlands and herb rich meadows but the majority of the reserve is used for sheep grazing and grouse shooting. The geology, soils and vegetation of much of Upper Teesdale NNR are similar to Moor House NNR. An unusual feature of Upper Teesdale is the "sugar limestone" soil which is derived from limestone which has been metamorphosed by the dolerite intrusion. It is this soil and damp river-side soils which support many of the rarer plant species. The reserve is subject to a Nature Reserve Agreement between English Nature and the land owners and tenants. As well as being combined as a single site for ECN purposes, the two reserves have been designated a single UNESCO Biosphere Reserve. Past Research While the uniqueness of the vegetation communities was recognised in Victorian times, scientific measurements were not begun until the 1930's when meteorological recording began at Moor House. At 560 m altitude this was much the highest point in Britain at which records had been kept, except for Ben Nevis where the station had closed at the turn of the century. Measurements were later extended to the summit of Great Dun Fell. Research began in earnest in 1952 with the opening of the Moor House Field Station. The impact and potential of moorland management were always important research themes. Experimental plots were established on a variety of vegetation types to examine the impact of sheep grazing intensity on vegetation and soils, either by fencing out sheep completely or by fencing in large numbers of animals. These experimental plots were compared with adjacent plots which had free range grazing. Plots were also established where heather burning for grouse and planting of trees took place. Moorland drainage ditches were studied on a small catchment basis. Annual variations in invertebrate populations, accumulation and erosion of peat and interactions between terrestrial and aquatic ecosystems were also examined. In the late 1960s and early 1970s the blanket bog ecosystem at Moor House was intensively studied as part of the UNESCO International Biological Programme. This work obtained estimates of primary and secondary biological production and quantified the main pathways and rates of circulation of dry matter and nutrients. At this time intensive work was undertaken at Upper Teesdale which stemmed from concerns over the building of Cow Green Reservoir, in particular its impact on fish populations and terrestrial plant communities. A weather station was established at Widdybank Fell to determine if the presence of the reservoir would have an impact on local meteorological variables and this has been in continuous operation up to the present day. In the 1980's research emphasis moved to the deposition of atmospherically transported pollutants. At Great Dun Fell the effects of altitude and the role of clouds in deposition were studied. The research work undertaken on the site has been funded from a wide variety of sources and conducted by a wide variety of organisations, and most has been undertaken to a very high standard. A meta-database is now available to researchers giving details of past and present research and an archive of data and documents is also maintained at ITE Merlewood. ECN Measurements ECN work at Moor House and Upper Teesdale is jointly sponsored by NERC and English Nature. English Nature has provided a steel portable building for use as a field laboratory by all researchers on the site and maintains the infrastructure of tracks and communications when these are not provided by other users of the site. English Nature also provides data from existing monitoring relevant to ECN and undertakes the ECN Moorland Bird Recording. All other ECN work is organised by staff from NERC's Institute of Terrestrial Ecology based at Merlewood Research Station in south Cumbria. NERC has also provided all the scientific equipment such as the Automatic Weather Station. During the entire period that Moor House Field Station operated, daily weather recordings were made on a site about 100 m from the building. ECN meteorological equipment, both hourly automatic and weekly-read instruments, have been installed at that location to increase compatibility between the old and new data. Atmospheric chemistry and precipitation chemistry equipment have been installed at the same location. The 1 ha area used for much of the biological monitoring, the Target Sampling Site or TSS, was selected as the nearest area of blanket bog that was undisturbed and reasonably homogeneous. This is 900 m north-west of the weather station and at 570 m, it is very similar in altitude. Other measurements including butterfly and bat recording take place in the area around the TSS but this has not proved possible for moth trapping because there is no mains electricity on the site apart from at the radar station at the summit of Great Dun Fell. Staff of the National Air Traffic Service which maintains the station run the trap there, but at 848 m there are operating problems such as the catching bottle filling with cloud water. Drainage water monitoring is conducted on the Trout Beck which, with a catchment of 1142 ha, is the largest river entirely on the site. The National Rivers Authority provides ECN with discharge data from a recently reinstated gauging station and water samples for chemical analysis are gathered upstream of the gauging station. We are lucky to have high quality vegetation maps of Moor House NNR and part of Upper Teesdale NNR which have reduced the amount of ECN base line vegetation recording required. To achieve the designated number of plots, baseline plots are 400 m apart which makes vegetation recording an arduous undertaking in the rougher parts of the site. TIGER and Other Research Moor House and Upper Teesdale has been designated a lead site for NERC's Terrestrial Initiative in Global Environmental Research (TIGER). Sampling for the programme is distributed across the site and there are three locations at which there are concentrations of equipment. On Great Dun Fell an altitude sequence of sites has been established. The main project using the sequence has simulated global warming by moving soil cores from high to low altitudes with some being retained at the higher site to act as controls. The vegetation and nutrient dynamics of the cores are being investigated. At Caw Bank, Cronkley, small open top plastic green-houses have been installed at the interface between bracken and heather to study the impact of increased temperature on competition between these species. At Bog End similar green-houses are being used to study the impact of increased temperature on invertebrate populations. Various non-TIGER researchers have started work at Moor House and Upper Teesdale since the inception of ECN, in part attracted by the high quality data which are being gathered for ECN purposes. These researchers are interested in using, for example, weather data to place their own data in a wider context. A newsletter is distributed from Merlewood to keep researchers in contact with developments on the site and with new publications that relate to the site. A site research register is also maintained. The Future Weekly visits to the site for ECN measurements have now been made for two years and in this time all the required plots have been located and permanently marked, and the required instruments installed. With the establishment phase now over some time is now becoming available to undertake research which can by built on to the ECN work. Initially this will focus on repeating measurements first made some decades ago. Possibilities include nitrogen dynamics of a stream, changes in botanical composition on a variety of vegetation types and erosion of long standing drainage ditches. It is hoped that in the more distant future it will be possible to extend the range of variables monitored on the Trout Beck so it can be designated an ECN Freshwater Site. All ECN sites have their particular difficulties for monitoring. At Moor House and Upper Teesdale these include the remoteness and size of the site, and severe weather conditions associated with altitude. Monitoring at all ECN sites is a team effort. At Moor House and Upper Teesdale we are fortunate to have team members with affection for the site and an enthusiasm to overcome these difficulties.
|
