Download or read book Control of bracken and the restoration of heathland V Effects of bracken control treatments on the rhizome and its relationship with frond performance written by R H. Marrs and published by . This book was released on 1993 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: 1. The effect of three bracken control treatments on the rhizome system of bracken (Pteridum aquilinum (L.) Kuhn) at Cavenham and Weeting Heaths in Breckland was assessed. Control treatments included cutting once and twice yearly between 1978 and 1990, and spraying the herbicide asulam at the recommended rate (4.4 kg a.i. ha-1) in 1978 and 1985. In addition, the effect of continuous treatment was compared with plots in which bracken control ceased after 6 years. The effects on rhizome biomass and length, numbers of active and dormant buds, and starch and soluble carbohydrate concentrations were measured. 2. Cutting twice yearly was the most effective treatment, but rhizomes persisted even after 12 years of continous treatment. Cutting once yearly and applying asulam gave intermediate reductions in all rhizome variables. 3. Where bracken control ceased there was a relatively rapid increase in all measures of rhizome performance. At Cavenham Heath, remission for 4 years increased the starch levels in rhizomes, and after 6 years increased all rhizome measures. At Weeting Heath all measures were significantly increased 5 years after control treatments ceased. 4. Regression analyses showed that the majority of the variation in summer frond performance (0.39-0.75) could be explained by rhizome biomass. At both sites amounts of starch and carbohydrate in the rhizome, and at Weeting the above-ground grass biomass and total bud number, improved the fit of some equations. 5. Some earlier published data for Weeting Heath were used to estimate rates of rhizome depletion and recovery. Extrapolation from these results suggested that it would take (a) a further 8-34 years to eradicate bracken depending on treatment, and (b) between 9 years (for the cut once yearly and asulam treatments) and 62 years (for the cut twice yearly treatment) for the bracken rhizome system to recover its starting biomass. Moreover, a large frond biomass would occur before the rhizome system recovered com.
Download or read book Fern Ecology written by Klaus Mehltreter and published by Cambridge University Press. This book was released on 2010-06-03 with total page 473 pages. Available in PDF, EPUB and Kindle. Book excerpt: Ferns are an integral part of the world's flora, appreciated for their beauty as ornamentals, problematic as invaders and endangered by human interference. They often dominate forest understories but also colonize open areas, invade waterways and survive in nutrient-poor wastelands and eroded pastures. Presented here is the first comprehensive summary of fern ecology, with worldwide examples from Siberia to the islands of Hawaii. Topics include a brief history of the ecological study of ferns, a global survey of fern biogeography, fern population dynamics, the role of ferns in ecosystem nutrient cycles, their adaptations to xeric environments and future directions in fern ecology. Fully illustrated concepts and processes provide a framework for future research and utilization of ferns for graduate students and professionals in ecology, conservation and land management.
Download or read book Ecology Abstracts written by and published by . This book was released on 1993 with total page 948 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Heaths and Moorland written by D. B. A. Thompson and published by Stationery Office Books (TSO). This book was released on 1995 with total page 436 pages. Available in PDF, EPUB and Kindle. Book excerpt: Western Europe has a wide range of heathers and moorland, with Great Britain and Ireland having optimum conditions for the full development of heather. Scotland has a mixture of blanket bogs, wet heathers and moorland scapes shaped by burning and other sorts of management mainly for red grouse, hill sheep and red deer. This text celebrates these landscapes - their history, habitats, wildlife and beauty. It also incorporates the ecologist Professor Charles H. Gimingham, to develop the study of heaths and moorland.
Download or read book Report of the Institute of Terrestrial Ecology written by and published by . This book was released on 1989 with total page 492 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Current Advances in Ecological Environmental Sciences written by and published by . This book was released on 1993-05 with total page 486 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Biological Agricultural Index written by and published by . This book was released on 1992 with total page 2652 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Agrindex written by and published by . This book was released on 1995 with total page 1088 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The effects of control on the biomass carbohydrate content and bud reserves of bracken Pteridium aquilinum L Kuhn and an evaluation of a bracken growth model written by R J. Pakeman and published by . This book was released on 1994 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: This paper examines the initial effects of bracken control on frond numbers and biomass, and the biomass, carbohydrate reserves and bud densities of bracken stands cut once per year, twice per year, subject to a single application of asulam or left untreated. The seasonal dynamics of these parameters are displayed; carbohydrate and biomass are both removed from the rhizome system to produce frond tissue, and are replenished at the end of the growing season. Asulam application reduced densities of both active and dormant buds, and both frond biomass and density. It did not significantly reduce rhizome biomass or carbohydrate reserves in the two years after treatment. Cutting, either once or twice per year reduced both rhizome biomass and rhizome carbohydrate reserves, as well as bud densities, though the latter were reduced in proportion to biomass. Cutting twice a year reduced the production of fronds, both in numbers and biomass. The collected data were used to evaluate a model of bracken growth, and subsequently to improve estimates of some of the model parameters. The model simulations of control treatments were compared to field data. The effects of cutting once per year and spraying with asulam were predicted accurately, but the bracken stand was more resilient to cutting twice per year than would be expected from model predictions. The combination of cutting and spraying is discussed as a potential tool in land management and the deficiencies of the model are discussed in relation to the need for future research into the biology of bracken.
Download or read book Integrated Bracken Control and Vegetation Restoration Final Report written by M. G. Le Duc and published by . This book was released on 1996 with total page 152 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Bibliography of Agriculture written by and published by . This book was released on 1986 with total page 1074 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book A model of bracken Pteridium aquilinum growth and the effects of control strategies and changing climate written by R J. Pakeman and published by . This book was released on 1994 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: 1. A mechanistic physiological model for the growth of bracken has been developed which describes its yearly cycle in terms of three compartments: frond biomass, rhizome tissue biomass and rhizome carbohydrate. 2. Difference equations for various processes (including rhizome respiration, tissue senescence, photosynthesis and fluxes between compartments) are presented. 3. These are combined to obtain equations for the three compartments for each stage in the yearly cycle of bracken growth. Collectively, these equations constitute the bracken growth model. 4. The model can be used to predict the effects of different control measures on the biomass present in the stand. 5. As a number of environmental factors are involved in the model, the effects of changes in these variables can be predicted. 6. The deficiencies of the model are discussed and these emphasize areas where research on bracken should be focused.
Download or read book Restoring Natural Capital written by James Aronson and published by Island Press. This book was released on 2012-09-26 with total page 400 pages. Available in PDF, EPUB and Kindle. Book excerpt: How can environmental degradation be stopped? How can it be reversed? And how can the damage already done be repaired? The authors of this volume argue that a two-pronged approach is needed: reducing demand for ecosystem goods and services and better management of them, coupled with an increase in supply through environmental restoration. Restoring Natural Capital brings together economists and ecologists, theoreticians, practitioners, policy makers, and scientists from the developed and developing worlds to consider the costs and benefits of repairing ecosystem goods and services in natural and socioecological systems. It examines the business and practice of restoring natural capital, and seeks to establish common ground between economists and ecologists with respect to the restoration of degraded ecosystems and landscapes and the still broader task of restoring natural capital. The book focuses on developing strategies that can achieve the best outcomes in the shortest amount of time as it: • considers conceptual and theoretical issues from both an economic and ecological perspective • examines specific strategies to foster the restoration of natural capital and offers a synthesis and a vision of the way forward Nineteen case studies from around the world illustrate challenges and achievements in setting targets, refining approaches to finding and implementing restoration projects, and using restoration of natural capital as an economic opportunity. Throughout, contributors make the case that the restoration of natural capital requires close collaboration among scientists from across disciplines as well as local people, and when successfully executed represents a practical, realistic, and essential tool for achieving lasting sustainable development.
Download or read book Long term recovery of bracken Pteridium aquilinum L Kuhn after asulam spraying written by R J. Pakeman and published by . This book was released on 1993 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: This paper investigates the effects of a single asulam application, sprayed from the air, on the rhizome biomass, bud density, fronds and carbohydrate reserves of bracken (Pteridium aquilinum (L.) Kuhn) using a time sequence approach. Regression models were used to investigate how these characteristics varied with time after spraying, and were used, where appropriate, to calculate the time taken for full recovery after treatment. Frond density and biomass recovered in approximately eight years, bud numbers in seven, but rhizome biomass and total carbohydrate reserves required 10 to 12 years to recover. The consequences of these results are compared with predictions from a computer model and discussed in relation to the best timing of re-treatment and the management needed for long term control.
Download or read book Silviculture in the Tropics written by Sven Günter and published by Springer Science & Business Media. This book was released on 2011-06-24 with total page 547 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book integrates the latest global developments in forestry science and practice and their relevance for the sustainable management of tropical forests. The influence of social dimensions on the development of silvicultural concepts is another spotlight. Ecology and silvicultural options form all tropical continents, and forest formations from dry to moist forests and from lowland to mountain forests are covered. Review chapters which guide readers through this complex subject integrate numerous illustrative and quantitative case studies by experts from all over the world. On the basis of a cross-sectional evaluation of the case studies presented, the authors put forward possible silvicultural contributions towards sustainability in a changing world. The book is addressed to a broad readership from forestry and environmental disciplines.
Download or read book Vegetation Dynamics written by R. Knapp and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 333 pages. Available in PDF, EPUB and Kindle. Book excerpt: During the International Botanical Congress in Edinburgh, 1964, Mrs. 1. M. WEISBACH-J UNK of The Hague discussed a plan for preparation by her publishing company (Dr. W. Junk b.v.) of an international Handbook of Vegetation Science. She proposed a series that should give a comprehensive survey of the varied directions within this science, and their achievements to date as well as their objectives for the future. The challenge of such an enterprise, and its evident value for the further development of vegetation research, induced the undersigned after some consideration to accept the offer of the honorable but also burdensome task of General Editor. The decision was encouraged by a well formulated and detailed outline for the Handbook worked out by the Dutch phytosociolo gists J. J. BARKMAN and V. WESTHOFF. A circle of scholars from numerous countries was invited by the Dr. Junk Publishing Com pany to The Hague in January 1966 to draw up a list of editors and contributors for the parts of the Handbook. The outline and list have served since for the organization of the Handbook, with no need for major change. The different burdens of editors and authors have compelled quite different timings for completion of the individual sections.
Download or read book Conserving Bogs written by Rob E. Stoneman and published by Stationery Office Books (TSO). This book was released on 1997 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Bogs are fascinating landscapes for ecologists, climatologists, archaeologists, environmental historians and water managers. But many bogs have been damaged, and legislative protection - as 29 case studies demonstrate - is not enough to conserve the rest.
