Evaluating weather effects on interannual variation in net ecosystem productivity of a coastal temperate forest landscape: A model intercomparison

Forest productivity is strongly affected by seasonal weather patterns and by natural or anthropogenic disturbances. However weather effects on forest productivity are not currently represented in inventory-based models such as CBM-CFS3 used in national forest C accounting programs. To evaluate different approaches to modelling these effects, a model intercomparison was conducted among CBM-CFS3 and four process models (ecosys, CN-CLASS, Can-IBIS and 3PG) over a 2500 ha landscape in the Oyster River (OR) area of British Columbia, Canada. The process models used local weather data to simulate net primary productivity (NPP), net ecosystem productivity (NEP) and net biome productivity (NBP) from 1920 to 2005. Other inputs used by the process and inventory models were generated from soil, land cover and disturbance records. During a period of intense disturbance from 1928 to 1943, simulated NBP diverged considerably among the models. This divergence was attributed to differences among models in the sizes of detrital and humus C stocks in different soil layers to which a uniform set of soil C transformation coefficients was applied during disturbances. After the disturbance period, divergence in modelled NBP among models was much smaller, and attributed mainly to differences in simulated NPP caused by different approaches to modelling weather effects on productivity. In spite of these differences, age-detrended variation in annual NPP and NEP of closed canopy forest stands was negatively correlated with mean daily maximum air temperature during July-September (T_amax) in all process models (R² = 0.4-0.6), indicating that these correlations were robust. The negative correlation between T_amax and NEP was attributed to different processes in different models, which were tested by comparing CO₂ fluxes from these models with those measured by eddy covariance (EC) under contrasting air temperatures (T_a). The general agreement in sensitivity of annual NPP to T_amax among the process models led to the development of a generalized algorithm for weather effects on NPP of coastal temperate coniferous forests for use in inventory-based models such as CBM-CFS3: NPP′ = NPP − 57.1 (T_amax − 18.6), where NPP and NPP′ are the current and temperature-adjusted annual NPP estimates from the inventory-based model, 18.6 is the long-term mean daily maximum air temperature during July-September, and T_amax is the mean value for the current year. Our analysis indicated that the sensitivity of NPP to T_amax was nonlinear, so that this algorithm should not be extrapolated beyond the conditions of this study. However the process-based methodology to estimate weather effects on NPP and NEP developed in this study is widely applicable to other forest types and may be adopted for other inventory based forest carbon cycle models.     

Daily Activity and Mobility of the Common Shrew (Sorex araneus L.)

Data on the daily activity and mobility of the common shrew (Sorex araneusL.) were obtained by the method of animal marking and recapturing in test plots. Sex- and age-related differences in the locomotor activity of animals were revealed, which depended on population size and the phase of the population cycle. Under natural conditions, animal activity in the daytime proved to decrease to a lesser extent than in captivity. The mobility (locomotor activity) of shrews was shown to depend on population density, reproductive rate, and weather.     

Critical flow-storm approach to total maximum daily load(TMDL) development: an analytical conceptual model

One of the key challenges in the total maximum daily load (TMDL) development process is how to define the critical condition for a receiving waterbody. The main concern in using a continuous simulation approach is the absence of any guarantee that the most critical condition will be captured during the selected representative hydrologic period, given the scarcity of long-term continuous data. The objectives of this paper are to clearly address the critical condition in the TMDL development process and to compare continuous and event-based approaches in defining critical condition during TMDL development for a waterbody impacted by both point and nonpoint source pollution. A practical, event-based critical flow-storm (CFS) approach was developed to explicitly addresses the critical condition as a combination of a low stream flow and a storm event of a selected magnitude, both having certain frequencies of occurrence. This paper illustrated the CFS concept and provided its theoretical basis using a derived analytical conceptual model. The CFS approach clearly defined a critical condition, obtained reasonable results and could be considered as an alternative method in TMDL development.     

付老文泡湿地贴地气层中CO_2日平均浓度沿环境梯度的空间分异特征

以付老文泡湿地为研究区,在典型样带内设置具有不同环境梯度的六个观测区,研究了样带内贴地气层CO2日平均浓度的空间分异特征。结果表明,付老文泡湿地在7月份的贴地气层CO2日平均浓度较低,总平均值为264.14μmol/mol;付老文泡湿地最大CO2日平均浓度出现在近地面层,CO2日平均浓度由近地面层向上呈现下降趋势。在四个高度水平上,CO2日平均浓度的水平分异特征明显,高值区和低值区分别出现在洼地和高地。在水分梯度作用下,洼地区内CO2日平均浓度在四个高度水平上均表现为样地A<样地B<样地C,且在垂直方向上均呈现出由近地层向上呈先减后增再骤然减少的变化趋势;样地D和样地E的CO2日平均浓度在垂直方向上变化趋势一致,由近地层向上呈现逐渐减少的变化趋势;而样地F的CO2日平均浓度的垂直变化不明显。     

基于地面站点观测降水资料的中国区域日降水融合产品精度评价

论文对中国国家气象信息中心研制的逐日融合降水资料（1998—2010年）和全国633个气象站点观测降水资料进行了对比,分析了融合降水资料误差的空间分布和时间变化特征,研究了海拔高度及地形起伏度对融合降水资料精度的影响,同时就日降水融合产品不同降水强度进行了误差分析。结果表明：日降水融合产品与台站资料的年平均降水量空间分布具有很强的一致性;全国大部分地区日降水融合产品与台站资料的累计年降水量相关系数大于0.8,东部地区则普遍在0.9以上;日降水融合产品的误差特征值及其空间分布均较为合理,年际变化不大;海拔高度对日降水融合产品平均偏差和平均相对偏差的影响比地形起伏度大,且海拔高度的影响在高海拔区域比低海拔区域更显著。     

Using experience sampling methodology in organizational behavior

Experience sampling methodology and daily diary (ESM/DD) research elicits repeated reports of immediate or very recent experiences from the same sample of people for several days or weeks. Experience sampling and diary methods were almost unheard of in organizational research 15 years ago, but the past decade has seen a rapid rise in their use. These methods are helpful in studying dynamic within‐person processes involving affect, behavior, interpersonal interactions, work events, and other transient workplace phenomena over time. Assessing cross‐level effects of traits or other stable features on within‐person processes and reactivity is also possible with ESM/DD data. We provide an introduction to issues in designing and carrying out an ESM/DD study, including data collection choices and schedules, measures, technology, training and motivation of participants, and analysis of multilevel data. We offer best practice recommendations and refer readers to further resources for additional detail on conducting and analyzing ESM/DD research. Copyright © 2012 John Wiley & Sons, Ltd.     

林农复合生态系统空气负离子浓度日进程比较

选择河南境内黄淮海平原主体区域的商丘市民权林场与梁园区黄河故道国家森林公园的林农复合生态系统,测定了生态系统1年内各月份的空气离子的日进程,分析其空气负离子的变化规律。结果表明：空气负离子浓度在不同林农复合生态系统中有一定差别,在系统内各点差别较小;杨树生态系统的日进程格局基本一致,表现出近似的＂U＂型,一天中的高峰值出现在09：00～10：00与17：00前后;泡桐生态系统的日进程虽然在09：00～10：00也出现高峰值,但随后表现出单调下降趋势。研究结果为林农复合生态系统生态效益计量提供基础依据。     

ADDRESSING TOTAL PHOSPHORUS IMPAIRMENTS WITH WATER QUALITY TRADING1

ABSTRACT: Water quality trading is a voluntary economic process that provides an opportunity for dischargers to reduce the costs associated with meeting a discharge limitation. Trading can provide a cost effective solution for point sources (i.e., wastewater treatment plants) to meet strict effluent limitations set in response to total maximum daily loads (TMDLs). A successful trading program often depends on first determining the trading suitability of a pollutant for a particular watershed. A simple technical approach has been developed to identify sub‐watersheds within the Raritan River Basin, New Jersey, where water quality trading could provide a cost effective and scientifically feasible method for addressing total phosphorus impairments. The methodology presented will serve as a model to conduct similar analyses in other watersheds. The Raritan River Basin was divided into 12 subwatershed‐based study areas. Point‐nonpoint source trading opportunities were examined for each study area by examining the point and nonpoint source total phosphorus loading to impaired water bodies. Of the 12 subwatersheds examined, four had a high potential for implementing a successful trading program. Since instream phosphorus concentrations are closely related to soil erosion, an additional analysis was performed to examine soil erodibility. Recommendations are presented for conducting an economic analysis following the feasibility study.     

典型汞污染地区食物汞含量及人体汞暴露健康风险

系统采集典型汞污染地区(铅锌冶炼、金矿冶炼和燃煤电厂)食物样品(大米、蔬菜和鱼肉) 409个,测定其总汞含量以评估当地居民食物摄入汞暴露的健康风险。结果显示:铅锌冶炼地区大米总汞含量的几何均值为5.99μg·kg~(-1)(3.02～30.7μg·kg~(-1)),仅有1个样品总汞含量超过我国大米汞限量标准(20μg·kg~(-1)),蔬菜和鱼肉总汞含量分别为0.646～5.44μg·kg~(-1)和1.80～26.4μg·kg~(-1),均未超过我国食品汞限量标准;金矿冶炼地区大米总汞含量的几何均值为4.46μg·kg~(-1)(3.13～8.67μg·kg~(-1)),蔬菜和鱼肉总汞含量分别为0.760～7.83μg·kg~(-1)和1.59～21.9μg·kg~(-1),所有食物均未超过我国食品汞限量标准;燃煤电厂地区大米总汞含量的几何均值为3.63μg·kg~(-1)(1.05～11.4μg·kg~(-1)),蔬菜和鱼肉总汞含量分别为1.12～3.78μg·kg~(-1)和2.24～12.3μg·kg~(-1),所有食物均未超过我国食品汞限量标准。铅锌冶炼、金矿冶炼和燃煤电厂3个地区居民通过食用食物(大米、鱼肉和蔬菜途径)总汞摄入量的均值分别为0.068、0.038和0.031μg·d~(-1)·kg~(-1),均未超出联合国粮农组织和世界卫生组织食品添加剂联合专家委员会(JECFA)推荐的人体安全总汞摄入量0.71μg·d~(-1)·kg~(-1);表明3个研究地区居民汞暴露的风险较低。大米汞摄入量占3个地区居民食物总汞摄入量的比例分别为77.2%、70.8%和71.4%,食用大米是当地居民汞暴露的主要途径。     

沙尘天气PM10对多种心血管疾病日门诊人数的影响

为研究沙尘天气大气可吸入颗粒物(PM10)与心血管系统疾病每日门诊人数的联系,采用半参数广义相加泊松回归模型(GAM),在排除了混杂因素如季节趋势、日历效应、气象因素和时间长期趋势等作用的前提下,分析2004年3月1日~5月31日沙尘暴频发区——甘肃省武威市大气PM10与多种心血管疾病每日门诊相对危险度(RR)的关系.结果表明,PM10与男、女总心血管系统疾病门诊RR均在滞后第2d(lag2)的联系有统计学意义.PM10分别在lag3和lag4对男、女性风湿性心脏病门诊RR的影响有统计学意义; PM10(lag2)与男性高血压门诊RR的联系有统计学意义.PM10在lag2对男性缺血性心血管疾病门诊RR的影响有统计学意义;PM10对男、女性心律失常以及充血性心力衰竭门诊RR的影响均无统计学意义.在调整了SO2和/或NO2后,PM10对男、女性心血管系统疾病门诊RR的作用有所下降,但在统计学上仍有意义.然而在分别调整了其他污染物后,SO2和NO2变得无统计学意义.沙尘天气PM10浓度分类模型分析表明,从正常清洁天、轻度污染天到扬沙天气、沙尘暴天气,随着PM10浓度水平的增大,心血管系统疾病(缺血性心血管疾病、充血性心力衰竭、心律失常、高血压、风湿性心脏病)门诊RR也随之增高,呈现一定的剂量效应关系.沙尘天气可吸入颗粒物可引起暴露居民多种心血管系统疾病(缺血性心血管疾病、充血性心力衰竭、心律失常、高血压、风湿性心脏病)门诊人数增多,且均呈现滞后效应. PM10浓度与心血管系统疾病门诊RR表现为一定的剂量效应关系.PM10浓度与沙尘天气强度有密切关系, 随着PM10浓度与沙尘天气强度的增大,暴露居民心血管系统多种疾病日门诊RR也增大,具体为:正常清洁天＜轻度污染天＜扬沙天＜沙尘暴天.