• THRIP
• Culloden Battlefield
• The Caledonian pinewoods of Mar Lodge Estate
• Plant Monitoring at Ben Lawers

THRIP
The Tarmachan Habitat Restoration and Improvement Project represents a natural progression and increase in scale from earlier, small-scale projects established in 1989 and 1990. The projects collectively aim to restore viable areas of woodland, up to the treeline, scrub up to its, higher altitude limit, and the herbaceous plants associated with both. These areas of trees and shrubs, once established, should provide the seed sources currently lacking on the hill to sustain the species and habitats into the future.

The treeline woodland on Ben Lawers, surviving only as tiny vestiges on cliff ledges, is a herb-rich birchwood, probably the most floristically diverse example in the Highlands. The project involves three fenced areas with a total of about 300 hectares / 741 acres, over an altitude range of 300-900 m / 1,000-3,000 feet. One was previously a poor quality conifer plantation and is now a young, developing mixed native woodland, another a mixed area planted with woodland and eared willow and bog myrtle scrub, and the third and largest area being planted with sparse treeline woodland and willow scrub, and with tall herbs regenerating.

Culloden Battlefield
The Battle of Culloden of 1746 between the Jacobite and Hanoverian armies was the last pitched battle fought on British soil, and the site of the battle is now in the care of the National Trust for Scotland. The Trust would like the battlefield to look the same as it did at the time of the Jacobite uprising - open, heather-clad moorland, with fields nearby.

However, when the Trust bought the battlefield it consisted of a commercial forestry plantation. The conifers were felled in 1982 and, surprisingly quickly, heather (Calluna vulgaris) recolonised of its own accord, with almost complete heather cover by 1990. However, there were still trees left around the battlefield and these, primarily birch, seeded rapidly into the re-created moorland. Various means of removing the regenerating trees were tried, including the use of volunteers and the use of prisoners from the local jail, but to no avail!

Burning was ruled out as an option owing to the impact on the landscape - the site welcomes over 100,000 visitors a year. There was only one other option left to try - grazing. Trials on nature reserves in Yorkshire indicated that Hebridean sheep were good at controlling scrub while retaining the heather, so a project was set up to try this approach out at Culloden.

Adjacent to the battlefield itself is the Field of the English which the National Trust for Scotland also owns: this was until recently species-poor improved grassland, and the Trust wanted to improve its species-richness. The best way to achieve this is to leave the sward ungrazed in the summer, so that flowers can grow and set seed, and then to graze it hard in the autumn and winter so that the summer's growth is grazed away.

Here was the ideal opportunity to achieve both objectives: the Hebridean sheep could graze the battlefield in the summer, eating the young trees, and then be moved to the Field of the English in winter to graze down the summer's growth. A management plan was produced, helped by sponsorship from Gales Honey, who also saw an opportunity to improve life for bees - by increasing the number of flowers in the fields and maintaining the heather cover of the moorland! In 1999 Gales Honey helped the National Trust for Scotland to buy a flock of Hebridean sheep - a small, dark-brown 'primitive' breed of sheep.

The sheep project has been up underway for four years and we now employ a local shepherd to manage a breeding flock of 150 ewes. An assessment of the project is in progress, but observations suggest that, in order of preference, the sheep graze grass, gorse/broom, willow, rowan, heather, birch, pine, juniper, with the latter two hardly touched. Gorse and broom have also been a problem at the site and the sheep are particularly good at controlling these, especially if the plants are first cut down by hand so that the sheep can eat the regrowth.

The sheep are not perhaps eating as much birch as hoped - although it is early days and they are still more effective at controlling the trees and shrubs than the humans ever were! For the future, we hope to involve students from Inverness College to monitor the effectiveness of the project; we will consider the use of additional livestock breeds; and we will look into ways of reducing the amount of fencing needed on the battlefield.

The Hebridean sheep have been very popular with the visitors, although sheep droppings on paths can be a problem, and it is a pity to have had to erect fences on the battlefield to manage the grazing. However, in spring 2003 the shop in the visitor centre started to sell articles made from the wool of these sheep for the first time!

The Caledonian pinewoods of Mar Lodge Estate
Mar Lodge Estate, acquired in 1995 by NTS, is renowned for its native Caledonian pine (Pinus sylvestris) woodland, which forms the eighth largest core pinewood remnant in Scotland (836ha) and is classified as a "key" habitat by the UK Biodiversity Steering Group. Previously the Mar Lodge pinewoods were larger in extent but a history of clearing woodland for timber and to create grazing land for sheep, along with periodic climatic changes has reduced their size. The increasing popularity of open hill deer stalking in the 19th century led to an increase in deer numbers and this probably put an end to any natural regeneration within the remaining pinewoods on the estate by the 1830's. Grazing levels have continued to be high since this time and consequently few young pine trees can now be seen within the woodland. Furthermore, the scattered patches of dwarf birch, juniper and willow scrub present today, indicate the potential for the development of extensive tree-line scrub but currently, growth of these species is commonly suppressed through deer browsing.

The primary focus of management on the estate since 1995 has been in reducing the deer numbers to allow regeneration of the native pinewood. When the NTS bought the estate in 1995 there was an estimated minimum of 3350 red deer and the aim was to reduce the red deer numbers to 1650 by 2005. This target figure allowed for a deer density of 5 per 100ha in the glens containing pinewood and 16 per 100 ha on the open moorland. These figures were scientifically derived (for woodland) and informed estimates (for moorland) of the density of deer required to allow regeneration of pinewood and sustainable management of heather moorland. To date deer numbers have been reduced to 2800 and already a response to this reduction in grazing is evident particularly on the heather moorland where growth forms of heather indicative of high grazing levels such as drumstick and carpet heather are declining. The response of tree seedlings to the deer reduction is a slower process and this is being monitored in two ways.

Since 1996, regeneration transects (1km) running through areas with the potential for pine regeneration, have been monitored annually to record recruitment of seedlings, to measure the number of seedlings surviving above vegetation height and to record browsing damage. With the exception of one transect, as yet there has been almost no pine regeneration recorded above vegetation height and where pine regeneration does occur above vegetation height the numbers of seedlings are very small (max. 14 seedlings on a transect). However, larger numbers of pine seedlings exist below vegetation height on the transects (range: 50-300 seedlings per transect) and most of these occur on river and track margins and free draining gravely knolls. This suggests two things. Firstly recruitment of seedlings is more likely in areas of disturbed, free draining ground with more open vegetation and bare ground. Secondly, at present browsing levels are still too high for successful regeneration, as once the seedlings appear above the vegetation height and are visible to deer then they are browsed. In 2001, 94% of the seedlings above vegetation height had browsing damage.

In order to follow the fate of individual seedlings and to identify at what time of year seedlings are getting browsed, a second monitoring scheme involving regeneration quadrats (10 x 10m) was established in July 2002. Twenty seedlings were individually marked within each quadrat and morphological along with browsing measurements of these seedlings were made. Furthermore, the number, height and browsing damage observed on all the other seedlings in each quadrat was also recorded. Eight of the regeneration quadrats were monitored monthly and all quadrats are monitored every two years.

Most importantly, the information gathered from the regeneration transects and quadrats acts as a habitat measure to inform us at which point deer density is low enough such that few trees are being browsed and regenerating is occurring successfully. Although we are working towards five deer per 100ha in the woodland, a figure that has been shown elsewhere to allow pine regeneration to occur, this figure is likely to vary depending on site specific habitat and environmental factors. Thus, the tree monitoring is a crucial back up to the deer counts in detecting the point at which browsing is no longer suppressing tree regeneration. The tree monitoring will also be useful in; a) informing us as to when trees are most susceptible to browsing thus allowing culling effort to be focussed on particular places at particular times, b) providing a measure of seedling mortality in response to browsing or other causes and c) providing information on seedling recruitment and in particular indicating areas/habitats where seedling recruitment is low.

Plant Monitoring at Ben Lawers
Ben Lawers is renowned for the concentration of rare species of plant that grow there. The best known of these are the 'higher plants', the flowering plants and ferns, but the site is equally if not more important for its 'lower plants', the lichens and mosses. The Trust acquired the property in 1950 with the primary aim of conserving these species for future generations. This general aim has been expressed as explicit, measurable objectives for management, e.g. to maintain the populations of rare species and the diversity of species and their habitats.

Conservation of living species requires a considerable knowledge of their populations, where they are, how numerous they are, and of the factors affecting them in both short-term and long-term changes. With so many threats to our native species we particularly need to know whether those we look after are healthy, i.e. whether current conditions are allowing them to survive for the future, or whether there is a decline resulting in a danger of local extinction.

To test whether we are succeeding in our objectives we need to gather information on the distribution and abundance of species, and repeat such surveys at intervals, in effect to carry out a regular census, just as our government does for the nation's human population. When the numbers are recorded, we also have to interpret them to identify long-term trends rather than short-term fluctuations that are natural features of wild populations living in dynamic habitats, which are especially characteristic of mountains. This may require additional studies to understand the changes during the intervals between the less frequent surveys.

This all adds up to a labour-intensive, time-consuming and therefore expensive project. While some species can be counted as individuals, with special techniques developed to enhance the accuracy of counting, others cannot for various reasons and different methods of detecting change must be devised, often adapted for each case. In some case no practical method has yet been found, but the main constraint on progress is usually time and money. However, over two decades we have shown that many of our rarest species have stable populations, although not necessarily at a favourable level, but others are declining towards extinction. In the latter cases management is being undertaken to reverse the process, for example as with the willows, described elsewhere. Monitoring is again necessary to measure success in such active management, or to inform further changes if success is not achieved.