北方典型设施菜地土壤CO2排放特征

为研究我国北方典型设施菜地的土壤CO₂排放特征及其影响因素,通过原位监测手段,研究山东省寿光市农田转变为不同种植年限（6、12 a）设施菜地及设施菜地荒废12 a后土壤CO₂排放规律及影响因素.结果表明:①种植6 a设施菜地较农田具有较高的土壤CO₂排放量,可能是由于设施菜地种植过程中大量施加有机肥造成的,并且设施菜地土壤温度及含水率较高,增加了土壤蔗糖酶活性,加剧土壤CO₂排放.②当种植年限超过10 a,设施菜地施肥量减少,降低了土壤微生物可利用底物的供应.因此,种植12 a设施菜地土壤CO₂排放量降至农田水平.③种植6 a设施菜地土壤的w（DOC）（DOC表示水溶性有机碳）比农田较高.④土壤CO₂排放年内分配不均匀,表现为农田及荒废设施菜地土壤CO₂排放主要集中在5—8月,其排放量占全年的75.09%、87.02%,峰值出现在7月.种植6 a设施菜地土壤CO₂排放主要集中在5—8月和11月—翌年2月,两阶段排放量分别占全年的48.48%、42.34%,峰值分别出现在7月、12月.研究显示,农田转变为设施菜地短期（种植6 a）内可显著促进土壤CO₂排放及DOC的输出,但随着种植年限延长至12 a,土壤CO₂排放降至农田水平.      

单次降水对高寒草地温室气体通量昼夜变化的影响研究

在全球变化背景下,青藏高原降水格局发生改变,并影响高寒草地温室气体排放.为了更好地认识降水变化与高寒草地温室气体排放的关系,在2015年7月24日,通过人工降水6.7 mm,研究了单次降水对高寒草地温室气体昼夜变化的影响.表明:(1)单次降水没有改变土壤温度,但显著增加了土壤湿度;(2)单次降水后24小时内,高寒草地CH4吸收量降低了2.46倍,CO2和N2 O排放量分别提高15.3%和98.9%;(3)单次降水弱化了高寒草地CH4和N2 O排放量与土壤温度的关系.     

中国城市温室气体排放清单编制和方法概述

介绍中国国家层面的温室气体排放清单编制现状,概述了中国城市层面温室气体排放清单研究进展,总结国际通用的城市清单方法(Urban Inventory Methods),包括以排放为中心的IPCC和WRI/WBCSD温室气体排放模型、以需求为中心的混合生命周期方法和中国现状城市温室气体排放清单编制方法,阐述在目前的城市温室...     

对城市污水厂污泥中矿物油和动植物油测定方法的改进

研究了用超声波萃取城市污水处理厂污泥中动植物油和矿物油的方法,并与索氏提取法进行比较.结果表明,超声波萃取法对污泥中矿物油和动植物油测定操作简单快速,标样回收率高,精密度好.     

Fluxes of CH4 and N2O from soil under a tropical seasonal rain forest in Xishuangbanna, Southwest China

CH4 and N2O fluxes from soil under a tropical seasonal rain forest in Xishuangbanna, Southwest China were measured for one year using closed static chamber technique and gas chromatography method. Three treatments were set in the studied field: (A) litter-free,(B) with litter, and (C) with litter and seedling. The results showed that the soil in our study was a sink of atmospheric CH4 and source of atmospheric N2O. The observed mean CH4 fluxes from treatments A, B, and C were -50.0±4.0, -35.9±2.8,-31.6±2.8 μgC/(m2·h),respectively,and calculated annual fluxes in2003 were -4.1,-3.1,and -2.9kgC/hm2,respectively.The observed mean N2O fluxes from treatments A,B,and C were 30.9±3.1,28.2±3.5,50.2±3.7μgN/(m2·h),respectively,and calculated annual fluxes in 2003 were 2.8, 2.6, and 3.7 kgN/hm2, respectively. Seasonal variations in CH4 and N2O fluxes were significant among all the three treatments. The presence of litter decreased CH4 uptake during wet season (P ＜ 0.05), but not during dry season. There was a similar increase in seedlings-mediated N2O emissions during wet and dry seasons, indicating that seedlings increased N2O emission in both seasons. A strong positive relationship existed between CH4 fluxes and soil moisture for all the three treatments, and weak relationship between CH4 fluxes and soil temperature for treatment B and treatment C. The N2O fluxes correlated with soil temperature for all the three treatments.     

Modeling effects of temperature and precipitation on carbon characteristics and GHGs emissions in Abies fabric forest of subalpine

Abies fabric forest in the eastern slope of Gongga mountain is one type of subalpine dark coniferous forests of southwestern China. It is located on the southeastern edge of the Qinghai-Tibet plateau and is sensitive to climatic changes. A process-oriented biogeochemical model, Forest-DNDC, was applied to simulate the e ects of climatic factors, temperature and precipitation changes on carbon characteristics, and greenhouse gases (GHGs) emissions in A. fabric forest. Validation indicated that the Forest-DNDC could be used to predict carbon characteristics and GHGs emissions with reasonable accuracy. The model simulated carbon fluxes, soil carbon dynamics, soil CO2, N2O, and NO emissions with the changes of temperature and precipitation conditions. The results showed that with variation in the baseline temperature from –2℃ to +2℃, the gross primary production (GPP) and soil organic carbon (SOC) increased, and the net primary production (NPP) and net ecosystem production (NEP) decreased because of higher respiration rate. With increasing baseline precipitation the GPP and NPP increased slightly, and the NEP and SOC showed decreasing trend. Soil CO2 emissions increased with the increase of temperature, and CO2 emissions changed little with increased baseline precipitation. With increased temperature and decreased baseline temperature, the total annual soil N2O emissions increased.With the variation of baseline temperature from –2℃ to +2℃, the total annual soil NO emissions increased. The total annual N2O and NO emissions showed increasing trends with the increase of precipitation. The biogeochemical simulation of the typical forest indicated that temperature changes strongly a ected carbon fluxes, soil carbon dynamics, and soil GHGs emissions. The precipitation was not a principal factor a ecting carbon fluxes, soil carbon dynamics, and soil CO2 emissions, but changes in precipitation could exert strong e ect on soil N2O and NO emissions.     

Effects of vegetable oil residue after soil extraction on physical-chemical properties of sandy soil and plant growth

Vegetable oil has the ability to extract polycyclic aromatic hydrocarbons(PAHs)from contaminated sandy soil for a remediation purpose,with some of the oil remaining in the soil.Although most of the PAHs were removed,the risk of residue oil in the soil was not known.The objective of this study was to evaluate the effects of the vegetable oil residue on higher plant growth and sandy soil properties after soil extraction for a better understanding of the soil remediation.Addition of sunflower oil and column ex...     

测定水中动植物油含量的不确定度简化评定

对红外分光光度法测定水中动植物油的不确定度来源进行了分析,构造出合理的数学模型,确定了各输入量之间的关系,量化各分量后,合成得到满意的结果。从而提出,根据被测量及其所依赖的输入量之间的关系构造数学模型,并运用不同的评定方法对各个分量进行量化,可实现对某些检测项目不确定度的简化评定。     

松藻矿区煤层气利用对温室气体减排的贡献

温室效应和全球变暖已经引起了世界各国的普遍关注,减少二氧化碳等温室气体的排放已成为大势所趋。开发和利用煤层气不仅可避免资源的浪费,还可减少温室气体排放、改善大气环境。本文结合重庆市松藻矿区蝶层气开发利用情况,分析评价了松藻矿区煤层气利用对温室气体减排的贡献。结果表明,煤层气利用具有显著的环境效益和经济效益。     

煤田火区温室气体通量测量方法研究进展

为提高煤田火区温室气体通量测量的准确性,科学制定温室气区减排措施,笔者对国内外煤田火区温室气体测量方法进行梳理,对比分析各种测量方法的原理、优缺点和适用范围等,提出测量方法存在的问题及以后的研究方向。研究表明:目前所用的测量方法存在测量精度低、连续性差、假设理想化等缺陷,检测设备的改进应朝着能适应当地地表高温环境并能实现连续监测的方向发展,测量方法应更注重和新技术的结合。