ANALYSIS OF BIOLOGICAL GEOCHEMISTRY OFCHEMICAL ELEMENTS IN Betula ermanii FORESTIN CHANGBAI MOUNTAINS,CHINA

匠he 乙hangbal Mountains Nature Reserve Is a al，1982ZHUANGetal，1989；HUANGetal，1982；state－grade nature rese。e，also Is a component part of LIU，1993；LIU，1988； ZHU et al，1991）．Most ofreserve net of International blosphere．its area Is large，their research works focus on the chemical structure andthe natural environment and ecosystem lsprotected material cycling In alpine tundra zone andcompletely．the natural elements and ecological envl－broadleatKorean pine fores…     

Transit time evaluation using a chloride concentration input step shift after forest cutting in a Japanese headwater catchment

Mean transit times were estimated for a small headwater catchment in Japan (the Fukuroyamasawa Experimental Watershed) using the step shift in input chloride (Cl^?) concentrations that occurred immediately after an episode of forest clear‐cutting. Measured Cl^? concentrations in stream water began to decrease immediately after clear‐cutting, and this trend continued for 6 years. Before clear‐cutting, the input Cl^? concentrations were controlled by wet and dry deposition processes, and most of the dry Cl^? deposition was collected by the forest canopy and reached the ground as throughfall and stemflow. After clear‐cutting, dry deposition was no longer collected by the canopy in this way, thus causing a sharp decrease in input Cl^? concentrations. By comparing measured Cl^? concentrations in stream water with estimates based on the input and evaporative Cl^? concentrations, it was shown that the decrease in stream water Cl^? concentrations was caused mainly by this step shift in the Cl^? input. It was proposed that the change in Cl^? concentrations after forest cutting could be used to represent the replacement of ‘old’ water that existed before cutting by ‘new’ water that was supplied after cutting. The breakthrough curve for the new water fraction gave an approximately exponential distribution of transit times in flow‐corrected time. The mean flow‐corrected transit time was estimated as 1068 days (runoff: 3497 mm). It was therefore concluded that the step change in input Cl^? concentrations immediately following forest clear‐cutting could be successfully used to estimate transit times for the entire catchment. Copyright © 2009 John Wiley & Sons, Ltd.     

RS AND GIS-BASED FOREST FIRE RISK ZONE MAPPING IN DA HINGGAN MOUNTAINS

1INTRODUCTIONForests are one of the major natural resources that per-form important environmental and recreational func-tions (COSTANZA and GROOT, 1997). It is well known that forests can absorb atmospheric carbon, maintain a certain degree of humidity in atmosphere, regulate rainfall, moderate temperature, and restrain soil erosion, etc. (AURELIA, 2003). So, the health of a forest in any given area is a very important indicator of the ecological conditions. But fire is the great…     

Streamflow response to Pinus plantation harvesting: Canobolas State forest,southeastern Australia

Streamflows were measured in two Pinus radiata plantation catchments and one native eucalypt forest catchment in Canobolas State forest from 1999 to 2007. In 2002/2003, clearfall harvesting of 43·2 and 40·3% of two plantation catchments occurred, respectively. Water yields increased by 54 mm (52%), 71 mm (35%) and 50 mm (19%) in the first three years post‐harvest in treated catchment A and by 103 mm (118%), 157 mm (82%) and 119 mm (48%) in treated catchment B relative to the native forest control catchment. In the fourth post‐harvest water year annual rainfall was only 488 mm, which resulted in negligible run‐off in all catchments, regardless of forest cover. In both plantation catchments, monthly streamflows increased significantly (p = 0·01, p < 0·001) due to a significant increase in baseflows (p < 0·001) after harvesting. Monthly stormflows were not significantly affected by harvesting. Flow duration curve analyses indicated a variable response between the two plantation catchments. Treated catchment A was converted from an ephemeral stream flowing 42% of the time pre‐harvest to a temporary stream flowing 82% of the time post‐harvest. These changes occurred throughout all seasons of the year but were most pronounced during summer and autumn when baseflows were maintained post‐harvest but were not observed under native forest or mature pine plantations. By contrast, flow duration increased in treated catchment B from 12% of the time pre‐harvest to 38% of the time post‐harvest with the greatest changes measured during the winter and spring months when streamflow would normally occur under native forest conditions. These observations have important implications for the development of models of plantation water use to be utilized in water resource planning in Australia. Copyright © 2009 John Wiley & Sons, Ltd.     

Soil partitioning and surface store controls on spring runoff from a boreal forest peatland basin in north‐central Manitoba,Canada

The mid‐ to high‐boreal forest in Canada occupies the discontinuous permafrost zone, and is often underlain by glaciolacustrine sediments mantled by a highly porous organic mat. The result is a poorly drained landscape dominated by wetlands. Frost‐table dynamics and surface storage conditions help to control runoff contributions from various landscape elements, hydrological linkages between these elements, and basin streamflow during spring snowmelt. Runoff components and pathways in a forested peatland basin were assessed during two spring snowmelts with contrasting input and basin conditions. Runoff from relatively intense melt (up to 16 mm day^?1) on slopes with limited soil thawing combined with large pre‐melt storage in surface depressions to produce high flows composed primarily of meltwater (78% of the 0·29 m³ s^?1 peak discharge) routed over wetland surfaces and through permeable upper peat layers. Melt intensity was less in the subsequent year (maximum of 10 mm day^?1) and active layer development was relatively greater (0·2 m deeper at the end of spring melt), resulting in less slope runoff. Coupling of reduced slope contributions with lower storage levels in basin wetlands led to relatively subdued streamflows dominated by older water (73% of the 0·09 m³ s^?1 peak discharge) routed through less‐permeable deeper peat layers and mineral soil. Interannual differences in runoff conditions provide important insight for the development of distributed hydrological models for boreal forest basins and into potential influences on biogeochemical cycling in this landscape under a warming climate. Copyright © 2001 John Wiley & Sons, Ltd.     

Energy budget above a temperate mixed forest in northeastern China

Components of the energy budget were measured continuously above a 300‐year‐old temperate mixed forest at the Changbaishan site, northeastern China, from 1 January to 31 December 2003, as a part of the ChinaFlux programme. The albedo values above the canopy were lower than most temperate forests, and the values for snow‐covered canopy were over 50% higher than for the snow‐free canopy. In winter, net radiation R_n was generally less than 5% of the summer value due to high albedo and low incoming solar radiation. The annual mean latent heat LE was 37·5 W m^?2, accounting for 52% of R_n. The maximum daily evaporation was about 4·6 mm day^?1 in summer. Over the year, the accumulated precipitation was 578 mm; this compares with 493 mm of evapotranspiration, which shows that more than 85% of water was returned to the atmosphere through evapotranspiration. The LE was strongly affected by the transpiration activity and increased quickly as the broadleaved trees began to foliate. The sensible heat H dropped at that time, although R_n increased. Consequently, the seasonal variation in the Bowen ratio β was clearly U‐shaped, and the minimum value (0·1) occurred on a sunny day just after rain, when most of the available energy was used for evapotranspiration. Negative β values occurred occasionally in the non‐growing season as a result of intensive radiative cooling and the presence of water on the surface. The β was very high (up to 13·0) in snow‐covered winter, when evapotranspiration was small due to low surface temperature and available soil water. Vegetation phenology and soil moisture were the key variables controlling the available energy partitioning between H and LE. Energy budget closure averaged better than 86% on a half‐hourly basis, with slightly greater closure on a daily basis. The degree of closure showed a dependence on friction velocity u*. Copyright © 2006 John Wiley & Sons, Ltd.     

额济纳旗胡杨林旅游气象条件分析

针对胡杨林观赏旅游对气象条件依赖性强的特点,利用额济纳旗1981—2010年气象观测资料,初步分析额济纳旗胡杨林旅游最佳时间和各气象要素对本地区旅游出行的影响,为合理安排旅游时间提供理论依据。研究表明:①额济纳旗胡杨林景区的旅游期一般在9月下旬至10月下旬之间,旅游黄金时间为10月5日至10月17日(近30a平均时间);②额济纳旗胡杨林旅游时节降水、风速对旅游出行影响不大,但游客应要做好白天的防晒、降温、保湿的同时要做好夜晚户外活动的保暖等相应的准备。     

The integrated socio-perceptual approach: Using ecological mental maps and future imaginaries to understand land use decisions

Rural places are important centers of environmental and social transformation. Landholders are not only affected by socio-environmental changes, but they are influencing futures related to climate change, food security, freshwater, biodiversity, and social and economic development. Much environmental land use work understands individual landholders as rational actors, portrayed through the economic lens of “producer.” These approaches generally focus on present capacities and limitations as the principal factors contributing to land use, and the individual farm as the reference unit for decisions. Our research takes steps to expand conceptualizations of rural landholders as active and knowledgeable in envisioning, managing, and shaping environmental futures. We design and test a new approach using ecological mental maps and future imaginaries to understand land use practices through a case study in the cocoa-producing and Atlantic Forest region of Southern Bahia, Brazil. The integrated socio-perceptual (ISP) approach combines qualitative and quantitative methodologies to honor the depth of landholders’ experiences and perspectives and to allow broader regional relationships and insights to emerge. We demonstrate that the ISP approach—through 49 surveys—has the capacity to capture variation and identify patterns in ecological mental maps and future imaginaries in a population, approximate the relevant spatial scales underlying these factors, and identify relationships between these and land uses. In this context, the types of narratives landholders hold about the region’s future are associated with current forest land use on their properties. We discuss potential applications of the ISP approach for land use study and practice.     

长白山针阔叶混交林花粉通量及垂直散布特征年际变化研究

长白山针阔叶混交林2008年和2009年不同高度花粉通量和花粉垂直散布特征研究表明;花粉组合以乔木植物花粉为主,百分比多大于83%,对植被指示性良好;2009年乔木植物花粉通量较2008年低,可能与2009年乔木植物花期气温低,降水量较多,花粉产量低,风速较小.不利于花粉传播和散布等因素有关;两年花粉通量垂直高度上的变...     

基于GPS的兴隆庄煤矿的近井网建设与十字中线恢复

兴隆庄煤矿近井网和井筒十字中线破坏严重,为了保障煤矿正常的生产需求,利用GPS技术建立了D级GPS近井网,利用三等水准测量确定了近井网各GPS点的正常高程,并利用高精度全站仪恢复了井筒十字中线,进行了垂直度检测,埋设了基桩点。