Development of risk matrices for evaluating climatic change responses of forested habitats     

Louis R. Iverson  Stephen N. Matthews  Anantha M. Prasad  Matthew P. Peters  Gary Yohe 《Climatic change》2012,114(2):231-243

We present an approach to assess and compare risk from climate change among multiple species through a risk matrix, in which managers can quickly prioritize for species that need to have strategies developed, evaluated further, or watched. We base the matrix upon earlier work towards the National Climate Assessment for potential damage to infrastructures from climate change. Risk is defined here as the product of the likelihood of an event occurring and the consequences or impact of that event. In the context of species habitats, the likelihood component is related to the potential changes in suitable habitat modeled at various times during this century. Consequences are related to the adaptability of the species to cope with the changes, especially the increasing intensity and/or frequency of disturbance events that are projected. We derived consequence scores from nine biological and 12 disturbance characteristics that were pulled from literature for each species. All data were generated from an atlas of climate change for 134 trees of the eastern United States (www.nrs.fs.fed.us/atlas). We show examples which depict a wide range of risk for tree species of northern Wisconsin, including species that may gain substantial habitat as well as lose substantial habitat, both of which will require the development of strategies to help the ecosystems adapt to such changes.  相似文献   

Chemical Separation of Tungsten and Other Trace Elements for TIMS Isotope Ratio Measurements Using Organic Acids     

Bradley J. Peters  Andrea Mundl‐Petermeier  Mary F. Horan  Richard W. Carlson  Richard J. Walker 《Geostandards and Geoanalytical Research》2019,43(2):245-259

One requirement for isotope ratio measurement results with small measurement uncertainties is that the element of interest is effectively separated from the sample matrix. Efficient chemical separation of W from matrix components, especially Ti, can be challenging, particularly for large test portion masses (> 1 g). We present a new W separation procedure that takes advantage of the distinct complexation behaviour of Ti and W with citrate ligand in a moderately low pH, oxidising solution. This preparation procedure can reduce the Ti/W ratio of large (4–10 g) basaltic (i.e., high‐matrix) test portions by a factor of 10⁵, relative to their original compositions, in a two‐step separation procedure. The procedure additionally provides a separate, well‐purified Mo fraction. We show that optimal separation requires precise selection of reagent concentrations and sample load. The procedure was employed to determine the μ¹⁸²W composition of BHVO‐2 as ?6.7 ± 4.2 (2 standard deviation, 2s). The principles derived from this method may prove useful for chemical separation of other elements used for geochemical and cosmochemical applications given an appropriate selection of organic acid. Future successful applications of this method may reveal that the use of organic acids as procedural reagents is a currently under‐utilised tool for efficient chemical separation protocols.  相似文献   

Mojave Mars simulant—Characterization of a new geologic Mars analog     

Gregory H. Peters  Gregory H. Bearman  J. Anthony Smith  Susanne Douglas 《Icarus》2008,197(2):470-479

We have identified and characterized a basaltic Mars simulant that is available as whole rocks, sand and dust. The source rock for the simulant is a basalt mined from the Tertiary Tropico Group in the western Mojave Desert. The Mojave Mars Simulant (MMS) was chosen for its inert hygroscopic characteristics, its availability in a variety of forms, and its physical and chemical characteristics. The MMS dust and MMS sand are produced by mechanically crushing basaltic boulders. This is a process that more closely resembles the weathering/comminution processes on Mars where impact events and aerodynamic interactions provide comminution in the (relative) absence of water and organics. MMS is among the suite of test rocks and soils that was used in the development of the 2007/8 Phoenix Scout and is being used in the 2009 Mars Science Laboratory (MSL) missions. The MMS development team is using the simulant for research that centers on sampling tool interactions in icy soils. Herein we describe the physical properties and chemical composition of this new Mars simulant.  相似文献   

Influence of stratospheric ozone changes on long-term trends in the meso- and lower thermosphere   总被引：2，自引：2，他引：0  

J. Bremer  D. Peters 《Journal of Atmospheric and Solar》2008,70(11-12):1473-1481

As predicted by model calculations, long-term changes in the stratospheric ozone content should influence trends in the meso- and thermosphere also. These predictions have been tested by means of ionospheric reflection height data in the low-frequency (LF) range and critical frequency data series of the ionospheric E layer, foE, observed at different stations around the world. It was shown that an essential part of the derived trends in the mesosphere and in the lower thermosphere is correlated with long-term changes of the atmospheric ozone content. During the sub-interval with the strongest ozone decrease (1979–1995) the detected ionospheric trends are most pronounced. Additionally was also demonstrated that the longitudinally dependent ozone trends are related to similar variations in the foE trends.  相似文献   

Prediction of capillary hysteresis in a porous material using lattice-Boltzmann methods and comparison to experimental data and a morphological pore network model     

B. Ahrenholz  J. Tölke  P. Lehmann  A. Peters  A. Kaestner  M. Krafczyk  W. Durner 《Advances in water resources》2008

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Principles and methods for determining ecological criteria on hydrobiocenoses: Editors: R. Amavis and J. Smeets (1976). Proceedings of the European Scientific Colloquium,Luxembourg 1975; 531 pp. Price: £16.00     

John Peters 《Marine pollution bulletin》1977,8(7):168

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Coordinated Observations of Comet Hale–Bopp between 32 and 860 GHz     

Wink  J. E.  Altenhoff  W. J.  Bieging  J.  Butler  B.  Butner  H.  Haslam  C.G.T.  Kreysa  E.  Martin  R.  Mauersberger  R.  McMullin  J.  Muders  D.  Peters  W.  Schmidt  J.  Schraml  J. B.  Sievers  A.  Stumpff  P.  Von Kapp-Herr  A.  Thum  C.  Zylka  R. 《Earth, Moon, and Planets》1997,77(3):165-165

Earth, Moon, and Planets - The concept of simultaneous multifrequency continuum observations, successfully tested on Comet Hyakutake, was applied to Comet Hale-Bopp, using the Heinrich Hertz...  相似文献   

Population education resources     

Larkin RP  Peters GL 《The Journal of geography》1981,80(5):186-189

This article provides information on those population education materials and services which are available from the Population Reference Bureau (PRB) and explores their usefulness in secondary school and college environments. PRB data sheets are a most useful source of information. Demographic and socioeconomic information (birth and death rates, natural increase, population doubling times, projections for the year 2000, life expectancies, per capita gross national product, etc.) are included. The World's Women Data Sheet is a special publication issued to mark the midway point of the UN Decade for Women. 161 countries are included with information on demographic, health, employment, and educational status of women. There is a nominal cost for these data sheets. To help students learn about population dynamics and world patterns of population, mapping exercises can be developed. The Population Bulletin is published 6 times/year and each issue concentrates on specific aspects of population. The 28 bulletins which have been published since January 1976 are listed. The PRB Chart Series is a multicolor graphic presentation of topical issues in population and development trends worldwide. A total of 26 charts in 4 series have been produced and cover such topics as world population growth, urbanization, world energy consumption, age structure in the U.S., and adolescent pregnancy in the U.S. This material is best used with high school students. A monthly international population news magazine called Intercom is desinged to inform about worldwide trends and activities in population and family planning. It is published in both English and Spanish and is a useful source of current information in capsulized form. For population educators there is the bimonthly newsletter Interchange. PRB's teaching-learning modules are valuable publications for teachers. Thus far there are 9, each of which is a self-contained unit with classroom activities for junior high to college students. Each one outlines a problem and then presents methods which can stimulate discussion and provoke interest. 2 special publications on special interest topics (Population Handbook; Population Education: Sources and Resources) are described. PRB may well be the best single source of population education materials which will hopefully be used and incorporated into teaching.  相似文献