Download or read book Rangeland Plant Response to Elevated CO sub 2 Progress Report written by and published by . This book was released on 2001 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: An experiment is being designed to examine the influence of elevating CO2 levels on tallgrass prairie rangeland. Changes in biomass production, photosynthesis rates, and species composition (C3 versus C4) over time are to be examined. This report covers the period from August 15, 1988 to January 1, 1989. During this period the authors have had planning meetings in Manhattan, KS, and Washington, DC, with various investigators of the measurement and modeling groups within the elevated CO[sub 2] program. During this period detailed discussions with regard to the methodology were carried out. In addition, short-term experiments and prototype constructions were completed to assess design and materials. Because of changes in the methodology and, to a certain degree, the scope, they are requesting changes in the funding cycle to implement the project at the beginning of the growing cycle of the tallgrass prairie.
Download or read book Rangeland Plant Responses to Elevated CO sub 2 Progress Report written by and published by . This book was released on 1992 with total page 38 pages. Available in PDF, EPUB and Kindle. Book excerpt: Several broad conclusions which can be drawn from the work that was accomplished during the first 3-year phase of the study is described. In prairie ecosystems dominated by C4 grasses, it is likely that elevated atmospheric CO2 will increase ecosystem level productivity, with a greater increase in belowground productivity. The increased productivity will primarily result from increased water use efficiency due to the anti-transpirant action of CO2. Fumigation chambers are directly confounded with elevated CO2 effects, in that both reduce evapotranspiration. The reduced evapotranspiration of the fumigation chamber is primarily through reduced wind speeds and reduced radiation. In very dry years, fumigation chamber effects are negligible, but in years with normal precipitation, chamber effects and elevated CO2 effects are essentially equal with respect to reduced evapotranspiration effects. Increased production under elevated CO2 results in reduced nitrogen concentration in the herbage and increased fiber concentrations. Consequently, digestibility of the herbage is reduced, and microbial degradation of surface litter and soil organic matter is slowed. On the negative side, ruminant productivity will likely be reduced substantially, but increased carbon storage in the soil may buffer against future rise in atmospheric CO2. Tallgrass prairie will not likely change greatly in botanical composition, since the C4 dominants responded to elevated CO2 more than the C3 subdominants.
Download or read book Rangeland plant Response to Elevated CO2 written by M. B. Kirkham 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 Rangeland Plant Response to Elevated CO2 Progress Report 1993 written by and published by . This book was released on 1993 with total page 7 pages. Available in PDF, EPUB and Kindle. Book excerpt: Plots of a tallgrass prairie ecosystem were exposed to ambient and twice-ambient CO2 concentrations in open-top chambers and compared to unchambered ambient CO2 plots during the entire growing season from 1989 through 1992. Relative root production among treatments was estimated using root ingrowth bags which remained in place throughout the growing season. Latent heat flux was simulated with and without water stress. Botanical composition was estimated annuallyin all treatments. Open-top chambers appeared to reduce latent heat flux and increase water use efficiency similar to elevated CO2 when water stress was not severe, but under severe water stress, chamber effect on water use efficiency was limited. In natural ecosystems with periodic moisture stress, increased water use efficiency under elevated CO2 apparently would have a greater impact on productivity than photosynthetic pathway. Root ingrowth biomass was greater in 1990 and 1991 on elevated CO2 plots compared to ambient or chambered-ambient plots. In 1992, there was no difference in root ingrowth biomass among treatments.
Download or read book Rangeland Plant Responses to Elevated CO Sub 2 written by and published by . This book was released on 1992 with total page 129 pages. Available in PDF, EPUB and Kindle. Book excerpt: Several broad conclusions which can be drawn from the work that was accomplished during the first 3-year phase of the study is described. In prairie ecosystems dominated by C4 grasses, it is likely that elevated atmospheric CO2 will increase ecosystem level productivity, with a greater increase in belowground productivity. The increased productivity will primarily result from increased water use efficiency due to the anti-transpirant action of CO2. Fumigation chambers are directly confounded with elevated CO2 effects, in that both reduce evapotranspiration. The reduced evapotranspiration of the fumigation chamber is primarily through reduced wind speeds and reduced radiation. In very dry years, fumigation chamber effects are negligible, but in years with normal precipitation, chamber effects and elevated CO2 effects are essentially equal with respect to reduced evapotranspiration effects. Increased production under elevated CO2 results in reduced nitrogen concentration in the herbage and increased fiber concentrations. Consequently, digestibility of the herbage is reduced, and microbial degradation of surface litter and soil organic matter is slowed. On the negative side, ruminant productivity will likely be reduced substantially, but increased carbon storage in the soil may buffer against future rise in atmospheric CO2. Tallgrass prairie will not likely change greatly in botanical composition, since the C4 dominants responded to elevated CO2 more than the C3 subdominants.
Download or read book Rangeland Plant Responses to Elevated CO2 Final Report October 1988 October 1993 written by and published by . This book was released on 1997 with total page 16 pages. Available in PDF, EPUB and Kindle. Book excerpt: Research is described on plant (tallgrass) response to elevated carbon dioxide. Variables addressed include biomass production, as well as water use efficiency, photosynthetic capacity, decomposition, nutrient cycling, and forage quality.
Download or read book Rangeland Plant Response to Elevated CO2 Annual Report 1991 written by and published by . This book was released on 1991 with total page 6 pages. Available in PDF, EPUB and Kindle. Book excerpt: Effects of carbon dioxide enrichment on a tallgrass ecosystem were monitored during the 1990 growing season. The chambers, CO2 delivery system, and data acquisition and control system were in place and operational by 4 April 1990. CO2 fumigation and data acquisition began on that date. Nitrogen fertilizer as ammonium nitrate was applied at a rate of 45 kg ha −1 on 1 April to the N-fertilized plots. The chambers were 4.5 m in diameter and 4 m in height to allow for destructive sampling for biomass accumulation, leaf area determination, and for grazing esophageally-fistulated sheep. The experimental site was located in pristine Tallgrass Prairie north of/and adjacent to the Kansas State University campus. Vegetation on the site was a mixture of C3 and C4 species and was dominated by big bluestem (Andropogon geradii vitman) and indiangrass (Sorghastrum nutans (L.) Nash). Subdominants included Kentucky bluegrass (Poa pratensis L.), sideoats grama (Bouteloua curtipendula (Michx.) Torr.), and tall dropseed (Sporobolus asper var. asper (Michx.) Kunth). Members of the sedge family made up 5-10% of the composition. Principal forbs included western ragweed (Ambrosia psilostachya DC.), Louisiana sagewort (Artemesia ludoviciana Nutt.), and mayflower scurfpea (Psoralea tenuiflora var. floribunda (Nutt.) Rydb.). Average peak biomass occurs in early August at 425 g m−2 of which 35 g m−2 is from forbs. The area was ideal for meeting the experimental objectives, in that the mixture of C3 and C4 plants would allow for assessment of competitive relationships among numerous species of both carbon fixation pathways.
Download or read book Government Reports Annual Index written by and published by . This book was released on 1993 with total page 1832 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Mysterie of the Tvvo Ivnto s Presbyterian and Independent Or The Serpent in the Bosome written by Clement Walker and published by . This book was released on 1647 with total page 19 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book International Conference of Engineering Design Graphics and Descriptive Geometry written by and published by . This book was released on 1998 with total page 772 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Government Reports Announcements Index written by and published by . This book was released on 1993-04 with total page 924 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Environmental Pollution Control written by and published by . This book was released on with total page 580 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Energy Research Abstracts written by and published by . This book was released on 1993 with total page 354 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Response of Gambel Oak to Tebuthiuron in Central Utah written by Warren P. Clary and published by . This book was released on 1985 with total page 4 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Progress Report of Research the Forest Service written by United States. Forest Service and published by . This book was released on 1968 with total page 264 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1992 with total page 292 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Modeling the Response of Plants and Ecosystems to Elevated CO Sub 2 and Climate Change written by and published by . This book was released on 1992 with total page 180 pages. Available in PDF, EPUB and Kindle. Book excerpt: While the exact effects of elevated CO2 on global climate are unknown, there is a growing consensus among climate modelers that global temperature and precipitation will increase, but that these changes will be non-uniform over the Earth's surface. In addition to these potential climatic changes, CO2 also directly affects plants via photosynthesis, respiration, and stomatal closure. Global climate change, in concert with these direct effects of CO2 on plants, could have a significant impact on both natural and agricultural ecosystems. Society's ability to prepare for, and respond to, such changes depends largely on the ability of climate and ecosystem researchers to provide predictions of regional level ecosystem responses with sufficient confidence and adequate lead time.
