Neil Cowie

The effects of conservation management of reed beds. II : The flora and litter disappearance

1. The effects of management were determined by comparing pairs of adjacent cut and uncut reed (Phragmites australis) beds at 12 sites, and by a randomized block experiment at a further site in which plots of reed were cut, burnt or left unmanaged. 2. Most plant species were more abundant in the managed reed beds than the unmanaged ones, and only three were more abundant in the unmanaged beds. Several were more common in burnt than cut plots. 3. Reeds were shorter and at higher densities where cut or burnt than where unmanaged. The proportion of reed flowering stems was highest in burnt plots. 4. The rate of decomposition of reed leaf litter at the experimental site was determined by weight loss from litter bags and leaf bundles. There was no difference in weight loss and no difference in associated soil invertebrates between treatments. 5. However, weight loss was inversely related to water depth in the plots and after 6 weeks correlated with the number of Oligochaetes, Psychodid larvae and some Coleoptera. 6. Cutting and burning positively affected floristic diversity and most marsh plants, but had no effect on the rate of litter breakdown.

Modelling edge effects of mature forest plantations on peatland waders informs landscape-scale conservation

Summary 1. Edge effects of native forest fragmentation have been well studied, but there are few studies of open-ground habitats fragmented by plantation forests. We measure forestry edge effects on open-ground breeding birds, following one of Europe’s biggest and most controversial land-use transformations. 2. The ‘Flow Country’ of northern Scotland is one of the world’s greatest expanses of blanket bog. It became fragmented by conifer forests planted in the late 20th century, and these now adjoin open peatlands protected under European conservation legislation. Detrimental edge effects on breeding birds were anticipated, but not apparent shortly after planting. 3. Using survey data collected in 2003–2006, and logistic regression modelling, we tested whether breeding distributions of three wader species of international conservation concern, dunlin, European golden plover and common greenshank, were influenced by distance to forest edge, controlling for habitat and topography. 4. All three species were more likely to occupy flatter, more exposed ground close to bog pools and were influenced by peatland vegetation structure. There was an additive and adverse effect of proximity to forest edge for dunlin and European golden plover, but not common greenshank. This effect was strongest within 700 m of forest edges. We used these results to predict which areas should benefit most from removal of adjacent forestry and so guide maintenance and restoration of the bird interests of the protected areas. 5. Synthesis and applications. Edge effects of mature forestry on dunlin and golden plover are apparent over several hundred metres and are now being used to guide forest planning in northern Scotland. The scale of edge effect is broadly consistent with other avian studies in open-ground habitats across Eurasia and North America, so buffer zones of this order are consistent with possible impacts of plantation forestry on open-ground habitats of bird conservation interest. Given renewed interest in conifer afforestation as a climate change mitigation measure, an improved understanding of edge effects and the mechanisms through which they operate is vital to managing plantation forestry in ways that maintain open-ground landscapes of high conservation value.

Scots pine growing on forested mires in Abernethy Forest, Strathspey, Scotland

Summary A substantial proportion of the Abernethy Forest Reserve has Scots pine (Pinus sylvestris) growing on the surfaces of a variety of mires. The hydrology of the mires has been affected by drainage and peat cutting but this area is unusual in having had a long period of protection from grazing by domestic stock. There are three main types of pine populations found on these mires. Woodland bog comprises predominantly bog vegetation with abundant pine seedlings due to the heavy seed rain from the surrounding woodland. Only a few very small trees survive, which are stunted, heavily diseased and have very low seed production. Wooded bog also comprises predominately bog vegetation but there are scattered mature trees of a moderate height with an open canopy. The trees are fertile and can form uneven aged stands with regeneration. Bog woodland is a predominantly woodland vegetation with tall, dense tree cover on deep peat. The trees are well grown with a dense canopy. A few remnants of bog vegetation remain in the ground flora although most have been replaced by woodland bryophytes and shrubs. Each of these three types is described and their development is discussed.

The importance of regeneration studies to the successful conservation management of Scottish rare plants

Summary Maintaining successful regeneration is clearly essential to the conservation management of threatened plants. We examine some of the considerations necessary to determine whether regeneration is successful.

Promoting survival prospects of rare plants

Summary The distributions of Scottish rare plants are well known and we have a good understanding of the communities and habitats in which they occur. But how do we ensure that populations are maintained or enhanced? The ecological processes that determine current population size and distribution must be understood. We review the type of information from monitoring that is required to assess change in species status and to guide conservation management. Managing for habitats must be the right approach to conserving species, but we need to take careful consideration of the individual requirements of different species. Environments fluctuate at a range of spatial and temporal scales; we review the evidence that rare plant species respond to such fluctuations. We consider that there might be a danger that overprotecting some habitats, by trying to maintain constant ideal management prescriptions, might be putting some species at risk. We believe that conservation managers can resolve the apparent conflicts between management for different species by ensuring environmental variation in space and time.