Stable isotopic signatures of the modern land snail Eremina desertorum from a low-latitude (hot) dry desert—A study from the Petrified Forest,New Cairo,Egypt

This study was conducted on recent desert samples—including (1) soils, (2) plants, (3) the shell, and (4) organic matter from modern specimens of the land snail Eremina desertorum—which were collected at several altitudes (316–360 m above sea level) from a site in the New Cairo Petrified Forest. The soils and shell_{E. desertorum} were analyzed for carbonate composition and isotopic composition (δ¹⁸O, δ¹³C). The plants and organic matter_{E. desertorum} were analyzed for organic carbon content and δ¹³C. The soil carbonate, consisting of calcite plus minor dolomite, has δ¹⁸O values from −3.19 to −1.78‰ and δ¹³C values −1.79 to −0.27‰; covariance between the two values accords with arid climatic conditions. The local plants include C3 and C4 types, with the latter being dominant. Each type has distinctive bulk organic carbon δ¹³C values: −26.51 to −25.36‰ for C3-type, and −13.74 to −12.43‰ for C4-type plants.The carbonate of the shell_{E. desertorum} is composed of aragonite plus minor calcite, with relatively homogenous isotopic compositions (δ¹⁸O_mean = −0.28 ± 0.22‰; δ¹³C_mean = −4.46 ± 0.58‰). Most of the δ¹⁸O values (based on a model for oxygen isotope fractionation in an aragonite-water system) are consistent with evaporated water signatures. The organic matter_{E. desertorum} varies only slightly in bulk organic carbon δ¹³C values (−21.78 ± 1.20‰) and these values suggest that the snail consumed more of C3-type than C4-type plants. The overall offset in δ¹³C values (−17.32‰) observed between shell_{E. desertorum} carbonate and organic matter_{E. desertorum} exceeds the value expected for vegetation input, and implies that 30% of carbon in the shell_{E. desertorum} carbonate comes from the consumption of limestone material.     

From matters of fact to places of concern? Energy,environmental movements and place-making in Chile and Thailand

As demand for energy is growing and resources become scarcer, energy increasingly becomes the site of heated controversies. In Latour’s terms, energy turns from a “matter of fact” into a “matter of concern”. In these energy controversies, environmental movements frequently play a central role, highlighting what is at stake in these developments. While these movements have often been studied, these studies rarely focus on the interaction between controversies, environmental movements, and place-making. In this article, we not only argue that energy is frequently turned from matter of fact into a matter of concern, but that this argument also extends to the notion of place. As such, energy controversies turn villages, cities, or regions themselves into “places of concern”. The article delves deeper into the production of places of concern through two case studies of energy controversies around power plants: a proposed coal plant in Bo Nok, Thailand, and HidroAysen, a hydropower project in Chilean Patagonia. We specifically focus on the issues that were opened up for debate in both countries, and on the role of environmental movements in the production of these places. Our examples are based on fieldwork and interviews in these two areas, as well as media and document analysis. While the two cases are from two different countries, we nonetheless find surprising parallels between them. These insights are instrumental to link theoretical debates on controversies and place-making. Moreover, they provide empirical insights into the transformative and lasting effects of energy controversies on people and places.     

聂尔库组植物化石新材料及其地层意义

聂尔库组分布于辽宁东北部新宾县南杂木一带的苏子河盆地,为一套河湖相砂页岩沉积。该组含有较丰富的动、植物化石,但由于系统采集和研究不够,自建组以来,在地层时代和对比方面迄今仍是众说纷云。作者通过系统采集,共获植物亿石12属13种,化石组合面貌与英国威尔登植物群可以比较;与辽西的海州组、辽北—吉中营城组、黑龙江东部的穆棱组植物组合亦很相似,其时代大体相当于早白垩世尼殴克姆晚期。文中对我国首次发现的属种作了描述。     

鄂尔多斯盆地东北缘中侏罗统延安组植物群与古气候分析

鄂尔多斯盆地东北缘中侏罗统延安组为一套以河流滨湖相沉积为主的中粒中细粒长石砂岩、粉砂岩(泥质粉砂岩)、黑色页岩、粘土岩夹煤层。其中产大量的植物化石,计20属39种。经分析认为,这个植物群是一个属于我国北方区以Coniopteris-Phoenicopsis为代表的中侏罗世早期植物群,植物群组合反映鄂尔多斯盆地东北缘中侏罗世为偏潮湿的暖温带气候。     

翠湖湿地公园水生植物资源及其保护与管理

翠湖湿地公园是北京市唯一一家国家级城市湿地公园。2009-2012年水生植物资源调查结果显示:翠湖湿地公园有水生植物52种,隶属于24科37属;其中挺水植物物种最多,其次是沉水植物和浮叶植物,漂浮植物种类最少。在这些水生植物中,不仅包括北方湿地的典型植物物种,而且还具有重点保护的珍贵稀有物种,如莲、芡实、茭白、花蔺、黑三棱等,以及急需得到保护的狸藻和水鳖。根据湿地植物类型应采取相应的管理和保护措施,保持翠湖湿地公园生态系统的健康。     

北京翠湖湿地维管束植物多样性及保护对策

结合北京地区湿地植物相关研究和翠湖湿地维管束植物调查结果,对翠湖湿地的维管束植物进行分类、整理和分析。结果显示:翠湖湿地有维管束植物306种,隶属76科228属,占北京市维管束植物总数的17.1%。翠湖湿地分布有多种国家级和北京市级重点保护野生植物,如野大豆Glycine soja、芡实Euryale ferox、茭白Zizania latifolia、花蔺Butomus umbellatus等。翠湖湿地还统计到外来和入侵植物共计13种,如豚草Ambrosia artemisiifolia、凤眼莲Eichhornia crassipes等。翠湖湿地维管束植物多样性丰富,需加强植物多样性保护和管理以及科普教育。     

西鄂尔多斯维管植物区系特征分析

 通过在西鄂尔多斯地区几年的植物标本采集以及参考前人对该地区植物名录的记载,对西鄂尔多斯地区野生维管植物种类组成、生活型、水分生态类型及植物区系地理成分进行了分析研究。结果表明:①西鄂尔多斯地区的野生维管植物共有64科、215属、433种;②植物的生活型以多年生草本为主,占52.66%,其他为乔木占0.69%、灌木占14.09%、半灌木占6.93%、一或二年生草本占24.25%、草质藤本占0.92%,类短命植物占0.46%;③植物的水分生态类型以旱生（包括强旱生、旱生和中旱生）为主,占49.42%,中生植物（包括旱中生、中生、湿中生）占47.58%,湿生植物占1.85%,水生植物仅占1.15%;④西鄂尔多斯地区植物区系地理成分组成复杂多样,在温带区系性质为主体的背景下,受欧亚草原区系、东亚森林区系、亚洲中部荒漠区系及古地中海区系的影响。     

New Devonian plant fossil occurrences on the New South Wales South Coast: geological implications

Devonian fossil localities are summarised for coastal southeastern Australia, including both marine invertebrates representing a major late Frasnian (Late Devonian) transgression, and plant remains of Middle–Late Devonian age in associated non-marine strata. Lycopsid plant specimens (Leptophloeum) from near Majors Creek, NSW, first documented by Edgeworth David and E. F. Pittman in association with marine fossils to demonstrate a Late Devonian age, are illustrated for the first time. Lycopsid plants of presumed Middle Devonian age are illustrated from three new localities: Yowrie River inland from Cape Dromedary, Tuross River northwest of Narooma and Charlies Forest Road northeast of Braidwood. The Yowrie River occurrence (in float) indicates probable Middle Devonian strata upstream that are not shown on published maps. The Tuross River occurrence is in sheared and folded strata previously mapped as Ordovician, and the Braidwood occurrence demonstrates Devonian black shales adjacent to previously mapped Ordovician. Evidence supporting alternative thrust or simple fold interpretations for the Budawang Synclinorium is discussed, and relevant Ordovician fossil localities are listed.