Effects of experimental nitrogen additions on plant diversity in tropical forests of contrasting disturbance regimes in southern China

Responses of understory plant diversity to nitrogen (N) additions were investigated in reforested forests of contrasting disturbance regimes in southern China from 2003 to 2008: disturbed forest (with harvesting of understory vegetation and litter) and rehabilitated forest (without harvesting). Experimental additions of N were administered as the following treatments: Control, 50 kg N ha⁻¹ yr⁻¹, and 100 kg N ha⁻¹ yr⁻¹. Nitrogen additions did not significantly affect understory plant richness, density, and cover in the disturbed forest. Similarly, no significant response was found for canopy closure in this forest. In the rehabilitated forest, species richness and density showed no significant response to N additions; however, understory cover decreased significantly in the N-treated plots, largely a function of a significant increase in canopy closure. Our results suggest that responses of plant diversity to N deposition may vary with different land-use history, and rehabilitated forests may be more sensitive to N deposition.     

Neural tube defects in the sample of genetic counselling

Objective This study was conducted to evaluate the major demographic details, diagnostical and clinical features, as well as the risk of recurrence of cases with the major types of neural tube defects (NTD). We also examined the efficiency of ultrasonography based on autopsy examinations during 26 years. Methods The investigations were made into the sample of 743 NTD diagnosed between 1 January 1976 and 31 December 2002. A computerized database was used to sum up the available information about the individual cases; in addition to surveying the couples' major demographic details, we also had the opportunity to collect detailed information about the history, diagnostics (ultrasound) and outcome of the pregnancies as well as the results of the autopsies during the investigation. Results In the 743 cases of NTD, maternal and paternal median ages turned out to be 23.7 years (±5.22 years) and 28.7 years (±5.81 years), respectively. The male:female ratio was 0.78. Comparable samples of anencephaly and spina bifida allowed for the conclusion that a positive genetic history was equally often found while a positive obstetrical history was almost twice as common in anencephaly. The sensitivity of the maternal serum-alpha fetoprotein (AFP) screening test is the highest in anencephaly and lowest in encephalocele. While the majority of cases of anencephaly were diagnosed before the 24th gestational week, examples of diagnosing spina bifida and encephalocele at a later time could also be found. Among the associated malformations other than those of the central nervous system special mentioning should be made of fetal pyelectasia, cleft palate as well as diaphragmatic herniation. No pathological karyotypes were found in association with encephalocele or spina bifida, but anencephaly was accompanied with trisomy 21 and trisomy 18 in one case each. Anencephaly was found to have the highest risk of recurrence in both nervous system malformations and malformations other than those of the nervous system. Sonography proved to be the most reliable method in cases of enecephalocele. Conclusion The respective median values of maternal and paternal age show that aetas has no role in the occurrence of NTDs. NTDs are more common among girls. Positive genetic, obstetrical and medical findings are of great importance in the incidence of NTDs. Although reliable to only a limited extent, maternal serum-AFP tests are considered to be useful and necessary in screening NTDs, while sonography is the gold standard method in recognizing these frequent malformations. The knowledge of the eventual associated malformations is mainly important in certain cases of spina bifida, which may also yield a good post-natal prognosis. Our data obtained from the sample of 26 years also confirm that the periconceptional administration of folic acid reduces the incidence and risk of recurrence of NTDs. Copyright © 2007 John Wiley & Sons, Ltd.     

金华市高山与平原无公害蔬菜生产的环境质量比较

对金华市高山、低山和平原无公害蔬菜基地的水、大气和土壤等环境质量的系统监测及对蔬菜生产现状的调查分析结果表明：三地环境优良，均适宜发展无公害蔬菜生产、高山区气候独特，昼夜温差大，蔬菜产量高，品质好，是发展经济途径之一，但山地环境脆弱，应加强环境保护。     

How changing fire management policies affect fire seasonality and livelihoods

There is a long history of fire management in African savannas, but knowledge of historical and current use of fire is scarce in savanna-woodland biomes. This study explores past and present fire management practices and perceptions of the Khwe (former hunter-gatherers) and Mbukushu (agropastoralists) communities as well as government and non-government stakeholders in Bwabwata National Park in north-east Namibia. Semi-structured interviews and focus groups were used in combination with satellite data (from 2000 to 2015), to investigate historical and current fire management dynamics. Results show that political dynamics in the region disrupted traditional fire practices, specifically a policy of fire suppression was initiated by colonial governments in 1888 and maintained during independence until 2005. Both the Khwe and Mbukushu communities use early season (i.e. between April and July) fires for diverse interrelated historical and current livelihood activities, and park management for managing late season fires. The Mbukushu community also use late season burns to prepare land for crops. In this study, we use a pyrogeographic framework to understand the human dimension of fires. This study reveals how today’s fire management practices and policies, specifically the resurgence of early season burning are entrenched in the past. Understanding and acknowledging the social and cultural dynamics of fire, alongside participatory stakeholder engagement is critical for managing fires in the future.Electronic supplementary materialThe online version of this article (10.1007/s13280-020-01351-7) contains supplementary material, which is available to authorized users.     

黄河下游历史泥沙灾害的宏观特征及其与流域因素及人类活动的关系(Ⅰ)──历史气候及植被因素的影响

以历史上黄河下游的决溢频率为泥沙灾害的代用指标；研究了黄河下游历史泥沙灾害的宏观特征．研 究表明，气候因素对黄河下游决溢频率有深远的影响．隋唐以前，天然植被尚未遭到显著破坏，当湿润指标 增大时，有利于植被的生长，故黄河下游决溢频率减小．１０世纪以后，二者的关系与此相反，当湿润指标增 大时，决溢频率也增大，反之亦然．每世纪大旱年颁次与每世纪决溢频次之间呈明显正相关，说明目前受到 各方面广泛关注的黄河下游“小水大灾”现象，在历史上已经存在．干旱时期中，河槽萎缩，一旦大水来 临，很容易发生决溢．以华山松树木年轮指数为气温的代用指标，研究了气温变化与决溢频率变化的关系， 结果表明，在５０ａ的尺度上，当气温降低时，决溢频率增大，反之亦然．人类活动是影响黄河下游泥沙灾害 的重要因素．     

Experimental exposure to cadmium affects metallothionein-like protein levels but not survival and growth in wolf spiders from polluted and reference populations

Both local adaptation and acclimation in tolerance mechanisms may allow populations to persist under metal pollution. However, both mechanisms are presumed to incur (energetic) costs and to trade-off with other life-history traits. To test this hypothesis, we exposed Pardosa saltans (Lycosidae) spiderlings originating from metal-polluted and unpolluted sites to a controlled cadmium (Cd) treatment, and compared contents of metal-binding metallothionein-like proteins (MTLPs), internal metal concentrations, and individual survival and growth rates with a reference treatment. While increased MTLP concentrations in offspring originating from both polluted and unpolluted populations upon exposure indicates a plastic tolerance mechanism, survival and growth rates remain largely unaffected, independent of the population of origin. However, MTLP and Cd concentrations were not significantly correlated. We suggest that MTLP production may be an important mechanism enabling P. saltans populations to persist in ecosystems polluted with heavy metals above a certain level.     

贵州岩下自然保护区的野生大鲵资源现状及历史动态

为了解野生大鲵在喀斯特区域的分布规律与种群历史动态，于2006年6月份、2007年8、10月份对长江支系沅江水域的贵州省贵定县岩下省级自然保护区野生大鲵（〖WTBX〗Andrias davidianus〖WTBZ〗）种群资源状况与捕获量进行了调查，并对繁殖洞穴涌苗现象进行了分析。初步查明岩下野生大鲵种群集中分布在一个以地下水域为依托，地面水网与地下河流相连的集中区域，栖息地由地下（洞穴）与地面水域广布缩小到以地下水域为主；根据繁殖洞穴的鲵苗涌出量与大鲵繁殖特征，推算岩下野生大鲵种群密度约为0085 kg/m2，总资源量约为1 700 kg；捕获量表明，种群数量在20世纪80年代末后急剧减少，90年代中期至2000年后，数量变化趋于缓和。岩下保护区野生大鲵分布的集中性、生境自然条件的优越性以及繁殖洞穴的大规模涌苗现象在全国均属少见。由于受到外在致危因素影响，大鲵的生境遭到破坏、种群生存受胁，亟待加强资源的保护与管理。     

Advancing the Integration of History and Ecology for Conservation

Abstract: The important role of humans in the development of current ecosystems was recognized decades ago; however, the integration of history and ecology in order to inform conservation has been difficult. We identified four issues that hinder historical ecological research and considered possible solutions. First, differences in concepts and methods between the fields of ecology and history are thought to be large. However, most differences stem from miscommunication between ecologists and historians and are less substantial than is usually assumed. Cooperation can be achieved by focusing on the features ecology and history have in common and through understanding and acceptance of differing points of view. Second, historical ecological research is often hampered by differences in spatial and temporal scales between ecology and history. We argue that historical ecological research can only be conducted at extents for which sources in both disciplines have comparable resolutions. Researchers must begin by clearly defining the relevant scales for the given purpose. Third, periods for which quantitative historical sources are not easily accessible (before AD 1800) have been neglected in historical ecological research. Because data from periods before 1800 are as relevant to the current state of ecosystems as more recent data, we suggest that historical ecologists actively seek out data from before 1800 and apply analytic methods commonly used in ecology to these data. Fourth, humans are not usually considered an intrinsic ecological factor in current ecological research. In our view, human societies should be acknowledged as integral parts of ecosystems and societal processes should be recognized as driving forces of ecosystem change.     

A room for living: Private and public aspects in the experience of the living room

This paper presents findings from a study on people's uses and experiences of their living rooms. The researcher conducted in-depth interviews with sixteen middle-class residents of the Metropolitan New York area. Interviews were conducted in participants' living rooms, and were supplemented by observations, sketches and still-photographs. In the past, social scientists have viewed the living room as serving the purpose of communicating the dwellers' image to guests. Findings from the present study show that dwellers may use their living rooms not only to host guests, but also for their own solitary uses, as well as for sharing time with partners. All uses were found to be meaningful and pertinent to the dwelling experience. Findings also reveal that the living room may provide opportunities for intimacy between dwellers and their partners, as well as between dwellers and their guests. For all participants living rooms contained objects that were highly meaningful to them. It is suggested that objects in the living rooms are used to instigate and mediate contemplation about significant others, as well as to regulate the amount of intimacy desired with guests.     

新疆区域创新系统演化发展历程与动力研究

为科学把握新疆维吾尔自治区区域创新系统的演进脉络和规律,将新疆区域创新系统40余年的发展历程划分为萌芽、过渡、构建与完善4个阶段,从环境要素、创新主体、企业创新、结网程度4个方面对各阶段进行盘点总结,分析推动区域创新系统发展的动力因素,总结出新疆区域创新系统发展的1个核心与4条历史主线,并得出两点基本经验:一是政府核心科技政策的实时引导与政策创新始终是系统发展的重要牵引力;二是系统的开放与市场化的深入始终为新疆区域创新系统发展的源动力。