E. Holden

Bio: E. Holden is an academic researcher. The author has contributed to research in topics: Threatened species & Hydnoid fungi. The author has an hindex of 4, co-authored 5 publications receiving 250 citations.

Progress towards implementing the Biodiversity Action Plan for stipitate hydnoid fungi in Scotland

Abstract: Summary Stipitate hydnoid (‘tooth’) fungi are considered to be threatened throughout much of central and northern Europe. In response to concern about the status of these fungi in the UK, a Biodiversity Action Plan has been developed for 14 species in this group. As a first step towards implementation of this plan, a number of surveys have been initiated, to determine the current status and distribution of hydnoid fungi. An overview of the results of these surveys is described. A series of distribution maps are presented, based on a compilation of early records and the results of a recent field survey in Scottish coniferous forests. The difficulties of interpreting early records are discussed, with particular reference to the taxonomie confusion that has surrounded this group of fungi. Although available data provide little evidence for decline of hydnoid fungi, a number of species display very restricted distributions within Scotland. The recent discovery of several species new to Britain emphasises the ...

Fungal conservation in Scotland: Recent progress and future priorities

Abstract: Summary In recent years, fungal conservation in Scotland has made substantial progress, particularly as a result of field surveys undertaken in support of the Biodiversity Action Plans developed for selected species. Results are presented from four recent surveys: (i) fungal diversity in conifer plantations, (ii) hydnoid (‘tooth’) fungi in coniferous forests, (iii) grassland fungi, (iv) fungal survey of the Mar Lodge Estate. These surveys have substantially improved knowledge of the conservation status of a number of threatened taxa, and have also provided insights into patterns of fungal diversity at a range of scales. The results indicate that some of the fungal communities of Scotland, such as those associated with unimproved grasslands, are of international conservation importance. The implications of the survey results for conservation management are discussed, and suggestions are made regarding priorities for future work. In particular, there is a need to provide conservation managers with guidance ...

Plantation forests and biodiversity: oxymoron or opportunity

Abstract: Losses of natural and semi-natural forests, mostly to agriculture, are a significant concern for biodiversity. Against this trend, the area of intensively managed plantation forests increases, and there is much debate about the implications for biodiversity. We provide a comprehensive review of the function of plantation forests as habitat compared with other land cover, examine the effects on biodiversity at the landscape scale, and synthesise context-specific effects of plantation forestry on biodiversity. Natural forests are usually more suitable as habitat for a wider range of native forest species than plantation forests but there is abundant evidence that plantation forests can provide valuable habitat, even for some threatened and endangered species, and may contribute to the conservation of biodiversity by various mechanisms. In landscapes where forest is the natural land cover, plantation forests may represent a low-contrast matrix, and afforestation of agricultural land can assist conservation by providing complementary forest habitat, buffering edge effects, and increasing connectivity. In contrast, conversion of natural forests and afforestation of natural non-forest land is detrimental. However, regional deforestation pressure for agricultural development may render plantation forestry a ‘lesser evil’ if forest managers protect indigenous vegetation remnants. We provide numerous context-specific examples and case studies to assist impact assessments of plantation forestry, and we offer a range of management recommendations. This paper also serves as an introduction and background paper to this special issue on the effects of plantation forests on biodiversity.

Plantation Forests and Biodiversity: Oxymoron or Opportunity?

Abstract: Losses of natural and semi-natural forests, mostly to agriculture, are a significant concern for biodiversity. Against this trend, the area of intensively managed plantation forests increases, and there is much debate about the implications for biodiversity. We provide a comprehensive review of the function of plantation forests as habitat compared with other land cover, examine the effects on biodiversity at the landscape scale, and synthesise context-specific effects of plantation forestry on biodiversity. Natural forests are usually more suitable as habitat for a wider range of native forest species than plantation forests but there is abundant evidence that plantation forests can provide valuable habitat, even for some threatened and endangered species, and may contribute to the conservation of biodiversity by various mechanisms. In landscapes where forest is the natural land cover, plantation forests may represent a low-contrast matrix, and afforestation of agricultural land can assist conservation by providing complementary forest habitat, buffering edge effects, and increasing connectivity. In contrast, conversion of natural forests and afforestation of natural non-forest land is detrimental. However, regional deforestation pressure for agricultural development may render plantation forestry a ‘lesser evil’ if forest managers protect indigenous vegetation remnants. We provide numerous context-specific examples and case studies to assist impact assessments of plantation forestry, and we offer a range of management recommendations. This paper also serves as an introduction and background paper to this special issue on the effects of plantation forests on biodiversity.

Planted forests and biodiversity.

Abstract: Expansion of planted forests and intensification of their management has raised concerns among forest managers and the public over the implications of these trends for sustainable production and conservation of forest biological diversity. We review the current state of knowledge on the impacts of plantation forestry on genetic and species diversity at different spatial scales and discuss the economic and ecological implications of biodiversity management within plantation stands and landscapes. Managing plantations to produce goods such as timber while also enhancing ecological services such as biodiversity involves tradeoffs, which can be made only with a clear understanding of the ecological context of plantations in the broader landscape and agreement among stakeholders on the desired balance of goods and ecological services from plantations.

Approaches to quantifying forest structures

Abstract: Summary For some time, structure indices ‐ quantifying spatial stand structure ‐ have been integrated into forest research and are used to provide a measure of biodiversity. In addition, correlation functions ‐ developed initially for problems outside forestry ‐ enable analysis and characterization of forest stand structures, generating more accessible information. This paper outlines a classification of structural indices measuring alpha diversity and examines typical representatives of the classification groups such as the Shannon index, the aggregation index of Clark and Evans, the contagion index, the coefficient of segregation of Pielou, the mingling index, the diameter differentiation index, the pair correlation and the mark correlation function. These can be used to measure differences between forests in time and space, to generate forest structures, to analyse the differences between observed and expected structures and to characterize modifications of forest structure resulting from selective harvesting. These algorithms are the keys for assessing complex forest structures, which can be the result of continuous cover forestry methods. Continuous cover forests with selective harvesting are being promoted in the new forest policies of Britain. Case studies have shown that from given spatial forest structures one can possibly conclude the suitability for habitats, a hypothesis which has yet to be proved by further appropriate analysis. The equations for the quantification of stand structure presented in this paper have the advantage that they are easier to survey during forest inventory than the more direct measures of ecological variety.

Wood ash use in forestry – a review of the environmental impacts

Abstract: The use of wood fuel for energy production in the UK is set to increase in the near future as part of a government commitment to increase renewable sources to 10 per cent by 2010. The ash generated as a by-product of combustion, whether for heat or power generation, has potential use as a fertilizer in forest systems. This review assesses the available information on factors affecting the quality of the ash and environmental implications arising from its application. The key determinants of wood ash chemistry are the tree species combusted, the nature of the burn process and the conditions at the application site. Wood ash from hardwood species produces higher levels of macronutrients in their ash than conifers, and the silica content is frequently lower. A furnace temperature between 500 and 900°C is critical to the retention of nutrients, particularly potassium, and determines the concentrations of potentially toxic metals including aluminium in the ash. Fly ash, the lightest component that accumulates in the fl ue system, can contain high concentrations of cadmium, copper, chromium, lead and arsenic and this ash should not be used as fertilizer. The form of the ash at application is important, with loose ash releasing Ca, K and Na more rapidly than granulated ash. Heavy metal, radionuclide and dioxin contamination of wood ash-based fertilizers is minimal and unlikely to affect ecosystem function. The effects of wood ash are primarily governed by application rate and soil type. The benefi ts are maximized at low dose rates, with possible toxicity from applications in excess of 10 t ha −1 . For most forest sites, a single wood ash application per rotation could replace all the nutrients lost after whole-tree harvesting (excepting N). Long-lasting positive effects on tree growth have been observed on shallow peats, in which the humus is slowly mineralized in response to elevated pH and increased nutrient availability. In contrast, wood ash application to podzols is only effective in enhancing tree growth when nitrogen availability is nonlimiting. To date, published research of wood ash effects on trees growing in clays and loams is minimal. A lag time for positive tree responses to wood ash application is often observed, and may be the result of phosphorous limitation at higher soil pH. The greatest reported adverse ecological effects are to acidophilic ecosystems, particularly the constituent bryophyte, soil bacteria and ectomycorrhizal communities.