Download or read book Potential mechanisms of acid mist injury to red spruce written by I D (Ian) Leith and published by . This book was released on 1995 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: One-year-old red spruce seedlings (Picea rubens Sarg.) were exposed to six simulated mist treatments in open-top chambers, between 25 May and 8 November 1988. Mists were applied twice weekly to foilage and soil, with each application equivalent to 2 mm precipitation, applied over 30 min. The treatments contained pairwise combinations of H+, NH4+, SO4(2-) and NO3- ions at concentrations of 1.6 or 3.2 mol m-3, with one treatment including all four ions. Effects of individual ions and ion combinations on visible injury, growth and nutrition were determined. After four applications of H2SO4 at 3.2 mol m-3 (pH 2.5), current year needles turned red-brown. Subsequent application of H2SO4 at a reduced concentration of 0.5 mol m-3 (pH 3.0) resulted in no further increase in foliar injury symptoms. No foliar injury symptoms developed on seedlings receiving HNO3 (pH 2.5), NH4NO3 or (NH4)2SO4 treatments. Twenty-five per cent of needles were damaged on seedlings receiving H2SO4 + NH4NO3 (pH 2.5), but only after 24 applications of mist, suggesting that either NH4+ or NO3- ions ameliorated the effect of H2SO4. There was a stimulation in shoot and root biomass in those treatments containing N, with or without H2SO4. Contrast analysis indicated a positive growth response to acidity. Significant uptake of S and N occurred in response to treatment. This experiment indicates that it is the simultaneous presence of H+ and SO4(2-) in occult precipitation that has the greatest potential for inducing foliar injury. The presence of NO3- was found to ameliorate the toxic effects. Potential mechanisms underpinning these observations are discussed.
Download or read book Effects of acid mist on visible injury nutrients and frost hardiness in Sitka Norway and red spruce written by L J (Lucy) Sheppard and published by . This book was released on 1992 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Responses of Northern U S Forests to Environmental Change written by Robert A. Mickler and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 634 pages. Available in PDF, EPUB and Kindle. Book excerpt: Five years of research carried out by the U.S. Department of Agriculture Forest Services' Northern Global Change Program, contributing to our understanding of the effects of multiples stresses on forest ecosystems over multiple spatial and temporal scales. At the physiological level, reports explore changes in growth and biomass, species composition, and wildlife habitat; at the landscape scale, the abundance distribution, and dynamics of species, populations, and communities are addressed. Chapters include studies of nutrient depletion, climate and atmospheric deposition, carbon and nitrogen cycling, insect and disease outbreaks, biotic feedbacks with the atmosphere, interacting effects of multiple stresses, and modeling the regional effects of global change. The book provides sound ecological information for policymakers and land-use planners as well as for researchers in ecology, forestry, atmospheric science, soil science and biogeochemistry.
Download or read book Conifer Cold Hardiness written by F.J. Bigras and published by Springer Science & Business Media. This book was released on 2013-03-14 with total page 593 pages. Available in PDF, EPUB and Kindle. Book excerpt: Conifer Cold Hardiness provides an up-to-date synthesis by leading scientists in the study of the major physiological and environmental factors regulating cold hardiness of conifer tree species. This state-of-the-art reference comprehensively explains current understanding of conifer cold hardiness ranging from the gene to the globe and from the highly applied to the very basic. Topics addressed encompass cold hardiness from the perspectives of ecology, ecophysiology, acclimation and deacclimation, seedling production and reforestation, the impacts of biotic and abiotic factors, and methods for studying and analyzing cold hardiness. The content is relevant to geneticists, ecologists, stress physiologists, environmental and global change scientists, pathologists, advanced nursery and silvicultural practitioners, and graduate students involved in plant biology, plant physiology, horticulture and forestry with an interest in cold hardiness.
Download or read book Acid mist frost hardiness and the decline of red spruce in the Appalachians written by David Fowler and published by . This book was released on 1989 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Acidic Deposition State of Science and Technology written by and published by . This book was released on 1991 with total page 680 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Causal mechanisms by which sulphate nitrate and acidity influence frost hardiness in red spruce written by L J (Lucy) Sheppard and published by . This book was released on 1994 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: This paper summarizes results from four experiments in which red spruce seedlings (Picea rubens Sarg.) were exposed to simulated acid mist containing SO42- , NH4+, NO3- and H+ ions. Seedlings were grown in compost, with or without fertilizer, in charcoal filtered air in open-top chambers near Edinburgh, Scotland. Plants were sprayed from bud burst between May and November with mist containing different concentrations and combinations of the four major ions to provide a range of doses, which were applied at different frequencies. Reductions in frost hardiness expressed in terms of the temperature which killed 50% of shoots (LT(50)) were significantly correlated with the dose of S received by the seedlings. Differences in foliar S concentrations between the controls and treated plants were correlated with S dose. Absolute S concentrations were, however, of limited use for predictive purposes. Seedlings appear to be more sensitive than older trees to S toxicity because the former have the greatest proportion of newly expanding needles which optimize conditions for foliar uptake. Seedlings are also least well equipped to export SO42- ions since they have a smaller resource of older foliage to supplement their assimilate pool. In conditions which promote uncontrolled SO42- ion uptake by foliage, i.e. high external SO42- concentrations and incompletely formed cuticles, the potential exists for the internal build up of SO42- ions. It is proposed that in the absence of sufficient assimilate and N the presence of these high concentrations of SO42- ions in the apoplast or cytosol can lead to protein denaturation and loss of membrane integrity. Reductions in frost hardiness appear to result through direct attack by SO42- ions on membrane proteins which impairs their function. Indirect effects on hardiness occur through both an increased consumption of sugars reducing the 'pool' available for cryoprotection and a reduction in photosynthetic function, the ability to produce suga.
Download or read book Crop Physiology Abstracts written by and published by . This book was released on 1996 with total page 644 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Terrestrial Effects Task Group V Peer Review written by and published by . This book was released on 1987 with total page 718 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book General Technical Report NE written by and published by . This book was released on 1980 with total page 86 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Air Pollution and Multiple Stresses written by Roger Cox and published by . This book was released on 1996 with total page 408 pages. Available in PDF, EPUB and Kindle. Book excerpt: Presents proceedings of an international conference on the combined effects of air pollutants together with other aspects of global change on all levels within forest ecosystems. Topics of papers presented include: air pollutants and natural stresses on forests; effects of single pollutants such as ozone, sulphur dioxide, carbon dioxide, and nitrogen compounds; effects of pollutants in combination; edaphic factors and nutrient cycling; effects of acid deposition; and inciting or predisposing factors for forest decline.
Download or read book Applied Botany Abstracts written by and published by . This book was released on 1995 with total page 660 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Ecology and Decline of Red Spruce in the Eastern United States written by Mary B. Adams and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 427 pages. Available in PDF, EPUB and Kindle. Book excerpt: In the early 1980s there were several published reports of recent, unexplained increases in mortality of red spruce in the Adirondack Mountains and the northern Appalachian Mountains of the eastern United States. These reports coincided with documentation of reductions in radial growth of several species of pine in the southeastern United States, and with the severe, rapid, and widespread decline of Norway spruce, silver fir, and some hardwoods in central Europe. In all of these instances, atmospheric deposition was hypothesized as the cause of the decline. (Throughout this volume, we use the term "decline" to refer to a loosely synchronized regional-scale deterioration of tree health which is brought about by a combination of stress factors. These may be biotic or abiotic in nature, and the combinations may differ from site to site. ) Heated public debate about the causes and possible cures for these forest declines ensued. Through the course of this debate, it became clear that information about forest health and air pollution effects on forests was inadequate to meet policymakers' needs. Ecology and Decline of Red Spruce in the Eastern United States addresses that gap for eastern spruce fir forests and represents the culmination of a great deal of research conducted in recent years. The focus is on red spruce because the decline of red spruce was both dramatic and inexplicable and because of the great amount of information gathered on red spruce.
Download or read book Report of the Institute of Terrestrial Ecology written by and published by . This book was released on 1993 with total page 588 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Acid mist affects dehardening budburst and shoot growth in red spruce written by L J (Lucy) Sheppard and published by . This book was released on 1993 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Red spruce seedlings growing in open top chambers in a nutrient-poor medium were exposed to mists containing one of five different combinations of H+, SO42-, NO3-, and NH4+ ions, three at pH 5.6 and two at pH 2.5. The mists were applied twice weekly from May until November, and the plants overwintered outdoors with no additional mist treatment. Seedlings that received mists containing sulphate (1.6 mol m-3) the previous growing season were more frost-hardy (i.e., their dehardening was delayed) the following April than seedlings that received lower concentrations of sulphate or none. Neither ammonium nor nitrate in the applied mist had any effect on dehardening, but they did advance budburst when applied together. In the presence of sulphate there was no effect of ammonium-N on the time of budburst. Exposure to mists containing nitrogen significantly increased the dry weight and length of the leading shoots that emerged from the buds and extended the following summer. There was no evidence that the stimulatory effects of nitrogen on growth made the seedlings less frost-hardy in spring.
Download or read book The effects of simulated acid mist on the frost hardiness of red spruce seedlings abstract written by L J (Lucy) Sheppard and published by . This book was released on 1990 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Influence of acidic mist on frost hardiness and nutrient concentrations in red spruce seedlings 2 Effects of misting frequency and rainfall exclusion written by L J (Lucy) Sheppard and published by . This book was released on 1993 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Two-year-old red spruce (Picea rubens Sarg.) of Pittston provenance and 3-yr-old plants of Chatham provenance were exposed to acid mist in replicated open-top chambers, supplied with charcoal-filtered air near Edinburgh, Scotland. Plants of Chatham provenance had already been exposed to acid mist throughout the previous growing season. The plants were exposed to mist, equivalent to 4 mm rainfall per week, containing an equimolar mixture of sulphuric acid and ammonium nitrate at pH 2.5 or pH 5.0 (1.6 or 0.01 mol m3) from May to November. This weekly dose was delivered at a low frequency (2 mm twice a week), or high frequency (1 mm on 4 consecutive days each week) to chambers fitted with ceilings to exclude rain. The low frequency dose was also a plied to chambers without ceilings, to examine the effect of natural washing by rain. Frost hardiness, estimated by exposing detached shoots to controlled freezing and then measuring rates of electrolyte leakage, was determined during the misting period at the end of October and in December. Foliar nutrient concentrations were measured during the dormant period after treatment had ceased. At the end of October, plants which had received acid mist were less frost hardy than plants receiving mist at pH 5. The temperature causing 50 % shoot death (LT50) increased by 6-degrees-C for low frequency application, and by 10-degrees-C at high frequency, relative to the plants receiving mist at pH 5. Exclusion of ambient rainfall had no detectable effect on the frost hardiness response to acid mist. In December, 3 wk after the cessation of misting, all plants were more frost hardy than in October. Significant effects of the acid mist treatment could no longer be detected. Differences in nutrient concentrations were small among treatments, although K+ concentrations in the low frequency treatment with acid mist with rain exclusion were 50 % below those in other treatments. Ca concentrations were 50 % larger in the acid mist treatment wit.
