Download or read book The Effects on Photosynthetic CO2 Assimilation to Long term Elevation of Atmospheric CO2 Concentration An Assessment of the Response of Trifolium Repens L CV Blanca Grown at F A C E written by and published by . This book was released on 1994 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book The Effects on Photosynthetic CO sub 2 Assimilation to Long term Elevation of Atmospheric CO sub 2 Concentration written by and published by . This book was released on 1994 with total page 38 pages. Available in PDF, EPUB and Kindle. Book excerpt: Understanding how photosynthetic capacity acclimates to elevated CO2 concentrations is vital in predicting the response of important grassland species such as Trifolium repens. Previous studies of acclimatization have been carried out in artificial experimental conditions, such as acrylic greenhouses or controlled environment chambers. The advent of FACE technology has enabled a large area of crop to be fumigated in the field, providing more realistic growing conditions. Pure stands of Trifolium repens L. cv. Blanca grown at either 355 or 600?mol mol−1 CO2 were examined, and their photosynthetic response to elevated Ca determined via gas exchange studies. Rates of photosynthesis of young, fully expanded leaves were increased between 21 and 36% when grown and measured at elevated CO2. This increase in A corresponded to a decrease in g{sub S} of between 18 and 52%. No acclimation effect was observed in the most frequently cut stands, whilst the response of stands clipped only 4 times per year was more variable. When down regulation of V{sub cmax} did occur, this was not nearly as marked as that which occurred in 3 other temperate species (Chrysanthemum leucanthemum, Ranunculus friesianus, Plantago lanceolata (L.) J. & C. Presl.), at similar growth regimes. No acclimation of stomatal frequency, SI or pore length was found to occur in the enriched clover stands.

Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1995 with total page 376 pages. Available in PDF, EPUB and Kindle. Book excerpt: Lists citations with abstracts for aerospace related reports obtained from world wide sources and announces documents that have recently been entered into the NASA Scientific and Technical Information Database.

Download or read book Energy Research Abstracts written by and published by . This book was released on 1995 with total page 770 pages. Available in PDF, EPUB and Kindle. Book excerpt: Semiannual, with semiannual and annual indexes. References to all scientific and technical literature coming from DOE, its laboratories, energy centers, and contractors. Includes all works deriving from DOE, other related government-sponsored information, and foreign nonnuclear information. Arranged under 39 categories, e.g., Biomedical sciences, basic studies; Biomedical sciences, applied studies; Health and safety; and Fusion energy. Entry gives bibliographical information and abstract. Corporate, author, subject, report number indexes.

Download or read book Co2 And Plants written by Edgar R. Lemon and published by CRC Press. This book was released on 2019-04-11 with total page 303 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book presents information on the direct effects of increased atmospheric CO2 on plants. It considers what we already know about plant responses to various CO2 concentrations. .

Download or read book Government Reports Announcements Index written by and published by . This book was released on 1995 with total page 718 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Elevated CO sub 2 in a Prototype Free air CO sub 2 Enrichment Facility Affects Photosynthetic Nitrogen Relations in a Maturing Pine Forest written by and published by . This book was released on 1998 with total page 45 pages. Available in PDF, EPUB and Kindle. Book excerpt: A maturing loblolly pine (Pinus taeda L.) forest was exposed to elevated CO2 in the natural environment in a perturbation study conducted over three seasons using the free-air CO2 enrichment (FACE) technique. At the time measurements were begun in this study, the pine canopy was comprised entirely of foliage which had developed under elevated CO2 conditions (atmospheric [CO2] ≈ 550 {micro}mol mol{sup −1}). Measurements of leaf photosynthetic responses to CO2 were taken to examine the effects of elevated CO2 on photosynthetic N nutrition in a pine canopy under elevated CO2. Photosynthetic CO2 response curves (A-c{sub i} curves) were similar in FACE trees under elevated CO2 compared with counterpart trees in ambient plots for the first foliage cohort produced in the second season of CO2 exposure, with changes in curve form detected in the foliage cohorts subsequently produced under elevated CO2. Differences in the functional relationship between carboxylation rate and N{sub a} suggest that for a given N{sub a} allocated among successive cohorts of foliage in the upper canopy, V{sub c max} was 17% lower in FACE versus Ambient trees. The authors also found that foliar Rubisco content per unit total protein derived from Western blot analysis was lower in late-season foliage in FACE foliage compared with ambient-grown foliage. The results illustrate a potentially important mode of physiological adjustment to growth conditions that may operate in forest canopies. Their findings suggest that mature loblolly pine trees growing in the field may have the capacity for shifts in intrinsic nitrogen utilization for photosynthesis under elevated CO2 that are not dependent on changes in leaf N. While carboxylation efficiency per unit N apparently decreased under elevated CO2, photosynthetic rates in trees at elevated CO2 concentrations ≈ 550 pmol mol{sub −1} are still enhanced compared to trees grown and measured at the current ambient CO2 concentration when compared at a common N status. The findings from this prototype study suggest a need for continued examination of internal feedbacks at the whole-tree and ecosystem level in forests that may influence long-term photosynthetic responses to elevated CO2.

Download or read book The Photosynthetic Acclimation of Lolium Perenne Growing in a Free air CO2 Enrichment FACE System written by and published by . This book was released on 1994 with total page 31 pages. Available in PDF, EPUB and Kindle. Book excerpt: Stands of Ryegrass (Lolium perenne L. cv. Bastion) were grown in the field at ambient or elevated (600[mu]mol/mol) CO2 concentration, high (560Kg/ha) or low (140Kg/ha) nitrogen addition and with a frequent (every 4 weeks) or infrequent (every 8 weeks) cutting regime. Plants were in the second year of a 3 year experiment. Exposure to elevated CO2 was carried out with a Free-Air CO2 Enrichment (FACE) system which provides the most {open_quote}realistic{close_quote} system of CO2 fumigation currently available. Elevated CO2 increased diurnal CO2 assimilation by between 34 and 88% whilst reducing rates of stomatal conductance by between 1 and 42%. However, analysis of the A vs. Ci response showed considerable acclimation of the photosynthetic apparatus in response to elevated CO2 - Vc{sub max} as an in vivo measure of RubisCO activity, decreased by between 29 and 35% in high CO2, whilst J{sub max}, as a measure of the RubP regeneration capacity, showed no significant change. Two out of three additional perennial grassland species studied showed similar acclamatory behavior to Ryegrass. Diurnal assimilation rate, J{sub max} and, in most cases, Vc{sub max}, increased significantly directly after cutting of Ryegrass stands, but nitrogen treatment had little effect on any of these parameters. Neither stomatal density, stomatal index nor stomatal pore length of Ryegrass were significantly altered by growth in elevated CO2. The results are discussed in terms of the limitation imposed on maximizing photosynthetic and growth responses of Ryegrass at elevated CO2, by the ability of perennial species to increase long-term sink capacity under these conditions.

Download or read book Plant Responses to Elevated CO2 written by A. Raschi and published by Cambridge University Press. This book was released on 1997-11-28 with total page 290 pages. Available in PDF, EPUB and Kindle. Book excerpt: The rise in the concentration of CO2 in the atmosphere since the start of industrialization, and the global warming associated with this greenhouse gas, has stimulated research into the response of plants to elevated levels of CO2. Much of this work has been carried out in controlled environments which provide limited information about long-term effects on vegetation. In contrast, CO2-emitting mineral springs provide a unique opportunity to consider vegetation which has endured over many generations at naturally elevated levels of CO2. This volume presents findings from a range of sites, confirming the potential of these natural laboratories in the investigation of this important aspect of climate change.

Download or read book Plasticity in Photosynthetic Performance and Energy Utilization Efficiency in Triticum Aestivum L Secale Cereale L and Brassica Napus L in Response to Low Temperature and High Co2 written by Keshav Dahal and published by . This book was released on 2012 with total page 466 pages. Available in PDF, EPUB and Kindle. Book excerpt: I assessed the effects of cold acclimation and long-term elevated CO2 on photosynthetic performance and energy conversion efficiency of winter (cv Musketeer, cv Norstar) and spring (cv SR4A, cv Katepwa) rye (Secale cereale) and wheat (Triticum aestivum) as well as wild type (WT) and BnCBF17-over-expressing line (BnCBF17-OE) of Brassica napus cv Westar. Plants were grown at either 20/16°C (non-acclimated, NA) or 5/5°C (cold acclimated, CA) and at either ambient (380 mol C mol-1) or elevated (700 mol C mol-1) CO2. Compared to NA controls, CA winter cereals, Norstar and Musketeer, exhibited compact dwarf phenotype, increased rates of light-saturated CO2 assimilation (42%) and photosynthetic electron transport (48%) and higher levels of rbcL, cytosolic FBPase, Lhcb1, PsbA and PsaA at ambient CO2. This was associated with enhanced energy conversion efficiency into biomass (31%) and seed yield (20%) coupled to decreased excitation pressure and decreased energy dissipation through non-photochemical quenching (NPQ) for a given irradiance and a given CO2 concentration in CA versus NA winter cereals. The increased photosynthetic performance and energy conversion efficiency of CA winter cereals at ambient CO2 were maintained under long-term growth and development at elevated CO2. In contrast, CA spring cereals, SR4A and Katepwa, exhibited decreased CO2 assimilation rates (35%) and decreased energy conversion efficiency in biomass (40%) not only at ambient CO2 but also at long-term elevated CO2. BnCBF17-over-expression in Brassica napus resulted into dwarf phenotype, increased rates of light-saturated CO2 assimilation (38%) and photosynthetic electron transport (18%), an enhanced energy conversion efficiency with concomitant decreased reliance on photoprotection to dissipate absorbed energy through NPQ for a given irradiance and a given CO2. Compared to WT Brassica napus, BnCBF17- over-expression reduced sensitivity to feedback-limited photosynthesis during long-term growth of B. napus under elevated CO2. CBFs (C-repeat binding factors) are transcriptional activators that induce the expression of cold-regulated genes. We suggest that CBFs regulate not only freezing tolerance but also control the photosynthetic performance and energy conversion efficiency in biomass and grain yield through morphological, physiological and biochemical adjustments. Hence, targeting the CBF pathways in major crop species can be a novel approach to improve crop yield and productivity.

Download or read book The Photosynthetic and Stomatal Response of Medicago Sativa Cv Saranac to Free air CO2 Enrichment F A C E and Nitrogen written by and published by . This book was released on 1996 with total page 70 pages. Available in PDF, EPUB and Kindle. Book excerpt: Plots of Medicago sativa cv. saranac were grown in the field at ambient (355 [mu]mol CO2 mol−1 air) or elevated (600[mu]mol CO2 mol−1 air) CO2 concentrations. High (200kg yr−1) or low (20kg yr−1) nitrogen levels were applied to two isogeneic lines, one able and one unable to use nitrogen fixing bacteria. Plants were in the second year of field growth. Exposure to elevated CO2 was via a Free-Air CO2 Enrichment System (FACE). Elevated CO2 increased diurnal assimilation by between 12% and 92%. Analysis of A/C{sub i} responses showed that effective nitrogen fertilisation was more important to rubisCO and RuBP activity than elevated CO2. No acclimation was consistently observed. Leaves lower down the canopy were found to have lower Vc{sub max} and J{sub max} values, though age may be the cause of the latter effect. FACE conditions have only a small effect on these responses. There was some evidence found for the down-regulation of photosynthesis in the late afternoon. The FACE conditions had no affect on stomatal density but did increase epidermal cell density.

Download or read book Terrestrial Ecosystems in a Changing World written by Josep G. Canadell and published by Springer Science & Business Media. This book was released on 2007-01-10 with total page 344 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book examines the impacts of global change on terrestrial ecosystems. Emphasis is placed on impacts of atmospheric, climate and land use change, and the book discusses the future challenges and the scientific frameworks to address them. Finally, the book explores fundamental new research developments and the need for stronger integration of natural and human dimensions in addressing the challenge of global change.

Download or read book Allelopathy written by Manuel Joaquín Reigosa Roger and published by Springer Science & Business Media. This book was released on 2006 with total page 660 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book provides the reader relevant information about actual knowledge about the process of allelopathy, covering all aspects from the molecular to the ecological level. Special relevance is given to the physiological and ecophysiological aspects of allelopathy. Several ecosystems are studied and methodological considerations are taken into account in several different chapters. The book has been written to be useful both for Ph.D. students and for senior researchers, so the chapters include all necessary information to be read by beginners, but they also include a lot of useful information and discussion for the initiated.

Download or read book References no 21505 25161 AAR ZUR written by Zdenek Sesták and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 330 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Diagnosis of the Nitrogen Status in Crops written by Gilles Lemaire and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 240 pages. Available in PDF, EPUB and Kindle. Book excerpt: Providing a link between theoretical and applied aspects of plant nutrition and agriculture, this book introduces new concepts in plant nutrition. It shows how these can be applied in order to assess the nitrogen status in crops and to improve nitrogen nutrition through optimized N fertilization management. In this way economic benefits can be obtained, while at the same time preventing detrimental effects on the environment. The main agricultural crops - grasses, wheat, barley, Durum wheat, maize, sorghum, grain legumes and potatoes - are covered. The book will be an invaluable source for agronomists.

Download or read book Cash Crop Halophytes Recent Studies written by Helmut Lieth and published by Springer Science & Business Media. This book was released on 2003 with total page 284 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume follows up a seminal meeting, presenting reports on progress made with recommendations made there. The text reports on the development of pilot projects and on the organization of an international organization. All this will serve as the foundation for future efforts to develop the common utilisation of cash crop halophytes.

Download or read book The Science of Grapevines written by Markus Keller and published by Academic Press. This book was released on 2015-01-19 with total page 522 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Science of Grapevines: Anatomy and Physiology is an introduction to the physical structure of the grapevine, its various organs, their functions and their interactions with the environment. Beginning with a brief overview of the botanical classification (including an introduction to the concepts of species, cultivars, clones, and rootstocks), plant morphology and anatomy, and growth cycles of grapevines, The Science of Grapevines covers the basic concepts in growth and development, water relations, photosynthesis and respiration, mineral uptake and utilization, and carbon partitioning. These concepts are put to use to understand plant-environment interactions including canopy dynamics, yield formation, and fruit composition, and concludes with an introduction to stress physiology, including water stress (drought and flooding), nutrient deficiency and excess, extreme temperatures (heat and cold), and the impact and response to of other organisms. Based on the author's years of teaching grapevine anatomy as well as his research experience with grapevines and practical experience growing grapes, this book provides an important guide to understanding the entire plant. - Chapter 7 broken into two chapters, now "Environmental Constraints and Stress Physiology and Chapter 8 "Living with Other Organisms" to better reflect specific concepts - Integration of new research results including: - Latest research on implementing drip irrigation to maximize sugar accumulation within grapes - Effect of drought stress on grapevine's hydraulic system and options for optimum plant maintenance in drought conditions - The recently discovered plant hormone – strigolactones – and their contribution of apical dominance that has suddenly outdated dogma on apical dominance control - Chapter summaries added - Key literature references missed in the first edition as well as references to research completed since the 1e publication will be added