Climate, Land Use And Plant Life Form Distribution In A Semi-Arid Savanna,
2024
Uppsala Universitet
Climate, Land Use And Plant Life Form Distribution In A Semi-Arid Savanna, Christina Skarpe
IGC Proceedings (1977-2023)
Number of plant species, total vegetation cover and the abundance of different life forms are compared over a rainfall gradient between savanna woodland and semi-desert. The effects of different land use intensities are superimposed on the differences in rainfall regimes. The outcome is discussed in the light of present global change scenarios,
Vegetation Response To Climate: A 35 Year Study At Bibury, Gloucestershire,
2024
The University of Sheffield
Vegetation Response To Climate: A 35 Year Study At Bibury, Gloucestershire, A J. Willis, R Hunt, J P. Grime, S R. Band, N Dunnett
IGC Proceedings (1977-2023)
Important information on the climate-responsiveness of plant species has been gleaned from an unlikely source. The annually recorded control {unsprayed) plots from a 35-year field e, experiment assessing the effects of spraying herbicide and a plant growth regulator onto the vegetation of roadside verges near Bibury, Gloucestershire, have provided an opportunity to examine the detailed effects of year-to year variations in climate on the yields of different ·species and functional types within the vegetation. The results confirm the usefulness of plant functional types and genome size as predictors of plant community response to climatic change.
Response Of White Clover To Soil Phosphate Levels At Different Temperatures And Carbon Dioxide Concentrations,
2024
AgResearch, NZ
Response Of White Clover To Soil Phosphate Levels At Different Temperatures And Carbon Dioxide Concentrations, R A. Carran
IGC Proceedings (1977-2023)
Nutrient availability is generally managed to remove limitations when the effects of elevated temperature or CO2 concentrations on plants are investigated. Relating the resulls of such experiments to field situations where nutrients are frequently in short supply is difficult. Phosphorous response curves were obtained for white clover (Trifolium repens L,) seedlings grown at temperatures of 18-13 or 28-23°C, nod 350 or 700 ppm CO2. At low P, response to other variables was non-significant and at 18-13° there was no response to increased CO2, Increasing temperature to 28-23° resulted in increased gcowth, apparently due to increased P availability, and at …
The Integrated Screening Programme: Patterns Of Ecological Specialization In British Species,
2024
University of Sheffield
The Integrated Screening Programme: Patterns Of Ecological Specialization In British Species, K Thompson, J P. Grime, R Colasanti
IGC Proceedings (1977-2023)
The Integrated Screening Programme (ISP), a major part of the UCPB research programme during the period 1987-1994, applies standardised procedures for the ecological, physiological and biochemical characterisation of plant species, populations or cultivars. The objectives are: (1) to establish the range of variation in selected plant attributes; (2) to recognise recurring patterns of ecological and evolutionary specialisation; (3) to devise a functional classification of plants relevant to the analysis of communities and ecosystems and the management of vegetation .. To date, the programme has been confined largely to the herbaceous species from central northern Britain. Later, and in particular as …
Interaction Of Climate Management As Controls On Species Composition,
2024
University of Sheffield
Interaction Of Climate Management As Controls On Species Composition, S H. Hillier, F Sutton, J P. Grime, R Colasanti
IGC Proceedings (1977-2023)
A new technique for the manipulation of temperature near the soil surface without the aid of cloches or screens has been developed at UCPE. This system is being used to manipulate the length of the growing season in an experiment in which the critical interaction between growth and the timing of two important meadow management activities - cutting and grazing - is being investigated. The technique has also been used to expose synthesised meadow communities to an artificially induced mild winter. Temperature manipulations of this kind offer a new approach to understanding the role which climate plays as a mechanism …
Comparison Of Photosynthetic Responses To Carbon Dioxide In Pasture Species,
2024
HortResearch, NZ
Comparison Of Photosynthetic Responses To Carbon Dioxide In Pasture Species, D H. Greer, W A. Laing, B D. Campbell
IGC Proceedings (1977-2023)
Thirteen major pasture species were grown in controlled environments at 3 temperatures (12n, 18/13 and 28/23°C) and at 350 nnd 700 ppm CO2 for 4-8 weeks and net photosynthesis measured under these conditions. In C1 cultivars, short-term (within minutes) exposure to elevated CO2 had the greatest effect on photosynthesis, with an average of 55% higher rates than that at ambient CO2. There was also a response to long-term growth at high CO2, with a,1 average of 40% higher rates of photosynthesis than at ambient CO2 (both measured al their growth CO2) and a marked alteration in the temperature dependence Qf …
Photosynthesis And Water Relations Of A C4 And A C3 Grass Under Doubled Carbon Dioxide,
2024
Kansas State University
Photosynthesis And Water Relations Of A C4 And A C3 Grass Under Doubled Carbon Dioxide, D Nie, M B. Kirkham, E T. Kanemasu
IGC Proceedings (1977-2023)
The objective of this project was to determine during an entire season the photosynthetic rate and water potential of a C3 grass (Kentucky bluegrass, Poa pratensis L.) and a C4 grass (big bluestem, Andropogon gerardii Vitman) grown with 2 levels of CO2 (ambient or twice ambient) and 2 water levels (field capacity or no water added). Elevated CO2 increased the photosynthetic rate of Kentucky bluegrass by an average of 76%. During mid-season (11 June-16 July), photosynthetic rate of high-water big bluestem with ambient CO2 was about the same as that of low-water big bluestem with doubled CO2• Under both water …
Simulating The Impact Of Global Warming On Regional Pasture Production Environment,
2024
CSIRO
Simulating The Impact Of Global Warming On Regional Pasture Production Environment, P J. Vickery, M J. Hill, E P. Furnival
IGC Proceedings (1977-2023)
Global warming scenarios predict increases in temperatures, evaporation and summer rainfall in the northern two-thirds of Australia. Pasture production models can be combined with spatial climate data in a geographic information system to predict net primary production from pastures. We used a pasture-sheep production model for a phalaris-white clover pasture together with interpolated climatic data to predict the outcome of increases in temperature, evaporation and summer rainfall for net primary production (NPP) from pastures in northern NSW. NPP was predicted to rise in winter due to elevated temperatures, to decline slightly In spring due to increased evaporation, and to change …
Changing The Climate Of A Limestone Dale,
2024
University of Sheffield
Changing The Climate Of A Limestone Dale, S M. Buckland, J P. Grime, J R. Tippets, A Jackson, K Thompson, J G. Hodgson, P C. Thorpe, C W. Macgillivray
IGC Proceedings (1977-2023)
The Unit of Comparative Plant Ecology based at Sheffield University is manipulating the weather artificially at a field site near Buxton, Derbyshire. This experiment is enabling us to study the way in which certain plants, both in the existing vegetation and among potential invaders, may behave in the future. As well as future climate scenarios, a range of land-use conditions are recreated in the experiment. Seeds of species with different geographical distributions have been sown in and their fate is being closely followed. The experiment began in 1990 and will run until at least 1997, by which time it should …
Improving Pasture Digestibility: Low Lignin Forages,
2024
CSIRO
Improving Pasture Digestibility: Low Lignin Forages, C Lynne Mcintyre, Sharon L. Abrahams, Heather M. Bettenay, Ruth A. Sandeman, Christine Hayes, Donovan Sharp, Adrian Elliot, John M. Manners, John M. Watson
IGC Proceedings (1977-2023)
High lignin content in forages reduces dry matter digestibility and voluntary feed intake by ruminants. Ribozyme and antisense RNA technologies are being investigated as methods of reducing lignin levels and increasing digestibility in temperate and tropical forages. Pirstly, potential target genes in the lignin biosynthetic pathway, against which ribozyme and antisense contructs may be targeted, are being isolated from the temperate and tropical legumes, lucerne and Sty/osa11thes lmmilis, respectively. Secondly, promoter sequences that may direct expression of ribozyme and antisense contructs to specific cells and tissues are being isolated, Thirdly, various ribozyme design and delivery systems are being investigated in …
Transfer Of Genes Encoding Proteins With High Nutritional Value Into Pasture Legumes,
2024
CSIRO
Transfer Of Genes Encoding Proteins With High Nutritional Value Into Pasture Legumes, W C. Mcnabb, C Higgins, L Tabe, T J.V Higgins
IGC Proceedings (1977-2023)
Gene transfer systems for the forage legumes, subterranean clover (Trlfolium subterraneum) and lucerne (Medicago saltva) have been developed and optimised for current commercial cultivars. A disarmed binary vector derived from the Agrobacterium tunefaciens tumour• inducing plasmid has been used to deliver a selectable marker gene conferring resistance to phosphinothricin (the active ingredient in the herbicide, Basta) and a series of chimeric gene constructs encoding proteins that are rich in sulphur amino acids and resistant to rumen degradation. Transgenic plants expressing a gene encoding either ovalbumin or a sunflower albumin have been obtained and analyzed with respect to …
Developing A Tall Fescue For Reduced Grass Tetany Risk,
2024
USDA, Agricultural Research Service
Developing A Tall Fescue For Reduced Grass Tetany Risk, H F. Mayland, D A. Sleper
IGC Proceedings (1977-2023)
Tall fescue (Festuca arundinacea Schreb,) is an important forage grass, and like other C3 grasses, has the potential to cause grass tetany in grazing ruminants. Genetic variation in cation uptake by fescue was exploited by selecting for high Mg and Ca relative to K CQncenlration in fescue, The grass tetany ratio, K/(Ca+Mg), was reduced about 18% after 2 selection cycles. The mean Mg and K/(Ca+Mg) values for 20 C1 plants, grown at pH 6.4, were weakly related (r2-0.42 and 0.48) to those of plants grown in calcareous soil pH 8.2. The P, Na, Mn, Fe, Cu, and Zn concentrations …
Volatile Constituents Of Tall Fescue Varieties In Relation To Palatability,
2024
Instituto Sperimentale Colture Foraggere
Volatile Constituents Of Tall Fescue Varieties In Relation To Palatability, Aldo Tava, Nicola Berardo, Miriam Odoardi
IGC Proceedings (1977-2023)
The chemical composition of the essential oil of tall fescue (Festuca arundinacea Schreb,), a poorly palatable species, was analysed by GC and GC-MS. The major components identified were alcohols, aldehydes and esters. The qualitative and quantitative differences detected among 6 cultivars of different geographical origin suggest the most abundant compounds may play a role in the grazing preference exhibited by animals.
Cell Wall Phenolic Content In Tissue Types Of Developing Maize Internodes,
2024
USDA, Agricultural Research Service
Cell Wall Phenolic Content In Tissue Types Of Developing Maize Internodes, T A. Morrison, D R. Buxton
IGC Proceedings (1977-2023)
Elongation and lignification was observed via daily photographs and phloroglucinol-HCI stain on internode 9 (1-9) of growth-chamber grown maize (Zea mays L.) line Mol7 x B73 to correlate internode development with lignification. 1-9 elongated sigmoidally from 8 to 130 mm in 12 days. Lignification began in the upper internode after 3 d and progressed top-down following a basipetal retreat of elongation activity. An improved acetyl bromide method was used to determine UV-absorptive cell wall phenolic concentrations in freeze. dried, ethanol and chloroform:methanol extracted pith parenchyma, pith vascular and rind vascular tissue excised from lower and upper sections of immature, lignifying, …
Partitioning Of Major Elements Concentrations In Grasses Into Four Cell Fractions Based On Enzymatic Solubility,
2024
Iwate University
Partitioning Of Major Elements Concentrations In Grasses Into Four Cell Fractions Based On Enzymatic Solubility, Suguru Saiga, Takanori Akiyama, Moegi Saski, Kiyoshi Watanabe
IGC Proceedings (1977-2023)
To investigate availability of major elements to animals, N, P, K, Ca and Mg of plant dry matter were partitioned into 4 cell fractions based on enzyme solubility. When the elemental concentration of forage was compared, Dactylis glomerata was higher in K (1.69%), Festuca aru11dinacea in N (2.35%), K (1.68%) and Mg (Q.341 %) and Lolimum perenne in N (2.54%), P (0.224%) and Ca (0.457%). When compared between plant parts, concentrations of all elements.were higher in leaf than in stem, especially P, Ca and Mg. As a result of partitioning, more than 85% of P, K and Mg resided …
Improvement Of The Feeding Value Of Senescent Grass Pastures By Molecular Genetic Manipulation,
2024
The University of Melbourne
Improvement Of The Feeding Value Of Senescent Grass Pastures By Molecular Genetic Manipulation, G D. Bonnett, K R. Stevenson, R J. Simpson
IGC Proceedings (1977-2023)
Senescent grass pasture has low feeding value end is the major limitation to animal productivity during summer in annual environments. The loss of fructan from the stems of temperate grasses as they senesce contributes significantly to the decline in feeding value of the grass, Temporary retention of fructan during senescence achieved by treating grass with a herbicide increases both the feeding value of the grass and the productivity of animals grazing the modified pasture. We have identified an enzyme responsible for initiating the loss of fructan from stems of Lolium rigidum. It has been purified, characterized and will be used …
Genetic Engineering Of Pasture Legume And Grasses For Reduced Lignin Content And Increased Digestibility,
2024
CSIRO
Genetic Engineering Of Pasture Legume And Grasses For Reduced Lignin Content And Increased Digestibility, C Lynne Mcintyre, J M. Manners, J R. Wilson, H Way, D Sharp
IGC Proceedings (1977-2023)
Plants of tropical pastures have a higher lignin content than those of temperate pastures, which limits the digestibility and nutritive value of these forages. Ribozyme and antisense RNA technology is being investigated as a method of reducing lignin levels and increasing digestibility in the tropical forage Stylosanthes spp, and in the model system tobacco. Ribozymes to the tobacco anionic peroxidase mRNA have been designed and shown to be capable of cleaving this mRNA in vitro. Constructs for the expression of antisense and ribozyme RNA to reduce peroxidase gene expression have been prepared, Transgenic tobacco plants containing these constructs have been …
Sulphur-Rich Protein Gene Modification For Optimized Expression In Transgenic White Clover,
2024
AgResearch, NZ
Sulphur-Rich Protein Gene Modification For Optimized Expression In Transgenic White Clover, Paul M. Ealing, K Hancock, D.W R. White, T/J V. Higgins
IGC Proceedings (1977-2023)
A gene encoding the sulphur-rich pea seed storage protein pea albumin I (PAI), transcriptionally fused to the CaMV 35S promoter has been introduced into Nicotiana Iabacum and white clover (Trifolium repens L.) using Agrobacterium-mediated transformation. PA I mRNA expression has been confirmed in transgenic tobacco and white clover plants. However, PAI protein accumulation, as assessed by ELISA using an anti-PAI monoclonal antibody, is either low or the antibody does not have the required avidity or titre. Strategies for improved accumulation and immunological surveillance of this protein in leaf tissue are described, including the construction of PA …
Modeling The Effects Of Climate Variability And Climate Change On A Pastoral Farming System,
2024
New Zealand Institute for Crop and Food Research
Modeling The Effects Of Climate Variability And Climate Change On A Pastoral Farming System, R J. Martin, D B. Baird, M J. Salinger, P R. Van Gardingen, D G. Mccall
IGC Proceedings (1977-2023)
A simulation model was used to investigate the pasture and animal production and gross margins of a typical all sheep permanent pasture farm in South Canterbury, New Zealand, using 60 years of current climate data, and also a climate change scenario. The model was run on a fixed management system at different stocking rates with and without destocking during feed shortages. Mean annual pasture production was 8060 kg/ha, with a coefficient of variation of 22%. Destocking enabled more stock to be carried on average, with higher, but rh.ore variable, returns. A climate change scenario of a 75% increase in CO2' …
Changes To Sheep Grazing Systems In Response To Climate Change,
2024
Massey University
Changes To Sheep Grazing Systems In Response To Climate Change, B M. Butler, S T. Morris, R S. Morris
IGC Proceedings (1977-2023)
Simulation models were used to predict changes in pasture growth and sheep farming systems as a result of changes in climate due to global warming. The results of long•lerm mean climate and 10 years' individual climate simulations show Iha! increases in stocking rate of up to 40% may be possible with climate change. Benefits of climate change included increased lamb carcass weight and pasture cover. Climate change also resulted in the feasibility of autumn lambing systems in an environment in which these systems are currently difficult lo maintain. A change from 100% spring lambing to 40% of the flock lambing …
