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吉林蛟河针阔混交林群落β多样性的影响因素 被引量:4
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作者 何存存 张春雨 赵秀海 《应用与环境生物学报》 CAS CSCD 北大核心 2022年第2期325-330,共6页
量化局部因素对区域群落间物种组成差异的相对作用,对于理解吉林蛟河针阔混交林群落β多样性的响应机制具有重要意义.将区域群落尺度定义成由3个、5个或9个样方构成的3个梯度,并把全部木本植物划分为3个垂直层,计算不同林层下各区域群... 量化局部因素对区域群落间物种组成差异的相对作用,对于理解吉林蛟河针阔混交林群落β多样性的响应机制具有重要意义.将区域群落尺度定义成由3个、5个或9个样方构成的3个梯度,并把全部木本植物划分为3个垂直层,计算不同林层下各区域群落的β多样性.采用回归模型和方差分解法分析地形和生物变量对不同区域群落β多样性的影响及相对贡献.结果表明:不同林层β多样性随着区域群落尺度的增大呈显著增大趋势(P<0.05),其中林下层变化范围为0.359-0.373,亚林层范围为0.502-0.514,林冠层范围为0.448-0.473;生物变量表征的林分结构属性对区域群落β多样性的影响最大,其解释比例总体上随区域群落尺度的增大而增大(林下层:0.27→0.40→0.33;亚林层:0.20→0.29→0.37;林冠层:0.16→0.21→0.27);不同林层中影响β多样性的生物因子种类不同,林下层和林冠层的决定性因素为物种丰富度,而亚林层的决定性因素为胸径变异系数;而地形因子对区域群落β多样性的解释量较低,其中海拔对林下层和林冠层具有显著的正向影响,坡度对亚林层具有显著的负向影响.本研究证实了区域群落尺度和林分结构特征对β多样性格局的形成具有重要作用,为今后全面揭示温带森林群落的多样性维持机制提供新视角.(图4表2参37) 展开更多
关键词 Β多样性 区域群落尺度 垂直分层 林分结构 地形因子
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A Numerical Study of Tropospheric Ozone in the Springtime in East Asia 被引量:15
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作者 张美根 徐永福 +1 位作者 Itsushi UNO Hajime AKIMOTO 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2004年第2期163-170,共8页
The Models-3 Community Multi-scale Air Quality modeling system (CMAQ) coupled with the Regional Atmospheric Modeling System (RAMS) is applied to East Asia to study the transport and photochemical transformation of tro... The Models-3 Community Multi-scale Air Quality modeling system (CMAQ) coupled with the Regional Atmospheric Modeling System (RAMS) is applied to East Asia to study the transport and photochemical transformation of tropospheric ozone in March 1998. The calculated mixing ratios of ozone and carbon monoxide are compared with ground level observations at three remote sites in Japan and it is found that the model reproduces the observed features very well. Examination of several high episodes of ozone and carbon monoxide indicates that these elevated levels are found in association with continental outflow, demonstrating the critical role of the rapid transport of carbon monoxide and other ozone precursors from the continental boundary layer. In comparison with available ozonesonde data, it is found that the model-calculated ozone concentrations are generally in good agreement with the measurements, and the stratospheric contribution to surface ozone mixing ratios is quite limited. 展开更多
关键词 regional pollution tropospheric ozone carbon monoxide community Multi-scale Air Quality modeling system
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NUMERICAL SIMULATION WITH A COMPREHENSIVE CHEMICAL TRANSPORT MODEL OF NITRATE,SULFATE,AND AMMONIUM AEROSOL DISTRIBUTIONS OVER EAST ASIA 被引量:3
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作者 Meigen Zhang 《China Particuology》 SCIE EI CAS CSCD 2005年第5期255-259,共5页
The transport and chemical production processes of nitrate, sulfate, and ammonium aerosols over East Asia were investigated by use of the Models-3 Community Multi-scale Air Quality (CMAQ) modeling system coupled wit... The transport and chemical production processes of nitrate, sulfate, and ammonium aerosols over East Asia were investigated by use of the Models-3 Community Multi-scale Air Quality (CMAQ) modeling system coupled with the Regional Atmospheric Modeling System (RAMS). For the evaluation of the model's ability in depicting their 3-dimensional concentration distributions and temporal variations, modeled concentrations of nitrate, sulfate, and ammonium aerosols are compared with the observations obtained at a ground station in Japan in March 2001 and onboard of an aircraft DC-8 on 18 and 21 March 2001 during the Transport and Chemical Evolution over the Pacific (TRACE-P) field campaign. Comparison shows that simulated values of nitrate, sulfate, and ammonium aerosols are generally in good agreement with their observed data, and the model captures most important observed features, and reproduces temporal and spatial variations of nitrate, sulfate, and ammonium aerosol concentrations reasonably well, e.g., the timing and locations of the concentration spikes of nitrate, sulfate, and ammonium aerosols are well reproduced, but large discrepancies between observed and simulated values are also clearly seen at some points and some times due to the coarse grid resolution and uncertainties of the emissions used in this study. This comparison results indicate that CMAQ is able to simulate the distributions of nitrate, sulfate, and ammonium aerosols and their related species in the troposphere over East Asia reasonably well. 展开更多
关键词 long-range transport regional pollution community Multi-scale Air Quality (CMAQ) East Asia
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街道的回归——杭荟城艺术街区设计
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作者 黎辰 《城市建筑空间》 2023年第11期45-48,共4页
为留存原有空间记忆,杭荟城艺术街区通过建筑布局、空间组织及立面语言表达再现建筑群组的“街道感”,以保持街道活力,通过对节点空间的塑造进一步拓展街道作为公共空间的可能性,以应对城市的有机更新。
关键词 地域性 街道感 建筑群组 空间尺度 立面语言
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