Wednesday, 4 January 2012

The landscape, ecology a future of Slapton Ley

Slapton Ley National Nature Reserve is a 214 Ha site which includes the largest natural lake in South-West England, Slapton Ley. It is managed by the Field Studies Council (FSC) alongside Whitley Wildlife Conservation Trust, Natural England (NE) and South Hams District Council. The site holds two designations the first being as a Site for Special Scientific Interest (SSSI) and the second designation as a National Nature Reserve (NNR). The site consists of a diverse range of habitat which includes open water, sea shore, woodland, shingle ridge, wetlands, grassland, headlands and cliffs (Trudgill et al. 1996). Figure 1 illustrates the general layout of the nature reserve. 

Figure 1 Map of Slapton Ley NNR
(Unknown 2010)

The landscape of Slapton Ley NNR                        

The key feature in the landscape of Slapton Ley NNR is the Ley itself and is effectively split into two parts, the upper and lower Ley. The lower Ley being the largest open water area is about 1 ½ Miles long with the upper Ley being more or less completely filled in with silt which supports areas of reed swamp and carr woodland (Benson-Evans et al 1967).  The Ley although situated right on the coast is fresh water and acts as a sink for surrounding streams including the River Gara (Mercer, I.D.,1966). These inflows of freshwater along with direct rainfall maintain water levels in the ley and on occasion cause it to overflow, with rainfall being the biggest factor in the variation of the depth of the Ley over the year (Benson-Evans et al 1967). The NNR is broken up into approximately 43Ha of Woodland, 98Ha of freshwater habitats, 34Ha of Shingle and what’s left of the 214Ha site is made up of fields (Brookes & Burns 1969).  The woodland is fragmented in and around Slapton Ley NNR and as Figure 1 illustrates there are three main areas of woodland: Slapton Wood, France Wood and Hartshorn Plantation. Slapton Wood has a small tributary of the River Gara known as the Slapton Wood Stream running through it and the woodland is classed in part as ancient woodland with no evidence of it having been agricultural land at any point (Mercer 1966). Slapton Wood is dominated by Quercus robur (Pedunculate Oak), Castanea sativa (Sweet Chestnut) and Fagus sylvatica (European Beech). France wood used to be agricultural land pre 19th Century as maps from the 18th Century clearly show no woodland and only fields in this area. The wood is dominated by Quercus robur (Pedunculate Oak), Castanea sativa (Sweet Chestnut) and Carpinus betulus (European Hornbeam). Hartshorn Planation is dominated by Pinus sylvestris (Scots Pine) and Acer pseudoplatanus (Sycamore).
The fields found in and around Slapton Ley NNR are used for arable and livestock farming with some partaking in various Agri-Environment schemes. These schemes are voluntary on the farmer’s behalf but promote sound environmental practices which then allow the farmer to be paid for doing so. The main schemes come in two modern forms as Entry Level Stewardship and then Higher Level Stewardship with two main older types Countryside Stewardship Scheme and Environmentally sensitive areas (ESA). The Countryside Stewardship Scheme was replaced by the higher and lower level schemes however those who signed up to the original scheme still operate under it until it expires. One of the farms right next to the Slapton Ley Field centre is on this scheme which expires shortly and as a result receives payments for using environmentally sound methods such as set aside, leaving field margins unmanaged and actively promoting wildlife within the farmland itself (Little etal 1998). This particular farm achieves the promotion of wildlife by encouraging Emberiza cirlus (Cirl Buntings) on the land through the use of set-aside, leaving field margins to grow, and the use of mixed farming i.e. a mixture of arable and livestock farming. The farm also works alongside the Slapton Ley FSC Study Centre to aid in the education of students and enthusiasts alike in conservation and good farming practice.

A view of the ley 

The landscape of Slapton Ley and its surrounding areas has changed throughout the centuries as has the demands that man has put on the area. It appears from various studies that man began to turn woodland in the Slapton Area into farmland during the mediaeval period (Foster, et al 2000) and gradually began to intensify in agricultural use over the centuries. During the mediaeval period field sizes were generally large and open however were worked or rather rented in small strips by farmers (Titow 1965) who worked a particular strip of land with live stock usually being communally grazed by commoners on common land (Titow 1965) as we progress through the centuries and the old mediaeval feudal manorial system becomes extinct, farmers begin to own their own fields and further intensify production in fields.

Shooting ahead to the early to mid 20th century and farmers begin to focus on single products for a field focussing on productivity and getting the absolute most out of each field (Leeuwis 2004) with little regard for the environmental consequences of such actions which has led to the decline of a number of species such as the aforementioned Emberiza cirlus.
This intensification during the 20th century led to a massive increase in the use of fertilizers, pesticides and herbicides which have seriously affected and altered the ecology of areas such as Slapton Ley over the years however, with the introduction of Agri-Environmental laws and policies to attempt to curb the environmental decline and indeed reverse it things have taken a turn for the better in and around Slapton Ley NNR as farms which have signed up to various agri-environmental schemes have increased the conservation function and value of their land.

The Ecology of Slapton Ley NNR

Slapton Ley NNR with its Mosaic of habitats from wetland to woodland to grassland and shingle is home to a variety of model ecosystems. Slapton Ley NNR is also home to a variety of rare species such as Emberiza cirlus (Cirl Bunting), Trifolium scabrum (Rough Clover), Muscardinus avellanarinus (Hazel Dormouse) and Corrigiola litoralis (Strapwort).

 Slapton Ley: view from the sea

The Slapton Sands Shingle Ridge (see Fig 1) is an area of ecological interest to many due to its proximity to both the ocean and the ley which provides a unique and rich habitat for a variety of rare plant species. T.Scabrum was rarely found on the shingle ridge pre 1971 but after management was carried out to prevent cars parking on the ridge as well as sealing off area of vegetation on the shingle ridge it has since become established (Burns 1996). Another species T.striatum (Knotted Clover) was absent pre the beginning of management in 1971 and is now classed as “occasional” in abundance on the ridge (Burns 1996). The shingle ridge that was once fairly devoid of vegetation due to mismanagement is now mostly covered in vegetation and requires both scrub management and mowing to help maintain the botanical value of the ridge (Burns 1996).

Strapwort in flower

The ley itself is home to a diverse range of flora and fauna both within the ley and around it. Around the ley the rare plant C.littoralis can be found although its distribution was very localised around the ley as a result of scrub encroachment and the restriction of cattle around the ley itself (Burns 1996) it is now increasing in abundance thanks to efforts by Natural England and the management team (plus Kew Gardens for providing seeds) and it is hoped the abundance will increase further in the coming years (Burns 1996). Both Lustra lustra (European Otter) and Neovison vison (American Mink) are found in and around the Ley. Studies on the prey of both species by Riley (1996) show that while L.lutra take Cyprinids, Eel, Perch and Pike, N.vison is responsible for taking a majority of lagomorphs, Rodentia and birds. Myotis daubentonii (Daubenton’s Bat) are regularly found skimming food off of the ley surface along with about 7 other bat species recorded at the NNR itself (Riley 1996) including a roost of the rare Rhinolophus ferrumequinum (Greater Horseshoe bat) found within the Slapton Village.

Greater horseshoe bat

Within the woodland and grassland areas a variety of mammal species have been recorded including Vulpes vulpes (Red fox), Myodes glareolus (Bank Vole), Microtus agrestis (Field Vole), Microtus arvalis (Common Vole), Micromys minutes (Harvest Mouse), Apodemus sylvaticus (Wood Mouse), Lepus europaeus (European Hare),  Meles meles (European Badger) and various Artiodactyla species.          

Slapton Ley NNR is home to four species of amphibian and four species of reptile. This includes Lissotriton helveticus (Palmate Newt), Lissotriton vulgaris (Common Newt), Natrix natrix (Grass-snake), Zootoca vivipara (Common Lizard), Vipera berus (Adder) and Anguis fragilis (Slow worm) (Riley 1996).

Grass snake hunting by a pool of water

Both freshwater and terrestrial invertebrates abound at Slapton Ley NNR, however research is lacking on the freshwater invertebrates (Riley 1996). 
Lepidoptera have been extensively studied at Slapton Ley due to their abundance in both the south of England as well as at the Nature Reserve itself (Riley 1996). A new species of Millipede was discovered in Slapton Wood by Gregory et al (1993).

The Future of Slapton Ley NNR

The future of Slapton Ley NNR is based around future policy both local and national in regards to conservation and planning as well as changes in the climate as a result of climate change.

Areas of consideration for both present and future scenarios relate to the impact of tourism on the NNR, sea level rise, pollution, management and maintaining biodiversity on the site.
There are problems and concerns for the future in regards to the intensification of farming in the area which can both result in a reduction of biodiversity as well as the current and future problem with nutrient leaching into the wetland areas, in particular the Slapton Ley. Trudgill et al (1991) talks about the problems associated with nutrient leeching into the wetlands of the Slapton ley NNR and the end result in increasing Hypertrophy within the ley itself. The River Gara which flows into the Ley has a catchment area that consists mostly of intensively farmed land which has free draining soils and banks which often have steep slopes which increases the problem of nitrates leaching into the water (Burt et al 1988). According to Trudgill (1996) the Slapton Ley conservation priorities for the future include the maintenance of the aquatic habitats to prevent pollution and water level change, to maintain and increase the populations of rare species, to maintain biodiversity for both flora and fauna, to maintain public rights of way, to maintain good relations with neighbours and to control succession at a favourable level.
As pressure on farmers increases as a result of Government policies and market changes there will be an increased need for farmers to either intensify on their land or diversify their practice/business which may come into conflict with conservation priorities for the area. The Agri-environmental schemes run by Natural England and funded by the UK Government and European Union which encourage farmers and also make it financially possible for them to use more environmentally sound methods for farming at their current state run until 2013 (Natural England 2009) and after that it will be up to the relevant authorities on how and if it is to be funded from there onwards or if new schemes will be created and implemented.
The future of these schemes, climate change and the intensification of farming will have a direct impact on the future management of Slapton Ley NNR.   


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Trudgill,S.T, et al.,1991.The Natural History of Slapton Ley Nature Reserve XIX:A Preliminary Study on the control of nitrate and phosphate pollution in wetlands.Field Studies, 7, pp.731-742

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Unknown.,2010.Slapton Ley National Nature Reserve: Walks and Trails.Devon.FSC

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