Results 21 to 30 of about 14,545 (165)
Study on latitudinal gradient of species diversity in forest communities [PDF]
, 2015 森林群落结构和物种多样性的空间分异规律一直是生态学研究的热点问题。近年来，关于森林群落结构的描述与物种多样性的测定方法等研究也都有所发展，但这些研究大多是对森林生态系统的定性描述，而且方法不一，数据之间也缺乏可比性。 群落的组成结构是群落的重要标志，研究群落结构是研究群落物种多样性意义的理论基础，所以从群落组成结构的角度来探讨生物群落的物种多样性具有重要的意义，为进一步深入研究生物多样性功能及确定功能群提供理论基础 ...
孙影
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Comprehensive framework for assessing and optimizing existing research networks
Conservation Biology, EarlyView.Abstract Conservation, monitoring, and research networks, or collections of ecological research sites unified under a common mission of data collection or a research mission, are essential infrastructure for understanding large landscapes. However, most networks developed opportunistically over decades rather than through systematic design, creating ...
Alyson East +2 more
wiley +1 more source
塔里木沙漠公路防护林土壤微生物生物量与土壤环境因子的关系 [PDF]
, 2009 为探讨极端干旱区风沙土土壤微生物与土壤环境因子的作用规律,采用相关分析法研究了塔里木沙漠公路防护林地土壤微生物生物量与理化因子和酶活性的关系.结果表明:土壤容重和粒径减小(R0.85)时,防护林地中土壤微生物数量和生物量有增大趋势,由容重与微生物量的相关性主导;土壤养分含量与土壤微生物数量和生物量呈正相关,主要由速效养分和放线菌、微生物生物量C、P的相关性所致;土壤酶活性与土壤微生物数量和生物量的相关性差异较大,R在0.51～0.91,主要取决于蔗糖酶、磷酸酶与放线菌、微生物量C的相关 ...
周宏伟 +7 more
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Conservation Biology, EarlyView.Abstract Human development is a driver of global change and a major threat to biodiversity. Protected areas maintain and support biodiversity, but outside stressors, such as climate change and land use change, can negatively influence natural resources within protected areas.
Leah J. Rudge +2 more
wiley +1 more source
Zhejiang Daxue xuebao. Lixue ban, 2007 新昌盆地地处中国东南沿海火山-侵入杂岩带的东北端，区内广泛出露晚中生代火山岩与使入岩类，岩石类型丰富，是研究岩石遥感光谱的理想地区.作者对该地区的岩石样品进行了可见-近红外光谱和热红外光谱分析测试，研究了火成岩矿物组成、蚀变特征、共生状态等与遥感光谱的关系，并对其形成机理进行了探讨.
ZHANGDeng-rong(张登荣) +3 more
doaj +1 more source
, 2002 对福建省牛姆林自然保护区常绿针阔叶混交林的区系组成、地理成分、垂直结构、物种多样性等特征研究结果表明,该混交林群落维管植物种类组成丰富,600m~2样地内有38科62属119种,其中以常绿高位芽植物占绝对优势;种子植物地理成分中热带性质属37属占64.91％,温带成分19属占33.33％;群落分层现象明显,乔木层可分4个亚层,乔、灌木及藤本植物种类和数量均丰富,草本植物较少;比较群落各部分多样性水平为灌木层>乔木层>草本层 ...
严重玲 +3 more
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Policy &Internet, Volume 18, Issue 1, March 2026.ABSTRACT This article investigates how TikTok Shop reproduces the e‐commerce model of Douyin Shop against a backdrop of divergent regulatory challenges and geopolitical distrust. One of the strategic changes we observe in TikTok Shop is the shift of consumer goods suppliers from local merchants to China‐based sellers.
Shuaishuai Wang, Jing Meng, Yitong Li
wiley +1 more source
, 2007 武湖现有鱼类50种,其中鲤科鱼类33种,占总数的66%。渔获物组成中,鲢、鳙、鲤、鲫、鲌的产量占总产量的93%左右,渔获物以低龄为主。武湖目前的主要增养殖方式是放养鲢鳙,通过投放无机和有机化肥培养浮游生物来达到增加鲢鳙鱼产量的目的。针对武湖的渔业资源现状和渔业可持续发展的需要 ...
刘家寿 +6 more
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Breaking Down Social Capital: Urban Families' Use of Public Benefits
Poverty &Public Policy, Volume 18, Issue 1, March 2026.ABSTRACT This article examines whether social capital facilitates or dissuades urban families from taking up safety net programs. Using longitudinal data from the Future of Families and Child Wellbeing Study, we explore how various components of social capital—operating at relational, organizational, and neighborhood levels—are related to participation
Denia Garcia
wiley +1 more source
The Synecological Studies on Castanopsis Forest in Fujian Province [PDF]
, 2017 锥属植物往往是亚热带常绿阔叶林的建群种，锥林研究可以为植被分类研究提供许多重要数据。本文在对福建省自然保护区内保护良好的锥林样地调查的基础上，结合收集的全省已有的多个锥林调查数据资料，对其进行群落结构、区系特征、生物多样性等群落生态学特征以及优势种种间关系研究。分析整个福建锥林群系组整体特征以及各锥林群系特征，并探讨不同锥属种群在群落中所处的作用与地位。主要结论如下： 1、锥属树种为建群种的常绿阔叶林（锥林）的乔木层常由多个种群共建，灌木层上下两层组成略有不同。由于乔灌层的郁闭度较高，草本层相对空旷 ...
江昕怡
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