泸水自把铅矿硫化矿石物质成份与赋存状态

自把铅矿V1矿体产于断层破碎带中，受地层及容矿断层双重控制，为硫化铅矿石。4种类型26种矿物互相穿插、相互包裹，影响解离和回收。     

Assessing Recent Eutrophication in Coastal Waters of the Gulf of Finland (Baltic Sea) using Subfossil Diatoms

Marine eutrophication of estuaries and coastal waters is considered to be a significant problem worldwide. In the semi-enclosed Baltic Sea, where the nutrient load has strongly increased from its natural level, this has led to marked changes in the coastal ecosystems. A key to successful management of coastal waters is reliable scientific evidence of their past state. The palaeolimnological record of subfossil diatoms was used to study the rate and magnitude of eutrophication over the last ca. 200 years in two urban and three rural sites. The urban sites showed marked increases in the percentage abundance of planktonic diatoms (from <50 to ca. 90% and from <5 to ca. 70%) and diatom-inferred total dissolved nitrogen (from <800 to ca. 3000 μg l⁻¹ and from <400 to ca. 800 μg l⁻¹), and a decrease in species richness starting in the 19th – early 20th century with increased urbanisation. At both sites a clear recovery was observed after the cessation of waste water loading by the mid 1980s. The present planktonic diatom assemblages of these embayments, however, show no change back to the pre-disturbance diverse benthic communities. In contrast, the changes observed in the rural sites were only moderate and occurred later starting in the 1940s. No marked increases in diatom-inferred total dissolved nitrogen were seen, however, all sites showed an increase in small planktonic taxa (from ca. 1–6% to 8–36%) indicating increased nutrient enrichment and turbidity. These small floristic changes could be seen as an early warning signal despite little change in the inferred nutrient concentrations. The results have implications for the European Water Framework Directive, which requires European surface waters to be of good ecological status, defined both by biological and chemical quality elements.     

Promoting species persistence through spatial association optimization in nature reserve design

An important concern for certain species in reserve network design is ensuring that selected sites are either clustered or dispersed. The task of structuring a clustered or dispersed reserve system is often achieved without considering the spatial distribution of the species involved. To address this issue, we develop a probabilistic design model that considers species-specific persistence in selecting reserve sites in order to enhance survival probability. The application results illustrate how the model accounts for spatial association between reserve sites. Differences to related approaches are discussed, focusing on how long-term species representation in reserve design is promoted.     

BOOK REVIEWS

Book Reviewed in this article: Rabat: Urban Apartheid in Morocco . Janet Abu -Lughod . Marketplaces in a Developing Country: The Case of Western Nigeria . Isaac Ayinde Adalemo . Farming Development and Space: A World Agricultural Geography . Bernd Andreae . Section and Party: A Political Geography of American Presidential Elections, from Andrew Jackson to Ronald Reagan . J. Clark Archer and Peter J. Taylor . Women and Space: Ground Rules and Social Maps . Shirley Ardener , ed. European Progress in Spatial Analysis . R. J. Bennett , ed. The Origins of Academic Geography in the United States . Brian W. Blouet Geographic Perspectives on Global Problems . Ronald Reed Boyce . Seasonal Dimensions to Rural Poverty . Robert Chambers , Richard Longhurst and Arnold Pacey eds. The New Nationalism and the Use of Common Spaces: Issues in Marine Pollution and the Exploitation of Antarctica . Jonathan I. Charney , ed. Communications Tomorrow: The Coming of the Information Society . Edward Cornish , ed. The Design of Suburbia . Arthur Edwards . Explorer on the Northern Plains: Lieutenant Gouverneur K. Warren's Preliminary Report of Explorations in Nebraska and Dakota in the Years 1855–56–57. With an Introduction by Frank N. Schubert . The Changing Climate: Responses of the Natural Flora and Fauna . Michael J. Ford . Essentials of Physical Geography . Robert E. Gabler , Robert J. Sager , Sheila Brazier , and Daniel L. Wise. The Road to Jaramillo . William Glen . Valued Environments . John R. Gold and Jacquelin Burgess , eds. Proximity and Preference: Problems in the Multidimensional Analysis of Large Data Sets . Reginald G. Golledge and John N. Rayner , eds. A Search for Common Ground . Peter Gould and Gunnar Olsson , eds. Geography: Its History and Concepts . Arild Holt -Jensen . A Population Geography . Huw R. Jones . The Human Mosaic: A Thematic Introduction to Cultural Geography, 3rd ed. Terry G. Jordan and Lester Rowntree . Urban Social Geography: An Introduction . Paul Knox . The Anatomy of Job Loss: The How, Why and Where of Employment Decline . Doreen Massey and Richard Meegan . The Information Society as Post-Industial Society . Yoneji Masuda . Map Librarianship, 2nd ed. Harold Nichols . India: Cultural Patterns and Processes . Allen G. Noble and Ashok K. Dutt , eds. The God that Limps: Science and Technology in the Eighties . Colin Norman . Geography: An Introductory Perspective . Robert E. Norris , Keith D. Harries and John D. Vitek . The Politics of Technology Assessment . David M. O'Brien and Donald A. Marchand . Ethnic Segregation in Cities . Ceri Peach , Vaughan Robinson and Susan Smith , eds. Churches and Church Membership in the United States, 1980 . Bernard Quinn , Herman Anderson , Martin Bradley , Paul Goetting and Peggy Shriver . Energy in Australia: Politics and Economics . Hugh Saddler . Development from Above or Below? The Dialectics of Regional Planning in Developing Countries . Walter B. Stóuhr and D. R. Fraser Taylor , eds. Human Impact on the Ecosystem . Joy Tivy and Greg O'Hare . Plants and People: Vegetation Change in North America . Thomas R. Vale . The Mapmakers: The Story of the Great Pioneers in Cartography from Antiquity to the Space Age . John Noble Wilford .     

蓄水后向家坝库区鱼类物种、分类和功能多样性变化

为了解向家坝水电工程对金沙江下游鱼类多样性的影响,基于2016—2018年邵女坪(库首)、绥江(库中)和桧溪(库尾)3个江段的鱼类群落调查数据,分析了向家坝库区鱼类物种、分类和功能多样性空间格局,结合蓄水前(2011年)和蓄水初期(2015年)的资料,探讨了蓄水后向家坝库区不同维度鱼类多样性的变化趋势。向家坝库区各江段以广适性的瓦氏黄颡鱼(Pelteobagrus vachelli)和静水性的(Hemiculter leucisculus)占优势,两者的数量百分比分别为30.15%±14.82%和13.91%±11.16%。非度量多维尺度分析显示,蓄水后向家坝库区库首邵女坪和库中绥江鱼类群落差异最小,库首邵女坪和库尾桧溪鱼类群落差异最大;库中绥江在蓄水前、蓄水初期和2016—2018年3个时期的鱼类群落差异均较大,表明蓄水后绥江江段鱼类群落经历了剧烈变化。库区不同江段鱼类Margalef丰富度指数、Shannon-Wiener多样性指数和Pielou均匀度指数均表现为:桧溪>邵女坪>绥江,鱼类分类多样性指数和分类差异指数均表现为:桧溪>绥江>邵女坪。库区鱼类摄食、运动和繁殖等不同维度的功能多样性(功能丰富度、功能均匀度、功能离散度)空间格局不同,但总体上库中绥江鱼类功能丰富度最高,功能均匀度最低。与蓄水前相比,绥江江段鱼类物种、分类多样性呈下降趋势,鱼类功能丰富度和均匀度也有下降趋势。蓄水后绥江江段鱼类群落主要功能性状发生了明显变化,如蓄水前以下位口、纺锤形体型鱼类占优势,蓄水后以端位口、侧扁形体型鱼类占优势。不同维度多样性指数侧重于鱼类多样性的不同方面,结合多种指数分析有利于更全面地了解鱼类群落对环境变化和外界干扰的响应。研究结果有助于深入了解水电工程建设对金沙江下游鱼类多样性的影响,为鱼类多样性保护提供依据,也可为长江“十年禁渔”效果评估提供本底资料。     

Soil physico-chemical properties affecting the distribution of biological soil crusts along an environmental transect at Zapotitlán drylands, Mexico

The composition of cyanobacteria, mosses, and lichens of biological soil crusts were correlated with soil characteristics and sun exposure along an environmental transect. The study was conducted in Zapotitlán drylands, a locality within the Tehuacán–Cuicatlán Valley, central Mexico, where a great variety of environments for crust development exist due to landscape fragmentation. Data were analyzed with redundancy and Sorensen analysis. Soil crusts consisted of different combinations of cyanobacteria (7 species), mosses (19 species), and lichens (8 species). The relative frequencies of these groups were positively correlated with soil apparent density and lichens were also positively correlated with soil pH. However, there were no significant correlations with sun exposure.     

辽宁沿海湿地生物多样性评价研究

辽宁沿海湿地资源对辽宁沿海经济带生物多样性保护具有重要意义。在辽宁沿海经济带战略环评中,根据科学性、代表性和实用性的原则,提出了生物多样性评价的4个指标,即物种丰富度、生态系统类型多样性、物种特有性和外来物种入侵度。建立了沿海湿地生物多样性评价指标体系,并对沿海湿地生物多样性进行了评价。评价结果表明:辽宁沿海6地市及其4个国家级自然保护区的生物多样性丰富。该项研究为辽宁沿海经济带的战略开发决策提供了科学的生物多样性保护措施和建议。     

Competition Between Littoral Cladocerans Macrothrix triserialis and Alona rectangula (Cladocera) in Relation to Algal Food Level and Inoculation Density

We studied the relative competitive abilities of littoral cladocerans M.triserialis and A. rectangula using green algal food at two levels (0.5 · 10⁶ and 2 · 10⁶ cells mL⁻¹ of Chlorella) under five different inoculation ratios. Both the cladoceran species were influenced by food availability and mutual competitive pressure. Macrothrix could withstand competition better under conditions of lower food availability while Alona grew better, despite competition, when more Chlorella was available. Population growth rates (r) ranged from 0.022…0.070 for Alona and from 0.024…0.075 for Macrothrix. There was a significant impact of the inoculation ratio on the maximal population density reached by either test species. Food concentration had a significant influence on the peak population density reached only for Alona rectangula. Data on the body sizes of M. triserialis and A. rectangula showed that there was a higher somatic growth with increasing food availability and decreased competitive pressure in both the test species. In Macrothrix, food concentration and the competition from Alona through different initial inoculation densities had a significant impact on the body size. At the lower food concentration, the body size was significantly smaller when the inoculation density was lowest (highest competitive pressure). The body size of Alona, on the other hand, was not affected by the competition but was significantly higher under conditions of greater food availability. These results have been discussed in light of different theories of competition.     

Local and regional species diversity of benthic Isopoda (Crustacea) in the deep Gulf of Mexico

Recent studies of deep-sea faunas considered the influence of mid-domain models in the distribution of species diversity and richness with depth. In this paper, I show that separating local diversity from regional species richness in benthic isopods clarifies mid-domain effects in the distribution of isopods in the Gulf of Mexico. Deviations from the randomised implied species ranges can be informative to understanding general patterns within the Gulf of Mexico. The isopods from the GoMB study contained 135 species, with a total of 156 species including those from an earlier study. More than 60 species may be new to science. Most families of deep-sea isopods (suborder Asellota) were present, although some were extremely rare. The isopod family Desmosomatidae dominated the samples, and one species of Macrostylis (Macrostylidae) was found in many samples. Species richness for samples pooled within sites ranged from 1 to 52 species. Because species in pooled samples were highly correlated with individuals, species diversity was compared across sites using the expected species estimator (n=15 individuals, ES₁₅). Six depth transects had idiosyncratic patterns of ES₁₅, and transects with the greatest short-range variation in topography, such as basins and canyons, had the greatest short-range disparity. Basins on the deep slope did not have a consistent influence (i.e., relatively higher or lower than surrounding areas) on the comparative species diversity. ES₁₅ of all transects together showed a weak mid-domain effect, peaking around 1200–1500 m, with low values at the shallowest and deepest samples (Sigsbee Abyssal Plain); no longitudinal (east–west) pattern was found. The regional species pool was analyzed by summing the implied ranges of all species. The species ranges in aggregate did not have significant patterns across longitudes, and many species had broad depth ranges, suggesting that the isopod fauna of the Gulf of Mexico is well dispersed. The summed ranges, as expected, had strong mid-domain patterns, contrasting with the local species richness estimates. The longitudinal ranges closely matched a randomized pattern (species ranges placed randomly, 1000 iterations), with significant deviations in the east attributable to lower sampling effort. The depth pattern, however, deviated from the mid-domain model, with a bimodal peak displaced nearly 500 m shallower than the mode of the randomized distribution. The deviations from random expectation were significantly positive above 1600 m and negative below 2000 m, with the result that regional species richness peaked between 800 and 1200 m, and decreased rapidly at deeper depths. The highest species richness intervals corresponded to the number of individuals collected. Residuals from a regression of the deviations on individual numbers, however, still deviated from the randomized pattern. In this declining depth-diversity pattern, the Gulf of Mexico resembles other partially enclosed basins, such as the Norwegian Sea, known to have suffered geologically recent extinction events. This displaced diversity pattern and broad depth ranges implicate ongoing re-colonization of the deeper parts of the Gulf of Mexico. The Sigsbee Abyssal Plain sites could be depauperate for historical reasons (e.g., one or more extinction events) rather than ongoing ecological reasons (e.g., low food supply).     

Predictors of species richness in the deep-benthic fauna of the northern Gulf of Mexico

Species richness in macrofauna and megafauna collected with box cores and trawls from 35 standard stations over a depth range of 175–3720 m in the northern Gulf of Mexico was examined in terms of two primary questions: (1) are observed patterns random? and (2) if not, what environmental factors might account for the patterns? A null model tested whether richness vs. depth distributions were random. Groups with species that had broad vertical depth ranges fit the null model better than groups with small ranges, but for almost all phyla a non-random pattern was indicated. With randomness as a proximal explanation ruled out, further examination of the relationship between richness and environmental factors was justified. A generalized linear model (GLM) showed that a suite of 18 factors categorized as food-related, habitat-related, pollution-related and location-related were significantly related to richness patterns, but that different mixes of factors applied to different phyla. No one factor accounted for any observed patterns. Thus, each taxonomic group needs to be examined individually, and no generally applicable explanation for the causes of richness patterns may exist. Nonetheless, mapping richness itself indicates valuable areas in the Mississippi Trough that must receive special consideration and possible protection.