闽东南沿海老红砂沉积地层与形成时代

采用岩石地层学、磁性地层学和地球化学等方法,结合TL、ESR和¹⁴C等测年,对广泛分布于闽东南沿海的老红砂沉积地层及其形成时代进行了划分。结果表明,该区老红砂沉积地层可综合划分为5个地层段,其中老红砂层可分出3个地层段,分属60~40 ka B.P.、30~25 ka B.P.和20~10 ka B.P.所形成;两个古土层,反映大约在40~30 ka B.P.和25~20 ka B.P.老红砂的发育有过两次较长时间的沉积间断或减弱。     

岩溶浸没－内涝灾害研究

水库周边岩溶浸没-内涝现象是水利水电设计的环境问题之一。80年代以来,已在若干水库发生了此类现象,造成了一定的经济损失,本文以红水河岩滩水电站库区的内涝为例,分析了岩溶浸没内涝的主要原因和形成条件,归纳为降雨、管道、水库三要素。讨论了岩溶浸没-内涝灾害的预测及对策。     

湖泊生态恢复的关键因子分析

中国是一个多湖泊的国家。由于经济快速发展及湖泊资源不合理的开发利用,中国湖泊的污染问题和生态系统退化相当普遍。特别是由于氮、磷等营养元素的富集造成的水体富营养化,导致蓝藻水华频繁发生,甚至出现了饮用水危机事件。由于缺乏基础理论的指导,中国湖泊富营养化治理曾经走过弯路。在没有实现控源截污的条件下,片面强调生态恢复来净化湖泊水环境,一度成为富营养化湖泊治理的主流思想。实际上,湖泊生态恢复是有条件的,而对这些条件的诊断和分析是开展湖泊生态恢复的前提和基础。通过对太湖水生植物分布及其影响因子分析,确定沉水植物恢复的核心条件是水下光照条件。水下光照条件受富营养水平、悬浮物浓度与水深等因子的影响。只有当一个水域的真光层深度接近水深的情况(比值>0.8),恢复水生植物才有可能。改善水下光照条件,包括降低水深,提高透明度,消除风浪等措施,实际上,都是增加真光层深度与水深的比值。在上述生态恢复条件不具备的情况下,湖泊治理与恢复的工作更多地应该聚焦在控源截污方面。这对中国湖泊污染治理与生态恢复具有普遍的意义。     

冰雪灾害造成森林乔木层C贮量损失评估与分析——以福建省长汀县为例

以因冰雪灾害造成森林资源损失较为严重的福建省长汀县为例,选取受灾乔木林为研究对象,结合实地踏查和典型抽样统计数据,评估森林乔木层C贮量损失并分析其主要影响因素.分析结果表明:冰雪灾害造成长汀县乔木林地受损面积达40 178.87 hm2,占灾前面积的19.1%;损失蓄积95.69×104 m3,占灾前蓄积的38.6%,折合成森林乔木层C贮量损失34.55×104 t,占灾前C贮量的41.4%,受损最为严重的四都、红山、古城等6个乡(镇、场)都靠近武夷山脉南麓;同一区域相同的立地条件下,针叶树种比阔叶树种受灾严重,松组和杉组C贮量相对损失比均超过阔叶树组的3倍,其中松组C贮量损失23.02×104 t,占总C贮量损失的66.6%,占灾前松组C贮量的65.0%;中龄林C贮量损失12.84×104 t,占灾前中龄林C贮量的56.6%,相对损失比最大,近成过熟林次之,幼龄林最小;海拔越高,C贮量损失比例越大,海拔450 m以上区域C贮量损失达30.15×104 t,占总C贮量损失的87.3%;迎风坡面和山脊西北侧的乔木林受灾相对严重,朝西、西北、北3个方向的C贮量损失20.11×104 t,占总C贮量损失的58.2%;位于中上部坡位的乔木林受灾相对严重,且坡位越高,C贮量损失越大.     

湖泊自生碳酸盐碳同位素在环境变化中的应用

湖泊自生碳酸盐碳同位素组成(δ13Cc)在区域气候与环境变化方面的应用研究近年来进展迅速,成果显著,保存在各类湖泊沉积物柱芯中的δ13Cc记录揭示了湖表水体与大气CO2的交换程度、暖季降水量的多少、流域C3和C4植被变化情况、水生生物光合作用或呼吸作用强弱、湖泊生产力大小、湖泊水体化学特征、湖水不同深度层的有机质变化过程等重要的气候和环境信息;对此进行归纳和述评。     

An Updated Coupled Model for Land-Atmosphere Interaction. Part Ⅰ: Simulations of Physical Processes

A new two-way land-atmosphere interaction model (R42_AVIM) is fulfilled by coupling the spectral at- mospheric model (SAMIL_R42L9) developed at the State Key Laboratory of Numerical Modeling for Atmo- spheric Sciences and Geophysical Fluid Dynamics, Institute of Atmospheric Physics, Chinese Academy of Sci- ences (LASG/IAP/CAS) with the land surface model, Atmosphere-Vegetation-Interaction-Model (AVIM). In this coupled model, physical and biological components of AVIM are both included. Climate base state and land surface physical fluxes simulated by R42_AVIM are analyzed and compared with the results of R42_SSIB [which is coupled by SAMIL_R42L9 and Simplified Simple Biosphere (SSIB) models]. The results show the performance of the new model is closer to the observations. It can basically guarantee that the land surface energy budget is balanced, and can simulate June-July-August (JJA) and December-January- February (DJF) land surface air temperature, sensible heat flux, latent heat flux, precipitation, sea level pressure and other variables reasonably well. Compared with R42_SSIB, there are obvious improvements in the JJA simulations of surface air temperature and surface fluxes. Thus, this land-atmosphere coupled model will offer a good experiment platform for land-atmosphere interaction research.     

Quantifying contributions of climate feedbacks to tropospheric warming in the NCAR CCSM3.0

In this study, a coupled atmosphere-surface “climate feedback-response analysis method” (CFRAM) was applied to the slab ocean model version of the NCAR CCSM3.0 to understand the tropospheric warming due to a doubling of CO₂ concentration through quantifying the contributions of each climate feedback process. It is shown that the tropospheric warming displays distinct meridional and vertical patterns that are in a good agreement with the multi-model mean projection from the IPCC AR4. In the tropics, the warming in the upper troposphere is stronger than in the lower troposphere, leading to a decrease in temperature lapse rate, whereas in high latitudes the opposite it true. In terms of meridional contrast, the lower tropospheric warming in the tropics is weaker than that in high latitudes, resulting in a weakened meridional temperature gradient. In the upper troposphere the meridional temperature gradient is enhanced due to much stronger warming in the tropics than in high latitudes. Using the CFRAM method, we analyzed both radiative feedbacks, which have been emphasized in previous climate feedback analysis, and non-radiative feedbacks. It is shown that non-radiative (radiative) feedbacks are the major contributors to the temperature lapse rate decrease (increase) in the tropical (polar) region. Atmospheric convection is the leading contributor to temperature lapse rate decrease in the tropics. The cloud feedback also has non-negligible contributions. In the polar region, water vapor feedback is the main contributor to the temperature lapse rate increase, followed by albedo feedback and CO₂ forcing. The decrease of meridional temperature gradient in the lower troposphere is mainly due to strong cooling from convection and cloud feedback in the tropics and the strong warming from albedo feedback in the polar region. The strengthening of meridional temperature gradient in the upper troposphere can be attributed to the warming associated with convection and cloud feedback in the tropics. Since convection is the leading contributor to the warming differences between tropical lower and upper troposphere, and between the tropical and polar regions, this study indicates that tropical convection plays a critical role in determining the climate sensitivity. In addition, the CFRAM analysis shows that convective process and water vapor feedback are the two major contributors to the tropical upper troposphere temperature change, indicating that the excessive upper tropospheric warming in the IPCC AR4 models may be due to overestimated warming from convective process or underestimated cooling due to water vapor feedback.     

High-quality Development Paths of Ice-snow Tourism in China from the Perspective of the Winter Olympics

Preparations for the Beijing Winter Olympics have promoted the rapid development of ice-snow tourism in China, which contributes to achieving the goal of having “300 million people participate in ice-snow sports”. This paper analyzes the status quo and problems associated with the growth of ice-snow tourism in China based on the methods of documentation and field investigation. The results indicate that China’s efforts have born abundant fruits. Notwithstanding, there are still some problems due to the limited time and hastened process of ice-snow tourism development, including unreasonable exploitation, low-quality products and services, imperfect investment and financing system, inadequate management, a single marketing mode, and insufficient talent teams. Compared with developed countries in Europe and the United States, ice-snow tourism in China is in the stage of rapid development. To achieve the high-quality development of ice-snow tourism in China, this paper proposes actions from eight aspects which involve policy, products and services, marketing, safety management and control, talent teams, standardization construction, science and technology, and community participation. This study can provide references for the high-quality development of ice-snow tourism in China, as well as perfecting Chinese theoretical research on ice-snow tourism.     

不同种植方式下柽柳光合生理参数光响应特性研究

为选择合适的间套模式,在塔干沙漠南缘绿洲外围利用Li-6400光合作用仪对四种种植模式(行间混交、带状混交、块状混交、块状套作)下多年生多枝柽柳(Tamarix ramasissima ledeb.)的光合水分生理指标对有效光辐射(PAR)的响应进行测定。结果表明:(1)柽柳具有高光饱和点(679~822μmol·m^-2·s^-1)和高光补偿点(50.0~61.1μmol·m^-2·s^-1)。(2)不同的光照强度和种植方式对柽柳净光合速率有明显的影响(p<0.01),当0< PAR< 1500μmol·m^-2·s^-1,除胞间CO₂浓度(Ci)外柽柳的各项生理指标均随光照的增强而增加。(3) PAR>1500μmol·m^-2·s^-1后,块状套作和块状混交气孔导度(Gs)下降,行间混交和带状混交Gs则随光强增加而递增;带状混交下胞间CO₂浓度(Ci)和蒸腾速率(Tr)均随光强增加而递增,其他3种种植方式下Ci和Tr均呈递减或平稳趋势。(4) 4种种植方式下柽柳光响应曲线的特征参数存在着差异(P<0.05),带状混交下的光饱和速率、光饱和点、表观量子效率均最高,块状混交的暗呼吸速率最大,水分利用效率(WUE)随着光强的增强而逐步增大,依次表现为带状混交>块状混交>行间混交>块状套作。通过4种种植方式柽柳光响应特征的综合分析可知,带状混交下的柽柳具有高光合和高水分利用效率的特点,对于极端干旱的塔南地区而言,该种植方式下的柽柳生理特征表现出最好的适应性。     

浙江桂凋落物中可溶性有机物对铜离子络合能力研究

采用单配位体模型对不同分解阶段浙江桂凋落物中溶解性有机物(DOM)与铜离子的络合进行了研究.结果表明,DOM中存在络合条件稳定常数较高但络合容量较小和络合条件稳定常数较低但络合容量较大的2种组分.各阶段条件稳定常数(K)和络合容量(L)各不相同,各阶段中1g K与L存在着显著的负相关性(r=0.88,P＜0.05);各组分对铜离子的络合能力排列顺序为:Ⅱa＞Ⅰa＞Ⅰb＞Ⅲa＞Ⅱb＞Ⅲb,半分解阶段中凋落物所释放的DOM对铜离子的络合条件稳定常数最大.这可能与其在分解不同阶段所释放物质不同有关.