Download or read book Top Dying of Norway Spruce in Great Britain written by J. S. Murray and published by . This book was released on 1957 with total page 14 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Top dying of Norway Spruce with Special Reference to Rhizosphaera Kalkhoffi Bubak written by Stephanos Diamandis and published by . This book was released on 1977 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: In recent years, in Great Britain and countries situated along the coastal fringe of Northwestern Europe, "top-dying" has become the most destructive disease of Norway spruce (Picea abies (L.) Karst.). The disease affects healthy trees in the dormant period during years characterized by mild, windy winters (March included). The first effect to appear on trees in the interior of thinned plantations is reduction of height growth which may be followed by foliage loss. It is thought that this pattern is also followed by edge trees. When dry flay to August periods follow such winters the growth reduction is steep, anddeterioration of the health status of affected trees is speeded up. Occurrence of severe outbreaks of the disease may result when weather such as the above takes place for more than two consecutive years. The present outbreak in N.E. Scotland is regarded as commencing in 1971t thereafter continuously developing due to unusually mild windy winters accompanied by dry summers (May included) during the period 1971-75. Data for wind duration, air temperature and rainfall for the years 1961-75 were used as variables and annual height increments from three repeat stands were used as the dependent variable in a stepwise multiple regression analysis. Significant correlations with height growth, which precedes needle-browning, were always found for edge trees of stands and occasionally for trees inside stands. Trees, once affected by the disease, go through four distinguishable stages of deteriorating health until they die. These stages can be recognized by the significantly different amounts of needle loss. During the "top-dying" annual cycles-1971-75 and 1975-76 needle-browning in all tree-health categories started building up in mid, late winter-spring and culminated just before and in the early flushing period. Sudden, sharp increase of the rate of needle-browning was found to be closely associated with short spells characterized by clear sunny, warm weather accompanied by high velocity wind and low or even freezing temperature at night, occurring in the dormant period. Needle-browning was successfully prevented by bagging shoots from the early flushing period until late August. Tip needles of current and second year were found to retain a significantly lower water content than base needles (expressed on needle dry weight) as did needles from bare 1 shoots compared withbaggedones during the period January-May. Water uptake by roots of Norway spruce plants, four years of age was significantly lower when cold water was supplied. Uptake at l u was found to be only 49.51% of that at 20G. Close observations and a number of experiments failed to show that R. kalkhoffii Bubak or any other needle fungus has a primary involvement in "top-dying". Similarly, no fungus likely to be strongly pathogenic to Norway spruce was isolated from various tissues of current and second year shoots. Strong evidence suggested that the fungus R. kalkhoffii isolated from Norway spruce and dealt with in this work is a different strain from those isolated in the U.S.A. and Japan from other host species. Its optimum temperature for diameter growth on malt agar was 18C. Malt agar pH's ranging from 3.5 to 9 (before autoclaving) did not have any significant effect on growth. It was shown to be a very successful colonizer of dying needles during its infection period which in 1976-77 started building up in August, culminated in October and stopped in late February. The hypothesis was developed that "top-dying" is caused by severe water stress created by adverse climatic conditions, chiefly mild, windy weather during the dormant period enforced by drought in the first part of the growing season. When conditions such as these occur for more than two consecutive years severe outbreaks of the disease may occur. In a test of this hypothesis, one young Norway spruce plant out of two tested, exhibited in vitro symptoms very similar to those recorded in the field after a 75 hr, exposure period under conditions consisting of air temperature 14C, relative humidity 70% and photoperiod of 12 hrs.
Download or read book Diseases of Forest and Ornamental Trees written by D. H. Phillips and published by Springer. This book was released on 1992-06-18 with total page 615 pages. Available in PDF, EPUB and Kindle. Book excerpt: Gives a review of the diseases of the major genera of forest and ornamental trees. The introduction deals with the causes, symptoms and diagnosis of disease, and with control measures which include plant health legislation. Over 100 diseases are illustrated with either photographs or drawings.
Download or read book USDA Forest Service Research Paper PNW written by Pacific Northwest Forest and Range Experiment Station (Portland, Or.) and published by . This book was released on 1970 with total page 262 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Mechanics of Debris Avalanching in Shallow Till Soils of Southeast Alaska written by Douglas N. Swanston and published by . This book was released on 1970 with total page 628 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Silviculture of Trees Used in British Forestry 3rd Edition written by Peter S Savill and published by CABI. This book was released on 2019-04-12 with total page 413 pages. Available in PDF, EPUB and Kindle. Book excerpt: British woodlands and forests are often located on sites and in regions that are marginal for agriculture; many are at high elevations and exposed, with short growing seasons. Wherever forests are located, site and climatic conditions must dictate species choice in forest management. This book provides a detailed guide to the biological suitability of different sites and soils for all important native trees and the most extensively used exotics. Apart from physical difficulties such as steepness and stoniness, forest soils also frequently have problems associated with them. They can be waterlogged or drought-prone, suffer from extremes of acidity or alkalinity, or have compacted layers. The book provides information on species' suitability for different purposes. It includes details of species' origin and introduction (where applicable), as well as their climatic and soil requirements and other silvicultural characteristics. Information about provenance, yield and timber is also provided. Fully updated throughout, this 3rd edition puts more emphasis on species suitable for changing climatic conditions, with accounts of several species that may become more prominent in British forests: including several silver firs, hickories, eucalypts, spruces, poplars and wingnuts. The book concludes with simple keys for identifying the trees most likely to be encountered in British forests. It is an essential resource for students, researchers and forestry professionals.
Download or read book Sitka Spruce written by and published by . This book was released on 1970 with total page 260 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Sitka Spruce written by Robert H. Ruth and published by . This book was released on 1970 with total page 260 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Global Climate Change and Human Impacts on Forest Ecosystems written by J. Puhe and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 604 pages. Available in PDF, EPUB and Kindle. Book excerpt: The inclusion of forests as potential biological sinks in the Kyoto Protocol to the United Nations Framework Convention on Climate Change (UNFCCC) in 1997 has attracted international attention and again has put scientific and political focus on the world's forests, regarding their state and development. The international discus sion induced by the Kyoto Protocol has clearly shown that not only the tropical rain forests are endangered by man's activities, but also that the forest ecosystems of boreal, temperate, mediterranean and subtropical regions have been drastically modified. Deforestation on a large scale, burning, over-exploitation, and the degra dation of the biological diversity are well-known symptoms in forests all over the world. This negative development happens in spite of the already existing knowledge of the benefits of forests on global energy and water regimes, the biogeochemical cycling of carbon and other elements as well as on the biological and cultural diversity. The reasons why man does not take care of forests properly are manifold and complex and there is no easy solution how to change the existing negative trends. One reason that makes it so difficult to assess the impacts of human activity on the future development of forests is the large time scale in which forests react, ranging from decades to centuries.
Download or read book Scottish Forestry written by and published by . This book was released on 1958 with total page 252 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Forest Record written by and published by . This book was released on 1965 with total page 764 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Rural Resource Management Routledge Revivals written by Paul Cloke and published by Routledge. This book was released on 2013-10-18 with total page 401 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book, first published in 1985, provides an overview of resource management, together with a geographical treatment of physical, landscape and social resources. Drawing on British, European and North American material, the book has three main objectives: to offer an integrated review of the rural resource system, to isolate potential and actual conflicts between resources in the countryside with the aid of detailed case studies, and to explore various broad management techniques and their applicability to differing types of resource use and resource conflict. This title will provide important insight for students of geography, resource management, environmental planning and conservation.
Download or read book Applied Agrometeorology written by Kees Stigter and published by Springer Science & Business Media. This book was released on 2010-06-29 with total page 1042 pages. Available in PDF, EPUB and Kindle. Book excerpt: Farmers Agricultural policymakers Environmentalists
Download or read book Forest Decline and Ozone written by Heinrich Sandermann and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 417 pages. Available in PDF, EPUB and Kindle. Book excerpt: The idea for this book arose in 1993, after the Free State of Bavaria through its Bayrisches Staatsministerium rur Landesentwicklung und Umweltfragen (Bavarian Ministry of Regional Development and the Environment) decided to discontinue both the Bavarian project management (PBWU) for forest decline research and the multidisciplinary field research on the Wank Mountain in the Alps near Garmisch. Forest decline through the action of ozone and other photooxidants was a main topic of the supported re search in the Alps and will be a topic of new investigations in the Bavarian Forest. Many interesting results were obtained, but the researchers involved have not had sufficient time to allow reliable conclusions to be drawn. It was therefore decided to ask inter national experts for contributions in order to summarize the best available evidence of a possible link between ozone and forest decline - a topic which has been studied in the USA since the late 1950s and in Europe since the early 1980s. The original idea of Waldsterben as an irreversible large-scale dieback of forests in Germany was soon recognized to be wrong (Forschungsbeirat 1989). However, the new criteria used for the official German and European damage inventories (loss or yel lowing of needles or leaves, tree morphology) indicate that per sistently high percentages of damaged spruce and pine remain, and there is an increasing percentage of damaged beech and oak, with a high proportion of biotic disease (Forschungsbeirat 1989; UN-ECE 1995).
Download or read book Bibliography of Agriculture written by and published by . This book was released on 1975 with total page 1922 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Proceedings written by and published by . This book was released on 1986 with total page 454 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Proceedings written by and published by . This book was released on 1987 with total page 608 pages. Available in PDF, EPUB and Kindle. Book excerpt:
