Cab international jun 1998 (5 Ergebnisse)

Taschenbuch. Zustand: Neu. Neuware - Resources for agricultural science are scarce across the world. Yet even as resources are shrinking, agricultural science has expanded its inquiry into many new areas - such as environmental preservation, food quality, and rural development - without forsaking its more traditional concerns. In a time of tight government budgets, research administrators are faced with the need to provide strong evidence that costs are justified by benefits. Science under Scarcity is an invaluable guide to the theory and methods necessary for evaluating research in agriculture and for setting priorities for resource allocation. Although economists have made significant progress in developing more sophisticated methods for research evaluation and priority setting, many research analysts and administrators do not have a working knowledge of those practices. Without the assistance of formal economic analysis it is particularly difficult to assess the social value of new technologies or to make informed judgements about the trade-offs that are involved in allocation decisions. Addressing that knowledge gap, this book reviews, synthesizes, and extends such methods as economic surplus analysis, econometric techniques, mathematical programming procedures, and scoring models. It discusses these practices in the context of scientific policy, describes their conceptual foundations, and explains how to do them. Originally published in 1995 in hardcover by Cornell University Press, it is now reissued in paperback by CAB INTERNATIONAL.…

Buch. Zustand: Neu. Neuware - Silviculture in tropical forests has a long history going back many centuries and active management for timber production began about two hundred years ago. There is therefore a considerable body of evidence regarding both sustainable and destructive forestry practices in these forests, the future of which is the subject of one of the great scientific and public debates of the late twentieth century. Based on fifty years experience by each author and extensive research of the literature, this book provides information, much of which was previously not widely available, on the development of silvicultural systems in tropical moist forest (a broad term which encompasses many forest types). The book begins by tracing the early history and goes on to describe the later, more technical phases and the growth of global exploitation. Examples from many countries are described in detail, considering all aspects including the economic, ecological and social implications. It is the aim of the authors to demonstrate that sustainable timber production in many of these forests is not only possible, but the techniques necessary have been known to foresters for many decades. This book is essential reading for forest managers in the tropics, advanced students and researchers in forestry and ecology concerned with natural resource management and will also be of interest to economists, policy makers and environmentalists.…

Buch. Zustand: Neu. Neuware - Forest is the natural vegetation of most of Europe. Although the majority has been destroyed by human activity over the centuries, a considerable amount remains and has been managed to varying degrees and for a wide variety of reasons. This has resulted in a large number of natural and semi-natural landscapes and habitat types over the region and a high diversity of plant and animal communities adapted to them. The growing interest in natural history and the environment in recent years has resulted in a greater demand for information on the complex ecological history of European forest. This book is unique in providing wide ranging and detailed case studies on specific aspects, including grazing, management practices and conservation and overviews, from recognised authorities, of the latest research on the ecological history of forests and woodland in Europe. It consists of selected papers given at an international conference of forest historians organised in association with the British Ecological Society and the International Union of Forest Research Organizations at Nottingham University in September 1996. Contributions come from the UK, Ireland, Scandinavia, the Low Countries, Germany, France, Spain, Italy and Turkey. This book is essential reading for ecologists, conservationists, landscape historians, foresters and geographers. It will also be of interest to advanced students in these areas.…

Buch. Zustand: Neu. Neuware - Improvements in adaptation and maturity leading to greater yield are the most important criteria for the acceptance of a new crop cultivar, since it is the yield which dictates the economic value of the crop. Therefore, yield improvement is one goal of virtually every crop breeding program. Many such programs have tended to concentrate on identifying the genetic traits responsible for higher yield and selecting each of them in the later stages of the breeding cycle. However, selection for yield per se is still the most effective method, since it is a combination of traits, operating within the limits of the system, which finally determines yield. This book presents a whole-system, or holistic viewpoint for the improvement of adaptation, maturity and yield. Central to its thesis is recognition that system-established changes in levels of the components of the plant system, within a constant capacity, i.e. within the limitations of the system, determines yield and other cultivar characteristics. It goes on to describe how this can improve our understanding of plant systems and enable breeders to maximise performance under prevailing field conditions. Based principally on 25 years research by the authors, the ideas presented in this book are essential reading for crop physiologists and plant breeders.…

Buch. Zustand: Neu. Neuware - Toxic plants and other natural toxicants have a variety of roles in the fields of human health, medical research and the production of safe food and also represent an economic problem in terms of animal health and crop production. Estimates of economic impact on livestock have ranged in the millions of dollars in countries such as Australia and the United States. This book brings together applied and fundamental research from botanists, chemists, biochemists, agricultural scientists, veterinarians and physicians and advice from regulatory bodies. It consists of more than 100 edited papers from the Fifth International Symposium on Poisonous Plants, held in Texas in May 1997. All aspects of poisonous plants, mycotoxicoses and herbal intoxications are covered. Their adverse effects are described, such as fatalities, reduced or failed reproduction, fetotoxicity, spontaneous abortions, deformities, reduced productivity and organ-specific toxicity. Methods of detection, isolation and identification of the chemical compounds responsible are included. The biochemistry of the plant-associated toxins and elucidation of their mechanism of action is investigated, including the protocols for management or eradication, immunization programs, behaviour modification, withholding periods for metabolic detoxification, regulatory advice concerning human usage of natural products and advice concerning toxin-residue in agricultural produce. The development of non-toxic strains of plants for use as fodder is also discussed. This book is essential reading for toxicologists concerned with animal and human health, food industry regulators and plant scientists.…