基于可拓工程方法的生态地理区域系统界线划分研究—以中温带半湿润、半干旱

利用可拓工程方法中的物元模型对生态地理区域系统的界线问题进行了研究，通过选取样本和指标对单指标关联函数和多指标综合关联函数进行了定量计算。在此基础上，通过专家集成确定了中国中温带半湿润、半干旱区之间的界线，弥补了单指标和定性划分的不足，有助于中国生态地理区域系统的构建。     

沙障成林的固沙工程及生态效益研究

温带亚湿润地区的流动沙地具有特殊的水分状况。某些风口地段的流动沙丘，植树难以成活，但利用活体杨树枝条扦插沙障，可以成活为林，是一项机械固沙与生物固沙相统一的治沙工程。沙障成林后，生态效益明显：春季大风日，林内风速削减１５％～４１．５％，夏季林内温度降低１～３℃，空气湿度增加１１％～２２％；林下土壤稳定发育，表土层粘粒增加５％～１０％，土壤有机质增加１％，土壤结构形成；沙丘植被逐渐演替，由裸沙地→沙蒿（Ａｒｔｅｍｉｓｉａｄｅｓｅｒｔｏｒｕｍ）＋沙蓬（Ａｇｒｉｏ－ｐｈｙｌｕｍｅｒｅｎａｒｉｕｍ）→沙地萎陵菜（ｐｏｔｅｎｔｉｌａｆｉｌｉｐｅｎｄｕｌａ）＋燕麦芨芨草（Ａｃｈｎａｔｈｅｒｕｍａｖｉｎｏｉｄｅｓ）→贝加尔针茅（Ｓｔｉｐａｂａｉｃａｌｅｎｓｉｓ）＋沙地萎陵菜、苔藓，使整个沙丘形成稳定的林草系统，并成为风口地段的防风屏障，改善了周边的生态环境     

Large-scale Circulation Control of the Occurrence of Low-level Turbulence at Hong Kong International Airport

This study identifies the atmospheric circulation features that are favorable for the occurrence of low-level turbulence at Hong Kong International Airport [below 1600 feet(around 500 m)]. By using LIDAR data at the airport, turbulence and nonturbulence cases are selected. It is found that the occurrence of turbulence is significantly related to the strength of the southerly wind at 850 h Pa over the South China coast. On the other hand, the east–west wind at this height demonstrates a weak relation to the occurrence. This suggests that turbulence is generated by flow passing Lantau Island from the south. The southerly wind also transports moisture from the South China Sea to Hong Kong, reducing local stability. This is favorable for the development of strong turbulence. It is also noted that the strong southerly wind during the occurrence of low-level turbulence is contributed by an anomalous zonal gradient of geopotential in the lower troposphere over the South China Sea. This gradient is caused by the combination of variations at different timescales. These are the passage of synoptic extratropical cyclones and anticyclones and the intraseasonal variation in the western North Pacific subtropical high. The seasonal variation in geopotential east of the Tibetan Plateau leads to a seasonal change in meridional wind, by which the frequency of low-level turbulence is maximized in spring and minimized in autumn.     

瑯琊山的顶极群落与江淮地区的地带性植被

瑯琊山森林进展演替的结果,亦即其顶极植物群落,将是以青檀、榉树、化香、五角枫、铜钱树等为优势树种的森林类型.苏皖江淮地区的地带性植被为落叶阔叶林,在中国植被区划系统中应属于暖温带落叶阔叶林区.     

Different times,same story: Native forest loss and landscape homogenization in three physiographical areas of south-central of Chile

Temperate forest represents the smallest area among the main world's forest biomes, but is one of those most threatened by forest loss. Chile contains most of the temperate forest in South America and more than half of the temperate forest in the southern hemisphere. Chilean temperate forest is considered to be one of the world's biodiversity hotspots. In this study we assessed the rate of land use and land cover (LULC) change over time, identified the main LULCs replacing native forest, and described how changes have evolved in contrasting physiographical conditions and through different historical phases of the landscape over the last 40 years. To achieve this, we analysed LULC change with particular focus on forest cover in three areas representing different physiographical conditions and histories of human occupation in the Araucanía Region of Chile, namely the Central Valley, the Coastal range, and the Andean range. We found substantial differences in temporal and intra-regional patterns of forest loss and LULC change. In the Central Valley, forest loss started long ago, and the area occupied by native forest nowadays is less than 5% of the landscape. In the Coastal range, rapid land cover change has taken place since 1973, with an increasing rate of forest loss over time. We detected a similar but less intense pattern in the forests of the Andean range. Overall, the general pattern points to a process of landscape homogenization in all three physiographical areas. Exotic tree plantations have spread over large geographical areas, becoming the dominant land cover. Land cover change in the Araucanía Region reflects a model of change in which areas with better environmental conditions and accessibility are occupied first for productive activities. As the availability of suitable areas for the expansion of productive activities diminishes, these activities start to move into physiographical areas which were previously “protected” by adverse environmental conditions or poor accessibility. This model of production growth could lead to the complete deforestation of areas outside national protected areas, and other areas which still remain inaccessible due to technological restrictions on exploitation.     

Development of a prograding carbonate wedge during sea level fall: Lower Pleistocene of Rhodes, Greece

A Lower Pleistocene carbonate platform is described from north-east Rhodes, Greece. It comprises a succession of warm temperate calcarenites (the Cape Arkhangelos calcarenite facies group) developed in a steep-sided coastal basin. The depositional setting for the sediments is a carbonate wedge developed within a larger-scale forced regression. Deposition began with aggradation of storm-dominated lower and upper shoreface deposits. Later, the development of a prograding platform produced giant clinoform foresets. A marked alternation of cross-bedded and bioturbated clinoforms indicates seasonal transport of carbonate material off the platform. Periodically, the platform edge has been deeply scoured by exceptional storms, after which further deposition repaired the platform margin, and progradation resumed. More than 20 such major storm cycles are preserved. Applying sequence stratigraphy to this succession leads to two different possible interpretations: one with a lowstand systems tract and one with a forced regressive systems tract, depending on the scale of view. The implications of this are discussed. The present example shows clearly that the application of sequence stratigraphic models to real carbonate sequences requires careful consideration of scale and context before interpretations are made.     

山地温性积雪内液体水含量的测定方法

通过在北欧ＡｕｓｔｒｅＯｋｓｔｉｎｄｂｒｅｅｎ冰川积雪内的实际测定结果,证明野外测量积雪内液体水含量的新方法－酒精量热法是可行和适用的,解决了过去测定积雪内液体水含量时遇到困难。５个雪坑剖面的测定结果清楚地显示雪内液体水含量的区带性和随高度的变化,积雪内液体水含量的垂直变化与雪层中物理结构,温度和密度的分布有关。     

横断山区典型海洋型冰川物质平衡研究

玉龙雪山发育着对气候变化响应极为敏感的典型海洋型冰川。基于2008-2013年共5个物质平衡年观测数据,对玉龙雪山规模最大的白水1号冰川物质平衡特征进行分析,为评估横断山区气候和冰川变化之间的关系奠定基础。结果表明：2008-2013年白水1号冰川物质平衡最大值仅为-907 mm w.e.,最小值则达到-1872 mm w.e.。2008年冰川平衡线高度为4972 m,2009-2013年白水1号冰川积累区近乎消失。白水1号冰川积累期主要集中于10月至次年5月,6-9月为强消融期,积累量几乎为零,消融量占全年80%,属冬春季积累型冰川。2008-2009、2011-2012和2012-2013年平均物质平衡梯度为1230 mm w.e. （100 m）^-1,消融期物质平衡梯度小于年物质平衡梯度,消融期初与消融期末物质平衡梯度小于100 mm w.e.（100 m）^-1。     

小冰期以来中国季风温冰川对全球变暖的响应

中国的季风温冰川主要分布在青藏高原东南部、冰川覆盖面积为 １３ ２０３．２ ｋｍ２,占我国冰川 总面积的２２．２％．由于这类冰川的特性、对气候变暖极为敏感自小冰期最盛时（１７世纪）以来,温冰 川区平均升温０．８℃,冰川面积减小相当现代面积的３０％,为３９２１．２ｋｍ２．预估中国季风湿冰川区 ２１００年的升温值２．１℃,届时冰川面积将减少７５％,达９９００ ｋｍ２左右,考虑到降水增加趋势等因 素,实际冰川退缩比例不大于８０％,但这已足以说明温冰川的大规模衰退．其后果将对当地水资源 和环境产生重大影响     

早中新世沟鞭藻模特地理区系

对早中新世的沟鞭藻植物地理作了初步研究,提出北半球在当时可划争为３以鞭藻地理区,即热带区、亚热带－温带区和北方区。热带区以典型的热带、亚热带种Ｐｏｌｙｓｐｈａｅｒｉｄｉｕｍｚｏｈａｒｙｉ丰富并存在偏胺热带、亚热带的种Ｔｕｂｅｒ ｃｅｕｌｌｄｉｎｉｕｍｄｉｎｉｕｍ ｖａｎｃａｍｐｏａｅ为特征,亚热带一温带区以同时存在Ｔｕｂｅｒｃｕｌｏｄｉｎｉｕｍｄｉｍｉｕｍ ｖａｎｃａｍｐｏａｅ和温带种Ｂｉｔｅｃｔ