山西运城市森林火险等级预报系统

利用有关气象及森林火灾资料，分析了林林火灾的发生与气象条件、火条件及森林含水率的关系，计算了森林火险综合预报指标，建立了以预报方程，经试用效果良好。     

CLIMATOLOGICAL CHARACTERISTICS FOR THE ONSET OF ASIAN SUMMER MONSOON AS REVEALED BY HIRS-Tb12 AND DROUGHT AND FLOODS IN EASTERN CHINA

As shown in comparison and study of the HIRS-Tb12 data and conventional data, temperature, humidity and vertical motion are structured differently in the Southern and Northern Hemispheres, which are well depicted with the HIRS-Tb12 data. When high pressures rapidly decrease over the regions of South China Sea and Arabian Sea with the HIRS-Tb12 less than 200 W/m2, monsoons will set off in the South China Sea, Arabian Sea and Bay of Bengal, respectively. From a year of significant drought to one of significant floods, the trend of evolution is significantly different in the downdraft areas of the subtropical highs between the two hemispheres.     

东亚地区春冬季与夏季大气环流异常相互关系的研究

利用1951~2000年共50年的北半球500 hPa月平均高度距平场资料和奇异值分解技术（SVD），重点对东亚地区季节间大气环流异常的相互关系进行了初步探讨。结果表明，东亚地区季节间大气环流异常存在着较为密切的关联，并且这种明显的非同步联系具有时空相关显著的特点，尤其是夏季大气环流异常与其前冬和前春大气环流异常的联系更为密切。当前冬和前春北半球东亚大槽和北美大槽及蒙古高压偏强（或偏弱），极涡偏弱（或偏强），中高纬度盛行经向环流（或纬向环流），以及低纬和热带地区高度正距平（或负距平）明显时，则对应于夏季东亚地区西太平洋副高和鄂霍次克海阻高强度偏强（或偏弱），位置偏南（或偏北），贝加尔湖阻高强度也偏强（或偏弱），但位置偏西（或偏东）的大尺度环流形势出现。当春季北半球大气环流具有上述特点以及夏季鄂霍次克海阻高和西太平洋副高强度偏强（或偏弱），位置偏南（或偏北），且极涡较弱（较强）时，则东亚地区秋季大气环流对应于蒙古高压加强（或较弱），西太平洋副高减弱（或加强），并向南和向东移动（或移动较慢），极涡向南扩散（或扩散减弱），大气环流向冬季过渡加快（或减慢）。另外，大气环流异常还具有一定的持续性特征。     

古炭屑与古森林火?

森林火普遍发生在地质历史时期中，它对自然植被系统的演替起着重要作用。不同强度和频率的森林火培育出不同类型的植被：频繁的森林火导致草甸的形成，而热带雨林形成的原因之一是森林火的缺乏。古炭屑作为古森林火的遗迹，具有分布广泛、细胞结构保存完好以及原地埋藏等特点，为研究古森林火发生的强度和频率提供了宝贵的材料。古炭屑的出现与当时的气候因素、植被类型和地理状况有密切关系：干旱、少雨的气候常常伴随高频率森林火的发生，表现出古炭屑的数量增多；易燃物种组成的植被易发生森林火，古炭屑的出现也会增多，而耐火树种会降低森林火的强度，古炭屑则出现少。因此，从古炭屑的数量和种类的变化，可探讨古森林火的发生规律，进而推断长期地质历史时期的气候、植被、地理状况的演变。     

Implications of the relationship between catchment vegetation type and the variability of annual runoff

The impact of changing catchment vegetation type on mean annual runoff has been known for some time, however, the impact on the variability of annual runoff has been established only recently. Differences in annual actual evapotranspiration between vegetation types and the potential effect of changing vegetation type on mean annual runoff and the variability of annual runoff are briefly reviewed. The magnitude of any change in the variability of annual runoff owing to a change in catchment vegetation type is related to the pre‐ and post‐change vegetation types and the seasonality of precipitation, assuming that the variability of annual precipitation remains constant throughout. Significant implications of the relationship between vegetation type and the variability of annual runoff are presented and discussed for water resource management, stream ecology and fluvial geomorphology. Copyright © 2002 John Wiley & Sons, Ltd.     

青藏高原土壤水热分布特征及冻融过程在季节转换中的作用

利用GAME-Tibet期间所取得的高分辩率土壤温度和含水量资料，对青藏高原（主要是藏北高原）土壤水热分布特征及冻融过程在季节转换中的作用进行了分析。指出藏北高原4cm学深处土壤在10月份开始冻结，次年4-5月份开始消融，冻结持续时间长达5-7个月。冻结过程有利于土壤维持其水分，因此，在刚刚开始消融时土壤含水量仍然很高。从而为夏季风爆发前土壤通过蒸发向大气提供水分打下了基础。指出土壤冻融过程可能在高原季节转换中起着重要作用。     

模拟酸雨对福建四种山地土壤的淋溶与风化作用

在不同pH值 (2 .0、3.5、5 .0、6 .0及蒸馏水 )的模拟酸雨作用下 ,对福建四种类型山地土壤进行了为期 12 0d的淋溶试验。结果表明 ,盐基离子的淋溶量随模拟酸雨pH值的降低而增加 ,尤其当pH≤ 3.5时 ,增加最明显。 4种类型土壤中各离子淋失量大小均为 :Ca2 >Mg2 >K >Na ,这与原土壤中交换性盐基含量一致。在pH≥ 3.5的酸雨作用下 ,土壤中铝的淋失较少 ,而当酸雨pH =2 .0时 ,铝的淋失骤然升高。pH2 .0的模拟酸雨不仅增加了土壤铝离子的释放 ,而且加速了矿物的风化。在pH2 .0的模拟酸雨淋溶下 ,红壤、黄壤、山地草甸土和紫色土中由矿物风化输入的 5种阳离子总量分别为 2 .94、4 .33、4 .35和 6 .0 4 (cmol kg)土 ,显著大于其它酸雨处理。土壤对酸沉降的缓冲作用由阳离子交换、氢氧化铝水解以及原生矿物风化缓冲作用三部分组成 ,其相对重要性不仅决定于土壤酸度、盐基饱和度和矿物组成 ,而且与酸雨的pH值密切相关     

Alpine medicinal plant trade and Himalayan mountain livelihood strategies

Commercial alpine medicinal plants are collected from the wild by local rural households throughout the Himalaya and sold in order to increase household incomes. Recent studies indicate that this annual trade amounts to thousands of tonnes of roots, rhizomes, tubers, leaves, etc., worth millions of US dollars. The main market is in India. Based on a national survey, including the most commonly traded species, and a village study this paper investigates the importance of the alpine medicinal plant trade at national and local levels in Nepal. The national survey included standardized open-ended interviews with 232 harvesters, 64 local traders, 66 central wholesalers, 47 regional wholesalers, and 16 production companies. The village survey is based on the daily records of household activities in 15 households in a one-year period. The annual Nepalese alpine and sub-alpine medicinal plant trade is conservatively estimated to vary from 480 to 2500 t with a total harvester value of US$0.8–3.3 million; the average harvester value is estimated at US$66.0 ± 99.0. The trade in 1997/98 amounted to 1600 t with a harvester value of US$2.3 million and an export value equivalent to 2.5% of total export from Nepal. Medicinal plant harvesting was found to constitute an integrated part of local livelihood strategies, contributing from 3 to 44% (average of 12%) of the annual household income. Importance at household level depended on land and animal holdings, and the availability of adult male labour. The validity and reliability of methods and analyses is evaluated, and issues of conservation and management of alpine medicinal plant species under the community forestry scheme are discussed.     

滇西北亚高山针叶林、硬叶栎类林的树种多样性

在滇西北香格里拉地区,以长苞冷杉(Abiesgeorgei)林、丽江云杉(Picealikiangensis)林作为亚高山针叶林的代表,以川滇高山栎(Quercusaquifolioides)林作为硬叶栎类林的代表,分别选择了6块样地,采用Shannon-Wiener多样性指数(H)、Simpson多样性指数的倒数(D')、Pielou均匀度指数(JH、JD)分别测定其树种多样性,并进行了比较研究。结果表明,三个森林类型的Shannon Wiener指数、Simpson指数的倒数、物种丰富度的顺序均为:长苞冷杉林>川滇高山栎林>丽江云杉林;而前两类森林的Pielou均匀度指数差异不大,但都高于丽江云杉林的均匀度指数值。滇西北的川滇高山栎具有很强的萌生能力。人工种植的亚高山针叶林的树种多样性较原始林低,需要较长时间的恢复过程。亚高山针叶林的存在极大地丰富了云南省的树种多样性,使云南植被的垂直地带性得到了充分体现。     

Microbial production of CO2 in red soil in Stone Forest National Park

Lunan stone forest is a kind of typical karst in China, which is mainly developed under red soil. In the winter of 1999, three study sites were chosen in stone forest national park according to vegetation cover, geomorphologic location and soil types. CO2 concentration was measured with Gastec pump at different depths of soil (20, 40, 60 cm) and at the same time soil samples were gathered and soil properties such as soil moisture, pH, soil organic content were analyzed and the total number of viable microbes were counted in laboratory. In the study, dependent variable was chosen as the mean soil log (PCO2), and soil properties were chosen as the independent variables. Multiple stepwise regression analysis showed that the total amount of microbes and soil moisture are the best indicators of the CO2 production, with the equation LOG(PCO2) = - 0.039(TNM) - 0.056(Mo) + 1.215 accounting for 86% of the variation of the soil CO2 concentration, where TNM is the total number of microbes in the soil and Mo is the moisture of soil sample.