期刊文献+
共找到559篇文章
< 1 2 28 >
每页显示 20 50 100
“无人区”,更需要规范标准的引领——访中国船级社(CCS)孙峰副总裁 被引量:1
1
作者 杨培举 孙峰 《中国船检》 2019年第1期18-22,共5页
近年来,智能船发展备受瞩目,以超出业界想象的速度破浪前行。自2017年12月5日中国第一艘(也是全球首艘)通过中国船级社(CCS)入级检验的智能船舶“大智”号正式交付使用以来,不断有智能船舶下水的报道,进一步预示着智能航运时代的加速来... 近年来,智能船发展备受瞩目,以超出业界想象的速度破浪前行。自2017年12月5日中国第一艘(也是全球首艘)通过中国船级社(CCS)入级检验的智能船舶“大智”号正式交付使用以来,不断有智能船舶下水的报道,进一步预示着智能航运时代的加速来临,业内外对智能船舶的关注度空前高涨。日前,本刊就业界关心的关于智能船的相关问题,专访了中国船级社(CCS)副总裁孙峰先生。 展开更多
关键词 中国船级社 CCS 总裁 无人区 标准 船舶下水 交付使用 智能
在线阅读 下载PDF
CCS《智能船舶规范》六大功能模块要求 被引量:42
2
作者 贺辞 《中国船检》 2016年第3期84-85,106,共3页
近年来由于智能船舶概念的兴起以及智能船舶技术的日益发展,船舶智能化已经成为全球航运的大势所趋。出于通过船舶智能化降低船舶控制和管理难度,减少人为误操作,提高设备及船舶营运的安全,优化船舶航行,控制燃油消耗、降低成本,提高收... 近年来由于智能船舶概念的兴起以及智能船舶技术的日益发展,船舶智能化已经成为全球航运的大势所趋。出于通过船舶智能化降低船舶控制和管理难度,减少人为误操作,提高设备及船舶营运的安全,优化船舶航行,控制燃油消耗、降低成本,提高收益等目的,目前智能船舶的研究已在全球范围内开展。 展开更多
关键词 船舶规范 智能化 功能模块 CCS 船舶控制 船舶技术 船舶营运 船舶航行
在线阅读 下载PDF
CCS-OTA船舶最佳纵倾解决方案 被引量:4
3
作者 陈永念 《中国船检》 2013年第10期76-77,共2页
目前全球航运业正历经上世纪三十年代经济大萧条以来最严重经济危机的影响,船东及航运业面临高油价、低运价的双重挑战。随着国家油价的不断攀升,燃油成本已经成为船舶运营成本的最大支出项。成本压力和严峻的市场形势让航运公司不得... 目前全球航运业正历经上世纪三十年代经济大萧条以来最严重经济危机的影响,船东及航运业面临高油价、低运价的双重挑战。随着国家油价的不断攀升,燃油成本已经成为船舶运营成本的最大支出项。成本压力和严峻的市场形势让航运公司不得不节省燃油开支。所有这些的解决之道都需要新的技术创新和科学化的管理手段作为支撑。 展开更多
关键词 最佳纵倾 船舶 OTA CCS 经济危机 运营成本 燃油成本 航运公司
在线阅读 下载PDF
CCS为压载水公约实施提供全方位服务
4
作者 王慧芳 张凌 《中国船检》 2017年第9期17-18,共2页
为配合船检验发证工作,CCS已经制定颁布了《船舶压载水管理检验发证指南》和《船舶压载水管理计划编制指南》,并可为船舶编制压载水管理计划提供指导。随着《国际船舶压载水及沉积物控制和管理公约》(以下简称压载水公约)生效日期的临... 为配合船检验发证工作,CCS已经制定颁布了《船舶压载水管理检验发证指南》和《船舶压载水管理计划编制指南》,并可为船舶编制压载水管理计划提供指导。随着《国际船舶压载水及沉积物控制和管理公约》(以下简称压载水公约)生效日期的临近,大批从事国际航行的现有船舶进入压载水公约检验发证进程。按照经修订的压载水管理系统(BWMS)认可导则(G8导则)规定申请BWMS型式认可的工作也正逐步展开。 展开更多
关键词 压载水 CCS 水管理系统 计划编制 生效日期 管理计划 造船工业 Australia 船级社 服务团队
在线阅读 下载PDF
CCS:为海上风电高质量发展保驾护航
5
作者 杜建港 《中国船检》 2019年第5期23-26,共4页
自“十二五”以来,我国海上风电进入快速发展期。截至2018年底,我国投入使用的海上风电超过360万千瓦,开工建设的项目已超过650万千瓦,已经核准的海上风电更是达到了4500万千瓦。中国船级社(CCS)自2000年开始服务于风电领域,10年间基本... 自“十二五”以来,我国海上风电进入快速发展期。截至2018年底,我国投入使用的海上风电超过360万千瓦,开工建设的项目已超过650万千瓦,已经核准的海上风电更是达到了4500万千瓦。中国船级社(CCS)自2000年开始服务于风电领域,10年间基本建立起了完善的陆上风电机组(相关设备)规范体系及服务能力。为了适应海上风电新能源行业的崛起,中国船级社于2010年前后进入海上风电设施及装备领域,开展规范标准研究与制定、装备入级与检验及相关认证和技术咨询工作。 展开更多
关键词 海上风电 CCS 中国船级社 护航 质量 服务能力 “十二五” 风电机组
在线阅读 下载PDF
CCS技术咨询和评议委员会举行2011年第一次会议
6
作者 王珏 《中国船检》 2011年第4期2-2,共1页
中国船级社(CCS)技术咨询和评议委员会2011年第一次会议4月2日在厦门举行.吴有生主席、陈映秋常务副主席及各位委员出席了会议。会议听取了陈映秋常务副主席有关船舶、海工技术发展方向与对策的主题发言.并围绕相关问题进行了热烈... 中国船级社(CCS)技术咨询和评议委员会2011年第一次会议4月2日在厦门举行.吴有生主席、陈映秋常务副主席及各位委员出席了会议。会议听取了陈映秋常务副主席有关船舶、海工技术发展方向与对策的主题发言.并围绕相关问题进行了热烈讨论。 展开更多
关键词 技术咨询 委员会 CCS 技术发展方向 中国船级社 副主席 船舶
在线阅读 下载PDF
CCS电站地下厂房混凝土生产系统产能及温控分析
7
作者 田峻旭 武孟强 《云南水力发电》 2014年第5期121-124,共4页
混凝土拌合系统是混凝土施工极为重要的辅助系统之一,其产能和温控是必须超前规划、研究的关键问题。为此中水厄瓜多尔CCS项目部厂房施工部在混凝土施工启动前,对开挖阶段已建成的1座HZS-90搅拌站的产能及温控进行了分析研究。
关键词 CCS电站 地下厂房 混凝土生产系统 产能及温控 分析
在线阅读 下载PDF
《CCS Chemistry》新媒体平台传播体系的构建与运行 被引量:4
8
作者 郝临晓 周素坤 郑素萍 《编辑学报》 CSSCI 北大核心 2021年第4期440-443,共4页
随着期刊市场化改革的深入,世界一流科技期刊建设迫在眉睫。新媒体平台是期刊充分发挥学术交流作用、提升国际影响力的重要阵地之一,期刊与新媒体融合是发展必由之路,一流的科技期刊必须要有一流的新媒体平台作辅助。本文以中国化学会... 随着期刊市场化改革的深入,世界一流科技期刊建设迫在眉睫。新媒体平台是期刊充分发挥学术交流作用、提升国际影响力的重要阵地之一,期刊与新媒体融合是发展必由之路,一流的科技期刊必须要有一流的新媒体平台作辅助。本文以中国化学会旗舰期刊《CCS Chemistry》的新媒体平台运营经验为例,对世界一流科技期刊建设背景下新媒体平台传播体系的构建与运行进行了归纳和分析,总结了目前存在的主要问题,并提出了建议。 展开更多
关键词 世界一流科技期刊 国际影响力提升 新媒体平台 融合发展
原文传递
厄瓜多尔CCS水电站国际EPC项目设备物资管理 被引量:3
9
作者 范美忠 江剑锋 《云南水力发电》 2014年第5期27-32,共6页
厄瓜多尔科卡科多辛克雷水电站(以下简称:厄瓜多尔CCS水电站)为引水式电站,电站由首部枢纽、输水隧洞、调节水库、发电系统组成,电站建设在厄瓜多尔的NAPO省Chaco市和Sucumbios省Lumbaqui地区coca河流域的Salado镇,首部枢纽至引水发电... 厄瓜多尔科卡科多辛克雷水电站(以下简称:厄瓜多尔CCS水电站)为引水式电站,电站由首部枢纽、输水隧洞、调节水库、发电系统组成,电站建设在厄瓜多尔的NAPO省Chaco市和Sucumbios省Lumbaqui地区coca河流域的Salado镇,首部枢纽至引水发电系统公路里程约70km,距首都基多约130km、装机容量为1 500 MW,是目前厄瓜多尔最大的水电建设项目,也是中国水电建设史上承建最大的国际EPC水电项目。 展开更多
关键词 EPC 大型国际项目 设备物资管理 施工组织 管理水平
在线阅读 下载PDF
CCS水电站金属结构桥施工质量管理与控制 被引量:1
10
作者 樊佳川 杨帆 宋继龙 《云南水力发电》 2015年第6期131-133,162,共4页
CCS水电站项目位于南美洲厄瓜多尔,金属结构桥均采用"美标ASTM、AWS标准",通过AWS标准的学习、理解和不断摸索,积累到一些关于金属结构桥的质量管理和控制验收经验。目前,CCS水电站金属结构桥的施工及质量控制都很正常、顺利... CCS水电站项目位于南美洲厄瓜多尔,金属结构桥均采用"美标ASTM、AWS标准",通过AWS标准的学习、理解和不断摸索,积累到一些关于金属结构桥的质量管理和控制验收经验。目前,CCS水电站金属结构桥的施工及质量控制都很正常、顺利,各项制作质量指标及吊装定位轴线指标均满足美标ASTM AWS标准。 展开更多
关键词 金属结构桥 美国标准 质量管理和控制
在线阅读 下载PDF
CCS—2第二项中国急性心肌梗死临床治疗研究试验方案
11
作者 刘力生 《岭南心血管病杂志》 2000年第5期307-309,共3页
关键词 急性心肌梗死 抗血小板 B受体阻滞剂 试验方案
暂未订购
自主创办世界一流科技期刊品牌实践初探——以CCS Chemistry为例 被引量:13
12
作者 郝临晓 周素坤 郑素萍 《中国科技期刊研究》 CSSCI 北大核心 2021年第8期1049-1054,共6页
【目的】探索自主创办世界一流期刊的方式和途径,为新环境下我国一流期刊建设的突破发展提供经验和借鉴。【方法】结合CCS Chemistry创刊和运营实践及取得的良好成绩,总结在我国期刊发展现有环境下自主创办世界一流期刊的主要途径、必... 【目的】探索自主创办世界一流期刊的方式和途径,为新环境下我国一流期刊建设的突破发展提供经验和借鉴。【方法】结合CCS Chemistry创刊和运营实践及取得的良好成绩,总结在我国期刊发展现有环境下自主创办世界一流期刊的主要途径、必要条件、创新举措和存在问题。【结果】CCS Chemistry通过对学术质量和出版品质的严格要求,学习和借鉴世界一流期刊品牌的运营理念,在创刊两年内迅速发展,受到广大化学工作者的肯定和认可,成长为较有影响力的品牌期刊。【结论】自主创办一流期刊应以严格把握学术质量为核心,坚持期刊定位,突破传统办刊理念,建立自身特色。CCS Chemistry的创刊经验可为我国一流期刊建设发展提供一些参考和借鉴。 展开更多
关键词 自主办刊 自建平台 世界一流期刊 CCS Chemistry
原文传递
DFT Insights into the Detection of NH_(3),AsH_(3),PH_(3),CO_(2),and CH_(4)Gases with Pristine and Monovacancy Phosphorene Sheets
13
作者 Naresh Kumar Anuj Kumar Abhishek K.Mishra 《Computers, Materials & Continua》 2026年第4期517-531,共15页
Density functional theory(DFT)calculations were employed to investigate the adsorption behavior of NH_(3),AsH_(3),PH_(3),CO_(2),and CH_(4)molecules on both pristine and mono-vacancy phosphorene sheets.The pristine pho... Density functional theory(DFT)calculations were employed to investigate the adsorption behavior of NH_(3),AsH_(3),PH_(3),CO_(2),and CH_(4)molecules on both pristine and mono-vacancy phosphorene sheets.The pristine phosphorene surface showsweak physisorption with all the gasmolecules,inducing onlyminor changes in its structural and electronic properties.However,the introduction ofmono-vacancies significantly enhances the interaction strength with NH_(3),PH_(3),CO_(2),and CH_(4).These variations are attributed to substantial charge redistribution and orbital hybridization in the presence of defects.The defective phosphorene sheet also exhibits enhanced adsorption energies,along with favorable sensitivity and recovery characteristics,highlighting its potential as a promising gas sensor for NH_(3),AsH_(3),PH_(3),CO_(2),and CH_(4)at ambient conditions. 展开更多
关键词 Phosphorene VACANCY defects DFT interaction sensitivity
在线阅读 下载PDF
Surface soil organic carbon losses in Dongting Lake floodplain as evidenced by field observations from 2013 to 2022
14
作者 Liyan Wang Buqing Wang +12 位作者 Zhengmiao Deng Yonghong Xie Tao Wang Feng Li Shao’an Wu Cong Hu Xu Li Zhiyong Hou Jing Zeng Ye’ai Zou Zelin Liu Changhui Peng Andrew Macrae 《Journal of Integrative Agriculture》 2026年第2期436-447,共12页
In floodplain wetlands,alterations in hydrological patterns resulting from climate change and human activities could potentially diminish the carbon sequestration capacity of the soils,thereby having a negative impact... In floodplain wetlands,alterations in hydrological patterns resulting from climate change and human activities could potentially diminish the carbon sequestration capacity of the soils,thereby having a negative impact on global climate change.However,the magnitude of the influence of hydrological regime change on soil carbon remains inadequately monitored.To address this research gap,we collected 306 upper layer(0–20 cm)soil samples from the Dongting Lake floodplain between 2013 and 2022.The random forest(RF)algorithm was used to analyze the spatial distribution of soil organic carbon(SOC)in the upper soil layer of Dongting Lake floodplain and the impact of climate and hydrological changes in the past decade on surface SOC in the East Dongting Lake area was studied.In 2022,the SOC concentration of the Dongting Lake floodplain upper layer soil ranged from 3.34 to 17.67 g kg^(-1),averaging 10.43 g kg^(-1),with a corresponding SOC density of(2.65±0.49)kg m^(-2) and total SOC stock of 6.82 Tg C(2.87–13.48 Tg C).From 2013 to 2022,the SOC concentration of the upper soil layer of the East Dongting Lake area decreased from 18.37 to 10.82 g kg^(-1).This reduction could be attributed to climate and hydrological changes which reduce SOC input by reducing vegetation growth and accelerating SOC decomposition.Above 21.4 m elevation,the amount of SOC loss increased with elevation,the loss being related to the decline in Miscanthus community biomass and greater susceptibility of higher altitude areas to climate and hydrological changes.Our results highlight the need for strengthening wetland SOC management to increase SOC in the soils to help combat climate change. 展开更多
关键词 floodplain wetland soil organic carbon spatial pattern dynamic change
在线阅读 下载PDF
Improving Control Performance by Cascading Observers:Case of ADRC With Cascade ESO
15
作者 Ahmed T.-E.Benyahia Momir Stanković +2 位作者 Rafal Madonski Oluleke Babayomi Stojadin M.Manojlović 《IEEE/CAA Journal of Automatica Sinica》 2025年第8期1702-1712,共11页
In this paper,we show the performance benefits of connecting multiple observers within a control system.We focus here on a particular observer-based control approach,namely the active disturbance rejection control(ADR... In this paper,we show the performance benefits of connecting multiple observers within a control system.We focus here on a particular observer-based control approach,namely the active disturbance rejection control(ADRC)with cascade extended state observer(ESO).For this framework,we analyze the control performance in terms of quality of observer estimation,reference tracking,disturbance rejection,sensitivity to measurement noise/unmodeled dynamics,and overall stability.A comprehensive frequency response analysis is performed to study the influence of cascading the observers on the selected quality criteria.To make the inquiry beneficial also to practitioners,FPGA-in-the-loop tests are conducted using a guided missiles gimbaled seeker.They validate the theoretical findings in discretetime settings,where the sampling time and hardware resource requirements become a factor.The results of the investigation are distilled into guidelines for prospective users on when and how a cascade observer structure can be useful for controls. 展开更多
关键词 Active disturbance rejection control cascade structure extended state observer FPGA experiments noise
在线阅读 下载PDF
Knowledge-Empowered,Collaborative,and Co-Evolving AI Models:The Post-LLM Roadmap 被引量:1
16
作者 Fei Wu Tao Shen +17 位作者 Thomas Back Jingyuan Chen Gang Huang Yaochu Jin Kun Kuang Mengze Li Cewu Lu Jiaxu Miao Yongwei Wang Ying Wei Fan Wu Junchi Yan Hongxia Yang Yi Yang Shengyu Zhang Zhou Zhao Yueting Zhuang Yunhe Pan 《Engineering》 2025年第1期87-100,共14页
Large language models(LLMs)have significantly advanced artificial intelligence(AI)by excelling in tasks such as understanding,generation,and reasoning across multiple modalities.Despite these achievements,LLMs have in... Large language models(LLMs)have significantly advanced artificial intelligence(AI)by excelling in tasks such as understanding,generation,and reasoning across multiple modalities.Despite these achievements,LLMs have inherent limitations including outdated information,hallucinations,inefficiency,lack of interpretability,and challenges in domain-specific accuracy.To address these issues,this survey explores three promising directions in the post-LLM era:knowledge empowerment,model collaboration,and model co-evolution.First,we examine methods of integrating external knowledge into LLMs to enhance factual accuracy,reasoning capabilities,and interpretability,including incorporating knowledge into training objectives,instruction tuning,retrieval-augmented inference,and knowledge prompting.Second,we discuss model collaboration strategies that leverage the complementary strengths of LLMs and smaller models to improve efficiency and domain-specific performance through techniques such as model merging,functional model collaboration,and knowledge injection.Third,we delve into model co-evolution,in which multiple models collaboratively evolve by sharing knowledge,parameters,and learning strategies to adapt to dynamic environments and tasks,thereby enhancing their adaptability and continual learning.We illustrate how the integration of these techniques advances AI capabilities in science,engineering,and society—particularly in hypothesis development,problem formulation,problem-solving,and interpretability across various domains.We conclude by outlining future pathways for further advancement and applications. 展开更多
关键词 Artificial intelligence Large language models Knowledge empowerment Model collaboration Model co-evolution
在线阅读 下载PDF
Plant growth-promoting rhizobacteria on peanut seedlings(Arachis hypogaea L.):Isolation,taxonomical,and functional characterization
17
作者 Ezequiel Darío Bigatton Ibrahim Ayoub +9 位作者 María Ángeles Castillejo Carolina Merlo Carolina Vázquez Mariela Valeria Archilla Marina Bruno María Paula Martín Romina Paola Pizzolitto Lucas Esteban Dubini Enrique Iván Lucini Ricardo Javier Haro 《Oil Crop Science》 2025年第2期87-99,共13页
To improve crop yields,global food production needs sustainable agronomic tools like Plant Growth-Promoting Rhizobacteria(PGPR).Region-adapted PGPR strains are crucial to increasing peanut production.Argentina is the ... To improve crop yields,global food production needs sustainable agronomic tools like Plant Growth-Promoting Rhizobacteria(PGPR).Region-adapted PGPR strains are crucial to increasing peanut production.Argentina is the seventh-largest peanut producer,and Cordoba is the main region with 250,000 ha(75%of the total sowing area).This study aimed to isolate,identify,and characterize the biocontrol and growth promotion capacity of PGPR strains belonging to the Bacillus and Pseudomonas genera.The strains were tested against Sclerotinia minor,Sclerotium rolfsii,Fusarium verticillioides,and Aspergillus flavus for biocontrol assays.For growth promotion,pot trials used two peanut cultivars,ASEM 400 INTA and Granoleico,under 40%and 60%field capacity under two water regimes.The isolated strains were Bacillus velezensis,B.subtilis,B.tequilensis,B.safensis,B.altitudinis,and Pseudomonas psychrophila.These strains demonstrated in-vitro phosphorus solubilization,nitrogen fixation,ammonification,nitrification,enzyme releasing,phytohormones production,and high biocontrol capacity of over 75%.SC6 and RI3(both B.velezensis)and P10(P.psychrophila)exhibited outstanding performance.They significantly promoted peanut root biomass by more than 50%and leaf area by 30%,with increased chlorophyll content index and leaf relative water content,particularly under water stress conditions(40%field capacity).According to the results,RI3,SC6,and P10 could be classified as PGPR,which supports the results obtained in other field studies with these same microorganisms.Future investigations should prioritize the development of industrial formulations to assess their effectiveness in alternative crops and to incorporate them into other agricultural practices. 展开更多
关键词 Root-associated microorganisms PHYTOHORMONES Biomass BIOCONTROL Water stress
在线阅读 下载PDF
The influence of the post-autotomy regeneration of a sexual trait and mating tactics in a fiddler crab
18
作者 Pablo D.Ribeiro Nahuel E.Farías +2 位作者 Emiliano H.Ocampo Jesús D.Nunez Tomás A.Luppi 《Current Zoology》 2025年第1期54-64,共11页
Male fiddler crabs own an enlarged claw which is a weapon and an ornament.The enlargement of this claw begins from the juvenile stage and continues throughout life.Males may voluntarily lose(i.e.,autotomize)this claw.... Male fiddler crabs own an enlarged claw which is a weapon and an ornament.The enlargement of this claw begins from the juvenile stage and continues throughout life.Males may voluntarily lose(i.e.,autotomize)this claw.After several molts males may regenerate a new claw,called leptochelous,which acquires a similar length but a lower muscle mass area than the original one,called brachychelous.In some species,regenerated claws develop permanently as leptochelous,the population having 2 discrete claw morphologies.Other species present morphological variations with leptochelous and brachychelous being 2 ends of a continuum.In the species Leptuca uruguayensis,we studied the morphological variation of this enlarged claw,whether it may be caused by its regeneration at different male sizes,and its consequences on mating success.We found that claws could not be discriminated as discrete morphs,suggesting a morphological continuum from brachychelous to leptochelous.Regenerated claws in the laboratory were initially small and proportional to body size,although a field experiment confirmed that claw size is recovered after several molts.Morphological variation may be caused by energetic limitations where males of different sizes must differently trade-off between restitution of claw length(ornament function)or claw muscle area(weapon function).Fiddler crabs use 2 mating tactics with different levels of female choice.However,regardless of the mating tactic,leptochelous males were at a disadvantage at high densities,although not at low densities,suggesting that the consequences of autotomy and regeneration on mating success may depend on the social context. 展开更多
关键词 claw allometry Leptuca uruguayensis multifunction trait sexual selection
原文传递
Split gauge-boson mass in SU(N)×SU(M)theories
19
作者 Julia Gómez Concejo Felipe J.Llanes-Estrada +1 位作者 Diego María-Almazán Alexandre Salas-Bernárdez 《Communications in Theoretical Physics》 2025年第9期61-71,共11页
We extend a well-known mass-gap equation for pure gluodynamics in global colour models(formulated in equal-time quantization in Coulomb gauge)to one in which gluons are split into two sets,each exhibiting different ma... We extend a well-known mass-gap equation for pure gluodynamics in global colour models(formulated in equal-time quantization in Coulomb gauge)to one in which gluons are split into two sets,each exhibiting different masses.If the theory is SU(N)×SU(M)with gluons in both groups having identical couplings(as suggested by Grand Unification arguments at large scales)it is immediate to see that different masses are generated for each subgroup.This global symmetry is not broken,but the split masses erase accidental symmetries that might be present due to the two couplings being the same at a large scale,such as SU(N×M)or similar.We also numerically explore a couple of low-dimensional examples of simple Lie groups,but in spite of the system of equations having a form that would seem to allow spontaneous symmetry breaking,it is not triggered for these groups whose algebra has no ideal,and the dispersion relations for the various gluons converge to the same form. 展开更多
关键词 global symmetry breaking gap equation CHROMODYNAMICS hamiltonian QCD
原文传递
Altitudinal patterns of plant diversity, cover, and life forms in a warm arid mountain: Insights from Sierra de Velasco, Argentina
20
作者 Sofia V.LIZARRAGA Omar VARELA Julieta CARILLA 《Journal of Mountain Science》 2025年第3期873-887,共15页
Mountains are important reservoirs of biodiversity and endemism on a global scale, but little is known about the altitudinal configuration of this diversity and its driving factors in arid mountains. We explored varia... Mountains are important reservoirs of biodiversity and endemism on a global scale, but little is known about the altitudinal configuration of this diversity and its driving factors in arid mountains. We explored variations in composition, diversity, cover,and life forms of vascular plants along a complete altitudinal gradient(1300-4000 m a.s.l) in Sierra de Velasco, an arid mountain in northwestern Argentina.We evaluated the influence of environmental variables on plant diversity and cover. Field sampling was conducted in the northern sector of the Sa. de Velasco,on the western slope in eight 50 m wide altitudinal bands at 400 m elevation intervals. We used rectangular plots(20 × 4 m;n:10/altitudinal band) to register the vascular plants of all the growth forms, and linear transects(20 m long.;n:30/altitudinal band) to quantify the vegetation cover using the point intercept method. Diversity was calculated using hill numbers.Data analysis included non-metric multidimensional scaling(NMDS), indicator species analysis,generalized linear models(GLMs), and variance partitioning analysis. A total of 232 species from 51families and 158 genera were registered. Species composition showed greater similarity at intermediate elevations. Plant diversity and cover exhibited a unimodal distribution, peaking at intermediate elevations(2100-2500 m). In contrast, life forms' distribution showed divergent patterns. Therophytes and succulents predominated at low altitudes,phanerophytes and hemicryptophytes at medium altitudes, and chamaephytes and geophytes at high altitudes. The altitudinal patterns of plant diversity and cover were primarily driven by climatic factors.Conservation efforts in the Sierra de Velasco should focus on the middle and upper zones due to their high biodiversity and vulnerability to climate change. 展开更多
关键词 Elevation gradient Plant diversity Life forms Arid mountains Diversity pattern Climatic drivers
原文传递
上一页 1 2 28 下一页 到第
使用帮助 返回顶部