Results 41 to 50 of about 15,154 (186)

Morpholoical variation of fruits and seeds of Sinocalycanthus chinensis and its correlation with environment factors(夏蜡梅果实和种子形态变异及其与环境因子相关性)

open access: yesZhejiang Daxue xuebao. Lixue ban, 2007
对天台大雷山4个不同生境(常绿阔叶林、灌丛、竹林和杉木林)夏蜡梅群体的果实、种子形态变异及其与环境因子的相关性进行了研究.测量的果实和种子12项形态学指标表明,果实和种子的性状以灌丛生境最优、其次是竹林生境、最差的是常绿阔叶林生境.表型性状在群体间和群体内都存在着一定程度的变异,其中群体间的变异系数的平均值从61.71(每果种子数)到7.51(种子厚).夏蜡梅种子形态较果实形态穗定.单因素方差分析显示,夏蜡梅果实和种子形态在不同生境间差异显著,其中80%以上的变异来源于生境内 ...
ZHANGWen-biao(张文标)   +1 more
doaj   +1 more source

Advancing conservation breeding programs for marine invertebrates

open access: yesConservation Biology, EarlyView.
Abstract In the face of ecosystem change and biodiversity loss caused by climate change and other stressors, conservation breeding, or captive breeding, with the aim of reintroduction for wild population recovery, is an emerging tool for preventing species’ extinction and rehabilitating ecosystems.
Elora H. López‐Nandam   +3 more
wiley   +1 more source

生境变化的种群效应——一种定量评价方法

open access: yes野生动物学报, 1991
野生动物的生境可能会在时间和空间上发生变化。在某一地区,各种生境所占比例的变化,可能引起该地区野生动物对整个生境适宜性的改变。因此,需要一个预测野生动物对生境变化所产生反应的生境关系模型(Verner et al, 1986)。本文根据野生动物短期的生境利用和野生动物管理中收集到的有关资料,提出了一种预测生境变化对野生动物影响的方法。生态学上关于生境选择理论是以种群密度大小表示生境质量好坏为前提的。故根据生境利用以及有关资料,便能直接地预测生境变化的结果。一、理论基础 ...
Robert Fagen, 张明海, 陈丽娟
doaj  

黄河流域经济带生态环境绩效评估及其提升路径

open access: yesShuitu Baochi Xuebao, 2023
黄河流域经济带是我国北方重要的经济走廊,科学评估黄河流域经济带生态环境绩效水平,提高黄河流域沿线9省生态环境质量是实现黄河流域经济带的高质量发展重要举措之一。运用生态环境质量评估、生态效率评估等研究方法,开展2012—2017年的生态环境质量、生态效率和绿色全要素生产率评估。结果表明:黄河流域经济带生态环境绩效水平总体呈现由较低水平不断提升的趋势;黄河沿线九省在生态环境质量和生态效率系统层中有明显差异,生态环境质量系统层中,上游地区的最优;生态效率系统层中,中下游地区的生态效率最优且稳定 ...
鲁仕宝, 尚毅梓, 王浩, 廉志端
doaj  

Potential harm of coastal sedimentary nutrient in inducing red tide(沿海沉积营养物质对引发赤潮的潜在影响)

open access: yesZhejiang Daxue xuebao. Lixue ban, 2004
从生物地球化学的角度阐述了引发赤潮的营养和环境控制因素,并在分析了赤潮藻的限制性营养元素(磷、氮、硅)和微量元素(铁、锰)环境地球化学行为的基础上,提出了沿海沉积营养元素的释放与赤潮之间的相关关系模式,同时指出了中国沿海近代沉积物中营养物的积累趋势及其对引发赤潮的潜在危害,这不仅为揭示赤潮发生机理开辟了新的研究方向,而且也为有效地防治赤潮危害提供了科学依据.
WENGHuan-xin(翁焕新)   +5 more
doaj   +1 more source

Structured machine learning modeling to support conservation of deep‐sea benthic biodiversity

open access: yesConservation Biology, EarlyView.
Abstract Biodiversity monitoring programs need to deliver accurate, timely, and actionable predictions. To establish a predictive monitoring program for deep‐sea benthos of the Santos Basin, Brazil, we developed a two‐stage structured model that allowed comparison of biodiversity predictions obtained from environmental simulations (2M‐Sim).
Gustavo Fonseca   +23 more
wiley   +1 more source

Characteristics of chemical compositions and sources of PM2.5 in winter at Lin′an(杭州市临安区冬季PM2.5化学组成特征和来源解析)

open access: yesZhejiang Daxue xuebao. Lixue ban
In order to study the pollution characteristics and source contributions of PM2.5 at Lin'an, located in Hangzhou City, the PM2.5 component online monitoring was conducted from December 23, 2021, to February 28, 2022, and the sources apportionment of PM2 ...
马勤(MA Qin), 许振波(XU Zhenbo)
doaj   +1 more source

Taxonomic and functional diversity of urban bees of the world

open access: yesConservation Biology, EarlyView.
Abstract Bees play a pivotal role in terrestrial environments. Urbanization can affect these organisms and the ecosystem services they provide. However, knowledge of the global diversity of urban bees is limited. Thus, we summarized data on urban bee species identities and occurrences; compared distributions of all bees with those found in urban ...
João C. F. Cardoso   +10 more
wiley   +1 more source

生态环境建设的区域配置

open access: yesShuitu Baochi Xuebao, 2002
从生态环境、生态环境问题、生态环境建设的概念入手,深入分析了生态环境建设的内涵.在划分的8个生态环境建设类型区的基础上,提出了以省(自治区)为单元进行生态环境建设分区的必要性,并以陕西省境内黄河流域为例,重点探讨了其生态环境建设分区的方法与成果,以及生态环境建设模式.最后提出了生态环境建设中的几点认识与建议.
王礼先 刘霞
doaj  

Spatial identification of areas suitable for other effective area‐based conservation measures in the European Union

open access: yesConservation Biology, EarlyView.
Abstract Although significant biodiversity has been safeguarded by protected areas (PAs), biodiversity trends continue downward. Within the frameworks of the EU Biodiversity Strategy for 2030 and the new EU Restoration Regulation (2024), conserving critical biodiversity areas is essential.
George Kefalas   +14 more
wiley   +1 more source

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