Results 41 to 50 of about 2,494 (164)
Field Study on Effects of Simulated Sea Level Rise on Main Processes of Organic Carbon in Kandelia obovata Mangrove Ecosystems [PDF]
本研究以厦门曾营海岸三个不同高程样地的秋茄红树林为研究对象,在模拟海平面上升80cm红树林(SLR80cm)、模拟海平面上升40cm红树林(SLR40cm)以及对照红树林(SLR0cm,大约相当于福建九龙江口红树林的滩面高程),探讨海平面上升对秋茄(Kandeliaobovata,以前学名为Kandeliacandel)红树林生态系统主要有机碳过程的影响。 SLR80cm样地的植株矮小、林相稀疏,生长状况明显不如SLR40cm和SLR0cm样地。各样地植株的生物量以及年增量总体均呈现出SLR0cm ...
高敏
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This paper proposes a ‘relaxed’ point‐count survey method to enhance accessibility and expand geographic coverage by easing these constraints. Surveys can be conducted in diverse locations, including urban areas and travel routes, within flexible timeframes (e.g., 6 h after sunrise or during the evening) and with adaptable spacing between survey points,
Masumi Hisano
wiley +1 more source
基于我国地磁台站的观测数据,首先根据地磁台垂直分量日变化曲线的形态特征,统计了15个地磁台站垂直分量的极小时间(地方时),并重点探讨了这些极小时间在我国区域内的分布特性及其与台站经度的关系。其次选取27个地磁台垂直分量太阳活动高年与太阳活动低年年均值日变幅,分析垂直分量日变幅与太阳黑子活动之间的关系,并按照劳埃德季节划分的分点月份,夏至点月份、冬至点月份等不同季节及太阳活动高低年分别探讨垂直分量日变幅在不同季节和太阳活动高低年的变化规律及特性。研究结果表明:① ...
Xiuling Zhang, Xudong Zhao, Xiaoyong Fan
doaj +1 more source
Diversity, geographical distribution and seasonal variation of Skeletonema (Bacillariophyta) in the coastal waters of China [PDF]
骨条藻(Skeletonema)是一类广泛分布的浮游硅藻,大量繁殖可引起赤潮和水华。以往对我国近海骨条藻的研究,绝大多数都是以中肋骨条藻(S.costatum)为主,种类单一,且研究的地理范围和季节性不够全面和系统,对其生态特征尚不明确。 本研究从2013年10月至2015年1月按每个季度对渤海、黄海、东海和南海四大海域的七个站点进行水样采集,应用光学显微镜和电子显微镜技术对分离纯化的株系和固定样品进行了形态学观察和细胞计数。共鉴定出9种骨条藻,分别为热带骨条藻(S.tropicum),曼氏骨条藻(S ...
刘洋
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Assessing the Corn Belt as an anthropogenic barrier to migrating landbirds in the United States
Abstract Migrating landbirds adjust their flight and stopover behaviors to efficiently cross inhospitable geographies, such as the Gulf of Mexico and the Sahara Desert. In addition to these natural barriers, birds may increasingly encounter anthropogenic barriers created by large‐scale changes in land use. One such barrier could be the Corn Belt in the
Fengyi Guo +7 more
wiley +1 more source
探究草地植被格局与土壤水源涵养功能的关系,对于评价和有效利用土壤及草地植被资源起着重要的作用。以黄河源区的高寒草地生态系统为研究对象,运用MODIS数据构建土壤水源涵养功能模型并探究其时空变化特征,明确草地植被的时空变化规律,以耦合协调度理论为基础探讨二者耦合关系的季节性变化和空间分布特征。结果表明:(1)2000-2021年土壤水源涵养功能指数和综合植被指数在各个季节上均呈增加趋势,22年的季平均值表现为夏季和秋季高于春季和冬季;(2)2000-2021年各个季节土壤水源涵养功能-植被(SWCF ...
张晓宁 +5 more
doaj
Study of NPZD Ecosystem Dynamical Model Application in Beibu Gulf [PDF]
北部湾是我国重要的海湾和渔场,被誉为我国“最后的洁净”,近年来在我国沿海经济发展的成就和潜力倍受关注,然而工业化、城镇化进程的持续加快,也给北部湾的生态环境带来了巨大压力。鉴于此,研究北部湾生态系统的时空分布特征及其对动力环境变化的响应过程具有重要意义,可为我国北部湾生态环境保护建设、资源管理开发和经济发展策略制定等提供科学参考依据。 本文在已建立的“北部湾三维水动力—NPZD生态耦合模型”的基础上进行了进一步的拓展和应用研究,结合历年观测数据、卫星遥感数据和数值模型结果 ...
郑艺妃
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On the normative roles of biodiversity and naturalness in conservation
Abstract Nature is an opaque concept. Consequently, the term biodiversity conservation has replaced nature conservation in most conservation contexts. We review the conceptual indeterminacies that plague the terms nature and natural but then show that comparable difficulties plague biodiversity.
David Saltz, Shlomo Cohen
wiley +1 more source
The Research on Sound Propagation Experiment and Numerical Simulation in Continental Slope Environment of the Northern China Sea [PDF]
南海大陆架和大陆斜坡是由浅海向深海过渡的海区,拥有强烈的地形变化和 较为复杂的水文动力条件,是一种复杂的声传播环境。理解这些典型条件下的声 传播现象并掌握其规律对南海的国防建设、资源开发、交通运输等均具有重大意 义。 本文首先对季节性的海洋环境变化做了分析,500m深温度断面的比较表明 季节间的变化特别体现在混合层深度的增减上,反映在声速上的变化则是混合层 声道的深度的季节性变化,声速梯度基本结构没有变化。对四个季节的声传播损 失数据,首先进行了距离与深度上的平均,然后利用长期非静态(LTNS ...
任海元
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Our study identifies southern China, including mountainous regions and islands, as key areas rich in phylogenetic diversity, and phylogenetic endemism of lizards that are currently under‐protected. Current protected areas however do not adequately cover regions that are critical for preserving the evolutionary history of lizards.
Tao Liang (梁涛) +8 more
wiley +1 more source

