Temporal and environmental significance of microbial lamination: Insights from Recent fluvial stromatolites in the River Piedra,Spain

Despite extensive research, the environmental and temporal significance of microbial lamination is still ambiguous because of the complexity of the parameters that control its development. A 13 year monitored record of modern fast‐accreting calcite stromatolites (mean 14 mm year^?1) from artificial substrates installed in rapid flow in the River Piedra (north‐east Spain) allows comparison of the sedimentological attributes of successive six‐month depositional packages with the known climatic, hydrophysical and hydrochemical parameters of the depositional system. The stromatolites are formed of dense, porous and macrocrystalline composite laminae. The dense and porous composite laminae, which are composed of two to eight laminae consisting largely of calcified cyanobacteria, are characterized by: (i) dense composite laminae, up to 15 mm thick, mostly with successive dense laminae and minor alternating dense and porous laminae; and (ii) porous composite laminae, up to 12 mm thick, consisting mainly of porous laminae alternating with thinner dense laminae. Most of the dense composite laminae formed during the warm periods (April to September), whereas most of the porous composite laminae developed in the cool periods (October to March). Each dense and porous composite lamina represents up to or slightly longer than six months. The alternation of these two types of composite laminae parallels seasonal changes in temperature. The dense and porous laminae result from shorter (for example, intraseasonal) variations in temperature, insolation and hydrological conditions. The macrocrystalline laminae, with crystals >100 μm long, occur isolated and grouped into composite laminae up to 1·7 mm thick. Their occurrence suggests the absence or poor development of microbial mats over periods of weeks to several months. Thus, stromatolite lamination can record different‐order, periodic and non‐periodic changes in the magnitude of environmental parameters over a single year. These results hold important implications for the temporal and environmental interpretation of lamination in microbial structures.     

Dangerous assemblages: Salts,trihalomethanes and endocrine disruptors in the water palimpsest of the Llobregat River,Catalonia

Water flows through time are connected to specific instances of socionatural and sociotechnical assemblages of human and non-human components. We propose the concept of “water palimpsest” in order to characterize the complex histories of chemical and metabolic alterations embodied in water flows, potentially disruptive for humans and other living beings. Through the concept of palimpsest we interpret the configuration of water flows as constantly evolving towards new patterns maintaining at the same time traces of past mixtures. In order to decipher water pollution by means of a political ecology approach we argue that it is necessary to characterize the historical contours under which certain substances in river waters appear, interact and become hazardous. Engaging critically with literature on assemblages but also with chemical and epidemiological scientific literature, and drawing from archival and oral sources, we provide an account of historically produced pollution in the waters of Llobregat River (Catalonia) by unravelling the assemblages that shape the water palimpsest in this river. In parallel, we narrate the advances in instrumentation and analysis which permitted to detect and measure substances beyond recognition by human senses and preceded legal regulations on pollutants, starting from milligrams and (thus far) arriving at nanoscales. Focusing on the emergence of three typologies of pollutants – salts, trihalomethanes (THMs) and endocrine disruptors (EDs) – we unveil how these three assemblages embody specific instances of Llobregat socioenvironmental history, pointing towards a palimpsest characterized by increasing levels of complexity and uncertainty. The concept of water palimpsest allows us to incorporate non-human agency into the analysis of water quality and to infuse political ecology with materiality and thus with a (largely missing) focus on physicochemical and biological processes.     

Paucispecific macroinvertebrate communities in the Upper Cretaceous of El Hassana Dome (Abu Roash,Egypt): Environmental controls vs adaptive strategies

Based on rock and fossil data from the Upper Cretaceous of the El Hassana Dome (Abu Roash, Egypt), factors controlling facies architecture and the nature of biotopes are highlighted. The succession formed on a non-rimmed shelf, the architecture of which varied from an inner to an outer shelf setting upsection. Macrobenthic biotopes are reconstructed and their palaeoecological significance assessed using a novel ternary plot. Based on diversity and community structure (770 specimens assigned to 28 bivalve and gastropod taxa), four paucispecific associations are identified. These are: 1. the ‘Cucullaea’ Assemblage, a low-energy, soft-substrate, oligotrophic outer shelf environment with reduced terrigenous input dominated by infaunal bivalves and hexactinellid sponges; 2. the ‘Plicatula’ Assemblage, a low-energy, restricted inner shelf lagoonal setting with soupy substrates and dysoxia below the sediment-water interface dominated by plicatulid and ostreid bivalves, 3. the ‘Durania’ Assemblage, a high-energy, high-temperature, shoal environment dominated by elevator rudists with minor numbers of echinoids, corals and bryozoans, which together form several biostromes. and 4. The ‘Trochactaeon’ Assemblage, which share the same characteristics of the ‘Durania’ Assemblage. The paucispecific nature of these biotopes is indicative of different stress factors. Consequently, the predominant taxa exhibit different degrees of adaptive strategies. In addition to global sea level, local tectonics have significantly affected facies distribution and biotope structure. The shallower facies during the early Turonian and the dysoxia spanning the Coniacian–Santonian were linked to synsedimentary tectonics, which formed many barriers and led to circulation restrictions.     

Research Advances of Coastal Ecological Carrying Capacity Evaluation Based on Sustainable Projects Plan

Coastal area is the region with the highest degree of economic and social development and the largest ecological stress in current China, where the proportions and the spatial patterns of developed coastal resource and environment are determined by projects planning. Ecological carrying capacity evaluation is the necessary prerequisite for sustainable utilization of natural resources and protecting ecological environment to ensure healthy and sustainable economic and social development to project planning. Based on the pressure types of projects planning on resources and environment, the concept and contents of coastal ecological carrying capacity were redefined for enhancing the practical value of ecological carrying capacity evaluation. The domestic and foreign research progress and advances related with coastal ecological carrying capacity evaluation were reviewed, which included habitat suitability evaluation, suitability assessment of construction land development, reclamation suitability evaluation and assessment of sea water environmental capacity. The conclusion noted that domestic research of coastal ecological carrying capacity needs to build a complete system of ecological carrying capacity evaluation methodology based on extensive reference to foreign research results, and quantitative evaluation and spatial visualization research related with coastal ecological carrying capacity should be carried out to provide strong support for ecological civilization process of economy and society in coustal areas.     

湖泊自生碳酸盐碳同位素在环境变化中的应用

湖泊自生碳酸盐碳同位素组成(δ13Cc)在区域气候与环境变化方面的应用研究近年来进展迅速,成果显著,保存在各类湖泊沉积物柱芯中的δ13Cc记录揭示了湖表水体与大气CO2的交换程度、暖季降水量的多少、流域C3和C4植被变化情况、水生生物光合作用或呼吸作用强弱、湖泊生产力大小、湖泊水体化学特征、湖水不同深度层的有机质变化过程等重要的气候和环境信息;对此进行归纳和述评。     

地震监测中环境因素对精密水准观测影响分析

区域精密水准测量在地震监测中发挥了重要的作用,但是由于其作业范围广、观测周期长,容易受外界复杂多变的环境因素影响。目前对环境因素的影响分析大多是定性描述,缺乏实验观测数据的支撑。针对这一问题,选取大约2000km区域精密水准观测数据,结合观测环境资料,统计分析不同环境因素对观测成果的影响程度,并提出了相应的改进措施。     

地质环境容量与评价研究

本文系统总结了当今地质环境容量研究存在的主要问题及发展趋势,应用地质环境容量评价指标体系,初步建立了地质环境容量评价理论框架.在此基础上结合上海市主要环境地质问题,分析其主要影响因素,分层次选取合适的评价指标,对上海市地质环境容量进行实证分析.     

环境水力学研究中的预报模型的研究现状

主要介绍目前世界上环境水力学研究中,湍流模式下,预报模型的发展、现状及种类。并简单分析了模型的原理以及模型的适用性与非适用性,来说明实际工程中对瑞流模式研究的重要性和可行性。     

Green Costs,Red Ink: Determinants of Municipal Defensive Expenditures inOntario

Book reviews are in these Articles.

Understanding Peasant Agriculture: An Integrated Land-Use Model for the Punjab Joseph H. Astroth, Jr. Chicago: University of Chicago, Committee on Geographical Studies, 1990. (Geography Research Paper No. 223). ix and 173 pp., maps, photos, figs., apps., biblio., and index; $12.00 paper (ISBN 0-89065-127-2).

National Integration in Indonesia: Patterns and Policies Christine Drake. Honolulu: University of Hawaii Press, 1989. xvi and 354 pp., maps, diags., tables, index, and biblio. $35.00 cloth ISBN 0-8248- 1229-8).

Urban Economic Theory: Land Use and City Size. Masahisa Fujita. New York: Cambridge University Press, 1989. x and 366 pp., diag., graphs, biblio. notes, append, biblio., index. $65.00 cloth (ISBN 0-521-34662-2).

The Sugar Cane Industry: An Historical Geography from Its Origins to 1914. J. H. Galloway. Cambridge, MA: Cambridge University Press, 1989. xiii and 266 pp., maps, tables, diags., index, and biblio. $44.50 cloth (ISBN 0-521-24853-1).

Government Policy and Industrial Change. David Gibbs, ED. New York: Routledge, 1989. xvi and 317 pp., 15 figs., 53 tables, index, and biblio. $59.95 cloth (ISBN 0-415-01032-2).

English Agriculture: An Historical Perspective. David Grigg. New York: Basil Blackwell, 1989. vii and 256 pp. $60.00 cloth (ISBN 0-631-16033-7).

London 2001. Peter Hall. London: Unwin Hyman, 1989. xii and 226 pp., maps, diags., index, and biblio. $34.95 cloth (ISBN 0-04-4451 61 -X).

The Land that Became Israel: Studies in Historical Geography. Ruth Kark, ED. Translated from the Hebrew by Michael Gordon. Jerusalem: The Magnes Press, The Hebrew University and New Haven and London: Yale University Press, 1990. x and 332 pp., maps, diags., plates. $27.50 cloth (ISBN 0-300- 04718-5).

Die Farmer-Genossenschaften in den USA – Eine agrargeographie Untersuchung. Werner Klohn. Vechta, Federal Republic of Germany: Vechtaer Druckerei, 1990. Vechtaer Arbeiten zur Geographie und Regionalwissenschaft, Band 9. 285 pp., maps, photos, diags., and biblio. 39.80 DM paper (ISBN 3-88441-083-0).

Agricultural Development in Japan: The Land Improvement District in Concept and Practice. Gil Latz. Chicago, IL University of Chicago Press, 1989. vii and 135 pp., maps, diags., index, and biblio. $12.00 paper (ISBN 0-89065-129-9).

Land Use Planning Made Plain. Hok Lin Leung. Kingston, Ontario: Ronald P. Frye &; Company, 1989. xv and 237 pp., maps, diags., tables, append., index, and refs. $19.95 paper (ISBN 0-919741-98-3).

Computers in Geography. David J. Maguire. New York: Halsted Press, 1989. xv and 248 pp., maps, photos, diags., index, and biblio. $31.95 paper (ISBN 0-470-21 194-6).

Maps with the News: The Development of American Journalistic Cartography. Mark Monmonier. Chicago: The University of Chicago Press, 1989. xii and 331 pp., maps, illus., index, and biblio. $24.95 cloth (ISBN 0-226-53411-1).

Geographic Information Systems and Cartographic Modeling. C. Dana Tomlin. Englewood Cliffs, NJ: Prentice Hall, 1990. xviii and 249 pp., maps, diags., review questions, selected readings, appendix, index, $44.20 cloth (ISBN 0-13-350927-3).