|Abstracts on Global Climate Change|
Ecosystem and paleohydrological response to Quaternary climate change in the Bonneville Basin, Utah
Balch, DP Cohen, AS Schnurrenberger, DW Haskell, BJ Garces, BLV Beck, JW Cheng, H Edwards, RL
PALAEOGEOGRAPHY PALAEOCLIMATOLOGY PALAEOECOLOGY 221:1-2 99-122
We report the results of a detailed paleoecological study of the Bonneville basin covering the last similar to 280,000 yr. Our study used fossil ostracodes and a sedimentological record obtained from the August 2000 GLAD800 drilling operation at Great Salt Lake. We analyzed 125 samples, taken at similar to 1 in intervals from Site 4 (GSL00-4), for ostracodes and other paleoecologic and sedimentologic indicators of environmental change. Multivariate analyses applied to the ostracode data and qualitative analyses of fossil and sedimentological data indicate an alternation between three major environments at the core site over the cored interval: (1) shallow saline or hypersaline lakes; (2) salt or freshwater marshes;, and (3) occasional deep freshwater lakes. These environmental changes are consistent with shoreline studies of regional lake level fluctuations, but provide considerable new detail on both the timing and environmental conditions associated with the various lake phases. Our age model (using C-14, U- series, tephra and biostratigraphic chronologies) allowed us to associate the core’s record of regional paleohydrology with the marine oxygen isotope stages of global climate change. The core contains continuous records for the last four glacial/interglacial sequences. Salt/freshwater marshes were common during the interglacials and deep freshwater conditions correspond with maximum global ice volume in OIS 2, and before a maximum in global ice during OIS 6. Immediately following deep lake phases, crashes in lake level from rapid desiccation resulted in the deposition of thick evaporite units. Our study suggests that the climate of the Great Salt Lake catchment appears to have been drier during OIS 6 than during OIS 2. We compare our record of environmental change during OIS 6 glaciation with other records from the western United States and find that the overall pattern of climate was similar throughout the West, but differences in the timing of climate change (i.e. when a region became drier or moister) are common. (c) 2005 Elsevier B.V. All rights reserved.
Dynamic changes of anti-oxidative enzymes of 10 wheat genotypes at soil water deficits
Shao, HB Liang, ZS Shao, MA Sun, Q
COLLOIDS AND SURFACES B-BIOINTERFACES 42:3-4 187-195
Drought is a world-spread problem seriously influencing crop production and quality, the loss of which is the total for other natural disasters, with increasing global climate change making the situation more serious. Wheat is the staple food for more than 35% of world population, so wheat anti-drought physiology study is of importance to wheat production and biological breeding for the sake of coping with abiotic and biotic conditions. Much research is involved in this hot topic, but the pace of progress is not so large because of drought resistance being a multiple-gene-control quantitative character and wheat genome being larger (16,000 Mb). On the other hand, stress adaptive mechanisms are quite different, with stress degree, different growth and developmental stages, time course, materials and experimental plots, thus increasing the complexity of the issue in question. Additionally, a little study is related to the whole life circle of wheat, which cannot provide a comprehensive understanding of its anti-drought machinery. We selected 10 kinds of wheat genotypes as materials, which have potential to be applied in practice, and measured change of relative physiological indices through wheat whole growing developmental circle (i.e. seedling, tillage and maturing). Here, we reported the dynamic anti-oxidative results of whole stage (i.e. seedling, tillage and maturing) in terms of activities of POD, SOD, CAT of 10 wheat genotypes as follows: (1) 10 wheat genotypes can be grouped into three kinds (A, B and C, respectively) according to their changing trend of the measured indices; (2) A group performed better resistance drought under the condition of treatment level 1, whose activities of anti-oxidative enzymes (POD, SOD, CAT) were higher; (3) B group exhibited stronger anti-drought under treatment level 2, whose activities of anti-oxidative enzymes were higher; (4) C group expressed anti-drought to some extent under treatment level 3, whose activities of anti-oxidative enzymes were stronger, MDA lower; (5) these results demonstrated that different wheat genotypes have different physiological mechanisms to adapt themselves to changing drought stress, whose molecular basis is discrete gene expression profiling (transcriptom); (6) our results also showed that the concept and method accepted and adopted by most researchers that 75% FC is a proper supply for higher plants - was doubted because this level could not reflect the true suitable level of different wheat genotypes; (7) our research can provide insights into physiological mechanisms of crop anti-drought and direct practical materials for wheat anti-drought breeding; (8) POD, SOD and CAT activities of different wheat genotypes had quite different changing trend at different stages and under different soil water stress conditions, which was linked with their origin of cultivation and individual soil water stress threshold; (9) our primary results also firstly displayed that the changing trend for wheat adapting to environmental stress during life circle was an S-shaped curve, which is, by chance, consistent with Plant Growth Grand Periodicity Curve. (C) 2005 Elsevier B.V. All rights reserved.
A cosmogenic nuclide chronology of the last glacial transition in North-West Nelson, New Zealand - New insights in Southern Hemisphere climate forcing during the last deglaciation
Shulmeister, J Fink, D Augustinus, PC
EARTH AND PLANETARY SCIENCE LETTERS 233:3-4 455-466
We present a new glacial chronology for the last glacial interglacial transition, c. 20 to 10 ka, from the Cobb Valley, NW Nelson, New Zealand, based on a suite of Be-10 and Al-26 cosmogenic exposure ages. This chronology describes one of the most comprehensive deglaciation sequences from a late Quaternary valley system in the Southern Hemisphere. We chronicle the decay from the last (local) glacial maximum as follows: onset of the last deglaciation that commenced no earlier than 18-19 ka, followed by numerous short-term still-stands and/or minor re-advances over the ensuing 3-4 kyr, and complete evacuation of ice by 14 ka. We find no evidence to indicate a late glacial re-advance commensurate with the Northern Hemisphere Younger Dryas chronozone. The absence of a major glacial re-advance in this valley during the latter stages of the last glacial interglacial transition (LGIT) precludes a thermal decline in excess of about 3 degrees C and suggests no decline. The absence of late LGIT re-advances in the mountains of North-West Nelson, while deglacial readvances occurred in the main ranges of the Southern Alps can be best explained if westerly wind forcing rather than large-scale thermal decline is the primary control on glacier fluctuations, at least during the deglaciation. These findings challenge models of global climate change predicated on synchrony of millennial-scale glacial transitions due to thermal changes between Northern and Southern Hemispheres. (C) 2005 Elsevier B.V, All rights reserved.
Changes of anti-oxidative enzymes and membrane peroxidation for soil water deficits among 10 wheat genotypes at seedling
Shao, HB Liang, ZS Shao, MA Wang, BC
COLLOIDS AND SURFACES B-BIOINTERFACES 42:2 107-113
Drought is one of the major factors limiting crop production globally, with increasing global climate change making the situation more serious. Wheat is the staple food for more than 35% of world population, so wheat anti-drought physiology study is of importance to wheat production and biological breeding for the sake of coping with abiotic and biotic conditions. Much research is involved in this hot topic, but the pace of progress is not so large because of drought resistance being a multiple-gene-control quantitative character and wheat genome being larger (16,000 Mb). On the other hand, stress adaptive mechanisms are quite different, with stress degree, time course, materials, and experimental plots, thus increasing the complexity of the issue in question. Additionally, a little study is related to the whole life circle of wheat, which cannot provide a comprehensive understanding of its anti-drought machinery. We selected 10 kinds of wheat genotypes as materials, which have potential to be applied in practice, and measured relative change of anti-oxidative enzymes and membrane peroxidation through wheat whole growth-developmental circle (i.e. seedling, tillering and maturing). Here, we firstly reported the results of seedling stage as follows: (1) 10 wheat genotypes can be grouped into three kinds (A-C, respectively) according to their changing trend of the measured indices; (2) A performed better resistance drought under the condition of treatment level 1 (appropriate level), whose activities of anti-oxidative enzymes (POD, SOD, CAT) were higher and MDA lower and chlorophyll a + b higher; (3) B exhibited stronger anti-drought under treatment level 2 (light stress level), whose activities of anti-oxidative enzymes were higher, MDA lower and chlorophyll higher; (4) C expressed anti-drought to some extent under treatment level 3 (serious stress), whose activities of anti-oxidative enzymes were stronger, MDA lower and chlorophyll higher; (5) these results demonstrated that different wheat genotypes have different physiological mechanisms to adapt themselves to changing drought stress, whose molecular basis is discrete gene expression profiling (transcriptom); (6) our results also showed that the concept accepted by most researchers, 70-75% QF [T.C. Hsiao, Plant responses to water stress, Ann. Rev. Plant Physiol. 24 (1973) 519-570] is a proper supply for plants, was doubted, because this level could not reflect the true suitable level of wheat. The study in this respect is the key to wheat anti-drought and biological saving-water; (7) our research can provide insights into physiological mechanisms of crop anti-drought and direct practical materials for wheat anti-drought breeding. © 2005 Elsevier B.V. All rights reserved.
Year-round measurements of net ecosystem CO2 flux over a montane larch forest in Mongolia
Li, SG Asanuma, J Kotani, A Eugster, W Davaa, G Oyunbaatar, D Sugita, M
JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES 110:D9 -
Mongolian boreal forest merits special attention since it is located in the transitional area between the southern Siberian boreal forest and the Asian steppe zone, a vulnerable region being potentially affected by global warming and anthropogenic activities. This paper presents the first full-year-long continuous measurements of net ecosystem CO2 flux (NEE) made over a montane larch (Larix sibirica Ledeb.) forest in Mongolia from 25 March 2003 to 24 March 2004 (366 days) using the eddy covariance technique. The hourly maximum uptake was -10.1 μ mol m(-2) s(-1). The maximum daily uptake of -4.0 g C m(-2) d(-1) (negative NEE values denote net carbon uptake by the canopy from the atmosphere) occurred in July. The annual cumulative NEE was -85 g C m(-2), indicating that the forest acted as a net sink of CO2. We examined the responses of NEE to environmental conditions in the growing season from May to September. Both daytime 30-min mean and daily integrated NEE responded to incident photosynthetically active radiation (PAR) in a rectangular hyperbolic fashion. Model results show that the apparent quantum yield (α) was -0.0133 &PLUSMN; 0.0011 mmol CO2 per μ mol of photons, and the bulk light use efficiency (LUE) on the daily basis was -6.7 mmol CO2 per mole of PAR photons over the entire growing season for this forest. Additionally, daily integrated NEE was also a linear function of the normalized difference vegetation index (NDVI), a linear function of mean daily air temperature (T-a), and a quadratic polynomial function of daily means of the atmospheric water vapor pressure deficit (VPD). Among these factors, LAI (as measured by NDVI) was dominant in affecting the dynamics of NEE, followed by T-a. Lower T-a was limiting the growth rate of this montane larch forest. As daily means of VPD exceeded 1.2 kPa, net CO2 uptake by the canopy declined. Nevertheless, water stress was not observed as a problem for the forest growth.
Latitudinal gradients of parasite species richness in primates
Nunn, CL Altizer, SM Sechrest, W Cunningham, AA
DIVERSITY AND DISTRIBUTIONS 11:3 249-256
Infectious disease risk is thought to increase in the tropics, but little is known about latitudinal gradients of parasite diversity. We used a comparative data set encompassing 330 parasite species reported from 119 primate hosts to examine latitudinal gradients in the diversity of micro and macroparasites per primate host species. Analyses conducted with and without controlling for host phylogeny showed that parasite species richness increased closer to the equator for protozoan parasites, but not for viruses or helminths. Relative to other major parasite groups, protozoa reported from wild primates were transmitted disproportionately by arthropod vectors. Within the protozoa, our results revealed that vector-borne parasites showed a highly significant latitudinal gradient in species richness. This higher diversity of vector-borne protozoa near the tropics could be influenced by a greater abundance or diversity of biting arthropods in the tropics, or by climatic effects on vector behaviour and parasite development. Many vector-borne diseases, such as leishmaniasis, trypanosomiasis, and malaria pose risks to both humans and wildlife, and nearly one-third of the protozoan parasites from free-living primates in our data set have been reported to infect humans. Because the geographical distribution and prevalence of many vector-borne parasites are expected to increase because of global warming, these results are important for predicting future parasite-mediated threats to biodiversity and human health.
Economic reform, energy, and development: the case of Mexican manufacturing
Aguayo, F Gallagher, KP
ENERGY POLICY 33:7 829-837
Given increasing concern over global climate change and national security there is a burgeoning interest in examining the relationship between economic growth and energy use in developed and developing countries. More specifically, decoupling energy use per unit of gross domestic product (GDP) has fast come to be seen as in the interests of national economies and the world as a whole. Recent attention has been paid to the dramatic decreases in the energy intensity of the Chinese economy, which fell by 55% between 1975 and 1995. Do other developing economies follow similar trajectories? This paper examines the energy intensity of the Mexican economy for the period 1988-1998. Although the long-term trend in Mexican energy intensity is rising, the energy intensity of the Mexican economy began to decline in 1988. This paper explores the factors that have contributed to this reduction. Diminishing Mexican energy use per unit of GDP has been driven by significant decreases in industrial energy intensity. We show that these changes have resulted from changes in the composition of Mexican industrial structure and technological change. (C) 2003 Elsevier Ltd. All rights reserved.
World crop residues production and implications of its use as a biofuel
ENVIRONMENT INTERNATIONAL 31:4 575-584
Reducing and off-setting anthropogenic emissions of CO, and other greenhouse gases (GHGs) are important strategies of mitigating the greenhouse effect. Thus, the need for developing carbon (C) neutral and renewable sources of energy is more than ever before. Use of crop residue as a possible source of feedstock for bioenergy production must be critically and objectively assessed because of its positive impact on soil C sequestration.. soil quality maintenance and ecosystem functions. The amount of crop residue produced in the US is estimated at 367x10(6) Mg/year for 9 cereal crops, 450x10(6) Mg/year for 14 cereals and legumes, and 488x10(6) Mg/year for 21 crops. The amount of crop residue produced in the world is estimated at 2802x10(6) Mg/year for cereal crops, 3107x10(6) Mg/year for 17 cereals and legumes, and 3758x10(6) Mg/year for 27 food crops. The fuel value of the total annual residue produced is estimated at 1.5x10(15) kcal, about I billion barrels (bbl) of diesel equivalent, or about 8 quads for the US; and 11.3x10(15) kcal, about 7.5 billion bbl of diesel or 60 quads for the world. However, even a partial removal (30-40%) of crop residue from land can exacerbate soil erosion hazard, deplete the SOC pool, accentuate emission of CO, and other GHGs from soil to the atmosphere, and exacerbate the risks of global climate change. Therefore, establishing bioenergy plantations of site-specific species with potential of producing 10-15 Mg biomass/year is an option that needs to be considered. This option will require 40-60 million hectares of land in the US and about 250 million hectares worldwide to establish bioenergy plantations. (c) 2004 Elsevier Ltd. All rights reserved.
Synthesis of industrial utility systems: cost-effective de-carbonisation
Varbanov, P Perry, S Klemes, J Smith, R
APPLIED THERMAL ENGINEERING 25:7 985-1001
The production processes on industrial sites require large amounts of heating, cooling and power for their operation. Therefore, the optimal synthesis of utility systems is of central interest to engineers in the process industries. Recently, the problem of the global climate change has brought forward the question of reducing significantly the emissions of greenhouse gases into the atmosphere. In this paper, a new approach is presented for cost-effective de-carbonisation of new utility systems in the process industries. This is based on improved models of utility equipment components and an improved model and procedure for optimal synthesis of utility systems. (C) 2004 Elsevier Ltd. All rights reserved.
Linkage mapping of osmotic stress induced genes of oak
Porth, I Scotti-Saintagne, C Barreneche, T Kremer, A Burg, K
TREE GENETICS & GENOMES 1:1 31-40
Water stress affecting long-lived trees is an important challenge in forestry. Due to global climate change, forest trees will be threatened by extreme conditions like flooding or drought. It is necessary to understand differences in stress tolerance within certain species and to investigate putative relations on genomic level. In this study, osmotic stress induced genes of Quercus ssp. were positioned on two genetic linkage maps of oak. An intra-specific cross 3P*A4 of Quercus robur consisting of 88 offspring and an inter-specific cross 11P*QS29 of Q. robur and Q. petraea comprising 72 full-sibs were analyzed for the inheritance of 14 loci represented by 34 individual single nucleotide polymorphisms. Seven genes in the intra-cross, as well as other six genes in the inter-cross could be mapped and one gene could not be localised due to the severe distortion of the segregation. The collection of expressed sequences involved ribosomal proteins, members of the oxylase/oxygenase gene family, betaine aldehyde dehydrogenase, Dc3 promoter-binding factor, a putative member of the nodulin family, glutathione-S-transferase and proteins with unknown functions. In the inter-cross, two linked markers exhibited 89% deficiency of heterozygosity. Thirteen genes were positioned on ten different oak chromosomes and can serve as orthologous markers in comparative mapping studies within Fagaceae.
Impacts of flooding and climate change on urban transportation: A systemwide performance assessment of the Boston Metro Area
Suarez, P Anderson, W Mahal, V Lakshmanan, TR
TRANSPORTATION RESEARCH PART D-TRANSPORT AND ENVIRONMENT 10:3 231-244
Global climate change is likely to affect urban infrastructure through sea level rise and increased frequency of extreme events. This paper assesses the potential impact of climate change on the system-wide performance of transportation networks using the Boston Metro Area as a case study. The methodology integrates projected changes in land use, demographic and climatic conditions into the urban transportation modeling system in order to explore the relative impacts of global warming on the system performance due to additional riverine and coastal flooding. Results indicate almost a doubling in delays and lost trips. These impacts are significant, but probably not large enough to justify a major effort for adapting the physical infrastructure to expected climatic conditions, except for some key links. (c) 2005 Elsevier Ltd. All rights reserved.
Carbon cycling and budget in a forested basin of southwestern Hokkaido, northern Japan
Shibata, H Hiura, T Tanaka, Y Takagi, K Koike, T
ECOLOGICAL RESEARCH 20:3 325-331
Quantification of annual carbon sequestration is very important in order to assess the function of forest ecosystems in combatting global climate change and the ecosystem responses to those changes. Annual cycling and budget of carbon in a forested basin was investigated to quantify the carbon sequestration of a cool-temperate deciduous forest ecosystem in the Horonai stream basin, Tomakomai Experimental Forest, northern Japan. Net ecosystem exchange, soil respiration, biomass increment, litterfall, soil-solution chemistry, and stream export were observed in the basin from 1999-2001 as a part of IGBP-TEMA project. We found that 258 g C m(-2) year(-1) was sequestered annually as net ecosystem exchange (NEE) in the forested basin. Discharge of carbon to the stream was 4 g C m(-2) year(-1) (about 2% of NEE) and consisted mainly of dissolved inorganic carbon (DIC). About 43% of net ecosystem productivity (NEP) was retained in the vegetation, while about 57% of NEP was sequestered in soil, suggesting that the movement of sequestered carbon from above-ground to belowground vegetation was an important process for net carbon accumulation in soil. The derived organic carbon from aboveground vegetation that moved to the soil mainly accumulated in the solid phase of the soil, with the result that the export of dissolved organic carbon to the stream was smaller than that of dissolved inorganic carbon. Our results indicated that the aboveground and belowground interaction of carbon fluxes was an important process for determining the rate and retention time of the carbon sequestration in a cool-temperate deciduous forest ecosystem in the southwestern part of Hokkaido, northern Japan.
A method for estimating vulnerability of Douglas-fir growth to climate change in the northwestern US
Littell, JS Peterson, DL
FORESTRY CHRONICLE 81:3 369-374
Borrowing from landscape ecology, atmospheric science, and integrated assessment, we aim to understand the complex interactions that determine productivity in montane forests and utilize such relationships to forecast montane forest vulnerability under global climate change. Specifically, we identify, relationships for precipitation and temperature that govern the spatiotemporal variability in Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) growth by seeking similarities in patterns of growth/climate models across a significant portion of the climatological range of the species. In the 21(st) century and beyond, sustainable forestry will depend on successful adaptation to the impacts of climate change and climate variability on forest structure and function. The combination of these foci will allow improved prediction of the fate of montane forests over a wide range of biogeoclimatic conditions in western North America and thus allow improved management strategies for adapting to climate change. We describe a multi-disciplinary strategy for analyzing growth variability as a function of climate over a broad range of local-to-regional influences and demonstrate the efficacy of this sampling method in defining regional gradients of growth-limiting factors.
Trends in twentieth-century tree growth at high elevations in the Sierra Nevada and White Mountains, USA
Bunn, AG Graumlich, LJ Urban, DL
HOLOCENE 15:4 481-488
We analysed a multispecies tree-ring data base to assess the degree to which twentieth-century growth trends reflect tree growth of the last millennium. We examined similar to 1000-yr chronologies for five species of high-elevation conifers at 13 sites in western North America. Using non-parametric ordination and cluster analysis, we decomposed the variability at annual to decadal timescales into two dimensions, both of which are significantly correlated to temperature and precipitation variation. Tree-ring sites map onto the ordination axes according to species and relative position on the landscape. A spectral analysis of the ordination axes indicates a secular trend and significant quasi-periodic variation on scales of years to decades. Further, we find that the pattern of high-elevation conifer growth rates during the last half of the twentieth century are different than any time in the past 1000 years, indicating a distinct biological signature of global climate change.
Polychaete (Spirobranchus giganteus) loading on South African corals
Floros, CD Samways, MJ Armstrong, B
AQUATIC CONSERVATION-MARINE AND FRESHWATER ECOSYSTEMS 15:3 289-298
1. Spirobranchus giganteus is a ubiquitous serpulid polychaete that is an obligate associate of living coral. At Sodwana Bay, South Africa, it is a conspicuous associate of Acropora clathrata plates. 2. This study explores the relationship between S. giganteus abundance and factors hypothesized to represent stress to the corals, in particular coral bleaching, diving intensity and exposure to destructive wave action as a function of depth. In addition, plate size was investigated to increase understanding of habitat selection by S. giganteus. 3. There was no significant correlation between diving intensity and S. giganteus abundance on the three reefs studied, suggesting either that the current level of diving intensity causes no stress or that S. giganteus does not indicate stress. 4. Depth influenced the size distribution of A. clathrata plates, with the larger plates being at greatest depths ( > 0.4 m(2) at depths > 14 m). 5. Extremely high S. giganteus densities 2 (most plates with number of individuals > 50 m(-2), maximum number of individuals 413.63 m(-2) at 9m depth on one reef) were recorded at depths > 14m, with density increasing overall with depth. 6. The high densities of S. giganteus on A. clathrata plates are possibly because the plates are a physically elevated platform above the reef, where factors such as predation, competition and smothering by sand are far less important than on the reef surface. In turn, upwelling of nutrients and dependent plankton may encourage S. giganteus to maintain high population levels. 7. Climatic or other stresses are not considered currently to be responsible for these high S. giganteus densities. Rather, the worm data reflect a healthy upwelling, which may change as the coral reef becomes stressed with global climate change. Copyright (c) 2005 John Wiley & Sons, Ltd.
The costs of mitigating carbon emissions in China: findings from China MARKAL-MACRO modeling
ENERGY POLICY 33:7 885-896
In this paper MARKAL-MACRO, an integrated energy-environment-economy model, is used to generate China’s reference scenario for future energy development and carbon emission through the year 2050. The results show that with great efforts on structure adjustment, energy efficiency improvement and energy substitution, China’s primary energy consumption is expected to be 4818 Mtce and carbon emission 2394 MtC by 2050 with annual decrease rate of 3% for the carbon intensity per GDP during the period 2000-2050. On the basis of this reference scenario, China’s marginal abatement cost curves of carbon for the year 2010, 2020 and 2030 are derived from the model, and the impacts of carbon emission abatement on GDP are also simulated. The results are compared with those from other sources. The research shows that the marginal abatement costs vary from 12USS/tC to 216USS/tC and the rates of GDP losses relative to reference range from 0.1% to 2.54% for the reduction rates between 5% and 45%. Both the marginal abatement costs and the rates of GDP losses further enlarge on condition that the maximum capacity of nuclear power is constrained to 240GW or 160GW by 2050. The paper concludes that China’s costs of carbon abatement is rather high in case of carbon emissions are further cut beyond the reference scenario, and China’s carbon abatement room is limited due to her coal-dominant energy resource characteristic. As economic development still remains the priority and per capita income as well as per capita carbon emission are far below the world average, it will be more realistic for China to make continuous contribution to combating global climate change by implementing sustainable development strategy domestically and playing an active role in the international carbon mitigation cooperation mechanisms rather than accepting a carbon emission ceiling. (C) 2003 Elsevier Ltd. All rights reserved.