滇西临沧褐煤放射性水平及区域污染分析

通过对临沧及云南省褐煤中放射性核素238U2、32Th2、26Ra比活度调查,类比各煤种放射性水平,得出临沧褐煤为铀煤伴生矿。通过临沧铀锗煤中放射性核素在利用过程中的转移估量和临沧城区放射环境现状调查,分析铀锗煤矿利用形成的小区域辐射污染及对放射环境的影响,得出煤中放射性核素的二次污染导致了区域放射环境水平的提高。     

天山东部雪冰中硝酸根浓度对中亚生物质燃烧的响应研究

研究了天山东部雪冰中NO3-浓度对中亚哈萨克斯坦生物质燃烧的响应情况.在天山乌鲁木齐河源1号冰川持续采集了52组表层雪与雪坑样本,分析了雪样中NO3-等成分的浓度,运用HYSPLIT模型模拟了空气轨迹,目的是考察雪冰中NO3-与2002年哈萨克斯坦草原大火的关系,探讨由生物质燃烧产生的NO3-在高海拔山岳冰川雪层中的沉...     

Importance of conserving large and old trees to continuity of tree-related microhabitats

Protecting structural features, such as tree-related microhabitats (TreMs), is a cost-effective tool crucial for biodiversity conservation applicable to large forested landscapes. Although the development of TreMs is influenced by tree diameter, species, and vitality, the relationships between tree age and TreM profile remain poorly understood. Using a tree-ring-based approach and a large data set of 8038 trees, we modeled the effects of tree age, diameter, and site characteristics on TreM richness and occurrence across some of the most intact primary temperate forests in Europe, including mixed beech and spruce forests. We observed an overall increase in TreM richness on old and large trees in both forest types. The occurrence of specific TreM groups was variably related to tree age and diameter, but some TreM groups (e.g., epiphytes) had a stronger positive relationship with tree species and elevation. Although many TreM groups were positively associated with tree age and diameter, only two TreM groups in spruce stands reacted exclusively to tree age (insect galleries and exposed sapwood) without responding to diameter. Thus, the retention of trees for conservation purposes based on tree diameter appears to be a generally feasible approach with a rather low risk of underrepresentation of TreMs. Because greater tree age and diameter positively affected TreM development, placing a greater emphasis on conserving large trees and allowing them to reach older ages, for example, through the establishment of conservation reserves, would better maintain the continuity of TreM resource and associated biodiversity. However, this approach may be difficult due to the widespread intensification of forest management and global climate change.     

Geospatial Analysis of Climatic and Geomorphic Interactions Influencing Stream Discharge, Appalachian Mountains, USA

Streamflow values are commonly synthesized for locations where flow measurement stations are lacking or where only intermittent measurements are available. In an Appalachian Mountains dataset comprised of 29 watersheds, the most appropriate among geomorphic, geologic, and hydrogeologic datasets were selected for use in prediction of streamflow at watershed scale. A statistical model was developed using principal components analysis (PCA) and cluster analysis (CA) for. Using CA on variables derived from the PCA, an optimum set of variables was derived for predicting streamflow. Results indicate there are two categories of watersheds in the study area. The first is strongly correlated with climatic variables (precipitation, temperature, elevation, and groundwater recharge). The second is strongly correlated with two geomorphic variables (watershed slope and percentage of forested area). The spatial distribution of cluster classifications shows that watersheds dominated by the climatic component are located along the Allegheny Front while watersheds dominated by the geomorphic component are located in the Allegheny Plateau and Valley and Ridge physiographic provinces. These variations between the Allegheny Plateau and Valley and Ridge physiographic provinces suggest that, to accurately model streamflow, modeling needs be done based on natural physiographic boundaries rather than political boundaries. In this physiographic setting, elevation seems to be a major control.     

瘦西湖风光电能驱动的曝气生物接触氧化水净化系统结构与功能

在瘦西湖选择中试河段,利用太阳能风能绿色能源,研发了风光电能驱动的曝气生物接触氧化水净化系统。系统由风光互补发电子系统、曝气生物接触氧化子系统、植物生态子系统组成。风光电能驱动的曝气生物接触氧化水净化系统运行正常。按照景观娱乐用水水质标准进行水质监测,采用模糊综合评价与贴近度计算方法,进行了系统水净化功能评价。结果表明,在试验段原水水质低于景观水C类,经该系统水净化后,可以达到景观水B类。系统的开发与实验,探索了利用绿色能源河湖水净化的新途径。     

过渡带中岳桦种群生态特征的研究

在长白山北坡halt1525m-1775m的岳桦云冷杉森林过渡带和1990m-2170m的岳桦苔原林线过渡带中,沿海拔高度,采用梯度取样方法,进行岳桦种群生态学研究,分析了岳桦种群存活曲线、种群分布格局和种群竞争指数。同时应用分形分析研究了岳桦种群的分形特征。结果表明：依据岳桦种群的存活曲线,在岳桦云冷杉过渡带中岳桦种群处于由衰退型向稳定型发展的阶段,而在岳桦苔原过渡带中则由稳定型向增长型过渡,从种群分布格局指数分析,岳桦在两个过渡带中的分布格局类型都是杂乱无章的,而且都偏离随机分布,处于由一个生态系统向另一个生态系统转换的相变区,从竞争指数和盒维数来看,在岳桦云冷杉过渡带中,这两项指标都是由小到大迅速递增,而在岳桦苔原过渡 情况刚好相反。     

A GIS tool to estimate West Nile virus risk based on a degree-day model

West Nile virus (Flaviviridae: Flavivirus) is a serious infectious disease that recently spread across the North America continent. A spatial analysis tool was developed on the ArcMap 9.x platform to estimate potential West Nile virus activity using a spatially explicit degree-day model. The model identifies when the virus Extrinsic Incubation Period (EIP) is completed within the vector longevity during mid-summer months. The EIP is treated as a threshold indicator of the potential for virus emergence and activity. Comparing the number of West Nile virus cases in Wyoming reported from 2003 to 2005 with model results, actual cases and predicted events of West Nile virus activity match relatively well. The model represents a useful method for estimating potential West Nile virus activity in a large spatial scale.     

Assessing environmental factors in red spruce (Picea rubens Sarg.) growth in the Great Smoky Mountains National Park, USA: From conceptual model, envirogram, to simulation model

This study provides a method for assessing a multiplicity of environmental factors in red spruce growth in the Great Smoky Mountains National Park (GSMNP) of Southeastern USA. Direct and indirect factors in the annual growth increment are first organized into a schematic input-output envirogram (ARIRS), and this information is then used to construct a simulation model (ARIM). The envirogram represents a structured conceptualization of most environmental factors involved in growth, as developed from relevant literature. This interdisciplinary synthesis distinguishes direct vs. indirect factors in growth and takes account of the systems ecology concept that indirect factors may be as important as or more important than direct ones in regulating growth. The ARIRS envirogram summarizes hierarchically organized, within- and cross-scale, local-to-global interactions, and its construction makes it obvious that growth is influenced by many cross-scale spatiotemporal interactions. More research on genecology is still needed to clarify the role of phenotypic plasticity and adaptive capacity in nutrient cycling, global change, and human disturbance.     

1960—2019年秦岭气候带界限的变化研究

受全球变化的影响,温度带边界在空间上的变化呈现出向高纬度方向显著移动的趋势,其中亚热带区空间分布对全球变暖的响应较为敏感,对其边界空间变化特征的研究对于认识全球变化对自然景观的潜在影响具有重要科学意义。基于秦岭及其周边74个气象站点1960—2019年日均气温数据,选取保证率80%的日均温≥10 ℃持续日220天等值线和1月0 ℃等温线为北亚热带北界指标,探讨了近60年气候变暖背景下秦岭气候带界限的变化趋势。研究表明：（1）1960—2019年秦岭日均温≥10 ℃持续日呈显著上升趋势,其变化率为3.268 d/10 a;秦岭1月平均气温呈弱显著上升趋势,其变化率为0.179 ℃/10 a。（2）60年来秦岭北亚热带北界发生了明显的抬升,平均抬升高度约为228.89 m;从经度上看,中段106°~111°E范围内北亚热带北界的变化最为强烈,60年来上升高度达308.81 m,明显高于东西北三段（东段上升165.69 m,西段上升243.33 m,北段上升267.01 m）。（3）60年来秦岭北亚热带过渡带出现了明显的攀升,且向北移动;秦岭以北“跨越式”地出现北亚热带气候格局。气温突变后,秦岭北亚热带过渡带形成从秦岭南坡延伸到秦岭东部,并向北推进向西进入关中平原的格局,秦岭南坡作为北亚热带和暖温带的分界作用有所减弱。随着气候的变暖,秦岭北亚热带过渡带可能部分或整体转变为北亚热带,北亚热带将从秦岭南坡到秦岭北坡呈连续带状分布,北亚热带北界可能会跨越秦岭山脉。     

秦巴山区生态系统服务与居民福祉耦合关系的时空变化

保护生态系统、提高居民福祉是实现联合国2030可持续发展目标的核心内容。在分析秦巴山区生态系统服务与居民福祉时空演化特征的基础上,采用弹性系数揭示了二者的时空耦合关系。研究发现：（1）1990—2018年秦巴山区水源涵养总量、土壤保持总量均呈波动下降趋势,碳储量总量则呈缓慢增长趋势,且各生态系统服务呈不同的空间分异特征。（2）1990—2018年居民福祉呈上升趋势,增幅高达220%,并呈“南高北低”的分布格局。（3）县域尺度上,三种生态系统服务与居民福祉明显不协调发展。其中,水源涵养、固碳服务与居民福祉的耦合关系均以“福祉增—服务减”为主,占比分别为88.75%、62.5%;而土壤保持服务与居民福祉的耦合关系则以“双增”为主,占比为57.5%。此外,各项生态系统服务与居民福祉反向变化区多分布于汉江河谷盆地和秦岭山脉中段。研究结果可为促进贫困山区生态系统服务与居民福祉协调发展提供决策依据。