鼎湖山森林地区臭氧及其前体物的变化特征和分析   总被引：18，自引：2，他引：16  

白建辉  徐永福  陈辉  王庚辰  石立庆  孟泽  黄忠良  孔国辉 《气候与环境研究》2003,8(3):370-380

通过对鼎湖山森林地区近地面O3和NOx浓度、太阳辐射、气象参数等为期一年的观测和资料分析,给出了地面O3和NOx浓度、太阳辐射的变化规律及其相互之间的关系.地面O3、NOx、CO、SO2浓度以及紫外辐射、太阳总辐射等有明显的日变化和季节变化.不同因子对O3的敏感性试验结果表明,晴天和实际天气,O3浓度对NO、NO2浓度的变化最为敏感,其次是水汽、气溶胶,最后是紫外辐射.所有因子的变化均引起O3在湿季比干季更大的变化率,因此在研究臭氧化学和光化学时,应该考虑水汽以及OH自由基的重要作用.对于晴天和实际天气的逐时值和日平均值而言,O3浓度与NO2/NO之间存在很好的正相关关系,比值NO2/NO可以作为判断O3峰值出现的一个指标.O3极值的出现既受NO和NOx影响,也受气象因素(温湿度、云、风、雾、降雨)和辐射的影响.周末O3、NOx浓度及NO2/NO有规律的增大,表明实验地点的大气受到人为污染源的影响.  相似文献   

大兴安岭中北段森林沼泽丘陵景观区的1∶5万化探方法技术研究   总被引：1，自引：1，他引：0       下载免费PDF全文

徐仁廷  孔牧  杨少平  喻劲松  王乔林  韩伟  郭志鹃  宋云涛  王成文 《中国地质调查》2014,1(1):19-27

在森林沼泽水系较不发育区开展土壤测量时,部分区段存在厚度为1~3 m的黏土层,采样困难,大家选用采样介质不一。通过对比研究残积土、腐殖土、黏土的粒级分布特征、元素分布特征及同点采集的样品元素含量的对比研究,认为在大兴安岭中北段森林沼泽丘陵景观区开展1∶5万化探时采用的方法为:采样介质为残坡积土;采样粒级为-10~+60目;采样密度为9点/km²;野外样品加工方法为水筛。  相似文献   

浙江省森林生态服务价值估算及其逐月变异分析   总被引：1，自引：0，他引：1  

刘东  黄海清  李艳  龚芳  张琳  栾虹 《地球信息科学学报》2014,16(2):225-232

森林生态服务价值的研究对构建绿色GDP核算体系、制定生态补偿标准、提高人类环境保护意识等有十分重要的意义。本文首先以卫星影像、地理空间数据、站点记录等资料,结合GIS、RS技术,估算了浙江省森林生态系统2010年的NPP、蒸散量、土壤保持量等;然后,采用能量替代法、机会成本法、影子工程法等估算了浙江省森林2010年的固碳释氧价值、有机物生产价值、水源涵养价值、营养物循环价值、水土保持价值;最后,对各种生态服务价值的逐月变异规律进行分析。结果表明：浙江省森林2010年的5种生态服务价值呈现明显的逐月变异规律;固碳释氧价值、有机物生产价值、营养物质循环价值、水土保持价值的逐月变异规律,均可用开口向下抛物线拟合;水源涵养价值的逐月变异规律,可用开口向上抛物线拟合。  相似文献   

机载LIDAR数据的树高识别算法与应用分析   总被引：1，自引：0，他引：1  

王轶夫  岳天祥  赵明伟  杜正平  刘向锋  刘爽  宋二非  孙文正  张彦丽 《地球信息科学学报》2014,16(6):958-964

利用机载激光雷达数据提取天然次生林的树高,旨在探索影响树高提取精度的主要因素。首先,采用高精度曲面建模平差算法(Adjustment Computation of High-accuracy Surface Modeling,HASM-AD)生成研究区不同空间分辨率的数字高程模型(Digital Elevation Model,DEM)、数字地表模型(Digital Surface Model,DSM)和冠层高度模型(Canopy Height Model,CHM);其次,用树顶点识别算法提取林木树高,设置不同树高识别范围,对比分析不同CHM分辨率和不同树高识别范围对树高提取精度的影响;最后,以天涝池流域30个实测样地数据为样本,对提取精度进行检验。结果显示：提取的样地平均树高与实测值具有明显线性相关关系,线性回归系数为0.694;树高识别范围是影响树高提取精度的重要因素,CHM分辨率对其影响较小。研究表明,采用高采样密度的雷达点云数据、正确选择CHM生成方法和改进树顶点识别算法是提高天然次生林树高提取精度的有效途径。  相似文献   

中国森林生态系统能值与服务功能价值的关系   总被引：4，自引：0，他引：4  

吴霜  延晓冬  张丽娟 《地理学报》2014,69(3):334-342

本研究利用1901-2009 年全球温度和降水数据以及全国1266 块森林样地主要森林类型数据作为基础数据,应用能值理论和生态系统服务功能理论,建立了中国森林能值与服务功能价值之间的函数关系,并且研究了1990 年和2009 年中国森林服务功能价值密度的变化。结果表明：应用函数关系模拟1994 年中国森林生态系统服务功能价值的结果与Costanza 评估结果在空间分布上具有较高的一致性。2009 年全国有林地栅格数目比1990 年增长14.02%,其平均森林生态系统服务功能价值密度增加了54.46 USD/hm²。北京、上海、江苏、天津、河北平均森林生态系统服务功能价值密度分别降低了86.87%、85.45%、81.99%、46.48%和23.07%。河南、湖南、吉林、江西、黑龙江和浙江平均森林生态系统服务功能价值密度分别下降了71.35%、58.65%、52.70%、34.56%、23.36%和22.03%。广西、西藏、甘肃、内蒙古、四川、云南、宁夏森林破坏也比较明显,这些省份的平均森林生态系统服务功能价值密度下降了2.89%~22.36%。根据全国第四次和第七次森林清查报告显示,近年来我国森林面积持续增加。但研究结果显示很多省份的森林生态系统服务功能价值密度仍然降低,这说明森林生态系统仍然没有完全恢复。中国森林生态系统服务功能普遍低于全球森林生态系统服务功能值的平均水平,说明我国森林生态环境并不理想,人类活动对生态系统产生巨大的负面影响。  相似文献   

气候变化和人类活动影响下澧水流域径流及其不同组分的变化     

郑明国  孙莉英 《地理研究》2014,33(2):237-250

目前径流变化相关研究较少涉及径流的不同组分。利用湖南省澧水流域4个水文站点长序列观测资料,不仅分析了2007-2011年相对于1985年以前径流总量及其历时曲线的变化,也分析了地表径流和基流及其历时曲线的变化。与1985年以前比,流域年降雨量保持不变,最显著的变化为森林覆盖率的增加和大量水库的修建。这些人类活动没有造成年径流总量、年基流量和年地表径流量的显著变化,但在日时间尺度上对径流过程产生了重要影响。地表径流和地下径流对人类活动存在差异性响应,2007年以后地表径流在洪峰期流量变小而其他时段变大,而地下径流汇水受人类活动影响较小,基流流量除枯水期外与1985年以前基本一致。本文所揭示的规律可能在中国南方具有一定的代表性。  相似文献   

Modeling the impacts of policy interventions from REDD+ in Southeast Asia: A case study in Indonesia     

HeLi Lu  GuiFang Liu 《中国科学:地球科学(英文版)》2014,57(10):2374-2385

Reducing Emissions from Deforestation and Forest Degradation (REDD+) and enhancing “removals of greenhouse gas emissions by forests” in developing countries through positive incentives is regarded as an essential component of the post-2012 climate regime for stabilizing greenhouse gas emissions and an important way of engaging developing countries in global mitigation efforts. We aimed to evaluate the potential effectiveness of REDD+ by integrating it into a land use option framework. One of our goals was to develop scenarios for evaluating the impacts of land use changes on carbon and environmental processes. In addition, we aimed to quantify the potential economic benefits to society of compensated reductions and to identify hotspots for applying REDD+. Three land use change scenarios were examined: (I) business as usual (BAU), (II) economic development, and (III) REDD+. A case study in Indonesia was examined using these land use scenarios and policy interventions, evaluating their effects on carbon emissions, socioeconomics, and environmental features of a spatial system using land use models. Significant emissions and water erosion reductions were predicted to be achieved under the REDD+ scenario, due to reduced deforestation of <6% over the next decade; >0.14 Mt CO₂e reduction was predicted relative to the BAU scenario. Furthermore, the spatial land use model indicated that REDD+ payments of forest carbon credits in the compliance market would play a key role in compensating rural communities and plantation companies for their opportunity cost in ending deforestation. This study provides an example of integrating land use modeling with a scenario analysis framework to evaluate plausible future forecasts and to evaluate the potential impacts of REDD+.  相似文献   

Fog water interception by Sophora denudata trees in a Reunion upper-montane forest, Indian Ocean     

Grald Gabriel  Laurent Jauze 《Atmospheric Research》2008,87(3-4):338-351

The forest water balance has never been studied in Reunion Island (Indian Ocean). This study focuses on the interception of fog water by Sophora denudata, an endemic tree, which provides an important water input into the hydrologic budget of the upper-montane forest. Canopy throughfall, rainfall and fog have been compared. The first data were obtained in 2001 in Nez de Bœuf, 2040 m asl, from manual rain gauges. The measurements were made during the day only. The aim was to propose a typology of events, to understand the spatial pattern of canopy throughfall, especially fogdrip, and their relation to the trade-wind direction. A second series of experiments, carried out in 2004 in Piton de Tangues, 2150 m asl, investigated how throughfall and atmospheric water varied with time, using automatic instruments such as the shielded Grunow-type fog collector. Here measurements were made continuously and night data were not excluded. Over a period of 8 months, the throughfall gauges, which were placed under the trees, indicated 1180 mm whereas the total amount of rainfall had reached only 948 mm. The difference (232 mm) is attributed to fog. Of 278 events, 234 showed fog contribution; fog occurred alone in 167 cases. The observations confirm what was found in Nez de Bœuf, namely that fog or rain can occur separately or together. The role of fog contribution to the forest water budget is significant: the spatial variation of canopy throughfall does not only depend on the type of event, but also on wind direction.  相似文献   

Simulation of snow processes beneath a boreal scots pine canopy     

李伟平  罗勇  夏坤  刘新 《大气科学进展》2008,25(3):348-360

A physically-based multi-layer snow model Snow-Atmosphere-Soil-Transfer scheme(SAST)and a land surface model Biosphere-Atmosphere Transfer Scheme(BATS)were employed to investigate how boreal forests influence snow accumulation and ablation under the canopy.Mass balance and energetics of snow beneath a Scots pine canopy in Finland at different stages of the 2003-2004 and 2004 2005 snow seasons are analyzed.For the fairly dense Scots pine forest,drop-off of the canopy-intercepted snow contributes,in some cases,twice as much to the underlying snowpack as the direct throughfall of snow.During early winter snow melting,downward turbulent sensible and condensation heat fluxes play a dominant role together with downward net longwave radiation.In the final stage of snow ablation in middle spring,downward net all- wave radiation dominates the snow melting.Although the downward sensible heat flux is comparable to the net solar radiation during this period,evaporative cooling of the melting snow surface makes the turbulent heat flux weaker than net radiation.Sensitivities of snow processes to leaf area index(LAI)indicate that a denser canopy speeds up early winter snowmelt,but also suppresses melting later in the snow season. Higher LAI increases the interception of snowfall,therefore reduces snow accumulation under the canopy during the snow season;this effect and the enhancement of downward longwave radiation by denser foliage outweighs the increased attenuation of solar radiation,resulting in earlier snow ablation under a denser canopy.The difference in sensitivities to LAI in two snow seasons implies that the impact of canopy density on the underlying snowpack is modulated by interannual variations of climate regimes.  相似文献   

Statistical and dynamical assessment of vegetation feedbacks on climate over the boreal forest   总被引：1，自引：1，他引：0  

Michael Notaro  Zhengyu Liu 《Climate Dynamics》2008,31(6):691-712

Vegetation feedbacks over Asiatic Russia are assessed through a combined statistical and dynamical approach in a fully coupled atmosphere–ocean–land model, FOAM-LPJ. The dynamical assessment is comprised of initial value ensemble experiments in which the forest cover fraction is initially reduced over Asiatic Russia, replaced by grass cover, and then the climatic response is determined. The statistical feedback approach, adopted from previous studies of ocean–atmosphere interactions, is applied to compute the feedback of forest cover on subsequent temperature and precipitation in the control simulation. Both methodologies indicate a year-round positive feedback on temperature and precipitation, strongest in spring and moderately substantial in summer. Reduced boreal forest cover enhances the surface albedo, leading to an extended snow season, lower air temperatures, increased atmospheric stability, and enhanced low cloud cover. Changes in the hydrological cycle include diminished transpiration and moisture recycling, supporting a reduction in precipitation. The close agreement in sign and magnitude between the statistical and dynamical feedback assessments testifies to the reliability of the statistical approach. An additional statistical analysis of monthly vegetation feedbacks over Asiatic Russia reveals a robust positive feedback on air temperature of similar quantitative strength in two coupled models, FOAM-LPJ and CAM3–CLM3, and the observational record. CCR Contribution # 931.  相似文献