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以SCIE论文数据库作为数据源,采用美国汤森路透集团开发的专业数据分析工具TDA(Thomson Data Analyzer)和UCINET软件对1985—2014年(数据库更新时间为2014年11月30日)绿洲研究论文进行数据挖掘和定量分析。结果表明:(1)近30年来,绿洲研究论文数量逐年持续增长,年均增长率达19%;(2)从学科分类来看,研究论文主要涉及的学科包括地球化学与地球物理学、生物多样性保护、植物科学、生态学、地球科学等;(3)高频主题关键词分析得出,绿洲研究具有典型的地域性,GIS、遥感等技术手段应用于绿洲研究,更加关注干旱区水资源的开发利用;(4)中国的研究机构在绿洲研究方面非常活跃,特别是中国科学院,其论文量遥遥领先于澳大利亚塔斯马尼亚大学、美国加州大学等其他机构,但研究水平、影响力以及国际合作能力仍有待提升。 相似文献
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喀斯特植被是喀斯特生态系统结构与功能稳定的重要维持者。国内外学者较早关注喀斯特植被的结构、功能和管理等方面研究并发表了诸多成果,但对该领域的发展历程、研究趋势和热点等却鲜有评论。利用1990—2017年Web of Science(WoS)和CNKI数据库中喀斯特植被生态学研究的相关文献信息,运用文献计量统计和可视化方法对年度发文量、引用频次、作者、国家、机构、期刊、关键词等进行分析,解析了28年间国内外该领域的研究态势并对未来发展提出了建议。结果表明,1990—2017年间WoS和CNKI数据库中分别收录了该领域文献457篇和1256篇,28年间发文量呈现波动增长趋势,且在2006年后步入快速发展期。WoS中的文献涉及全球60个国家,我国的发文量占发文总量的50.33%,遥居全球榜首,其次是美国和斯洛文尼亚等国。此外,发文量前10的作者均来自我国,发文量较多的机构也多来自我国,这充分表明我国学者在喀斯特植被生态学方面的研究非常活跃,是全球该领域前沿动向和发展趋势的引领者。期刊分析结果表明,《Environmental Earth Sciences》和《生态学报》分别是该领域外文和中文... 相似文献
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聚焦森林生态学领域,通过文献计量研究方法全景式、多维度揭示该领域学科发展特点。以Web of Science数据库1905—2014年110年间森林生态学领域研究文献数据为研究对象,借助文本挖掘软件(DDA)、知识图谱分析软件(SCI2)、Excel等工具,从总体发展态势(论文产出、国际合作关系、主题相似度),基于文献增长中不同阶段的研究主体论文产出分布,高频词时序与高被引论文研究主题3个层面,全面揭示该学科领域110年以来全球发展态势、研究主体力量和主题演变。研究结果表明:(1)近110年森林生态学研究论文逐年持续增长,根据文献增长特点,可以将森林生态学研究划分为孵化期、培育期、发展期、加速期以及爆发期5个阶段;(2)全球森林生态研究合作网络可划分为大、中、小3种类型;(3)不同国家之间由于科研合作、地理地貌等因素在主题研究上既存在共性,也不乏差异与特色;(4)不同阶段的研究力量呈现不同特点,其中美国在各个时期的论文产出均位居首位,且在国际科研合作中处于核心地位,与多个国家在研究主题上具有显著相似度,是领跑、推动森林生态学研究的主要力量;(5)各阶段研究主题呈现较强的阶段性和生态发展... 相似文献
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合成生物学作为一种颠覆性技术可应用于农业领域的创新发展,解决当前农业学科中的瓶颈问题。利用文献计量学方法从领域发表论文的时序数量分布、主题分布等探测当前合成生物学的基本态势。基于领域的主题分布可知,其中植物合成生物学这一主题是稳定存在的且主题规模处于稳定增长趋势。聚焦植物合成生物学这一主题方向,在构建引文网络的基础上利用主路径分析方法从知识流动角度探测植物合成生物学领域重要知识节点,内容涵盖介子油苷生物合成途径,重要催化酶功能解析、转录因子的调控作用,组学方法的应用,利用微生物酵母进行生物物质合成,这些内容表征了合成生物的核心理论技术。 相似文献
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合成生物学作为一种颠覆性技术可应用于农业领域的创新发展,解决当前农业学科中的瓶颈问题。利用文献计量学方法从领域发表论文的时序数量分布、主题分布等探测当前合成生物学的基本态势。基于领域的主题分布可知,其中植物合成生物学这一主题是稳定存在的且主题规模处于稳定增长趋势。聚焦植物合成生物学这一主题方向,在构建引文网络的基础上利用主路径分析方法从知识流动角度探测植物合成生物学领域重要知识节点,内容涵盖介子油苷生物合成途径,重要催化酶功能解析、转录因子的调控作用,组学方法的应用,利用微生物酵母进行生物物质合成,这些内容表征了合成生物的核心理论技术。 相似文献
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国际和中国生物科学十年发展态势的文献计量分析 总被引:1,自引:0,他引:1
本利用献计量数据库,定量描述全球生物科学领域论产出的学科分布、国家分布、机构分布及分布、主要国家生物科学研究影响力的对比、中国生物学论的状况,从而定量反映国际及中国生物科学的发展态势。 相似文献
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海洋在调节全球气候和生物地球化学循环等方面起着关键作用。基于1900—2017年间Web of Science数据库中的SCI论文,利用TDA等工具对海洋科学领域进行了文献计量,并对比分析了国际主要海洋科研机构的学术影响力,以期从宏观尺度上为海洋保护决策提供参考。结论如下:(1)发文量较多的国家有美国、英国、法国、中国和德国;(2)发文量较多的机构有中国科学院、美国海洋和大气管理局、美国加尼福利亚大学、俄罗斯科学院和美国伍兹霍尔海洋研究所;(3)Journal of Geophysical Research-Oceans是海洋科学领域刊文量最大的SCI期刊,刊文主题主要集中于海洋物理、海洋地质和海洋气候等方面;中国在Acta Oceanologica Sinica的发文量最大,但其高水平的海洋科学论文数量需进一步突破;(4)基于h-指数的学术影响力分析结果表明,美国伍兹霍尔海洋研究所和美国斯克里普斯海洋学研究所在15个国际主要海洋研究机构中的排名分别居于第1、2位,中国亟待提升其在海洋领域的国际学术影响力;(5)当前主要关注点为:热点海洋区域(北冰洋、南大洋、北极、南极洲)、海洋监测技术(遥感技术、稳定同位素)、海洋生态系统结构(浮游植物、浮游动物、沉积物)、海洋环境变化(气候变化、海洋酸化、海冰);(6)未来重要研究方向有:海洋生态系统-全球气候变化耦合关系、利用新兴技术监测海洋动态、深海生态系统结构与功能、多领域涉海学科的交叉融合等。 相似文献
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近年来,人们能越来越明显地感受到全球气候的变化,例如气温升高、降水量增加和极端气候事件增多等。而生物入侵由于对生物多样性和经济造成了巨大影响,也逐渐受到研究人员和各国政府的重视。全球气候变化因素众多,不可避免地影响到了生物入侵进程和成功率,而大规模生物入侵对森林和海滨生态系统的破坏反过来也将对全球气候造成影响。本文探讨了全球气候变化与生物入侵的关系,以及造成这些关系的相关机理。 相似文献
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Ruth Kelly Katie Leach Alison Cameron Christine A. Maggs Neil Reid 《Diversity & distributions》2014,20(8):884-894
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Local range expansions might either be the response of populations to climate or landscape change, or be caused directly by human intervention. In the latter case the expansion would be considered the first in the steps leading to a biological invasion. In species typically not the subject of human commerce, distinguishing the causes of local range expansions is problematic. Range dynamic theory provides a basis for doing so, and, when used to assess phylogeographical information, can be a powerful conservation biogeographical approach. Here we adopt this approach to resolve the controversial case of the recent range expansion of the painted reed frog (Hyperolius marmoratus) in southern South Africa. Within the last decade, H. marmoratus has spread westward approximately 500 km from its historical range. This local range expansion could either represent human‐mediated jump dispersal, or a response to landscape or climate change. To date, the latter has been assumed, although not universally. Using a phylogeographic approach to investigate these competing hypotheses, a portion of the mitochondrial COI gene was sequenced for individuals from within the historical range (n = 178), and four putatively introduced populations in dams (n = 121). There was substantial geographical population structure within the historical range, and these populations were significantly different from the dam populations (ΦST = 0.817, P < 0.001). The presence of one or a few dissimilar haplotypes in the dams suggests that introductions are from a number of different sources. This, in conjunction with new survey data, supports the hypothesis that recent establishment of these populations is the result of human‐mediated jump dispersal. The impact of this range expansion on ecosystem functioning is unknown, but given the rapid spread of this species and its potential influence on ecosystems, safeguards should be put in place to control further introductions and to restrict the currently invasive populations. 相似文献
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Macrophysiology for a changing world 总被引:4,自引:0,他引:4
The Millennium Ecosystem Assessment (MA) has identified climate change, habitat destruction, invasive species, overexploitation and pollution as the major drivers of biodiversity loss and sources of concern for human well-being. Understanding how these drivers operate and interact and how they might be mitigated are among the most pressing questions facing humanity. Here, we show how macrophysiology--the investigation of variation in physiological traits over large geographical, temporal and phylogenetic scales--can contribute significantly to answering these questions. We do so by demonstrating, for each of the MA drivers, how a macrophysiological approach can or has helped elucidate the impacts of these drivers and their interactions. Moreover, we illustrate that a large-scale physiological perspective can provide insights into previously unrecognized threats to diversity, such as the erosion of physiological variation and stress tolerance, which are a consequence of the removal of large species and individuals from the biosphere. In so doing we demonstrate that environmental physiologists have much to offer the scientific quest to resolve major environmental problems. 相似文献
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Christina Alba Julienne E. NeSmith Catherine Fahey Christine Angelini Stephen Luke Flory 《Ecology and evolution》2017,7(5):1442-1452
Abiotic global change drivers affect ecosystem structure and function, but how they interact with biotic factors such as invasive plants is understudied. Such interactions may be additive, synergistic, or offsetting, and difficult to predict. We present methods to test the individual and interactive effects of drought and plant invasion on native ecosystems. We coupled a factorial common garden experiment containing resident communities exposed to drought (imposed with rainout shelters) and invasion with a field experiment where the invader was removed from sites spanning a natural soil moisture gradient. We detail treatments and their effects on abiotic conditions, including soil moisture, light, temperature, and humidity, which shape community and ecosystem responses. Ambient precipitation during the garden experiment exceeded historic norms despite severe drought in prior years. Soil moisture was 48% lower in drought than ambient plots, but the invader largely offset drought effects. Additionally, temperature and light were lower and humidity higher in invaded plots. Field sites spanned up to a 10‐fold range in soil moisture and up to a 2.5‐fold range in light availability. Invaded and resident vegetation did not differentially mediate soil moisture, unlike in the garden experiment. Herbicide effectively removed invaded and resident vegetation, with removal having site‐specific effects on soil moisture and light availability. However, light was generally higher in invader‐removal than control plots, whereas resident removal had less effect on light, similar to the garden experiment. Invasion mitigated a constellation of abiotic conditions associated with drought stress in the garden experiment. In the field, where other factors co‐varied, these patterns did not emerge. Still, neither experiment suggested that drought and invasion will have synergistic negative effects on ecosystems, although invasion can limit light availability. Coupling factorial garden experiments with field experiments across environmental gradients will be effective for predicting how multiple stressors interact in natural systems. 相似文献
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- Exotic cladoceran Daphnia lumholtzi is a highly invasive species in the north and south American continents and can potentially also invade European freshwaters and outcompete native Daphnia populations. However, European waterbodies are frequently dominated by less edible filamentous cyanobacteria including also invaders such as Raphidiopsis raciborskii, which might affect the fitness of D. lumholtzi. Furthermore, temperature may influence the sensitivity of D. lumholtzi to R. raciborskii filaments.
- In this study, we determined whether the presence of R. raciborskii could obstruct the invasion of Europe by D. lumholtzi, through reducing its fitness, and whether this depends on temperature. We compared the population growth rate (r) and the somatic growth rate of D. lumholtzi maintained at two temperatures (20 or 26°C) and fed with two diets: green microalgae alone or green microalgae mixed with filaments of R. raciborskii. Three clones of D. lumholtzi were used to evaluate potential variation in response to the treatments among different clones.
- At 20°C, the population growth rate of D. lumholtzi fed with cyanobacterial filaments declined sharply. This reduction was caused by increased egg abortion, egg degeneration, and mortality of newborn daphnids. At 26°C, R. raciborskii lost its harmful effect on the population growth of D. lumholtzi. The presence of cyanobacteria did reduce the somatic growth rate of D. lumholtzi at both temperatures and in all three clones except for one that had a similar somatic growth rate on both diets at 26°C.
- The presence of filamentous cyanobacteria does affect growth in D. lumholtzi and may thereby substantially reduce its invasive potential, but only at lower temperatures. Therefore, the presence of filamentous cyanobacteria may not present an obstacle to the invasion of Europe by D. lumholtzi in a warmer future climate.
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Justin A. G. Hubbard D. Andrew R. Drake Nicholas E. Mandrak 《Diversity & distributions》2023,29(8):986-996
Aim
We employed a climate-matching method to evaluate potential source regions of freshwater invasive species to an introduced region and their potential secondary spread under historical and future climates.Location
Global source regions, with primary introductions to the Laurentian Great Lakes and secondary introductions throughout North America.Methods
We conducted a climate-match analysis using the CLIMATE algorithm to estimate global source freshwater ecoregions under historical and future climates with an ensemble of global climate models for climate-change scenario SSP5-8.5. Given existing research, we use a climate match of ≥71.7% between ecoregions to indicate climatic conditions that will not inhibit the survival of introduced freshwater organisms. Further, we estimate the secondary spread of freshwater invaders to the ecoregions of North America under historical and future climates.Results
We identified 54 global freshwater ecoregions with a climate match ≥71.7% to the recipient Laurentian Great Lakes under historical climatic conditions, and 11 additional ecoregions were predicted to exceed the threshold under climate change. Three of the 11 ecoregions were located in South America, a continent where no matches existed under historical climates and eight were located in the southern United States, southern Europe, Japan and New Zealand. Further, we identify 34 North American ecoregions of potential secondary spread of freshwater invasions from the Great Lakes under historical climatic conditions, and five ecoregions were predicted to exceed the threshold under climate change.Main Conclusion
We provide a climate-match method that can be employed to assess the sources and spread of freshwater invasions under historical and future climate scenarios. Our climate-match method predicted increases in climate match between the recipient region and several potential source regions, and changes in areas of potential spread under climate change. The identified ecoregions are candidates for detailed biosecurity risk assessments and related management actions. 相似文献18.
Spatial and temporal variability across life's hierarchies in the terrestrial Antarctic 总被引:3,自引:0,他引:3
Chown SL Convey P 《Philosophical transactions of the Royal Society of London. Series B, Biological sciences》2007,362(1488):2307-2331
Antarctica and its surrounding islands lie at one extreme of global variation in diversity. Typically, these regions are characterized as being species poor and having simple food webs. Here, we show that terrestrial systems in the region are nonetheless characterized by substantial spatial and temporal variations at virtually all of the levels of the genealogical and ecological hierarchies which have been thoroughly investigated. Spatial variation at the individual and population levels has been documented in a variety of genetic studies, and in mosses it appears that UV-B radiation might be responsible for within-clump mutagenesis. At the species level, modern molecular methods have revealed considerable endemism of the Antarctic biota, questioning ideas that small organisms are likely to be ubiquitous and the taxa to which they belong species poor. At the biogeographic level, much of the relatively small ice-free area of Antarctica remains unsurveyed making analyses difficult. Nonetheless, it is clear that a major biogeographic discontinuity separates the Antarctic Peninsula and continental Antarctica, here named the 'Gressitt Line'. Across the Southern Ocean islands, patterns are clearer, and energy availability is an important correlate of indigenous and exotic species richness, while human visitor numbers explain much of the variation in the latter too. Temporal variation at the individual level has much to do with phenotypic plasticity, and considerable life-history and physiological plasticity seems to be a characteristic of Antarctic terrestrial species. Environmental unpredictability is an important driver of this trait and has significantly influenced life histories across the region and probably throughout much of the temperate Southern Hemisphere. Rapid climate change-related alterations in the range and abundance of several Antarctic and sub-Antarctic populations have taken place over the past several decades. In many sub-Antarctic locations, these have been exacerbated by direct and indirect effects of invasive alien species. Interactions between climate change and invasion seem set to become one of the most significant conservation problems in the Antarctic. We conclude that despite the substantial body of work on the terrestrial biodiversity of the Antarctic, investigations of interactions between hierarchical levels remain scarce. Moreover, little of the available information is being integrated into terrestrial conservation planning, which lags far behind in this region by comparison with most others. 相似文献
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Ernesto Azzurro Valerio Sbragaglia Jacopo Cerri Michel Bariche Luca Bolognini Jamila Ben Souissi Giulio Busoni Salvatore Coco Antoniadou Chryssanthi Emanuela Fanelli Raouia Ghanem Joaquim Garrabou Fabrizio Gianni Fabio Grati Jerina Kolitari Guglielmo Letterio Lovrenc Lipej Carlotta Mazzoldi Nicoletta Milone Federica Pannacciulli Ana Pei Yanna Samuel‐Rhoads Luca Saponari Jovana Tomanic Nur Eda Topu Giovanni Vargiu Paula Moschella 《Global Change Biology》2019,25(8):2779-2792
Climate change and biological invasions are rapidly reshuffling species distribution, restructuring the biological communities of many ecosystems worldwide. Tracking these transformations in the marine environment is crucial, but our understanding of climate change effects and invasive species dynamics is often hampered by the practical challenge of surveying large geographical areas. Here, we focus on the Mediterranean Sea, a hot spot for climate change and biological invasions to investigate recent spatiotemporal changes in fish abundances and distribution. To this end, we accessed the local ecological knowledge (LEK) of small‐scale and recreational fishers, reconstructing the dynamics of fish perceived as “new” or increasing in different fishing areas. Over 500 fishers across 95 locations and nine different countries were interviewed, and semiquantitative information on yearly changes in species abundance was collected. Overall, 75 species were mentioned by the respondents, mostly warm‐adapted species of both native and exotic origin. Respondents belonging to the same biogeographic sectors described coherent spatial and temporal patterns, and gradients along latitudinal and longitudinal axes were revealed. This information provides a more complete understanding of the shifting distribution of Mediterranean fishes and it also demonstrates that adequately structured LEK methodology might be applied successfully beyond the local scale, across national borders and jurisdictions. Acknowledging this potential through macroregional coordination could pave the way for future large‐scale aggregations of individual observations, increasing our potential for integrated monitoring and conservation planning at the regional or even global level. This might help local communities to better understand, manage, and adapt to the ongoing biotic transformations driven by climate change and biological invaders. 相似文献