Scottish Woodland Research Articles

White bark in birch species as a warning signal for bark-stripping mammals

Background : Birch species such as Betula pendula have conspicuous white bark and the evolutionary drivers for this colouration remain unresolved. Aims We evaluated our hypothesis that the white bark is a visual warning signal to deter mammals from bark-stripping. Many species of deer (Cervidae) and multiple other mammals consume bark. White birch species’ bark contains betulin and other compounds which likely make the bark unprofitable for herbivores. The white bark has features consistent with a visual signal for mammalian herbivores and could act as a visual aposematic signal of chemical defence. Methods We compared deer bark-stripping between tree species in Scottish woodlands. For Betula pendula, we compared stripping of juvenile brown bark with mature white bark. We also reviewed existing literature to find the tree-species preference for a wide-range of bark-stripping mammals. Results In Scotland, we found that white-barked birch bark was less preferred. We also found mature white birch bark was avoided compared to juvenile brown bark. Existing literature for multiple herbivores showed that white birch species’ bark was often either not preferred or avoided. Conclusion We suggest that the conspicuous white colouration of birch bark may act as an aposematic visual signal to deter bark-stripping mammals.

An evaluation of Scottish woodland grant schemes using site suitability modelling

Woodland expansion is a key component of Scottish land use policy, with targets to increase woodland cover from 18% towards 25% of land area by 2050. However, to date there has been little assessment of whether forestry policy is achieving its objectives. Here, we present an evaluation of woodland grant schemes based on site suitability modelling for the Lochaber Forest District in northwest Scotland. We perform a spatial analysis of woodland creation between 1988 and 2014 using site suitability scores generated through the Forest Research Ecological Site Classification (ESC) methodology. We further conduct in-depth interviews with fourteen stakeholders within the grant-scheme application process to explore the influence of ecological suitability on woodland planning. We find that 92% of woodlands are suited to current climate conditions, and that suitability has improved under the latest grant scheme. This is concurrent with an increased emphasis on suitability modelling in decision-making, though could be explained by cultural changes or a more rigorous approvals process. We find that ecological variables are used to inform woodland location and species selection, but that woodland type is more commonly determined by grant structure. Finally, we discuss other potential limits to grant scheme success, including climate change, edaphic variables and woodland management.

Perception and partnership: Developing forest resilience on private estates

Scotland has the highest concentration of private land ownership in Europe and private estates in the Highland region cover the vast majority of the land. On many private estates forests share the land with a strong tradition of sporting use that has inhibited the development of forest management culture. Land managers are seeking ways to diversify that are relevant to both local practice and wider environmental issues to align with Scottish woodland expansion policy, increasing emphasis on resilience strategies and adoption of ecosystem approaches. This research focusses on four regionally diverse case study areas, each containing three neighbouring private estates in the Scottish Highlands. Using mixed-methods that includes an adapted walking interview technique, collaborative action discussions and a novel approach to mapping spatial resilience this study explores resilience and forest culture through individual perceptions of the participating land managers. This work expands understanding of spatial resilience that is relevant and meaningful to land manager decision-making and local practice, which could offer policy makers with an effective avenue to realise and implement resilience aims through local action. Key synergies between renewable energy, carbon marketing and forest development are identified alongside perceptions of resilient forest types. Support mechanisms such as regionally trusted capacity building and facilitation are recognised as crucial to mobilising six landscape partnerships (land manager identified) that could both strengthen estate and forest resilience.

Impacts of Human Disturbance on Capercaillie Tetrao urogallus Distribution and Demography in Scottish Woodland

Leisure activities in fragmented western European forests are thought to threaten local populations of capercaillie Tetrao urogallus. We studied impacts of human disturbance on capercaillie in three Scottish woods by documenting the distribution of their droppings in relation to woodland tracks and entrances, surrogates for human activity. Droppings were sparser within 300–800 m of entrances and 70–235 m of tracks, depending on track use and habitat. Some 75% of each wood lay within 130 m of a track. In the most disturbed wood, droppings were most abundant in the centres of larger patches of trackless boggy ground, which acted as refuges. The reproductive rate (chicks reared per hen) at our three study areas was no less than in other, less disturbed parts of the same valley. The ratio of full‐grown hens to cocks, however, was unusually low in the two most disturbed woods. Disturbance reduces the birds' living space, possibly affecting hens more than cocks. It might therefore impact metapopulation dynamics and contribute to genetic impoverishment in small populations. Ensuring that people and dogs keep to tracks, closing tracks and creating refuges should mitigate such effects.

Incidence and severity of dieback in birch plantings associated with Anisogramma virgultorum and Marssonina betulae in Scotland

Betula pendula and B. pubescens were surveyed at nine Scottish Woodland Grant Scheme (WGS) sites in 2004 to assess the incidence and severity of two fungal pathogens, Anisogramma virgultorum and Marssonina betulae, and their association with crown dieback. Of the surveyed trees, 47% had at least 40% crown dieback, with B. pendula more severely affected than B. pubescens at most sites. Overall, 57% of surveyed birch trees had A. virgultorum and 28% had M. betulae, with the incidence of trees infected with both species varying among sites. Incidence and severity of A. virgultorum were greater on B. pubescens than on B. pendula, whereas the reverse was true for M. betulae. The relationship between incidence of M. betulae foliar disease and sunken cankers was significant, with 83% of M. betulae-infected trees having these cankers. The presence of M. betulae foliar disease resulted in a greater percentage of crown dieback compared with non-infected trees in both birch species, whereas the presence of A. virgultorum caused greater crown dieback in B. pubescens only. Across all sites and both birch species, as severity of infection with either A. virgultorum or sunken cankers increased, so did the severity of crown dieback. This study showed that A. virgultorum and M. betulae appear to contribute significantly to birch dieback at the nine sites surveyed.

The Historical Geography of Scotland Since 1707 (review)

Reviewed by: The Historical Geography of Scotland since 1707 Ian D. Whyte The Historical Geography of Scotland since 1707. By David Turnock. Pp. 11, 352. ISBN 0 521 89229 5. Cambridge: Cambridge University Press. 2004. £22.99. The first point that anyone who is considering buying this book should note that it is a paperback reprint of the original 1982 edition. Occasionally a book becomes a classic and this status justifies keeping it in print without any revisions. One of the most celebrated examples must be W.G. Hoskins' Making of the English Landscape, first published in 1955 and still immensely readable after 50 years because of its style, erudition and enthusiasm, even when it is clear that many modern ideas about the evolution of the English countryside have changed markedly. It is certainly good to see Dr. Turnock's book available as a paperback although the price of £22.99 hardly makes it a cheap one. Reprints should perhaps, however, carry an academic health warning for there are pitfalls in reissuing such a book without allowing the author any revisions after nearly a [End Page 151] generation of scholarship has passed. There are pitfalls too for the unwary undergraduate, hurriedly preparing material for an essay, in using a book which is not as up to date as the year of publication might suggest. I reviewed this book when it was originally published. I liked it then and I still do: but how have my reactions to it changed after twenty-three years? How well has it stood the test of time? In some ways it is a book very much of its time. When the author originally wrote it there were a number of other historical geographers working on Scottish themes, myself included. The last quarter of a century has witnessed something of a decline in their numbers. In addition, historical geography itself, in Britain at any rate, has taken a strong cultural turn which has steered it into exploring unexpected and challenging new directions. At its best, the scholarship of this approach can be appreciated in books like Charles Withers' Geography, Science and Identity: Scotland since 1520 (2001)—but this is a very different kind of historical geography. It is also true that there have been several areas within the scope of Dr. Turnock's book where major advances have been made in the last two decades or so. The most recent books in the bibliography date from 1979. Whole research careers have ripened and come to maturity since then. One immediately thinks of the contribution of Robert Dodgshon to our understanding of eighteenth-and nineteenth-century Highland agriculture, settlement, and the Highland economy in general, and of the work of Christopher Smout and his environmental history colleagues at St. Andrews on Scottish woodlands. The structure of the book, with its focus on the North East, an area in which Dr. Turnock carried out much detailed research, comes out as a refreshing change to what has sometimes been called the 'Lothiancentric' approach to Scottish history. After an introduction to pre-Union Scotland the book divides into three main chronological sections, breaking at the Napoleonic and First World Wars. Each section contains a general review and then more specialist chapters on themes which the author considers to be especially significant for that period: agricultural improvement, planned villages and whisky manufacture for the eighteenth century for instance. The last section of the book finishes in the mid 1970s. Since then there has been so much change in the geography of Scotland that the most recent sections are now historical geography themselves. One only has to consider trends in industry, housing, the re-invention of Glasgow and the appearance of Scotland's first national parks, to mention only a few themes. It is a shame that the author has not been allowed at least a new postscript. Ian D. Whyte Lancaster University Copyright © 2007 Edinburgh University Press

Ecological interactions between fungi, other biota and forest litter composition in a unique Scottish woodland

The composition of forest litter and understorey layer, and fungal biomass (in terms of ergosterol) were measured in eight subplots over a winter–spring period (January to April). The sampling site was positioned in a range of woodland habitats (variously dominated by beech, Fagus sylvatica; birch, Betula pendula × pubescens, and oak Quercus petraea) and a clear area covered with grass (dominated by Holcus lanatus). The results were analysed together with data on bacteria and microinvertebrates available from parallel research. Levels of ergosterol in individual subplots ranged between 50 and 160 μg g−1 DW. Fungal biomass decreased in March, and then increased significantly in April. Stepwise regression models for ergosterol indicated positive relationships with moisture content (February), bacteria (all but February and March), flagellates (February) and plant-feeding nematodes and flies (January, overall). The relationships with roots, seeds, the collective variable ‘other microinvertebrates’ (all March), amoebae (February) and fragments (March, overall) were negative, while the relationship between fungi- and microbial-feeding nematodes changed sign between February (−) and March (+). Results of analysis of covariance for fungal ergosterol were significant only for January and the combined dataset. In January, fungi were shown to be significantly related to amoebae, bacteria and a collembolan Folsomia candida, while the only significant predictor returned by the overall model was bacteria. Correlation analysis confirmed some effects already noted, and revealed a number of further interactions. The results highlighted the complexity of factors influencing temporal dynamics and spatial variability of fungal biomass in forest litter. Most of the registered interactions appeared to be transient, and this should be taken into account while interpreting environmental observations. Interpretation of the specific relationships is given and implications for further research and overall ecosystem functioning are discussed.

Ecological study of the forest litter meiofauna of a unique Scottish woodland

Abstract The micro and meso-invertebrate abundance was measured, together with forest litter composition, in eight plots of differing vegetation (dominated by beech and birch) over a winter-spring period. The litter moisture content was a mean of 76% during the sampling period and the beech sites were the driest. The results were analysed using a suite of statistical techniques, together with data on protozoa, fungi and bacteria available from parallel research. Nematodes were analysed according to the trophic levels, which included microbial feeders, plant feeders and predators. The majority of arthropods found were the collembolan, Folsomia candida and cryptostigmatid mites, with very small quantities of other micro- and mesoarthropods (such as larvae and mesostigmatid mites). The microarthropod populations peaked in January and fell during subsequent months, while population numbers of nematodes showed a decrease between January and February, followed by an increase in March. ANOVA showed a significant date effect, but no site-date interactions for the population abundance of both nematodes and microarthropods. Ecological interactions of meiofauna were analysed by ANCOVA, stepwise regression, and correlation analysis. Examples of relationships revealed include positive relationships of plant-feeding nematodes (PFN) with microbial feeding nematodes (MFN), and of F. candida with cryptostigmatid mites. Other positive interactions were found for PFN, MFN, F. candida, cryptostigmatid and mesostigmatid mites with litter components, such as beech leaves and litter thickness, moisture and grass, and protozoa. Negative interactions were recorded for PFN, MFN, F. candida, cryptostigmatid and mesostigmatid mites with beech leaves, fungi, protozoa and bacteria. The results have highlighted a very complex structure of factors influencing the temporal and spatial dynamics of the forest litter community. It is suggested that temperature and moisture content particularly influence the invertebrates present. The invertebrates appear to be present in a range of microhabitats, which may have resulted in a reduced level of competition and a high level of positive interactions revealed.

Some aspects of complex interactions involving soil mesofauna: analysis of the results from a Scottish woodland

Stepwise regression modelling and canonical correspondence analysis were used to analyse data on soil properties and the abundance of soil mesofauna collected from a woodland typical of the Borders of Scotland. The pattern of relationships revealed by stepwise regression models was different for each month, and the models compiled on the overall dataset were generally weaker than those compiled for separate months. Functional relationships among different microarthropods revealed by stepwise regression modelling are summarised in a structural model of their statistical associations. Interpretation of specific relationships revealed is given and implications for dynamic simulation models are discussed. Canonical correspondence analysis revealed that both microbial feeding nematodes (MF) and plant feeding nematodes (PF) appear to prefer a high level of bacteria and moisture, glomalin and organic matter in the soil. Close scrutiny, however, reveals that microbial feeding nematodes have a particularly high affinity to the sites with a high level of bacteria and organic matter, whilst plant feeding nematodes appear to be more associated with moisture and glomalin. Folsomia candida was abundant in sites with a higher pH level (pH ranged between 3.1 and 4.9), but was not abundant in sites with high ergosterol or a high bacteria, moisture, glomalin and organic matter level. However, other Collembola (mainly represented by Folsomia quadrioculata) appeared to be associated with high levels of ectomycorrhizal fungi. As F. candida is known to feed on fungal food sources, the results suggest that the relatively high local abundances of this collembolan might have caused local declines in ectomycorrhizal fungi, reflected, in turn, in the increase in pH. In addition, environmental plasticity of this species might have allowed them to expand into areas with low fungal density by utilising alternative food sources. The fact that F. candida was a dominant microarthropod in the majority of the samples collected in this research also supports this point. However, for those samples where F. candida were less abundant, overcompensatory fungal growth due to grazing by mites and other Collembola was implicated. Overall, our results suggest that both direct negative and indirect positive effects of the microarthropod community on specific fungal groups appear to take place. The differential effect of specific mesofaunal groups on other soil biota justifies their detailed representation in dynamic simulation models of soil ecosystems.

Integrative analysis of ecological patterns in an untended temperate woodland utilising standard and customised software

The integration of a comprehensive monitoring programme conducted in a temperate woodland through statistical analysis and simulation modelling is presented here. The Heron Wood Reserve in Peebleshire, Scotland is a 7.5-ha wood, left untended to facilitate investigation into a natural Scottish Woodland Ecosystem. Data on fungal fruiting have been collected since 1994, and since November 2000 physico-chemical and biotic experiments on soil and woodland litter have also been conducted with the aim to construct and integrate a number of simulation submodels of the various ecological systems present in an untended Scottish woodland. Important systems for modelling include patterns of fungal succession, habitat characteristics and fungal biochemical patterns. A large volume of data has been collected so computer software is used for the storage and handling of data. Microsoft Access was the database used for storage; integration of functions available in Microsoft Excel with a customised software written in Microsoft Visual Basic and Microsoft VBA allowed various statistical modelling tests (e.g. Scheffé analysis of contrast) to be carried out, and the quick display of data in a suitable manner. Model Maker software is used to construct and test simulation models formulated from the data and ultimately to facilitate the running of various simulations. Integration of the separate lines of investigation is demonstrated on the example of a case study describing differences in the dynamics of decomposers in beech- and birch-dominated habitats. Integration of the information obtained allowed us to put forward the following hypothesis. The leaf litter produced by beech trees is of lower quality compared to birch, and decomposition in beech-dominated habitats is delayed (i.e. in comparison to birch-dominated) because of the differences in the extent to which these plants create and maintain a litter and humus layer ( sensu Wardle, Communities and Ecosystems. Linking the Aboveground and Belowground Components, Princeton University Press, Princeton, 2002). Hence, the decomposition in beech-dominated habitats mainly occurs somewhat deeper in the soil profile, and may be carried out with some considerable involvement of ectomycorrhizal fungi. The correct understanding of the site-specific peculiarities of the ecological patterns is important for the improvement of biodiversity of woodland and forest ecosystems both in Scotland and worldwide.

Book Reviews

BOOK REVIEWS Paolo Di Martino, Storia del Paesaggio Forestale del Molise (sec. XIXÑXX) [History of the Forest Landscape of Molise (19th and 20th centuries)] (OLIVER RACKHAM) Blaine Harden, A River Lost: the life and death of the Columbia (A.T. GROVE) Dale H. Porter, The Thames Embankment: Environment, Technology and Society in Victorian London (JOHN SHEAIL) T.C. Smout (ed.), Scottish Woodland History (OLIVER RACKHAM)

Scottish woodlands: Their ancient past and precarious present

Summary The highly complex history of Pinus sylvestris in Scotland is outlined and new radiocarbon ages for stumps in west central Scotland are published. What Roman and later authors meant by the Great Wood of Caledon is critically appraised. Contrary to the long held and often repeated belief, the Romans marched into a lowland Scotland already largely cleared of woodland. There are oak woodlands in Scotland, such as Mugdock and Garscadden Woods, that show very clear signs of ancient woodmanship, as discussed for England by Rackham. Enthusiasts for the reconstruction of the wildwood in Scotland face a very difficult task; they need to take account of period, place and plants other than trees.

Regional variation in the origin, extent and composition of Scottish Woodland

Summary Results from the Nature Conservancy Council's Inventory of Ancient Woodland show regional variations in the extent, origin and composition of Scottish woods and the degree to which they are recognized as important sites for nature conservation. Around 14.5% of Scotland is forested but not more than 2% of the land area is ancient woodland. Nearly half of the ancient area has been replanted, mainly with introduced conifers. Thus the area retaining ancient semi-natural woodland covers just 1 % of Scotland. Woodland within Sites of Special Scientific Interest or nature reserves covers 38,154 ha. The majority of this is ancient semi-natural woodland, but 68% of the total ancient semi-natural woodland area is not so protected. The value for nature conservation of many ancient sites has declined because of the extent of replanting and overgrazing. Recent beneficial changes in land use policies and practices need to be continued to prevent further decline in the nature conservation value of these important woods.

Relationship of Some European Scots Pine Populations to Native Scottish Woodlands Based on Monoterpene Analysis

Relationship of Some European Scots Pine Populations to Native Scottish Woodlands Based on Monoterpene Analysis

SCOTTISH WOODLAND OWNERS ASSOCIATION—the Timber Producers' Representative in Scotland

SCOTTISH WOODLAND OWNERS ASSOCIATION—the Timber Producers' Representative in Scotland