Results 61 to 70 of about 8,158 (171)
野生动物学报, 2008 根据扎龙湿地实际情况,将其划分为3种人为干扰强度地区,并进行了鸟类群落结构调查。统计3种干扰地区的物种丰富度,用Shannon-Winener指数计算物种多样性指数,用Pielou指数式计算物种均匀度指数,并用数量数据的β多样性测度公式分析人为干扰强度对扎龙湿地鸟类群落结构的影响。结果表明扎龙湿地鸟类的物种丰富度、物种多样性和物种均匀度与人为干扰强度成紧密的负相关关系。
杨敏, 吴庆明, 齐锐, 孔维尧
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Zhejiang Daxue xuebao. Lixue ban, 2006 在对凤阳山白豆杉种群进行野外调查的基础上，分析了其群落的区系及物种多样性.结果表明：凤阳山白豆杉群落中共有维管植物59科104属160种（含变种），其中蕨类植物5科6属8种，裸子植物4科7属8种，被子植物49科88属142种.区系成分复杂，大部分属于温带和热带分布类型，其中温带类型占总属数的58.
DINGBing-yang(丁炳扬“) +3 more
doaj +1 more source
Study on changes of ecological characteristics of four demersal fishes in the Taiwan Strait and its adjacent sea [PDF]
, 2014 鱼类的生活方式、鱼类种群数量变动的规律、控制及预报其数量变化的趋势等是鱼类生态学研究的重要内容，其研究结果可为渔业资源保护和开展渔业生态系统管理提供依据。鱼类生态学特征的变化，尤其是鱼类种群数量和生态学参数的变化的研究结果可以为管理和利用渔业资源提供预警。本文选取台湾海峡及其邻近海域四种底层及近底层鱼类开展其生态学特征变化的研究，以期能为台湾海峡及其邻近海域的渔业资源保护和生态系统管理研究提供数据基础。 台湾海峡位于中国的东南部，是连接东海和南海的重要通道，台湾海峡及邻近海域拥有我国著名闽东渔场 ...
鞠培龙
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International Journal of Applied Linguistics, EarlyView.ABSTRACT The study investigated how writing motivation and self‐regulated read‐to‐write (SRL‐R2W) strategy use was related to writing performance and how the relationship between motivation and SRL‐R2W strategy use varied among different writing performance groups.
Huixuan Zhou +3 more
wiley +1 more source
岷江上游山地森林/干旱河谷交错带不同植被恢复模式对根际土壤微生物量碳氮及固氮菌群落结构的影响
Shuitu Baochi Xuebao, 2011 以岷江上游山地森林/干旱河谷交错带5种植被恢复模式的根际与非根际土壤为研究对象,对土壤微生物生物量碳、氮和土壤固氮菌群落结构的影响进行了初步研究.结果表明,5种不同植被根际与非根际土壤的微生物生物量存在显著差异且根际土壤含量大于非根际土壤,依次为:青冈次生林＞灌木林＞刺槐林＞人工幼林＞针阔混交林;DGGE图谱显示,5种植被根际与非根际土壤固氮类群有一条明显的共有条带,其中刺槐林和灌木林的固氮菌多样性最高;多样性指数、群落丰富度分析表明,灌木根际土壤固氮菌的群落种群结构最丰富,其次为刺槐;聚类分析结果显示,
钟熙敏 +6 more
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A STUDY ON THE STRUCTURE AND SPATIAL PATTERNS of CYCLOBALANOPSIS GLAUCA POPULATIONS IN WESTERN HUANGSHAN [PDF]
, 1996 黄山西坡青冈种群结构与分布格局研究陈小勇，张庆费，吴化前，宋永昌（华东师范大学环境科学系，上海，200062）ASTudyOnTHESTruCTurEAndSPATIAlPATTErnSOfCyClObAlAnOPSISglAuCAPOPulATIO ...
吴化前 +3 more
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International Journal of Applied Linguistics, EarlyView.ABSTRACT This study examines how foreign language teachers’ beliefs about the medium of instruction and translanguaging evolve over time by revisiting three in‐service teachers twelve years after their initial interviews. Using a qualitative longitudinal design, the study traces how translanguaging was initially framed as pedagogically deficient but ...
Danping Wang
wiley +1 more source
Policy Studies Journal, EarlyView.ABSTRACT The social construction of target populations (SCTP) framework emphasizes the ways in which target populations' levels of political power and deservingness shape the allocation of policy benefits, but less attention has been devoted to the conditions under which the same target population may be considered deserving in one policy context but ...
Elizabeth Bell +3 more
wiley +1 more source
野生动物学报, 2021 以陕西省第4次大熊猫（Ailuropoda melanoleuca）调查数据为基础，通过文献查阅及走访调查，对陕西秦岭地区大熊猫种群数量及扩散、栖息地消长、保护管理现状进行客观分析。结果表明：与第3次调查时相比，大熊猫种群数量增长、种群及栖息地扩散明显；但种群发展及生境威胁尚未解除，仍面临种群分割、内部竞争压力大、遗传压力加剧、栖息地破碎程度加大、潜在栖息地增长缓慢且质量较低、不确定性因素增加以及人为干扰等问题。以现状为基础，从实际问题出发，以保护规划的视角提出构建秦岭大熊猫“一心两翼多点 ...
南晓娜王茸仙张新兵
doaj
The Inclusion Trade‐Off: Comparing the Design and Functionality of Collaborative Governance Forums
Policy Studies Journal, EarlyView.ABSTRACT Environmental challenges require collaboration across jurisdictions, often through forums or intermediary spaces for repeated interaction. A persistent forum design question concerns inclusion criteria, or which actors should be included.
Adam Wiechman +3 more
wiley +1 more source