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1.
The composition of precipitation is being monitored in collectors sited throughout the United Kingdom. In the first year, 1986, hydrogen ion, nitrate, ammonium and non-marine sulphate were measured in samples from 47 sites and annual mean concentrations determined. Spatial analysis based on Regionalized Variable Theory revealed autocorrelation in all four ions and reasonable bounded models were fitted to the sample variogram of all four. These were then used to estimate values of a fine mesh grid by simple kriging, and the estimates were then contoured. The estimation errors were similarly mapped, and both sets of maps are presented. The maps show that concentrations of these ions are greatest in eastern parts of the country, as expected from consideration of European emissions and weather patterns. For the first time estimation errors were also mapped and show how the network could be improved. 相似文献
2.
Lu Y Beeman RW Campbell JF Park Y Aikins MJ Mori K Akasaka K Tamogami S Phillips TW 《Die Naturwissenschaften》2011,98(9):755-761
We report that the abdominal epidermis and associated tissues are the predominant sources of male-produced pheromones in the
red flour beetle, Tribolium castaneum and, for the first time, describe the stereoisomeric composition of the natural blend of isomers of the aggregation pheromone
4,8-dimethyldecanal (DMD) in this important pest species. Quantitative analyses via gas chromatography–mass spectrometry showed
that the average amount of DMD released daily by single feeding males of T. castaneum was 878 ± 72 ng (SE). Analysis of different body parts identified the abdominal epidermis as the major source of aggregation
pheromone; the thorax was a minor source, while no DMD was detectable in the head. No internal organs or obvious male-specific
glands were associated with pheromone deposition. Complete separation of all four stereoisomers of DMD was achieved following
oxidation to the corresponding acid, derivatization with (1R, 2R)- and (1S, 2S)-2-(anthracene-2,3-dicarboximido)cyclohexanol to diastereomeric esters, and their separation on reversed-phase high-performance
liquid chromatography at −54°C. Analysis of the hexane eluate from Porapak-Q-collected volatiles from feeding males revealed
the presence of all four isomers (4R,8R)/(4R,8S)/(4S,8R)/(4S,8S) at a ratio of approximately 4:4:1:1. A walking orientation bioassay in a wind tunnel with various blends of the four synthetic
isomers further indicated that the attractive potency of the reconstituted natural blend of 4:4:1:1 was equivalent to that
of the natural pheromone and greater than that of the 1:1 blend of (4R,8R)/(4R,8S) used in commercial lures. 相似文献
3.
George P. Ingersoll M. Alisa Mast Donald H. Campbell David W. Clow Leora Nanus John T. Turk 《Atmospheric environment (Oxford, England : 1994)》2008,42(24):6098-6113
Seasonal snowpack chemistry data from the Rocky Mountain region of the US was examined to identify long-term trends in concentration and chemical deposition in snow and in snow-water equivalent. For the period 1993–2004, comparisons of trends were made between 54 Rocky Mountain Snowpack sites and 16 National Atmospheric Deposition Program wetfall sites located nearby in the region. The region was divided into three subregions: Northern, Central, and Southern. A non-parametric correlation method known as the Regional Kendall Test was used. This technique collectively computed the slope, direction, and probability of trend for several sites at once in each of the Northern, Central, and Southern Rockies subregions. Seasonal Kendall tests were used to evaluate trends at individual sites.Significant trends occurred during the period in wetfall and snowpack concentrations and deposition, and in precipitation. For the comparison, trends in concentrations of ammonium, nitrate, and sulfate for the two networks were in fair agreement. In several cases, increases in ammonium and nitrate concentrations, and decreases in sulfate concentrations for both wetfall and snowpack were consistent in the three subregions. However, deposition patterns between wetfall and snowpack more often were opposite, particularly for ammonium and nitrate. Decreases in ammonium and nitrate deposition in wetfall in the central and southern rockies subregions mostly were moderately significant (p<0.11) in constrast to highly significant increases in snowpack (p<0.02). These opposite trends likely are explained by different rates of declining precipitation during the recent drought (1999–2004) and increasing concentration. Furthermore, dry deposition was an important factor in total deposition of nitrogen in the region. Sulfate deposition decreased with moderate to high significance in all three subregions in both wetfall and snowpack. Precipitation trends consistently were downward and significant for wetfall, snowpack, and snow-telemetry data for the central and southern rockies subregions (p<0.03), while no trends were noted for the Northern Rockies subregion. 相似文献
4.
Sutton MA Nemitz E Erisman JW Beier C Bahl KB Cellier P de Vries W Cotrufo F Skiba U Di Marco C Jones S Laville P Soussana JF Loubet B Twigg M Famulari D Whitehead J Gallagher MW Neftel A Flechard CR Herrmann B Calanca PL Schjoerring JK Daemmgen U Horvath L Tang YS Emmett BA Tietema A Peñuelas J Kesik M Brueggemann N Pilegaard K Vesala T Campbell CL Olesen JE Dragosits U Theobald MR Levy P Mobbs DC Milne R Viovy N Vuichard N Smith JU Smith P Bergamaschi P Fowler D Reis S 《Environmental pollution (Barking, Essex : 1987)》2007,150(1):125-139
Recent research in nitrogen exchange with the atmosphere has separated research communities according to N form. The integrated perspective needed to quantify the net effect of N on greenhouse-gas balance is being addressed by the NitroEurope Integrated Project (NEU). Recent advances have depended on improved methodologies, while ongoing challenges include gas-aerosol interactions, organic nitrogen and N(2) fluxes. The NEU strategy applies a 3-tier Flux Network together with a Manipulation Network of global-change experiments, linked by common protocols to facilitate model application. Substantial progress has been made in modelling N fluxes, especially for N(2)O, NO and bi-directional NH(3) exchange. Landscape analysis represents an emerging challenge to address the spatial interactions between farms, fields, ecosystems, catchments and air dispersion/deposition. European up-scaling of N fluxes is highly uncertain and a key priority is for better data on agricultural practices. Finally, attention is needed to develop N flux verification procedures to assess compliance with international protocols. 相似文献
5.
Karley Campbell Ilkka Matero Christopher Bellas Thomas Turpin-Jelfs Philipp Anhaus Martin Graeve Francois Fripiat Martyn Tranter Jack Christopher Landy Patricia Sanchez-Baracaldo Eva Leu Christian Katlein C. J Mundy Sren Rysgaard Letizia Tedesco Christian Haas Marcel Nicolaus 《Ambio》2022,51(2):318
Sea ice continues to decline across many regions of the Arctic, with remaining ice becoming increasingly younger and more dynamic. These changes alter the habitats of microbial life that live within the sea ice, which support healthy functioning of the marine ecosystem and provision of resources for human-consumption, in addition to influencing biogeochemical cycles (e.g. air–sea CO2 exchange). With the susceptibility of sea ice ecosystems to climate change, there is a pressing need to fill knowledge gaps surrounding sea ice habitats and their microbial communities. Of fundamental importance to this goal is the development of new methodologies that permit effective study of them. Based on outcomes from the DiatomARCTIC project, this paper integrates existing knowledge with case studies to provide insight on how to best document sea ice microbial communities, which contributes to the sustainable use and protection of Arctic marine and coastal ecosystems in a time of environmental change.Supplementary InformationThe online version contains supplementary material available at 10.1007/s13280-021-01658-z. 相似文献
6.
Cuyler Christine Rowell Janice Adamczewski Jan Anderson Morgan Blake John Bretten Tord Brodeur Vincent Campbell Mitch Checkley Sylvia L. Cluff H. Dean Côté Steeve D. Davison Tracy Dumond Mathieu Ford Barrie Gruzdev Alexander Gunn Anne Jones Patrick Kutz Susan Leclerc Lisa-Marie Mallory Conor Mavrot Fabien Mosbacher Jesper Bruun Okhlopkov Innokentiy Mikhailovich Reynolds Patricia Schmidt Niels Martin Sipko Taras Suitor Mike Tomaselli Matilde Ytrehus Bjørnar 《Ambio》2020,49(3):805-819
Ambio - Muskoxen (Ovibos moschatus) are an integral component of Arctic biodiversity. Given low genetic diversity, their ability to respond to future and rapid Arctic change is unknown, although... 相似文献
7.
Jeffrey A. Sayer Chris Margules Agni K. Boedhihartono Terry Sunderland James D. Langston James Reed Rebecca Riggs Louise E. Buck Bruce M. Campbell Koen Kusters Chris Elliott Peter A. Minang Allan Dale Herry Purnomo James R. Stevenson Petrus Gunarso Agus Purnomo 《Sustainability Science》2017,12(3):465-476
Landscape approaches attempt to achieve balance amongst multiple goals over long time periods and to adapt to changing conditions. We review project reports and the literature on integrated landscape approaches, and found a lack of documented studies of their long-term effectiveness. The combination of multiple and potentially changing goals presents problems for the conventional measures of impact. We propose more critical use of theories of change and measures of process and progress to complement the conventional impact assessments. Theories of change make the links between project deliverables, outputs, outcomes, and impacts explicit, and allow a full exploration of the landscape context. Landscape approaches are long-term engagements, but short-term process metrics are needed to confirm that progress is being made in negotiation of goals, meaningful stakeholder engagement, existence of connections to policy processes, and effectiveness of governance. Long-term impact metrics are needed to assess progress on achieving landscapes that deliver multiple societal benefits, including conservation, production, and livelihood benefits. Generic criteria for process are proposed, but impact metrics will be highly situation specific and must be derived from an effective process and a credible theory of change. 相似文献
8.
Energy Systems Theory (EST) provides a framework for understanding and interpreting sustainability. EST implies that "what is sustainable" for a system at any given level of organization is determined by the cycles of change originating in the next larger system and within the system of concern. The pulsing paradigm explains the ubiquitous cycles of change that apparently govern ecosystems, rather than succession to a steady state that is then sustainable. Therefore, to make robust decisions among environmental policies and alternatives, decision-makers need to know where their system resides in the cycles of change that govern it. This theory was examined by performing an emergy evaluation of the sustainability of a regional system, the San Luis Basin (SLB), CO. By 1980, the SLB contained a climax stage agricultural system with well-developed crop and livestock production along with food and animal waste processing. The SLB is also a hinterland in that it exports raw materials and primary products (exploitation stage) to more developed areas. Emergy indices calculated for the SLB from 1995 to 2005 revealed changes in the relative sustainability of the system over this time. The sustainability of the region as indicated by the renewable emergy used as a percent of total use declined 4%, whereas, the renewable carrying capacity declined 6% over this time. The Emergy Sustainability Index (ESI) showed the largest decline (27%) in the sustainability of the region. The total emergy used by the SLB, a measure of system well-being, was fairly stable (CV?=?0.05). In 1997, using renewable emergy alone, the SLB could support 50.7% of its population at the current standard of living, while under similar conditions the U.S. could support only 4.8% of its population. In contrast to other indices of sustainability, a new index, the Emergy Sustainable Use Index (ESUI), which considers the benefits gained by the larger system compared to the potential for local environmental damage, increased 34% over the period. 相似文献
9.
Traditional command-and-control regulations provide few opportunities for total quality environmental management because they usually do not take into account cost and efficiency factors. However, in the past several years both Congress and EPA have shown increasing interest in using incentive-type approaches to regulate the environment. These include taxes, marketable pollution privileges, deposits and refunds, information disclosure provisions, and subsidies. The author details examples of each and discusses how they can effectively complement a quality program. 相似文献
10.
ABSTRACT: A Helley-Smith pressure differential bedload sampler was used to measure bedload transport at consecutive riffle sections of a riffle-pool-riffle sequence on Bambi Creek, a small (154 ha), second-order stream on Chichagof Island, Alaska, during four storms over a 2-year period. Maximum bedload transport rate measured was 4920 kg/h at a streamflow of 2.35 m3/s corresponding to a storm having a 5-year return interval. Transport of larger sediment (> 8 mm) varied systematically with streamflow at the two sampling locations. At flows up to approximately bankfull, transport of large sediment was greatest at the upstream site; at flows above bankfull, transport of large sediment was greatest at the downstream site. The net import of large sediment to the pool during moderate stormflows and net export of large sediment from the pool during flows above bankfull may be related to a “convergence” or “reversal” of competence between the upstream riffle and subsequent pool at flows approximating bankfull stage. Cross-sections monitored within the study reach indicate that stormflows resulted in net filling of the riffle sections and net scour of the pool; periods of low streamflow resulted in net scour of the riffles and net filling of the pooL 相似文献