Adrian C. Newton

Bio: Adrian C. Newton is an academic researcher from James Hutton Institute. The author has contributed to research in topics: Hordeum vulgare & Biodiversity. The author has an hindex of 74, co-authored 453 publications receiving 21814 citations. Previous affiliations of Adrian C. Newton include Seattle Children's Research Institute & University of Peradeniya.

Silvicultural Systems for Big-Leaf Mahogany Plantations

Abstract: The different silvicultural techniques for establishing big-leaf mahogany plantations have been well documented, but these methods frequently take little account of the long-term development of stands or subsequent rotations and cannot properly be called silvicultural systems. As existing plantations begin to mature, the need to consider establishing the next rotation grows, and, therefore, the need to adopt a suitable silvicultural system. Where plantations of big-leaf mahogany have begun to regenerate naturally, the traditional system of clear-cutting and replanting may not be appropriate. Natural regeneration has the advantages of reducing nursery and establishment costs and possibly the extent of damage by shoot borer (Hypsipyla sp.). Early attempts to apply a single tree selection system to big-leaf mahogany plantations were unsuccessful, but recent plans to adopt a modified uniform shelterwood system in Sri Lanka and a group selection system in St. Lucia have been more carefully developed. The proposed systems are described in detail. Successful long-term management of big-leaf mahogany plantations depends on choosing a system that accommodates both the light requirements of the species and key local constraints under which plantation managers are operating. Local constraints should be carefully considered before a silvicultural system is adopted.

Use of additive models to represent trends in a barley field trial

Abstract: Summary Even when a field experiment has been designed with care, subsequent examination of the plot values may reveal additional unforeseen trends. In this paper we examine data from a barley pathology field trial and show that additive models provide a flexible representation of environmental trends, in one or two dimensions. Such models smooth out noise in the observed data, rather than fit an equation specified in advance. This approach tends to increase the precision of treatment comparisons relative to a classical analysis of variance. We recommend the use of residual plots to explore experimental data for underlying trends, and additive models to display these trends and estimate treatment effects.

Susceptibility of oat cultivars to groat discoloration: causes and remedies

Abstract: Fungal isolations and fungicide efficacy trials were carried out to determine the possible causes of discoloration in oat groats and potential control measures. Alternaria species and Microdochium nivale were isolated from field samples, and Fusarium poae was found in glasshouse tests. Symptoms could be induced reliably in the field through the use of a mist irrigation system. The cultivar 'Gerald' was most resistant followed by 'Jalna'. Cultivar 'Image' was most severely affected by discoloration and 'Millennium' was of intermediate susceptibility. None of the 28 fungicide-timing combinations used in the field trials affected the occurrence of discoloured groats. It was concluded that the best strategy for minimizing risk of discoloured groats would be screening new cultivars or breeding material in mist-irrigated field trials for genetically based resistance.

The potential for community-based forest management in Chiapas, Mexico: a comparison of two case studies.

Abstract: Chiapas is among the poorest of Mexico's states and has been characterized by political instability, civil unrest, escalating population and widespread deforestation. Recent history and current land use issues were investigated in two highland communities, Juzanajab and Palma Real, to assess the factors influencing forest management decisions and the potential for sustainable forest use on communally-owned land. The two communities contrasted markedly, Juznajab possessing a larger forest resource, a higher population density, but a lower degree of marginalization. These differences were found to result from the contrasting historical development of the two areas, particularly with respect to the pattern of land use prior to agrarian reform and the impact of agrarian reform itself. More recently, agricultural intensification and intensive timber harvesting have impacted on the forest resources of both communities. The communities also differed in pattern of forest use, five and fourteen different ...

The Theory of Island Biogeography

Abstract: Preface to the Princeton Landmarks in Biology Edition vii Preface xi Symbols Used xiii 1. The Importance of Islands 3 2. Area and Number of Speicies 8 3. Further Explanations of the Area-Diversity Pattern 19 4. The Strategy of Colonization 68 5. Invasibility and the Variable Niche 94 6. Stepping Stones and Biotic Exchange 123 7. Evolutionary Changes Following Colonization 145 8. Prospect 181 Glossary 185 References 193 Index 201

The Design and Analysis of Experiments

Abstract: THE DESIGN AND ANALYSIS OF EXPERIMENTS. By Oscar Kempthorne. New York, John Wiley and Sons, Inc., 1952. 631 pp. $8.50. This book by a teacher of statistics (as well as a consultant for \"experimenters\") is a comprehensive study of the philosophical background for the statistical design of experiment. It is necessary to have some facility with algebraic notation and manipulation to be able to use the volume intelligently. The problems are presented from the theoretical point of view, without such practical examples as would be helpful for those not acquainted with mathematics. The mathematical justification for the techniques is given. As a somewhat advanced treatment of the design and analysis of experiments, this volume will be interesting and helpful for many who approach statistics theoretically as well as practically. With emphasis on the \"why,\" and with description given broadly, the author relates the subject matter to the general theory of statistics and to the general problem of experimental inference. MARGARET J. ROBERTSON

Ecosystems and human well-being: a framework for assessment

Abstract: This first report of the Millennium Ecosystem Assessment describes the conceptual framework that is being used in the MA. It is not a formal assessment of the literature, but rather a scientifically informed presentation of the choices made by the assessment team in structuring the analysis and framing the issues. The conceptual framework elaborated in this report describes the approach and assumptions that will underlie the analysis conducted in the Millennium Ecosystem Assessment. The framework was developed through interactions among the experts involved in the MA as well as stakeholders who will use its findings. It represents one means of examining the linkages between ecosystems and human well-being that is both scientifically credible and relevant to decision-makers. This framework for analysis and decision-making should be of use to a wide array of individuals and institutions in government, the private sector, and civil society that seek to incorporate considerations of ecosystem services in their assessments, plans, and actions.