Electron tomography of nanoparticle clusters: Implications for atmospheric lifetimes and radiative forcing of soot

van Poppel, LH Friedrich, H Spinsby, J Chung, SH Seinfeld, JH Buseck, PR

GEOPHYSICAL RESEARCH LETTERS 32:24 -

Nanoparticles are ubiquitous in nature. Their large surface areas and consequent chemical reactivity typically result in their aggregation into clusters. Their chemical and physical properties depend on cluster shapes, which are commonly complex and unknown. This is the first application of electron tomography with a transmission electron microscope to quantitatively determine the three-dimensional (3D) shapes, volumes, and surface areas of nanoparticle clusters. We use soot (black carbon, BC) nanoparticles as an example because it is a major contributor to environmental degradation and global climate change. To the extent that our samples are representative, we find that quantitative measurements of soot surface areas and volumes derived from electron tomograms differ from geometrically derived values by, respectively, almost one and two orders of magnitude. Global sensitivity studies suggest that the global burden and direct radiative forcing of fractal BC are only about 60% of the value if it is assumed that BC has a spherical shape.

sarubh:unrelated | /unrelated | 285

Global warming is changing the dynamics of Arctic host-parasite systems

Kutz, SJ Hoberg, EP Polley, L Jenkins, EJ

PROCEEDINGS OF THE ROYAL SOCIETY B-BIOLOGICAL SCIENCES 272:1581 2571-2576

Global climate change is altering the ecology of infectious agents and driving the emergence A disease in people, domestic animals, and wildlife. We present a novel, empirically based, predictive model for the impact of climate warming on development rates and availability of an important parasitic nematode of muskoxen in the Canadian Arctic, a region that is particularly vulnerable to climate change. Using this model, we show that warming in the Arctic may have already radically altered the transmission dynamics of this parasite, escalating infection pressure for muskoxen, and that this trend is expected to continue. This work establishes a foundation for understanding responses to climate change of other host-parasite systems, in the Arctic and globally.

sarubh:endorseimp | /endorse/endorseimp | 297

Earlier winter wheat heading dates and warmer spring in the US Great Plains

Hu, Q Weiss, A Feng, S Baenziger, PS

AGRICULTURAL AND FOREST METEOROLOGY 135:1-4 284-290

Phenological change of plants is an indication of local and regional climate change, independent of the instrumentation records and associated bias/error. Although some phenological changes have been identified for native and perennial species and used to infer climate change in various regions of the world, little has been known for changes in agricultural plants/crops. In this study, heading or flowering dates of winter wheat cultivar Kharkof are examined from 70 years of data at six locations in the U.S. Great Plains. Results indicate a consistent trend of earlier heading or flowering dates across all sites, but rates of the trend differ (from 0.8 to 1.8 days per 10-year). Because the heading or flowering date is governed primarily by temperatures, the earlier heading or flowering dates indicate warming temperatures in the spring. Further examinations reveal increase in spring daily minimum temperatures. Findings of this study add a diverse species to the plant community for detecting the “fingerprint” of regional and global climate change. (c) 2006 Elsevier B.V. All rights reserved.

sarubh:endorseimp | /endorse/endorseimp | 263

Fish use and size of eelgrass meadows in southeastern Alaska: A baseline for long-term assessment of biotic change

Johnson, SW Thedinga, JF

NORTHWEST SCIENCE 79:2-3 141-155

Eelgrass meadows at six sites in southeastern Alaska were sampled for fish assemblages and mapped to establish a baseline of information for long-term assessment of biotic change. All sites were sampled in spring 2001, 2002, and 2003: four of the sites were also sampled in winter 2003. A total of 44 seine hauls from all sampling periods yielded 58,902 fish comprising 45 species. Fish abundance in spring differed significantly among sites but not among years. The most abundant commercially important or forage fish species captured were chum salmon, Pacific herring. pink salmon, coho salmon, and Pacific sand lance: mean size of each of these species was <= 100 mm FL. For those sites sampled seasonally in 2003, fish were significantly more abundant in spring than in winter. At each site, three different species accounted for most (>= 69%) of the total catch. Size of eelgrass meadows varied annually; maximum percent change in area ranged from -13% to +27%. Eelgrass density ranged from 336 shoots/m(2) to 1,544 shoots/m(2), and dry biomass ranged from 36 g/m(2) to 71 g/m(2). Periodic re-sampling of the eelgrass sites established in this study will allow resource managers to track long-term and large-scale changes in fish communities and habitat that may result from shoreline development or global climate change.

sarubh:unrelated | /unrelated | 291

Salt lakes in Australia: present problems and prognosis for the future

Timms, BV

HYDROBIOLOGIA 552: 1-15

Australia is a land of salt lakes and despite low human population density, many lakes are adversely impacted by a range of factors. Secondary salinisation is the most pernicious force degrading lakes, especially in south-west Western Australia where up to 30% of the landscape is predicted to be affected. Mining also impinges on many salt lakes in this state, mainly through the dewatering of saline groundwater. Exploitation of groundwater for irrigation caused some lakes in Victoria, Australia, to dry, especially the significant Red Rock Complex. Global climate change will result in new water balances in endorheic lakes, with most having less water, particularly the seasonal lakes of southern Australia. This has already happened in Lake Corangamite, Victoria, but the prime reason is diversion of inflowing floodwater. Consequently, the lake has retreated and become salinised compromising its status as a Ramsar site. Various other lakes suffer from enhanced sedimentation, have introduced biota or their catchments are being disturbed to their detriment. Enlightened management should be able to maintain some important lakes in an acceptable condition, but, for most others, the future is bleak.

sarubh:endorseimp | /endorse/endorseimp | 301

Marine research in the Latitudinal Gradient Project along Victoria Land, Antarctica

Berkman, PA Cattaneo-Vietti, R Chiantore, M Howard-Williams, C Cummings, V Kvitek, R

SCIENTIA MARINA 69: Suppl. 2 57-63

This paper describes the conceptual framework of the Latitudinal Gradient Project that is being implemented by the New Zealand, Italian and United States Antarctic programmes along Victoria Land, Antarctica, from 72 degrees S to 86 degrees S. The purpose of this interdisciplinary research project is to assess the dynamics and coupling of marine and terrestrial ecosystems in relation to global climate variability. Preliminary data about the research cruises from the R/V “Italica” and R/V “Tangaroa” along the Victoria Land Coast in 2004 are presented. As a global climate barometer, this research along Victoria Land provides a unique framework for assessing latitudinal shifts in ‘sentinel’ environmental transition zones, where climate changes have an amplified impact on the phases of water.

sarubh:methods | /neutral/methods | 278

Global assessment of coral bleaching and required rates of adaptation under climate change

Donner, SD Skirving, WJ Little, CM Oppenheimer, M Hoegh-Guldberg, O

GLOBAL CHANGE BIOLOGY 11:12 2251-2265

Elevated ocean temperatures can cause coral bleaching, the loss of colour from reef-building corals because of a breakdown of the symbiosis with the dinoflagellate Symbiodinium. Recent studies have warned that global climate change could increase the frequency of coral bleaching and threaten the long-term viability of coral reefs. These assertions are based on projecting the coarse output from atmosphere-ocean general circulation models (GCMs) to the local conditions around representative coral reefs. Here, we conduct the first comprehensive global assessment of coral bleaching under climate change by adapting the NOAA Coral Reef Watch bleaching prediction method to the output of a low- and high-climate sensitivity GCM. First, we develop and test algorithms for predicting mass coral bleaching with GCM-resolution sea surface temperatures for thousands of coral reefs, using a global coral reef map and 1985-2002 bleaching prediction data. We then use the algorithms to determine the frequency of coral bleaching and required thermal adaptation by corals and their endosymbionts under two different emissions scenarios. The results indicate that bleaching could become an annual or biannual event for the vast majority of the world’s coral reefs in the next 30-50 years without an increase in thermal tolerance of 0.2-1.0 degrees C per decade. The geographic variability in required thermal adaptation found in each model and emissions scenario suggests that coral reefs in some regions, like Micronesia and western Polynesia, may be particularly vulnerable to climate change. Advances in modelling and monitoring will refine the forecast for individual reefs, but this assessment concludes that the global prognosis is unlikely to change without an accelerated effort to stabilize atmospheric greenhouse gas concentrations.

sarubh:endorseex | /endorse/endorseex | 293

Consortium for Atlantic Regional Assessment: Information tools for community adaptation to changes in climate or land use

Dempsey, R Fisher, A

RISK ANALYSIS 25:6 1495-1509

To inform local and regional decisions about protecting short-term and long-term quality of life, the Consortium for Atlantic Regional Assessment (CARA) provides data and tools (for the northeastern United States) that can help decisionmakers understand how outcomes of their decisions could be affected by potential changes in both climate and land use. On an interactive, user-friendly website, CARA has amassed data on climate (historical records and future projections for seven global climate models), land cover, and socioeconomic and environmental variables, along with tools to help decisionmakers tailor the data for their own decision types and locations. CARA Advisory Council stakeholders help identify what information and tools stakeholders would find most useful and how to present these: they also provide in-depth feedback for subregion case studies. General lessons include: (1) decisionmakers want detailed local projections for periods short enough to account for extreme events, in contrast to the broader spatial and temporal observations and projections that are available or consistent at a regional level; (2) stakeholders will not use such a website unless it is visually appealing and easy to find the information they want; (3) some stakeholders need background while others want to go immediately to data, and some want maps while others want text or tables. This article also compares what has been learned across case studies of Cape May County, New Jersey, Cape Cod, Massachusetts, and Hampton Roads, Virginia, relating specifically to sea-level rise. Lessons include: (1) groups can be affected differently by physical dangers compared with economic dangers; (2) decisions will differ according to decision makers’ preferences about waiting and risk tolerance; (3) future scenarios and maps can help assess the impacts of dangers to emergency evacuation routes, homes, and infrastructure, and the natural environment; (4) residents’ and decisionmakers’ perceptions are affected by information about potential local impacts from global climate change.

sarubh:endorseex | /endorse/endorseex | 290

Fossil fuels in the 21st century

Lincoln, SF

AMBIO 34:8 621-627

An overview of the importance of fossil fuels in supplying the energy requirements of the 21st century, their future supply, and the impact of their use on global climate is presented. Current and potential alternative energy sources are considered. It is concluded that even with substantial increases in energy derived from other sources, fossil fuels will remain a major energy source for much Of the 21st century and the sequestration of CO2 will be an increasingly important requirement.

sarubh:endorseex | /endorse/endorseex | 281

Fates of eroded soil organic carbon: Mississippi basin case study

Smith, SV Sleezer, RO Renwick, WH Buddemeier, R

ECOLOGICAL APPLICATIONS 15:6 1929-1940

We have developed a mass balance analysis of organic carbon (OC) across the five major river subsystems of the Mississippi (MS) Basin (an area of 3.2 X 10(6) km(2)) This largely agricultural landscape undergoes a bulk soil erosion rate of similar to 480 t center dot km(-2)center dot yr(-1) (similar to 1500 x 10(6) t/yr, across the MS Basin), and a,soil organic carbon (SOC) erosion rate of similar to 7 t center dot km(-2 center dot)yr(-1) (similar to 22 x 10(6) t/yr). Erosion translocates upland SOC to alluvial deposits, water impoundments, and the ocean. Soil erosion is generally considered to be a net source of CO2 release to the atmosphere in global budgets. However, our results indicate that SOC erosion and relocation of soil apparently can reduce the net SOC oxidation rate of the original upland SOC while promoting neu replacement of eroded SOC in upland soils that were eroded. Soil erosion at the MS Basin scale is, therefore, a net CO2 sink rather than a source.

sarubh:methods | /neutral/methods | 298

Analysing countries’ contribution to climate change: scientific and policy-related choices

den Elzen, M Fuglestvedt, J Hohne, N Trudinger, C Lowe, J Matthews, B Romstad, B de Campos, CP Andronova, N

ENVIRONMENTAL SCIENCE & POLICY 8:6 614-636

This paper evaluates the influence of different policy-related and scientific choices on the calculated regional contributions to global climate change (the “Brazilian Proposal”). Policy-related choices include the time period of emissions, the mix of greenhouse gases and different indicators of climate change impacts. The scientific choices include historical emissions and model representations of the climate system. We generated and compared results of several simple climate models. We find that the relative contributions of different nations to global climate change-from emissions of greenhouse gases alone-are quite robust, despite the varying model complexity and differences in calculated absolute changes. For the default calculations, the average calculated contributions to the global mean surface temperature increase in 2000 are about 40% from OECD, 14% from Eastern Europe and Former Soviet Union, 24% from Asia and 22% from Africa and Latin America. Policy-related choices, such as time period of emissions, climate change indicator and gas mix generally have larger influence on the results than scientific choices. More specifically, choosing a later attribution start date (1990 instead of 1890) for historical emissions, decreases the contributions of regions that started emitting early, such as the OECD countries by 6 percentage points, whereas it increases the contribution of late emitters such as Asia by 8 percentage points. However, only including the fossil CO, emissions instead of the emissions of all Kyoto gases (fossil and land use change), increases the OECD contributions by 21 percentage points and decreases the contribution of Asia by 14 percentage points. (c) 2005 Elsevier Ltd. All rights reserved.

sarubh:endorseex | /endorse/endorseex | 299

Seductive simulations? Uncertainty distribution around climate models

Lahsen, M

SOCIAL STUDIES OF SCIENCE 35:6 895-922

This paper discusses the distribution of certainty around General Circulation Models (GCMs) - computer models used to project possible global climatic changes due to human emissions of greenhouse gases. It examines the trope of distance underpinning Donald MacKenzie’s concept of ‘certainty trough’, and calls for a more multi-dimensional and dynamic conceptualization of how uncertainty is distributed around technology. The certainty trough describes the level of certainty attached to particular technoscientific constructions as distance increases from the site of knowledge production, and proposes that producers of a given technology and its products are the best judges of their accuracy. Processes and dynamics associated with GCM modeling challenge the simplicity of the certainty trough diagram, mainly because of difficulties with distinguishing between knowledge producers and users, and because GCMs involve multiple sites of production. This case study also challenges the assumption that knowledge producers always are the best judges of the accuracy of their models. Drawing on participant observation and interviews with climate modelers and the atmospheric scientists with whom they interact, the study discusses how modelers, and to some extent knowledge producers in general, are sometimes less able than some users to identify shortcomings of their models.

sarubh:rejectimp SPotGS:unrelated | /unrelated | 288

American risk perceptions: Is climate change dangerous?

Leiserowitz, AA

RISK ANALYSIS 25:6 1433-1442

Public risk perceptions can fundamentally compel or constrain political, economic, and social action to address particular risks. Public support or opposition to climate policies (e.g., treaties, regulations, taxes, subsidies) will be greatly influenced by public perceptions of the risks and dangers posed by global climate change. This article describes results from a national study (2003) that examined the risk perceptions and connotative meanings of global warming in the American mind and found that Americans perceived climate change as a moderate risk that will predominantly impact geographically and temporally distant people and places. This research also identified several distinct interpretive communities, including naysayers and alarmists, with widely divergent perceptions of climate change risks. Thus, “dangerous” climate change is a concept contested not only among scientists and policymakers, but among the American public as well.

timlambert:discuss | /neutral/discuss | 289

A conceptual model of ecological interactions in the mangrove estuaries of the Florida Everglades

Davis, SM Childers, DL Lorenz, JJ Wanless, HR Hopkins, TE

WETLANDS 25:4 832-842

A brackish water ecotone of coastal bays and lakes, mangrove forests, salt marshes, tidal creeks, and upland hammocks separates Florida Bay, Biscayne Bay, and the Gulf of Mexico from the freshwater Everglades. The Everglades mangrove estuaries are characterized by salinity gradients that vary spatially with topography and vary seasonally and inter-annually with rainfall, tide, and freshwater flow from the Everglades. Because of their location at the lower end of the Everglades drainage basin, Everglades mangrove estuaries have been affected by upstream water management practices that have altered the freshwater heads and flows and that affect salinity gradients. Additionally, interannual variation in precipitation patterns, particularly those caused to El Nino events, control freshwater inputs and salinity dynamics in these estuaries. Two major external drivers on this system are water management activities and global climate change. These drivers lead to two major ecosystem stressors: reduced freshwater flow volume and duration, and sea-level rise. Major ecological attributes include mangrove forest production, soil accretion, and resilience; coastal lake submerged aquatic vegetation; resident mangrove fish populations; wood stork (Mycteria americana) and roseate spoonbill (Platelea ajaja) nesting colonies; and estuarine crocodilian populations. Causal linkages between stressors and attributes include coastal transgression, hydroperiods, salinity gradients, and the “white zone” freshwater/estuarine interface. The functional estuary and its ecological attributes, as influenced by sea level and freshwater flow, must be viewed as spatially dynamic, with a possible near-term balancing of transgression but ultimately a long-term continuation of inland movement. Regardless of the spatio-temporal timing of this transgression, a salinity gradient supportive of ecologically functional Everglades mangrove estuaries will be required to maintain the integrity of the South Florida ecosystem.

sarubh:endorseimp | /endorse/endorseimp | 287

Fine-scale predictions of distributions of Chagas disease vectors in the state of Guanajuato, Mexico

Lopez-Cardenas, J Bravo, FEG Schettino, PMS Solorzano, JCG Barba, ER Mendez, JM Sanchez-Cordero, V Peterson, AT Ramsey, JM

JOURNAL OF MEDICAL ENTOMOLOGY 42:6 1068-1081

One of the most daunting challenges for Chagas disease surveillance and control in Mexico is the lack of community level data on vector distributions. Although many states now have assembled representative domestic triatomine collections, only two triatomine specimens bad been collected and reported previously from the state of Guanajuato. Field personnel from the state’s Secretaria de Salud conducted health promotion activities in 43 of the 46 counties in the state and received donations of a total of 2,522 triatomine specimens between 1998 and 2002. All specimens were identified, and live insects examined for Trypanosoma cruzi. In an effort to develop fine-scale distributional data for Guanajuato, collection localities were georeferenced and ecological niches were modeled for each species by using evolutionary-computing approaches. Five species were collected: Triatoma mexicana (Herrich-Schaeffer), Triatoma longipennis (Usinger), Triatoma pallidipennis (Stal), Triatoma barberi (Usinger), and Triatoma dimidiata (Latreille) from 201 communities located at elevations of 870 - 2,200 m. Based on collection success, T mexicana had the broadest dispersion, although niche mapping indicates that T barberi represents the greatest risk for transmission of Chagas disease in the state. T dimidiata was represented in collections by a single adult collected from one village outside the predicted area for all species. For humans, In estimated 3,755,380 individuals are at risk for vector transmission in the state, with an incidence of 3,500 new cases per year; overall seroprevalences of 2.6% indicate that 97,640 individuals are infected with T cruzi at present, including 29,300 chronic cases.

| /unclassified/todo | 309

Fine-scale processes regulate the response of extreme events to global climate change

Diffenbaugh, NS Pal, JS Trapp, RJ Giorgi, F

PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA 102:44 15774-15778

We find that extreme temperature and precipitation events are likely to respond substantially to anthropogenically enhanced greenhouse forcing and that fine-scale climate system modifiers are likely to play a critical role in the net response. At present, such events impact a wide variety of natural and human systems, and future changes in their frequency and/or magnitude could have dramatic ecological, economic, and sociological consequences. Our results indicate that fine-scale snow albedo effects influence the response of both hot and cold events and that peak increases in extreme hot events are amplified by surface moisture feedbacks. Likewise, we find that extreme precipitation is enhanced on the lee side of rain shadows and over coastal areas dominated by convective precipitation. We project substantial, spatially heterogeneous increases in both hot and wet events over the contiguous United States by the end of the next century, suggesting that consideration of fine-scale processes is critical for accurate assessment of local- and regional-scale vulnerability to climate change.

| /unclassified/todo | 308

Trace metal analysis in arctic aerosols by an inductively coupled plasma-time of flight-mass spectrometer combined with an inductively heated vaporizer

Ludke, C Skole, J Taubner, K Kriews, M

SPECTROCHIMICA ACTA PART B-ATOMIC SPECTROSCOPY 60:11 1412-1422

Two newly developed instruments were combined to analyze the trace metal content in size separated arctic aerosols during the measurement campaign ASTAR 2004 (Arctic Study of Tropospheric Aerosols, Clouds and Radiation 2004) at Spitsbergen in May-June 2004. The aim of this extensive aerosol measurement campaign was to obtain a database for model-calculations of arctic aerosol, which play an important role in the global climate change. The ASTAR project was centered on two aircraft measurement campaigns, scheduled from 2004 to 2005, addressing both aerosol and cloud measurements, combined with ground-based and satellite observations. In the present paper one example for the analysis of ground-based aerosol particles is described. The sampling of aerosol particles was performed in a well-known manner by impaction of the particles on cleaned graphite targets. By means of a cascade impactor eight size classes between 0.35 and 16.6 mu m aerodynamic diameters were separated. To analyze the metal content in the aerosol particles the targets were rapidly heated up to 2700 degrees C in an inductively heated vaporizer system (IHVS). An argon flow transports the vaporized sample material into the inductively coupled plasma (ICP) used as ionization source for the time of flight-mass spectrometer (TOF-MS). The simultaneous extraction of the ions from the plasma, as realized in the TOF instrument, allows to obtain the full mass spectrum of the sample during the vaporization pulse without any limitation in the number of elements detected. With optimized experimental parameters the element content in arctic aerosol particles was determined in a mass range between Li-7 and Bi-209. Comparing the size distribution of the elemental content of the aerosol particles, two different meteorological situations were verified. For calibration acidified reference solutions were placed on the cleaned target inside the IHVS. The limits of detection (LOD) for the element mass on the target range between 2 and 200 pg for the elements studied, except Na, Mg, and Cr, which are influenced by high background. (c) 2005 Elsevier B.V. All rights reserved.

| /unclassified/todo | 295

Global climate change and the equity-efficiency puzzle

Manne, AS Stephan, G

ENERGY 30:14 2525-2536

There is a broad consensus that the costs of abatement of global climate change can be reduced efficiently through the assignment of quota rights and through international trade in these rights. There is, however, no consensus on whether the initial assignment of emissions permits can affect the Pareto-optimal global level of abatement. This paper provides some insight into the equity-efficiency puzzle. Qualitative results are obtained from a small-scale model; then quantitative evidence of separability is obtained from MERGE, a multiregion integrated assessment model. It is shown that if all the costs of climate change can be expressed in terms of GDP losses, Pareto-efficient abatement strategies are independent of the initial allocation of emissions rights. This is the case sometimes described as ‘market damages’. If, however, different regions assign different values to nonmarket damages such as species losses, different sharing rules may affect the Pareto-optimal level of greenhouse gas abatement. Separability may then be demonstrated only in specific cases (e.g. identical welfare functions or quasi-linearity of preferences or small shares of wealth devoted to abatement). (c) 2004 Elsevier Ltd. All rights reserved.

| /unclassified/todo | 348

From regional to global dynamics structure of the climatic proxy

Wan, SQ Feng, GL Dong, WJ Li, JP

ACTA PHYSICA SINICA 54:11 5487-5493

Global change science is a new research domain nowadays, and one of the most important studies of which is the climate change,to which great attention is paid by all governments in world. It is mainly based on the climatic proxy that we can study the past climate change. Although many achievements have been obtained, majority of the results are limited to the external characteristics of the proxy due to lagged analysis methods. For example, we judge if the climate is flood/drought or cold/warm through linear trend of the time series, however, we do not know whether it is a natural variation or the result of external forces, the mechanism is not uncovered. Because complexity of the open global climate system, there are different characteristics among the climatic proxies from different region of the world, from which it is difficult to reveal the intrinsic general principles i.e. the globality. For the further study on the past climate change, especially to reveal the rules of the global climate change in past 2000a and predict future climate change, a new method making use of the dynamical lag correlation exponent (named Q index in the text), a dynamics exponent based on the phase-space reconstruction, is introduced in this paper, which can effectively discern the similarities or differences between the dynamics of the two series. With Q index, we analyze the dynamics structure of some typical climatic proxies. The results show that the dynamics of climatic proxies are almost similar, and the regional climate keeps the same change with the global. In other words, regional climate is controlled by the global climate change. Besides, there are two dynamics jump periods (namely 700-900a and 1300-1700a) in past 2000a of the climate system, which may correspond to the periods of the medieval warm period and the little ice age, respectively.

| /unclassified/todo | 306

Flood risk, uncertainty, and scientific information for decision making - Lessons from an interdisciplinary project

Morss, RE Wilhelmi, OV Downton, MW Gruntfest, E

BULLETIN OF THE AMERICAN METEOROLOGICAL SOCIETY 86:11 1593-+

The magnitude of flood damage in the United States, combined with the uncertainty in current estimates of flood risk, suggest that society could benefit from improved scientific information about flood risk. To help address this perceived need, a group of researchers initiated an interdisciplinary study of climate variability, scientific uncertainty, and hydrometeorological information for flood-risk decision making, focused on Colorado’s Rocky Mountain Front Range urban corridor. We began by investigating scientific research directions that were likely to benefit flood-risk estimation and management, through consultation with climatologists, hydrologists, engineers, and planners. In doing so, we identified several challenges involved in generating new scientific information to aid flood management in the presence of significant scientific and societal uncertainty. This essay presents lessons learned from this study, along with our observations on the complex interactions among scientific information, uncertainty, and societal decision making. It closes by proposing a modification to the “end to end” approach to conducting societally relevant scientific research. Although we illustrate points using examples from flood management, the concepts may be applicable to other arenas, such as global climate change.

| /unclassified/todo | 303

Refugial forests of the southern Appalachians: photosynthesis and survival in current-year Abies fraseri seedlings

Johnson, DM Smith, WK

TREE PHYSIOLOGY 25:11 1379-1387

Fraser fir (Abies fraseri (Pursh) Poiret) is an endemic, high-elevation conifer confined to six relict mountain-top communities in the southern Appalachian Mountains, USA. High adult mortality has occurred over the past 50 years, possibly the result of an introduced insect (Adelges piceae Ratzeburg), air pollution, or both. Knowledge of the mechanisms of and limitations to seedling establishment may allow reestablisment and perpetuation of this unique community type, notwithstanding global climate change. We monitored seedling emergence and mortality in relation to photosynthetic performance and water relations in microsites differing in canopy openness (sunlight exposure) over the summer of 2004. Abundance of cotyledonous seedlings in early summer was 2.3 times greater (849 versus 366 seedlings m(-2)) in microsites with lower sky exposure (greater canopy closure) than in microsites with greater sky exposure (greater canopy openness). In contrast, late-season abundance and survival were greater in areas beneath more open canopies than in areas beneath less open canopies (3.3 times and 11.7 times greater, respectively). However, newly emerged seedling survival in a completely open site (no overhead canopy) was zero, despite an initial density of 124 seedlings m(-2). Seedling water status was similar in open- and closed-canopy sites (-0.52 and -0.74 MPa, respectively). Photosynthetic carbon gain was higher in newly emerged seedlings at open canopy than at closed canopy sites, especially during early morning. Based on photosynthetic light response curves and measured sunlight regimes, seedlings in open canopy sites were estimated to assimilate 3.3-4.5 times more carbon than seedlings at closed sites. Reductions in carbon gain of closed-site seedlings, primarily a result of limited sunlight, corresponded to substantial increases in seedling mortality (98 versus 79% in open canopy sites). Thus, sunlight exposure, which reflects overstory canopy structure, appears to be an important factor influencing newly emerged seedling survival and distribution.

| /unclassified/todo | 307

Direct constraints on Antarctic Peninsula Ice Sheet grounding events between 5.12 and 7.94 Ma

Bart, PJ Egan, D Warny, SA

JOURNAL OF GEOPHYSICAL RESEARCH-EARTH SURFACE 110:F4 -

How has the Antarctic Ice Sheet responded to or influenced global climate change? This simple question has been difficult to address because the long-term records of the ice sheet’s fluctuations are poorly constrained with geologic data from Antarctica. Thus studies to date have not convincingly established how specific Antarctic Ice Sheet events correlate with climatic, eustatic, or other phenomena known from low-latitude and deep-sea records. This study focused on documenting the direct record of ice sheet advance and retreat to the Antarctic Peninsula’s shelf edge. On the peninsula’s outer shelf, seismic reflectors interpreted to be subglacial unconformities were correlated with published results from Ocean Drilling Program Leg 178. Lithologic and chronologic control at two drill sites provided ground truth for the seismic interpretation and the timing of the Antarctic Peninsula Ice Sheet grounding events. This synthesis showed that grounded ice advanced to the shelf edge on at least 12 occasions between 5.12 and 7.94 Ma.

| /unclassified/todo | 310

Variation of karst spring discharge in the recent five decades as an indicator of global climate change: A case study at Shanxi, northern China

Guo, QH Wang, YX Ma, T Li, LX

SCIENCE IN CHINA SERIES D-EARTH SCIENCES 48:11 2001-2010

Karst in Shanxi Province is representative of that in northern China, and karst water systems discharge in the form of springs that are among the most important sources for local water supply. Since the 1950s, attenuation has been the major trend of discharge variation of most karst springs at Shanxi. Based on the case study of 7 karst springs including Niangziguan, Xin’an, Guozhuang, Shentou, Jinci, Lancun, and Hongshan springs, the discharge variation process of karst springs was divided into natural fluctuation phase and anthropogenic impact phase. Discharge attenuation of the 7 karst springs was controlled mainly by climate and human activities, with their contributions being respectively about 60% and 40%. According to the difference of the effect of climate and human activities for each spring, attenuation modes of spring discharge fall into three types: natural process dominated attenuation type, exploitation induced process dominated attenuation type, and mixed attenuation type. The total restored discharge variation of 7 karst springs matched well with the global air temperature change in 1956-2000, clearly indicating the trend of global warming and aridity in the last several decades, and the analysis of discharge variation processes of karst springs can be used as a new tool for global change studies.

| /unclassified/todo | 284

A model to predict climate-change impact on fish catch in the world oceans

Biswas, BK Svirezhev, YA Bala, BK

IEEE TRANSACTIONS ON SYSTEMS MAN AND CYBERNETICS PART A-SYSTEMS AND HUMANS 35:6 773-783

Water temperature plays a very important role in fish production. The assessment of the impact of water-temperature changes on fish catches in world fishery is essential for the sustainable management of world fishery resources. Fish catch includes different species, but using information analysis, it is shown that total fish catch can be used without significant loss of information about the dynamic properties of the system. A new method for the forecasting of the fish catch of the major fishing areas in the world’s oceans under global climate change (temperature) has been developed. This method predicts the tendency (increase or decrease) for fish catch, with quantitative predictor’s power, if the temperature is known. This method has been applied to the Indian Ocean to assess the climate-change impact on fish catch. Based on the temperatures predicted using the CLIMate-BiospheRE model for the years 2000-2100, a decrease of fish catch in the Indian Ocean, with the confidence of the predictor’s power at >= 90%, has been predicted.

| /unclassified/todo | 312

Soil carbon sequestration for sustaining agricultural production and improving the environment with particular reference to Brazil

Lal, R

JOURNAL OF SUSTAINABLE AGRICULTURE 26:4 23-42

Agricultural ecosystems generally contain less soil organic carbon (SOC) pool than their potential capacity because of the low return and high rate of mineralization of biosolids, and severe losses due to accelerated erosion and leaching. Conversion of natural to agricultural ecosystems usually causes depletion of 50 to 75 percent of the antecedent SOC pool, thereby creating a potential sink capacity of as much as 35 to 40 Mg C/ha. The depletion of SOC pool leads to decline in soil quality and resilience with attendant reduction in biomass productivity, decreased capacity to degrade and filter pollutants, increased risks of soil degradation by erosion and other processes, and increase in emission of greenhouse gases (GHGs). The magnitude of depletion of SOC pool is greater for soils of the tropics than temperate regions, and for farms which are resource-based and managed with low-input than those managed with science-based and judicious off-farm inputs. The SOC sequestration, increasing SOC pool through conversion to an appropriate land use and adoption of recommended management practices (RMPs), can reverse soil degradation trends, improve soil quality and resilience, increase biomass production and decrease emission of GHGs. A strong link exists between the labile fraction of SOC pool and soil biodiversitythe activity and species diversity of soil fauna (micro, meso and macro) and micro-organisms. Soil biodiversity is usually higher under pastures and planted fallow systems than under crops, and is likely to increase with adoption of conservation tillage and mulch farming, integrated nutrient management and manuring, mixed farming systems and integrated pest management (IPM) techniques. The gross rates of SOC sequestration through adoption of RMPs range from 400 to 800 kg/ha/y for cool and humid regions and 100 to 200 kg/ha/y for dry and warm climates. The potential of soil C sequestration in Brazil is estimated at about 50 Tg C/y. In addition, 60 Tg C/y emitted by erosion-induced mineralization can also be avoided through effective erosion control measures.

| /unclassified/todo | 311

Climate changes and tree phylogeography in the Mediterranean

Petit, RJ Hampe, A Cheddadi, R

TAXON 54:4 877-885

The Mediterranean Basin is expected to be more strongly affected by ongoing global climate change than most other regions of the earth. Given the magnitude of forecasted trends, there are great concerns for the particularly rich biodiversity found in the region. Studies of the consequences of past climate shifts on biodiversity represent one of the best sources of data to validate models of the ecological and evolutionary consequences of future changes. Here we review recent findings from palaeoecology, phylogeography and climate change research to (1) explore possible antecedents of the predicted climate warming in the younger geological history of the Mediterranean Basin, (2) assess how tree populations have reacted to them, and (3) evaluate the significance of the evolutionary heritage that is at stake. A major question of our retrospective approach is whether Quaternary tree extinctions took place primarily during glacial or during interglacial episodes. Available data are scanty and somewhat conflicting. In contrast, abundant phylogeographic evidence clearly indicates that the bulk of genetic diversity in European temperate tree species is almost invariably located in the southernmost part of their range. Long-term persistence of isolated populations have been common phenomena in the Mediterranean, to the point that the current genetic structure in this area probably often reflects population divergence that pre-dates the onset of the Mediterranean climate in the Pliocene. In particular, Tertiary migrations into the Mediterranean of tree taxa originating from Asia seem to have left their footprints in the current genetic structure in these slowly evolving organisms. Moreover, phylogeographic studies point to heterogeneous rates of molecular evolution across lineages that are inversely related with their stability. We conclude that relict tree populations in the Mediterranean Basin represent an evolutionary heritage of disproportionate significance for the conservation of European plant biodiversity.

| /unclassified/todo | 277

Photoreactivation in two freshwater ciliates: differential responses to variations in UV-B flux and temperature

Sanders, RW Macaluso, AL Sardina, TJ Mitchell, DL

AQUATIC MICROBIAL ECOLOGY 40:3 283-292

The effects of UV-B radiation on 2 ciliate species (Glaucoma sp. and Cyclidium sp.) from a clear oligotrophic lake were examined under laboratory conditions with and without photoreactivating radiation (PRR: UV-A and visible light). Glaucoma sp. was exposed to 3 UV-B intensities at 4 temperatures to simulate a range of environmentally relevant conditions. Population growth of Glaucoma sp. declined with increasing levels of UV-B exposure in treatments receiving PRR; blocking PRR generally resulted in 100% mortality. Occurrence of cyclobutane pyrimidine dimers (CPDs [mb DNA](-1)) was significantly reduced in Glaucoma sp. receiving PRR relative to those without PRR. These data indicate that photoenzymatic repair is a major component of UV-B tolerance in Glaucoma. At UV-B levels that Glaucoma sp. tolerated, Cyclidium sp. suffered 100% mortality and accumulated a similar level of CPDs whether or not PRR was blocked. Incubation of the 2 ciliates under UV-transparent and UV-blocking acrylics in the oligotrophic lake confirmed their relative sensitivities to UV radiation (UVR). Photoenzymatic repair in Glaucoma sp. was more efficient at 20 degrees C than at 10, 15 and 25 degrees C. The temperature-dependent nature of photoenzymatic repair underscores the need to consider the interactive effects of temperature and UVR on biota, particularly in the face of global climate change and rising incident UVR due to ozone depletion.

| /unclassified/todo | 302

Paleoceanographic records and sea ice extension history on the slope of the northern Bering Sea over the last 100 ka BP

Wang, RJ Li, X Xiao, WS Xia, PF Chen, RH

ACTA OCEANOLOGICA SINICA 24:6 117-126

Quantitative analytic results of the biogenic components in Core B2-9 from the northern Bering Sea slope indicate that the coarse fraction and opal content, serving as proxies of surface productivity, have increased stepwise since the marine isotope stage(MIS)5.3, reflecting periodic enhancement in surface productivity. The surface productivity attained its highest level during the Holocene, followed by MIS 3.2 to 2 and then MIS 5.3 to 3.3 with a lowest level. High total organic carbon(TOC) contents, together with high C/N ratios, which stand mostly between 7 and 20, show that the TOC was deposited from mixing sources. Therefore,one has to be cautious to use TOC as a proxy of surface productivity. The high TOC and C/N ratio during MIS 5.1, 3.3 to 3.2 and the Holocene reflect that the terrigenous organic matter input increased during interglacial periods. Increases in the fine- and silt-grained terrigenous components from MIS 5.3 to the middle Holocene imply that with the cooling climate, sea ice on the Bering Sea slope extended continuously. Ice-rafted and charcoal detritus increased during glacial, interstadial and the last deglaciation periods and decreased during interglacial periods, suggesting that sea ice on the slope increased and melted, respectively, during glacial and interglacial periods. The extension of sea ice during glacial periods,which was linked with the climate over the North American Continent, responded to global climate change during late Quaternary glacial and interglacial cycles.

sarubh:paleo | /neutral/paleo | 286

Derivation of quantitative management objectives for annual instream water temperatures in the Sabie River using a biological index

Rivers-Moore, NA Jewitt, GPW Weeks, DC

WATER SA 31:4 473-481

Adaptive management of river systems assumes uncertainty and makes provision for system variability. Inherent within this management approach is that perceived limits of ‘acceptable’ system variability are regarded not only as testable hypotheses, but also as playing a central role in maintaining biodiversity. While the Kruger National Park currently functions as a flagship conservation area in South Africa, projected increases in air temperatures as a consequence of global climate change present challenges in conserving this biodiversity inside the established land boundaries. Within the rivers of the Kruger National Park, a management goal of maintaining biodiversity requires a clearer understanding of system variability. One component of this is water temperature, an important water quality parameter defining the distribution patterns of aquatic organisms. In this study, Chiloglanis anoterus Crass (1960) (Pisces: Mochokidae) was selected as a biological indicator of changes in annual water temperatures within the Sabie River in the southern Kruger National Park. Relative abundances of C. anoterus were determined using standard electro-fishing surveys. The presence or absence of C. anoterus was linked to cumulative annual heat units using a logistic regression model, and a critical annual cumulative water temperature threshold estimated. A correlative relationship between this temperature threshold and a biological index using a C. anoterus condition factor provides river ecologists with a tool to assess ecologically significant warming trends in Sabie River water temperatures. A similar approach could be applied with relative ease to other Southern African river systems. Further testing of this hypothesis is suggested, as part of the adaptive management cycle.

| /unclassified/todo | 300

Possible impact of urbanization on the thermal climate of some large cities in Mexico

Jauregui, E

ATMOSFERA 18:4 249-252

Urbanization has been the dominant demographic trend during the second half of the 20th century in Mexico. In 2000 there were 69 cities with more than 100,000 inhabitants of which 9 of them exceeded one million population, totalizing 53.4 million. Using time series of mean monthly temperature for about a dozen available stations, this paper sets out to examine temperature changes occurring during the late 20th century. Since it is well established that urban warming is mainly a nocturnal phenomenon minimum temperature series were selected after a test for homogeneity. Trend analysis was applied to the minimum temperature series and a linear regression coefficient was obtained. Tests of significance were performed. Most of the positive trends proved to be significant (>90%). Although temperature trend variability amongst the individual cities was large (from 0.02 degrees C/decade to 0.74 degrees C/decade) average temperature increase in large (>= 10(6) inhabitants) cities was (0.57 degrees C/decade) considerably higher than that corresponding to medium size urban centers where on the average temperature increase was 0.37 degrees C/decade. These temperature increases express not only the urbanization effect but also that due to global climate change (of the order of 0.07 degrees C/decade) and natural variability. In concluding it may be said that increasing urbanization in Mexico has originated a positive trend in urban temperatures which has implications for human comfort and health.

| /unclassified/todo | 305

Alterations in the production and concentration of selected alkaloids as a function of rising atmospheric carbon dioxide and air temperature: implications for ethno-pharmacology

Ziska, LH Emche, SD Johnson, EL George, K Reed, DR Sicher, RC

GLOBAL CHANGE BIOLOGY 11:10 1798-1807

The influence of recent and projected changes in atmospheric carbon dioxide concentration [CO2] with and without concurrent increases in air temperature was determined with respect to growth characteristics and production of secondary compounds (alkaloids) in tobacco (Nicotiana tabacum L.) and jimson weed (Datura stramonium L.) over a ca. 50-day period. Rising [CO2] above that present at the beginning of the 20th century resulted in consistent, significant increases in leaf area, and above ground dry weight (both species), but decreased leaf area ratio (LAR) and specific leaf area (SLA) in jimson weed. Increased temperature resulted in earlier development and increased leaf area for both species, but increases in above ground final dry weight were observed only for jimson weed. The secondary compounds evaluated included the alkaloids, nicotine, atropine and scopolamine. These compounds are generally recognized as having impacts with respect to herbivory as well as human physiology. Rising [CO2] reduced the concentration of nicotine in tobacco; but had no effect on atropine, and increased the concentration of scopolamine in jimson weed. However, because of the stimulatory effect of [CO2] on growth, the amount of all three secondary compounds increased on a per plant basis in both species. Temperature per se had no effect on nicotine or scopolamine concentration, but significantly increased the concentration and amounts of atropine per plant. Overall, the underlying mechanism of CO2 induced changes in secondary compounds remains unclear; however, these data suggest that the increase in [CO2] and temperature associated with global climate change may have significant effects not only with respect to herbivory, but on the production of secondary compounds of pharmacological impact.

| /unclassified/todo | 321

Influence of land use on plant community composition and diversity in Highland Sourveld grassland in the southern Drakensberg, South Africa

O’Connor, TG

JOURNAL OF APPLIED ECOLOGY 42:5 975-988

1. Biodiversity conservation of grasslands in the face of transformation and global climate change will depend mainly on rangelands because of insufficient conservation areas in regions suited to agriculture. Transformed vegetation (pastures, crops and plantations) is not expected to conserve much biodiversity. This study examined the impact of land use on the plant diversity and community composition of the southern Drakensberg grasslands in South Africa, which are threatened with complete transformation to pastures, crops and plantations. 2. The main land uses in this high rainfall region are: ranching or dairy production under private tenure using indigenous grassland, pastures (Eragrostis curvula, kikuyu and ryegrass) and maize; plantation forestry; communal tenure (maize and rangelands); and conservation. 3. Plant diversity and composition were assessed using Whittaker plots. Transformed cover types were depauperate in species and ranged from kikuyu (1.4 species m(-2)) and ryegrass (2.9), to pine plantation (3.1), E. curvula pasture (3.1), commercial maize (3.2) and communal maize (7.8). With the exception of pine plantations, these communities supported mostly exotic (50 of 70 species) or ruderal indigenous species and made little contribution to plant species conservation. Abandoned communal cropland reverted to an indigenous grassland almost devoid of exotic species within c. 20 years. 4. It was predicted that frequently cultivated sites (maize and ryegrass) would support less diversity than long-lived pastures (kikuyu and E. curvula). This was contradicted by the relatively high species diversity of communal maize fields, which was attributed to a lack of herbicides, and the depauperate communities of kikuyu and of E. curvula pasture, which were attributed, respectively, to a dense growth form and a severe mowing regime. 5. Pine plantations harboured fourfold more indigenous species per plot (27) than other transformed types. Species were mostly shade-tolerant grassland relics that had persisted for 12 years since planting, and some forest colonizers. Indigenous species were unlikely to be maintained because of aggressive invasion by the exotic Rubus cuneifolius and severe disturbance associated with tree harvest and replanting. 6. The richness of indigenous grasslands was expected to differ in response to grazing pressure but they differed only in composition. Grasslands were dominated by grasses, despite the richness of herbaceous species. The dominance of Themeda triandra was reduced under livestock grazing in favour of more grazing-tolerant species. Exotic species were inconspicuous except for the dicotyledon Richardia brasiliensis, a subdominant under communal grazing. 7. Southern Drakensberg grasslands are probably now stocked with livestock six- to 35-fold higher than during pre-settlement times. A grassland protected for c. 50 years supported twofold greater richness (101 species plot(-1)) than grazed grasslands, suggesting that a 150-year history of increased mammalian grazing had already reduced plant diversity. 8. Synthesis and applications. Land acquisition is costly, thus conservation of plant diversity in the southern Drakensberg requires a policy that inhibits transformation of rangelands. This can be achieved by enhancing their economic viability without changing the vegetation composition. Their inherent value must be recognized, such as for water production. The viability of commercial ranches can be improved by increasing their size. Conservation efforts need to be focused on plant taxa that only occur on unprotected rangelands.

| /unclassified/todo | 323

Changes of anti-oxidative enzymes and MDA content under soil water deficits among 10 wheat (Triticum aestivum L.) genotypes at maturation stage

Shao, HB Liang, ZS Shao, MA

COLLOIDS AND SURFACES B-BIOINTERFACES 45:1 7-13

Drought is a world-spread problem seriously influencing grain 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, time course, materials, soil quality status 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, tillering and maturing). Here, we reported the anti-oxidative results of maturation stage (the results of seedling and tillering stage have been published) in terms of activities of POD, SOD, CAT and MDA content 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 group 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; (3) B group exhibited stronger anti-drought under treatment level 2 (light-stress level), whose activities of anti-oxidative enzymes were higher and MDA lower; (4) C group expressed anti-drought to some extent under treatment level 3 (serious-stress level), 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 [T.C. Hsiao, Plant response to water stress, Ann. Rev. Plant Physiol. 24 (1973) 519-570], 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. The study in this respect is the key to wheat anti-drought and biological-saving water agriculture; (7) our research can provide insights into physiological mechanisms of crop anti-drought and direct practical materials for wheat anti-drought breeding; (8) the physiological study of wheat is more urgent up-to-date and molecular aspects are needed, but cannot substitute this important part. The combination of both is an important strategy and a key and (9) POD, SOD and CAT activities and MDA content 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 threshold. (c) 2005 Elsevier B.V. All rights reserved.

| /unclassified/todo | 330

Growing typhoon influence on east Asia

Wu, LG Wang, B Geng, SQ

GEOPHYSICAL RESEARCH LETTERS 32:18 -

Numerical model studies have suggested that the ongoing global climate change will likely affect tropical cyclone activity. Since the global warming has been underway, it is meaningful to ask: Are there evidences of observed changes in tropical cyclone activity? Using best-track data from 1965 to 2003, we show for the first time that over the past four decades the two prevailing typhoon tracks in the western North Pacific (WNP) have shifted westward significantly; thus the subtropical East Asia has experienced increasing typhoon influence; but the typhoon influence over the South China Sea has considerably decreased. Our trajectory model simulation indicates that the long-term shifts in the typhoon tracks result primarily from the changes in the mean translation velocity of typhoons or the large-scale steering flow, which is associated with the westward expansion and strengthening of the WNP subtropical high.

| /unclassified/todo | 324

Changes in tropical cyclone number, duration, and intensity in a warming environment

Webster, PJ Holland, GJ Curry, JA Chang, HR

SCIENCE 309:5742 1844-1846

We examined the number of tropical cyclones and cyclone days as well as tropical cyclone intensity over the past 35 years, in an environment of increasing sea surface temperature. A large increase was seen in the number and proportion of hurricanes reaching categories 4 and 5. The largest increase occurred in the North Pacific, Indian, and Southwest Pacific Oceans, and the smallest percentage increase occurred in the North Atlantic Ocean. These increases have taken place while the number of cyclones and cyclone days has decreased in all basins except the North Atlantic during the past decade.

| /unclassified/todo | 328

The contribution of sulfuric acid and non-volatile compounds on the growth of freshly formed atmospheric aerosols

Wehner, B Petaja, T Boy, M Engler, C Birmili, W Tuch, T Wiedensohler, A Kulmala, M

GEOPHYSICAL RESEARCH LETTERS 32:17 -

The formation of atmospheric aerosol particles ( homogeneous nucleation, forming of stable clusters similar to 1 nm in size), their subsequent growth to detectable sizes (> 3 nm), and to the size of cloud condensation nuclei, remains one of the least understood atmospheric processes upon which global climate change critically depends. However, a quantitative model explanation for the growth of freshly formed aerosols has been missing. In this study, we present observations explaining the nucleation mode ( 3 - 25 nm) growth. Aerosol particles typically grow from 3 nm to 60 - 70 nm during a day, while their non-volatile cores grow by 10 - 20 nm as well. The total particle growth rate is 2 - 8 nm/h while the non-volatile core material can explain 20 - 40%. According to our results, sulfuric acid can explain the remainder of the growth, until the particle diameter is around 10 - 20 nm. After that secondary organic compounds significantly take part in growth process.

| /unclassified/todo | 332

The role of plants and land management in sequestering soil carbon in temperate arable and grassland ecosystems

Rees, RM Bingham, IJ Baddeley, JA Watson, CA

GEODERMA 128:1-2 130-154

Global climate change and concerns about soil quality have led to a widespread interest in the opportunities that are available to sequester carbon in soils. To achieve a better understanding of the changes in C storage, we need to be able to accurately measure and model inputs and losses of C from soils. This in turn requires a thorough understanding of the biological processes involved and the way in which they are influenced by the soil’s physical and chemical environment. The amount of C present in a soil is determined by the difference between C addition and C loss. Because these fluxes are large relative to changes in C storage, net storage can be very difficult to measure, particularly in the short term. Carbon is added to soil from plant and animal materials deposited on the soil surface. It is known that approximately 50% of C assimilated by young plants can be transferred below ground; some is used for root construction and maintenance as well as root respiration; some organic C is lost to the soil through exudation and root turnover. A comparison of eight studies has shown that the input to the soil of root derived organic C during a growing season can range between 0.1 and 2.8 t C ha(-1). Quantifying inputs from different processes has proved difficult and the relative importance of exudation and root death under field conditions remains uncertain. The chemical composition of substrates released by exudation and root death is known to be very different. Exudates contain high concentrations of soluble organic substrates and as a consequence are highly labile, whereas additions of C from root death have structural organic substrates with lower potential decomposition rates. Losses of C from soil occur as a consequence of plant and microbial respiration. However, identifying the source of evolved CO2, whether it be from root or microbial respiration, is much more difficult. Some new methods using isotopic labelling and pool dilution have been developed to separate plant and microbial respiration, and despite difficulties, these promise to provide valuable information on the processes of C input and loss from soils.At a field scale measurements and models would suggest that soil and crop management can play a significant role in determining the extent of C sequestration by soils and the proportion of labile C present. A comparison of 11 field studies showed that soil respiration varies between 4 and 26 t C ha(-1) year(-1), with management such as tillage, drainage, grazing and manure application exerting a strong influence on the magnitude of fluxes. Net ecosystem exchange of C has been shown to be at least an order of magnitude lower than respiratory losses in comparable studies, but land management is important in determining the direction and magnitude of the C flux. Recent studies have suggested that although the overall quantity of C stored in European soils is increasing, this increase is confined largely to forested areas and that many cropped soils are losing soil organic matter. It is has been suggested that that the biological potential for C storage in European cropland lies between 9 and 120 Mt C year(-1). In order to take advantage of this potential and to develop management systems that promote C storage we need to achieve a better understanding of the processes of C input and loss, and develop improved models using pools that coincide with measurable soil C fractions. (c) 2004 Elsevier B.V. All rights reserved.

| /unclassified/todo | 349

Transient future climate over the western United States using a regional climate model

Snyder, MA Sloan, LC

EARTH INTERACTIONS 9: -

Regional climate models (RCMs) have improved our understanding of the effects of global climate change on specific regions. The need for realistic forcing has led to the use of fully coupled global climate models (GCMs) to produce boundary conditions for RCMs. The advantages of using fully coupled GCM output is that the global-scale interactions of all components of the climate system ( ocean, sea ice, land surface, and atmosphere) are considered. This study uses an RCM, driven by a fully coupled GCM, to examine the climate of a region centered over California for the time periods 1980 - 99 and 2080 - 99. Statistically significant increases in mean monthly temperatures by up to 7 degrees C are found for the entire state. Large changes in precipitation occur in northern California in February ( increase of up to 4 mm day(-1) or 30%) and March ( decrease of up to 3 mm day(-1) or 25%). However, in most months, precipitation changes between the cases were not statistically significant. Statistically significant decreases in snow accumulation of over 100 mm (50%) occur in some months. Temperature increases lead to decreases in snow accumulation that impact the hydrologic budget by shifting spring and summer runoff into the winter months, reinforcing results of other studies that used different models and driving conditions.

| /unclassified/todo | 173

Irradiance models

Solanki, SK Krivova, NA Wenzler, T

INFLUENCE OF THE SUN’S RADIATION AND PARTICLES ON THE EARTH’S ATMOSPHERE AND CLIMATE 35:3 376-383

Measurements of solar irradiance have revealed variations at all the sampled time scales (ranging from minutes to the length of the solar cycle). One important task of models is to identify the causes of the observed (total and spectral) irradiance variations. Another major aim is to reconstruct irradiance over time scales longer than sampled by direct measurements in order to consider if and to what extent solar irradiance variations may be responsible for global climate change. Here, we describe recent efforts to model solar irradiance over the current and the previous two solar cycles. These irradiance models are remarkably successful in reproducing the observed total and spectral irradiance, although further improvements are still possible. (c) 2005 COSPAR. Published by Elsevier Ltd. All rights reserved.

| /unclassified/todo | 325

Plant growth and water use efficiency of four Chinese conifer tree species under different air humidity

Zheng, Y Shimizu, H

PHYTON-ANNALES REI BOTANICAE 45:4 575-582

Air humidity is an important controlling factor for the establishment of tree seedlings. It is predicted that the annual amount of rainfall will decline in some parts of China due to the global climate change in the foreseeable future. There is limited information on the potential responses of this region’s forest to the global climate change. Our study investigated the responses of four major Chinese conifer tree species to air humidity variations. Seedlings of Pinus massoniana Lamb. var. massoniana, Pinus tabulaeformis Carr. var. tabulaeformis, Platycladus orientalis (Linn.) Franco cv. Sieboldii and Cunninghamia lanceolata (Lamb.) Hook were grown in controlled environment chambers under four different air humidity (RH: 40, 50, 60 and 70% or VPD: 2.4, 2.0, 1.6 and 1.2 kPa). Results showed that the growth of these four species responded to air humidity differently. P. massoniana was the most sensitive species, P. tabulaeformis and P. orientalis were less sensitive and C. lanceolata was the least sensitive species. However, the biomass increment (Delta biomass) and the relative growth rate (RGR) over the experimental period were higher under the RH 70% treatment than that under the 40% treatment for all the four species. Delta biomass and RGR were reduced by 54% and 47%, respectively, under the RH 40% treatment compared with those under the RH 70% treatment for P. massoniana, 24% and 12% for P. tabulaeformis, 22 % and 16 % for P. orientalis, 9% and 5% for C. lanceolata. The decreased growth under drier air conditions was partially due to the closure of leaf stomata and subsequently the depression of photosynthesis. Plants under higher humidity conditions had higher water use efficiency (WUE). There was a positive linear relationship between WUE and RH in all the four species. Our results may suggest that if air humidity becomes lower in some regions of China in the future, the area of distribution for the humidity sensitive species P. Massoniana may become smaller or this species may move to higher humidity region while the other three species will be less affected by this change.

| /unclassified/todo | 146

The quantitative effects of population density and winter weather on the body condition of white-tailed deer (Odocoileus virginianus) in Nova Scotia, Canada

Garroway, CJ Broders, HG

CANADIAN JOURNAL OF ZOOLOGY-REVUE CANADIENNE DE ZOOLOGIE 83:9 1246-1256

Understanding the underlying mechanisms that cause variation in survival and the reproductive success of animals is essential for predicting variation in population parameters. To gain an understanding of the effects of density and winter weather severity on white-tailed deer, Odocoileus virginianus (Zimmermann, 1780), we examined the effects of current-year deer density and cumulative weekly average values for snow depth, rainfall, and the number of degrees below -15 degrees C until the time of death, as well as cumulative effects of density and snow depth over the previous one and two winters, on the body condition of adult females, adult males, and fawns. Model selection using Akaike’s Information Criterion and multi-model inference suggested that snow depth was the best predictor of body condition for all three age/sex groups. Winter rainfall was the next most influential predictor for adult females and adult males but was not important in determining fawn body condition. Temperature had the least influence on the body condition of all three age/sex groups. Deer density during the winter of death had minimal effects for all groups and we found no evidence that cumulative multiyear variables influenced body condition. We hypothesize that cohort variation may better explain previous findings showing effects of multiyear variables. A model for estimating the proportion of animals in poor body condition for each age/sex group is presented.

| /unclassified/todo | 304

A hydrologic contribution to risk assessment for the Caspian Sea

Helms, M Evdakov, O Ihringer, E Nestmann, F

LIMNOLOGICA 35:3 114-122

The Caspian Sea (CS), the world’s largest inland sea, may also be considered as large-scale limnic system. Due to strong fluctuations of its water level during the 20th century and the flooding of vast areas in a highly vulnerable coastal zone, economic and environmental risk potentials have to be considered. Since the major water input into the CS is attributed to the Volga river, the understanding of its long-term flow process is necessary for an appropriate risk assessment for the CS and its coastal area. Therefore, a top-down approach based on statistical analyses of long-term Volga flow series is pursued. For the series of annual mean flow (MQ) of the Volga river basin during the 20th century, a complex oscillation pattern was identified. Analyses for multiple gauges in the Volga river basin and Eurasian reference basins revealed that this oscillation pattern resulted from the superposition of oscillations with periods of similar to 30 years (MQ) in the western part of the Volga river basin, and similar to 14 years (flow volume of snowmelt events) and similar to 20 years (flow volume of summer and autumn) in the eastern part of the Volga river basin (Kama river basin). Almost synchronous minima or maxima of these oscillations occurred just in the periods of substantial changes of the Caspian Sea level (CSL). It can thus be assumed that the described mechanism is fundamental for an understanding of the CSL development during the 20th century. Regarding the global climate change, it is still difficult to predict reliably the development of the CSL for the 21st century. Consequently, we suggest an ongoing, interdisciplinary research co-operation among climatology, hydrology, hydraulics, ecology and spatial data management. (c) 2005 Elsevier GmbH. All rights reserved.

| /unclassified/todo | 322

Characterization of microsatellite loci in Schoenoplectus americanus (Cyperaceae)

Blum, MJ McLachlan, JS Saunders, CJ Herrick, JD

MOLECULAR ECOLOGY NOTES 5:3 661-663

Schoenoplectus americanus is a model organism for studying ecological and ecosystem responses of salt marsh plant communities to global climate change. Here we characterize 16 microsatellite loci in S. americanus to facilitate studies on the genetic basis of phenotypic responses to changing climate conditions such as elevated atmospheric carbon dioxide. Most loci also amplified in the morphologically similar sister species, Schoenoplectus pungens. Five loci exhibited species-specific alleles or distinct allelic size distributions that discriminate S. americanus from S. pungens.

| /unclassified/todo | 334

Rates of soil creep, worldwide: weak climatic controls and potential feedback

Oehm, B Hallet, B

ZEITSCHRIFT FUR GEOMORPHOLOGIE 49:3 353-372

The rate of soil creep sets the tempo at which material is transferred from hill-slopes to fluvial systems over major portions of terrestrial landscapes. Hence, soil creep rates affect the rates of landscape evolution and delivery of terrigenous material to floodplains and eventually to the oceans. Herein, we compile data from all sources worldwide that arc readily available in the literature, and derive common, quantitative characteristics of soil creep from digitized soil displacement profiles that permit estimates of soil flux and comparison between diverse studies. We also search for systematic variations of creep rates with climate and explore potential feedbacks between creep rates and climate. Significant creep is found in a range of environments worldwide and is fueled by diverse physical and biological processes. The considerable inter-site variability overwhelms the dependence of creep rates on hillslope gradient and obscures, but does not conceal, the climate influence. We speculate that the general tendency for rapid creep to be associated with colder climates could exacerbate global climate change. A global rise in temperature, for example, could slow the sequestration of atmospheric CO2 as creep rates decrease by slowing two distinct pedogcnic processes: mineral weathering, which is sensitive function of processes that create and freshen mineral surfaces, and the subaerial delivery of organic carbon stored in soils to rivers and long-lived reservoirs.

| /unclassified/todo | 313

Animal-borne sensors successfully capture the real-time thermal properties of ocean basins

McMahon, CR Autret, E Houghton, JDR Lovell, P Myers, AE Hays, GC

LIMNOLOGY AND OCEANOGRAPHY-METHODS 3: 392-398

Climate change is perhaps the most pressing and urgent environmental issue facing the world today. However our ability to predict and quantify the consequences of this change is severely limited by the paucity of in situ oceanographic measurements. Marine animals equipped with sophisticated oceanographic data loggers to study their behavior offer one solution to this problem because marine animals range widely across the world’s ocean basins and visit remote and often inaccessible locations. However, unlike the information being collected from conventional oceanographic sensing equipment, which has been validated, the data collected from instruments deployed on marine animals over long periods has not. This is the first long-term study to validate in situ oceanographic data collected by animal oceanographers. We compared the ocean temperatures collected by leatherback turtles (Dermochelys coriacea) in the Atlantic Ocean with the ARGO network of ocean floats and could find no systematic errors that could be ascribed to sensor instability. Animal-borne sensors allowed water temperature to be monitored across a range of depths, over entire ocean basins, and, importantly, over long periods and so will play a key role in assessing global climate change through improved monitoring of global temperatures. This finding is especially pertinent given recent international calls for the development and implementation of a comprehensive Earth observation system ( see http://iwgeo.ssc.nasa.gov/documents.asp?s=review) that includes the use of novel techniques for monitoring and understanding ocean and climate interactions to address strategic environmental and societal needs.

| /unclassified/todo | 261

Prediction of expected global climate change by forecasting of galactic cosmic ray intensity time variation in near future based on solar magnetic field data

Belov, AV Dorman, LI Gushchina, RT Obridko, VN Shelting, BD Yanke, VG

INFLUENCE OF THE SUN’S RADIATION AND PARTICLES ON THE EARTH’S ATMOSPHERE AND CLIMATE 35:3 491-495

A method of prediction of expected part of global climate change caused by cosmic ray (CR) by forecasting of galactic cosmic ray intensity time variation in near future based on solar activity data prediction and determined parameters of convection-diffusion and drift mechanisms is presented. This gave possibility to make prediction of expected part of global climate change, caused by long-term cosmic ray intensity variation. In this paper, we use the model of cosmic ray modulation in the Heliosphere, which considers a relation between long-term cosmic ray variations with parameters of the solar magnetic field. The later now can be predicted with good accuracy. By using this prediction, the expected cosmic ray variations in the near Earth space also can be estimated with a good accuracy. It is shown that there are two possibilities: (1) to predict cosmic ray intensity for 1-6 months by using a delay of long-term cosmic ray variations relatively to effects of the solar activity and (2) to predict cosmic ray intensity for the next solar cycle. For the second case, the prediction of the global solar magnetic field characteristics is crucial. For both cases, reliable long-term cosmic ray and solar activity data as well as solar magnetic field are necessary. For solar magnetic field, we used results of two magnetographs (from Stanford and Kitt Peak Observatories). The obtained forecasting of long-term cosmic ray intensity variation we use for estimation of the part of global climate change caused by cosmic ray intensity changing (influenced on global cloudiness covering). (c) 2005 COSPAR. Published by Elsevier Ltd. All rights reserved.

| /unclassified/todo | 326

Estimation of long-term cosmic ray intensity variation in near future and prediction of their contribution in expected global climate change

Dorman, LI

INFLUENCE OF THE SUN’S RADIATION AND PARTICLES ON THE EARTH’S ATMOSPHERE AND CLIMATE 35:3 496-503

On the basis of results obtained in our paper [Dorman, L.I. Long-term cosmic ray intensity variation and part of global climate change, controlled by solar activity through cosmic rays, Paper D2.1/C2.2/E3.1-0097-04. Adv. Space Res., 2004 (accepted)], we determine: the dimension of the Heliosphere (modulation region), radial diffusion coefficient and other parameters of convection-diffusion; drift mechanisms of long-term variations of cosmic ray (CR) dependence on particle energy; level of solar activity (SA); and generally, the solar magnetic field. We obtain this important information on the basis of CR and SA data in the past, taking into account the theory of convection-diffusion and global drift modulation of galactic CR in the Heliosphere. By using these results and other regularly published predictions of expected SA variation in the near future, as well as predictions of the next SA cycle, we may make predictions of long-term cosmic ray intensity variation expected in the near future (up to 10-12 years). In [Dorman, L.I. Long-term cosmic ray intensity variation and part of global climate change, controlled by solar activity through cosmic rays, Paper D2.1/C2.2/E3.1-0097-04. Adv. Space Res., 2004 (accepted)], properties of connections between long-term variation in CR intensity and some part of a global climate change were estimated, controlled by solar activity through CR. We show that in this way we may make predictions of some part of a global climate change expected in the near future (up to 10-12 years and maybe more, depending upon the period during which definite predictions of SA can be made), controlled by solar activity through CR. In this case, estimations of expected long-term changes in the planetary distribution of cutoff rigidities, which also influence CR intensity, as well as CR-influenced effects on global climate variation, become important. (c) 2005 COSPAR. Published by Elsevier Ltd. All rights reserved.

| /unclassified/todo | 327

Model of the net primary productivity of terrestrial ecosystems in china and its response to climate change

Zheng, YR Xie, ZX Jiang, LH Chen, LJ Yu, YJ Zhou, GS Shimizu, H

PHYTON-ANNALES REI BOTANICAE 45:4 193-200

The present study proposed to distinguish agricultural vegetation from natural vegetation when modelling net primary productivity (NPP), and developed a NPP model specifically for agricultural vegetation in China. The new model and the ZHOU & ZHANG model 1996 were then used to simulate NPP for agricultural land and natural ecosystems in China, respectively. The results showed that the overall accuracy improved when simulating the present NPP. As a general trend, NPP declined from southeast to northwest, with the lowest NPP in the Xinjiang Autonomous region. Except in extremely and or extremely humid areas, agricultural NPP was usually lower than natural NPP, especially in northeastern China and the North China plain. The two models were also used to simulate NPP in China under three climatic change scenarios. The results demonstrated that if air temperature increased by 2 degrees C and rainfall decreased by 20 %, both low NPP and high NPP area would decrease, resulting in an increase of medium NPP area. The other two scenarios, characterized by a temperature increase of 2 degrees C, combined with precipitation increase of 20 % and with precipitation unchanged, showed a decrease in low NPP area and a increase in medium and high NPP area, however, the former resulted in a greater medium NPP increase. In conclusion, our approach supplied better predictions than those based on only a natural NPP model.

| /unclassified/todo | 145

Sensitivity analysis of the tree distribution model PHENOFIT to climatic input characteristics: implications for climate impact assessment

Morin, X Chuine, I

GLOBAL CHANGE BIOLOGY 11:9 1493-1503

Species distributions are already affected by climate change. Forecasting their long-term evolution requires models with thoroughly assessed validation. Our aim here is to demonstrate that the sensitivity of such models to climate input characteristics may complicate their validation and introduce uncertainties in their predictions. In this study, we conducted a sensitivity analysis of a process-based tree distribution model PHENOFIT to climate input characteristics. This analysis was conducted for two North American trees which differ greatly in their distribution and eight different types of climate input for the historic period which differ in their spatial (local or gridded data) and temporal (daily vs. monthly) resolution as well as their type (locally recorded, extrapolated or simulated by General Circulation Models). We show that the climate data resolution (spatial and temporal) and their type, highly affect the model predictions. The sensitivity analysis also revealed, the importance, for global climate change impact assessment, of (i) the daily variability of temperatures in modeling the biological processes shaping species distribution, (ii) climate data at high latitudes and elevations and (iii) climate data with high spatial resolution.

| /unclassified/todo | 339

On climate response to changes in the cosmic ray flux and radiative budget

Shaviv, NJ

JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS 110:A8 -

We examine the results linking cosmic ray flux ( CRF) variations to global climate change. We then proceed to study various periods over which there are estimates for the radiative forcing, temperature change and CRF variations relative to today. These include the Phanerozoic as a whole, the Cretaceous, the Eocene, the Last Glacial Maximum, the 20th century, as well as the 11- yr solar cycle. This enables us to place quantitative limits on climate sensitivity to both changes in the CRF, and the radiative budget, F, under equilibrium. Under the assumption that the CRF is indeed a climate driver, the sensitivity to variations in the globally averaged relative change in the tropospheric ionization I is consistently fitted with mu &3bond; ( dT(global)/ dI) approximate to 7.5 +/- 2 degrees K. Additionally, the sensitivity to radiative forcing changes is lambda &3bond; dT(global)/ dF = 0.35 +/- 0.09 degrees KW(-1)m(2), at the current temperature, while its temperature derivative is undetectable with (d lambda/ dT)(0) = - 0.01 +/- 0.04 m(2)W(-1). If the observed CRF/ climate link is ignored, the best sensitivity obtained is lambda = 0.54 +/- 0.12 degrees KW-1 m(2) and ( d lambda/ dT)(0) = - 0.02 +/- 0.05 m(2) W-1. Note that this analysis assumes that different climate conditions can be described with at most a linear function of T; however, the exact sensitivity probably depends on various additional factors. Moreover, l was mostly obtained through comparison of climate states notably different from each other, and thus only describes an average sensitivity. Subject to the above caveats and those described in the text, the CRF/ climate link therefore implies that the increased solar luminosity and reduced CRF over the previous century should have contributed a warming of 0.47 +/- 0.19 degrees K, while the rest should be mainly attributed to anthropogenic causes. Without any effect of cosmic rays, the increase in solar luminosity would correspond to an increased temperature of 0.16 +/- 0.04 degrees K.

timlambert:rejectex | /reject/rejectex | 336

Snow and glacier cover assessment in the high mountains of Sikkim Himalaya

Krishna, AP

HYDROLOGICAL PROCESSES 19:12 2375-2383

This study highlights the assessment of snow and glacier cover for possible inferences of global climate change impacts in high mountains like the Himalaya. The test catchment of the River Tista lies in the Sikkim state of the Indian Himalayan region, with steep mountains crossing nearly all ecozones, from subtropical to glacial. River flows are highly fluctuating, especially during the peak rainy season and snowmelt periods. Annual rainfall patterns are non-uniform and can cause large floods. Runoff and discharge downstream are highly dependent upon snow and glacier extent. The temporary storage of frozen water brings about a delay in seasonal runoff. Snow cover built up in the higher regions during the winter months melts in the spring-summer-autumn cycles and contributes to groundwater recharge. A spatial baseline inventory of snow cover/glacier, the permanent snowline and its short-term temporal changes in the remote high-mountain areas have been analysed using multidate Indian Remote Sensing Satellite data of 1992 to 1997. A geographic information system-based overlay has led to inferences on snow cover characteristics and the alignment, dimension, slope disposition, heights of the snout and associated features of each of the glaciers. Snow and glacier recession are to be monitored in future on a long-term basis to derive correlations with climate-change parameters. Copyright (c) 2005 John Wiley & Sons, Ltd.

| /unclassified/todo | 338

The science, politics and economics of global climate change: Implications for the carbon sink projects

Jacob, J

CURRENT SCIENCE 89:3 464-474

| /unclassified/todo | 341

Drier summers cancel out the CO2 uptake enhancement induced by warmer springs

Angert, A Biraud, S Bonfils, C Henning, CC Buermann, W Pinzon, J Tucker, CJ Fung, I

PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA 102:31 10823-10827

An increase in photosynthetic activity of the northern hemisphere terrestrial vegetation, as derived from satellite observations, has been reported in previous studies. The amplitude of the seasonal cycle of the annually detrended atmospheric CO2 in the northern hemisphere (an indicator of biospheric activity) also increased during that period. We found, by analyzing the annually detrended CO2 record by season, that early summer (June) CO2 concentrations indeed decreased from 1985 to 1991, and they have continued to decrease from 1994 up to 2002. This decrease indicates accelerating springtime net CO2 uptake. However, the CO2 minimum concentration in late summer (an indicator of net growing-season uptake) showed no positive trend since 1994, indicating that lower net CO2 uptake during summer cancelled out the enhanced uptake during spring. Using a recent satellite normalized difference vegetation index data set and climate data, we show that this lower summer uptake is probably the result of hotter and drier summers in both mid and high latitudes, demonstrating that a warming climate does not necessarily lead to higher CO2 growing-season uptake, even in high-latitude ecosystems that are considered to be temperature limited.

| /unclassified/todo | 342

Marmots on Great Basin mountaintops: Using genetics to test a biogeographic paradigm

Floyd, CH Van Vuren, DH May, B

ECOLOGY 86:8 2145-2153

Boreal mammals in the Great Basin have long been viewed as island-bound Pleistocene relicts because they occupy island-like patches of montane habitat separated by desert lowlands that presumably are impermeable to dispersal. Recent work, however, raised the possibility that dispersal among mountain ranges is an important process in the biogeography of boreal mammals in the Great Basin. We test this proposition using genetic variation in a representative species, the yellow-bellied marmot (Marinota flaviventris). A total of 332 marmots was sampled from 10 ranges and genotyped at six microsatellite loci. If the intervening desert lowlands are impermeable barriers to dispersal, then there should be no relationship between genetic distance and geographic distance among mountaintop populations, and genetic diversity should be diminished because gene flow would not be available to replace alleles lost over thousands of generations of isolation. Our results did not support these predictions. There was a strong correlation between genetic and geographic distance, demonstrating an isolation-by-distance pattern, and genetic diversity was high. Our results suggest that marmot populations in the Great Basin may be linked by dispersal, providing a mechanism to replenish genetic variation lost by drift. However, global climate change over the next several decades could make the desert lowlands more difficult to traverse, eventually transforming the boreal faunas of Great Basin mountaintops into the isolated relicts they were originally portrayed to be.

| /unclassified/todo | 344

Are long-distance migrants constrained in their evolutionary response to environmental change? Causes of variation in the timing of autumn migration in a blackcap (S-atricapilla) and two garden warbler (Sylvia borin) populations

Pulido, F Widmer, M

BIRD HORMONES AND BIRD MIGRATIONS: ANALYZING HORMONES IN DROPPINGS AND EGG YOLKS AND ASSESSING ADAPTATIONS IN LONG-DISTANCE MIGRATION 1046: 228-241

Long-distance migratory birds often show little phenotypic variation in the timing of life-history events like breeding, molt, or migration. It has been hypothesized that this could result from low levels of heritable variation. If this were true, the adaptability of long-distance migratory birds would be limited, which would explain the vulnerability of this group of birds to environmental changes. The amount of phenotypic, environmental, and genetic variation in the onset of autumn migratory activity was assessed in two garden warbler (Sylvia borin) populations differing in breeding phenology and the length of the breeding season with the aim of investigating the effects of selection on the adaptability of long-distance migrants. High heritabilities and additive genetic variance components for the timing of autumn migration were found in both populations. Although genetic variation in the mountain population was lower than in the lowlands, this difference was not statistically significant. Moreover, no evidence was found for reduced levels of genetic variation in the garden warbler as compared to its sister species, the blackcap (S. atricapilla). Environmental variation, however, was markedly reduced in the garden warbler, suggesting that low levels of phenotypic variation typically found in long-distance migrants may be a consequence of environmental canalization of migratory traits. The buffering of environmental variation may be an adaptive response to strong stabilizing selection on the timing of migration. High environmental canalization of migration phenology in long-distance migrants could potentially explain low rates of immediate phenotypic change in response to environmental change.

| /unclassified/todo | 318

Warming in Arctic intermediate and deep waters around Chukchi Plateau and its adjacent regions in 1999

Zhao, JP Gao, GP Jiao, YT

SCIENCE IN CHINA SERIES D-EARTH SCIENCES 48:8 1312-1320

Based on the data measured during Arctic scientific expedition of China in 1999, the characteristics of temperature and salinity distributions around the Chukchi Plateau and its adjacent regions have been studied. It was found that the intermediate water with temperature higher than 0.5 degrees C existed in all parts of a 640 km section with a maximum temperature of 0.85 degrees C indicating a strong signal of the warming in Arctic Intermediate Water in 1999. Two important phenomena are described in this paper. First, the temperature of warm water was horizontally nonuniform. In the area of Chukchi Plateau, the temperature was higher, the layer of warm water was thicker and the depth of the warm water core was shallower than those in the area of continental slope. The horizontal nonuniformity of the temperature distribution of warming water implies that the upward heat flux should also be nonuniform, thus exerting different effects on sea ice thickness, ice extent, and air-sea heat exchange. The mechanism to generate higher temperature in the plateau region was the bypassing of current around the plateau area caused by the special local topography, which restricted water exchange across the plateau and conserved heat in the water body. Second, the deep water down to 1400 m was also warming with a temperature increase of 0.2 degrees C. The warming in deep water reflects the occurrence of complicated heat redistribution processes in the intermediate water, which altered the thermal structure in the upper 1400 m. The warming data embody the obvious impact of global climate change on the Arctic Ocean and further studies are wanted.

| /unclassified/todo | 319

Rates of erosion and topographic evolution of the Sierra Nevada, California, inferred from cosmogenic Al-26 and Be-10 concentrations

Stock, GM Anderson, RS Finkel, RC

EARTH SURFACE PROCESSES AND LANDFORMS 30:8 985-1006

Concentrations of cosmogenic Al-26 and Be-10 in cave sediments and bedrock surfaces, combined with studies of landscape morphology, elucidate the topographic history of the southern Sierra Nevada over the past 5 Ma. Caves dated by Al-26/Be-10 in buried sediments reveal that river incision rates were moderate to slow between c. 5 and 3 Ma (<= 0.07 mm a(-1)), accelerated between 3 and 1.5 Ma (c. 0.3 ram a(-1)), and then have subsequently become much slower (c. 0.02 mm a(-1)). Although the onset of accelerated incision coincides in time with both,postulated Pliocene tectonism and pronounced global climate change, we argue that it primarily represents the response to a discrete tectonic event between 3 and 5 Ma. Dated cave positions reveal that, prior to 3 Ma, river canyons displayed up to 1.6 km of local relief, suggesting that Pliocene rock uplift elevated pre-existing topography. Renewed incision beginning c. 3 Ma deepened canyons by up to 400 m, creating narrow inner gorges. Tributary streams exhibit strong convexities, indicating that the transient erosional response to Pliocene uplift has not yet propagated into upland surfaces. Concentrations of Al-26 and Be-10 in bare bedrock show that upland surfaces are eroding at slow rates of c. 0.01 mm a(-1). Over the past c. 3 Ma, upland surfaces eroded slowly while adjacent rivers incised rapidly, increasing local relief. Although relief production probably drove at least modest crestal uplift, considerable pre-Pliocene relief and low spatially averaged erosion rates suggest that climatically driven rock uplift is not sufficient to explain ail uplift implied by tilted markers at the western edge of the range. Despite the recent pulse of erosion, spatially averaged erosion rates are low, and have probably acted to preserve the broad topographic form of the Sierra Nevada throughout much of the late Cenozoic. Copyright (c) 2005 John Wiley & Sons, Ltd.

| /unclassified/todo | 337

The case for carbon capture and storage

Stephens, JC Van der Zwaan, B

ISSUES IN SCIENCE AND TECHNOLOGY 22:1 68-76

Human activity releases approximately 25 billion tons of carbon dioxide into the atmosphere every year, building up the levels of greenhouse gases that are responsible for global climate change. The world’s forests store about 2 or 3 billion tons of that output annually, and the ocean absorbs 7 billion tons. Itis estimated that another 5 to 10 billion tons, as much as 40% of man-made carbon dioxide, could be removed from the atmosphere and safely stored away. Methods of storage are being researched, for example underground geological storage. Issues of safety and cost and feasibility need to be addressed before the government can push for carbon capture and storage.

| /unclassified/todo | 320

Early tectonic uplift of the northern Tibetan Plateau

Dai, SA Fang, XM Song, CH Gao, JP Gao, DL Li, JJ

CHINESE SCIENCE BULLETIN 50:15 1642-1652

The Hexi Corridor is the northmost foreland basin of the Tibetan Plateau and its formation is controlled by the northern marginal fault of Tibet, Altyn Tagh Fault (ATF)-North Qilian Shan marginal Fault (NQF), and the southern Kuantan Shan-Longshou Shan Fault (KLF). So its study is important to understanding the mechanism of Tibet formation and its influence on global climate change. The oldest Cenozoic sediments in the Corridor is the Huoshaogou Formation which consists of terrigenous fine conglomerate, sandstone, sandy mudstone and mudstone, depositing in alluvial to lacustrine and fan delta sedimentary environments. Detailed paleomagnetic measurements of this sequence at Yumen clearly reveal eleven pairs of normal and reversed polarities. Fossil mammals found around the section support that most of the observed polarities can be well correlated with chrons between 13n and 18r of the standard geomagnetic polarity time scale, yielding ages of 40.2-33.35 Ma. The mean declinations of this sequence and its immediately above stratigraphy indicate an 18.3 degrees rapid clockwise rotation of the Hexi Corridor. Since this sequence has been strongly folded and is capped by an angular unconformity, we think that the presence of the thick alluvial fan conglomeration at the bottom of the foreland basin may indicate the initial deformation and uplift of the northern Qilian Shan. This process could occur at latest at 40.2 Ma, driven by the faults NQF and KLF that thrust onto the Hexi corridor respectively from its southern and northern margins. These faults are in an early response to the collision of India with Asia, while the unconformable termination and rotation of the Huoshaogou Formation at similar to 33.35 Ma indicate other early episode of rapid tectonic deformation and uplift of the northern Tibet.

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