The conservation of the Glen Tanar native pinewood, near Aboyne, Aberdeenshire
1. An understanding of the natural regeneration of Scots pine was considered essential for effective management of the Glen Tanar native pinewood. The aim of this project was to review previous work on regeneration of Scots pine and to carry out experiments at Glen Tanar which further this knowledge. 2. Two contrasting study areas, the Bush and Monrae, were chosen to represent extremes from the range of site types found at Glen Tanar. Experiments involved both naturally disseminated and sown Scots pine seed. Individual germinants were identified as soon as possible after germination and then subsequent survival and development of seedlings up to two years old were determined. The effect of browsing on older seedlings was also assessed. 3. Cage experiments indicated that seed predation by birds and rodents was responsible for. a loss of up to 85% of seed between reaching the ground and germination. 4. Ground treatments were carried out to produce a range of seedbeds. There was a large variation in production of germinants on different seedbeds but only small differences in the subsequent survival of seedlings. Very few seedlings became established in intact vegetation and only ground treatments which removed field, moss and litter layers gave a consistent increase in germination. 5. Temperature and moisture measurements showed that conditions were generally more favourable for germination on bare humus substrate than in the and moss and litter layer, Shallow trenches cut to the depth of the mineral soil also appeared to provide favourable conditions for germination. 6. Mortality was generally highest among seedlings less than four weeks old. The most important factors causing early losses were slug damage and desiccation. On a freely-drained site, winter mortality was low but on a poorly-drained site, with a steeper slope, surface-erosion and frost- lift caused fairly high losses during winter. 7. Exclusion of grazing animals did not have a significant effect on the early establishment of seedlings. During the second season luxuriant growth of ungrazed grass competed with pine seedlings and reduced development. Outside the exclosure seedlings were browsed by rabbits. Observations of planted and naturally regenerated Scots pines and birches showed seedlings attracted larger browsing animals, particularly deer and capercailzie, as they reached above the level of the field layer. Most birch browsing occurred in summer, while pine browsing was most severe in winter. It was concluded that the density of naturally regenerated seedlings could probably be increased in most parts of the native pinewood by 'screefing' the ground surface. It would not be necessary to fence regeneration areas, however, until an adequate stock of seedlings becomes established in the field layer.