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.

Mahogany conservation: status and policy initiatives.

Abstract: Genuine or American mahogany is obtained from trees of the genus Swietenia (S. mahagoni, S. macrophylla, and S. humilis), and is one of the premier timbers of international commerce. The trade in mahogany commenced almost five centuries ago with S. mahagoni from the Caribbean; but following ‘commercial’ extinction of this resource, trade became centred on mahogany populations in South and Central America (S. macrophylla). The trade in mahogany is predominantly from primary forests, and has led to population and genetic resource declines — particularly in the Caribbean and Central America. More recently, there have been an increasing number of ‘commercial’ extinctions in South America. As the resource declines, pressures mount to accelerate the illegal extraction of mahogany from National Parks and lands reserved for indigenous (‘Indian’) peoples. Inability to control this trade threatens mahogany populations and genetic resources throughout its range, at the same time adversely affecting the livelihoods of indigenous peoples in the process.Mahogany often regenerates poorly following logging operations that are conducted using current management practices, and further research is required to determine the optimum biological and economic conditions for in situ silviculture. Attempts to cultivate mahogany in plantations have met with little success in the Americas, due mainly to effects of the shoot-borer (Hypsipyla grandella), a moth larva that damages terminal shoots, so leading to excessive branching and reduced timber value (Figs 3 and 4). The success of mahogany plantations in the neotropics will require the development of an integrated pest-management system, perhaps involving the incorporation of pestresistant genotypes within agro-forestry or mixed plantation systems.It is vital that appropriate silvicultural and trade practices are adopted to ensure sustainable mahogany extraction, while at the same time conserving an adequate population and genetic resource-base. To this end, effective trade monitoring and resource-regulation measures must be introduced to assist in controlling illegal trade and to encourage a scientifically managed, sustainable, utilization of mahogany. Two of the three mahogany species, S. humilis and S. mahagoni, have been listed in Appendix II of the Convention on International Trade in Endangered Species (CITES). The third and only other recognized species of Swietenia, S. macrophylla, should also be considered for listing in CITES Appendix II, thereby benefiting from the international trade-monitoring and resource regulation requirements consequent upon such listing.

Impact of alternative metrics on estimates of extent of occurrence for extinction risk assessment

Abstract: In International Union for Conservation of Nature (IUCN) Red List assessments, extent of occurrence (EOO) is a key measure of extinction risk. However, the way assessors estimate EOO from maps of species’ distributions is inconsistent among assessments of different species and among major taxonomic groups. Assessors often estimate EOO from the area of mapped distribution, but these maps often exclude areas that are not habitat in idiosyncratic ways and are not created at the same spatial resolutions. We assessed the impact on extinction risk categories of applying different methods (minimum convex polygon, alpha hull) for estimating EOO for 21,763 species of mammals, birds, and amphibians. Overall, the percentage of threatened species requiring down listing to a lower category of threat (taking into account other Red List criteria under which they qualified) spanned 11–13% for all species combined (14–15% for mammals, 7–8% for birds, and 12–15% for amphibians). These down listings resulted from larger estimates of EOO and depended on the EOO calculation method. Using birds as an example, we found that 14% of threatened and near threatened species could require down listing based on the minimum convex polygon (MCP) approach, an approach that is now recommended by IUCN. Other metrics (such as alpha hull) had marginally smaller impacts. Our results suggest that uniformly applying the MCP approach may lead to a one-time down listing of hundreds of species but ultimately ensure consistency across assessments and realign the calculation of EOO with the theoretical basis on which the metric was founded.

Multiple hybrid origins, genetic diversity and population genetic structure of two endemic Sorbus taxa on the Isle of Arran, Scotland

Abstract: Understanding the processes that have given rise to polyploid hybrid taxa is central to our understanding of plant evolution. In this study, we use an array of genetic markers in a population analysis to elucidate the hybrid origins of the Arran whitebeams Sorbus arranensis and S. pseudofennica, two woody plant taxa endemic to the Isle of Arran, Scotland. It has been proposed that S. arranensis was derived by hybridization between S. aucuparia and S. rupicola, and that subsequent hybridization between S. arranensis and S. aucuparia gave rise to S. pseudofennica. Analyses of species-specific isozyme, nuclear intron and chloroplast DNA markers confirm the proposed origin of S. arranensis, and indicate that S. aucuparia was the female parent in the hybridization. Analysis of microsatellite markers suggests that there have been at least three origins of S. arranensis on Arran. Microsatellite markers also support the proposed hypothesis for the origin of S. pseudofennica, and indicate at least five hybrid origins of this taxon. In total, three multilocus genotypes of S. arranensis and eight of S. pseudofennica were detected on Arran and multilocus genotypic diversity levels Hg were 0.09 and 0.63, respectively. Genetic differentiation (thetaST) values based on multilocus genotypes are substantial (0.344 and 0.470 for S. arranensis and S. pseudofennica, respectively) implying limited seed flow among populations. These results indicate that the endemic Sorbus taxa on Arran are the products of multiple and ongoing evolutionary events. This information must be incorporated into management policies for their future conservation.

Capture of genetic variation by vegetative propagation: processes determining success

Abstract: Vegetative propagation offers the opportunity to rapidly overcome the limitations to domestication imposed by long generation times, irregular fruiting/flowering and outbreeding. Vegetative propagation techniques are increasingly being applied to a wide range of tree species, of both moist and dry tropics. Identification of the critical factors determining adventitious root development is crucial to sustained, cost-effective propagation, even in 'species in which these factors are not currently limiting. Over the past ten years, research at ITE has identified a wide range of factors which influence rooting, including the stockplant growth environment, cutting origin, post-severance treatments applied to cuttings, and the propagation environment. In order to understand the influence of these different factors and their interactions, an appreciation of the physiological, biochemical and cytological processes involved in rooting is required. The primary processes occurring in the leaf are net photosynthesis and transpiration, while those in the stem are starch hydrolysis, translocation of sugars, water and nutrients, respiration, mitosis and cell differentiation. Each of these processes is influenced by a number of environmental, morphological and physiological variables, such as leaf area and thickness, internode length, chlorophyll content, stomatal density stem Uglification, etc. Suggestions are made for experimental approaches to improve further the understanding of the mechanisms of rooting of leafy stem cuttings. These approaches include the development of a mechanistic model of adventitious root development. The practical implications arising from a process-based approach to propagation are also discussed.

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.