Biomass and carbon budgeting of sustainable agroforestry systems as ecosystem service in Indian Himalayas

Adoption of agroforestry is paramount as a climate change mitigation and adaptation strategy. The assessment of plant biomass is crucial for understanding the vulnerability of biological systems to climate change. In the present study, agroforestry systems viz., agrisilviculture (AS), agrihorticulture (AH), agrihortisilviculture (AHS) and agrisilvihorticulture (ASH) were investigated for biomass production and carbon stock in vegetation as well as in soil in the Indian central Himalaya along the elevation i.e. E₁ (<1100 m), E₂ (1100–1400 m), E₃ (1400–1700 m), E₄ (1700–2000 m) and E₅ (>2000 m). Mean aboveground and belowground biomass were 73.9% and 26.1%, respectively, of total biomass (64.4 t ha^?1) in agroforestry systems. Fodder and/or timber trees accounted for 31% (in AHS) to 74% (in AS) of total biomass, while fruit trees accounted for 18% (in ASH) to 73% (in AH) of total biomass. The contribution of agriculture crops to total biomass fluctuated between 19% (in ASH) and 26% (in AH). Total vegetation biomass, soil carbon and total carbon density in agroforestry systems increased significantly along the elevation, with maximum biomass at elevation E₅ (32.0 t ha^?1, 64.7 t C ha^?1 and 96.7 t C ha^?1). Total biomass of vegetation among agroforestry systems differed significantly. Soil carbon stock was highest in AHS (59.5 t C ha^?1) and total carbon density (vegetation + soil) was highest in ASH (93.0 t C ha^?1). Thus, in Indian Himalayas, vegetation biomass, carbon stock, soil and total carbon (vegetation + soil) stock increased along the elevation.

Abbrviations: AG: aboveground; BG: belowground; WD: wood density; VOB: volume over bark; BEF: biomass expansion factor; AS: agrisilviculture; AH: agrihorticulture; ASH: agrisilvihorticulture; AHS: agrihortisilviculture; E: elevation; C: carbon; CO₂: carbon-di-oxide; IPCC: Intergovernmental Panel on Climate Change; DBH: diameter at breast height; AGBD: aboveground biomass density; BGBD: belowground biomass density; GSVD: growing stock volume density     

电催化氧化降解大气中甲醛的研究

将有机废气通过高效微孔曝气转移到液相,采用活性碳纤维作为电极,研究不同鼓气速率和不同电压对处理效果的影响.结果表明,本方法适用于低浓度高气量有机废气的处理.在实验范围内,当曝气速率为20L·h-1,外加电压为5V的条件下,处理速率最稳定.     

中国能源消费导致的CO2排放量的差异特征分析

运用一种不产生残差的方法——对数平均迪氏指数法LMDI(logarithmicmeanDivisiaindex),对中国部分省份、区域能源消费导致的二氧化碳排放量进行了分解分析。将二氧化碳排放总量的变化分解成五个主要影响因素,即化石燃料的排放系数、能源消费结构、能源强度、人均GDP和人口总数。研究表明我国各省(地区)的二氧化碳排放量在1996年后呈现零(或负)增长趋势,主要影响因素是能源强度的提高;各省(地区)的二氧化碳排放量地区差异显著。因此,要在全国实现二氧化碳排放量的总体减排,应从提高能源利用效率,调整产业结构,消除地区发展的不平衡,逐步改善能源消费结构等方面考虑。     

森林土地利用变化及其对碳循环的影响

由于人口剧增，人类活动的影响不断加大，在过去100年全球土地利用／土地覆被发生了巨大的变化。最常见的土地利用变化是由森林转变为农业用地。森林砍伐使森林生态系统地上部生物量大大减少，砍伐后作农业用地，降低了植被生产力，减少了土壤有机质的输入，增强了腐殖质的矿化作用，有机质分解速率增加，有机碳贮量随之降低，从而影响到森林生态系统的碳循环，使大量碳元素释放到大气中，引起温室效应，导致全球变暖。另一个常见的土地利用变化是植树造林和森林恢复，这一过程可以增加森林生态系统的碳储量，从而减缓大气CO2体积分数的上升。     

Dichlorvos degradation studied by 31P-NMR

We studied the hydrolysis and TiO₂ photocatalysis of the pesticide dichlorvos at pH 2.6–9 using phosphorus-31 nuclear magnetic resonance (³¹P NMR). We found that the hydrolysis of dichlorvos led to the formation of dimethyl phosphate at pH 5.6–9. On the other hand, TiO₂ photocatalysis decomposed dichlorvos into dimethyl phosphate, which further reacted to form monomethyl phosphate at pH 2.6 and 9. Monomethylphosphate was hydrolysed into phosphate at pH 2.6. ³¹P NMR is therefore a promising tool to study the degradation of organophosphorus pesticides.     

锦州市大气污染现状及控制措施

利用大气污染源和环境质量监测等资料，计算分析了锦州市区大气污染现状。结果表明：在锦州市区空气污染以煤烟类为主，汽车尾气成为大气污染源之一。PM10和SO2超过二级标准的天数将近95％出现在采暖期。提出了可行的具体措施，指出采用以集中供热、推广使用天然气、小型锅炉改造工程和控制汽车尾气为主要措施，廉顾绿化，制定市区大气污染治理方案比较合理。     

臭氧—活性炭组合工艺对饮用水中AOC的去除

研究了以O3/GAC为主的饮用水深度处理工艺对AOC去除效果 ,结果表明 :原水 (某江水 )AOC浓度为 6 1 9μg乙酸碳 /L ;生物陶粒滤池对AOC的去除率为 54% ;O3 +GAC对AOC的去除率为 83.8% ;加氯消毒后AOC浓度增加 1 .38倍 ;常规水处理工艺对AOC的去除率为 4 3.7% ,不能保证饮用水的生物稳定性     

复合螯合剂/活性碳分离富集和ICP—AES同时测定水样中痕量元素

本文提出将复合螯合剂（NaDDTC／8—Oxin）饱和吸附于活性碳上作为吸附材料．分离富集和ICP—AES同时测定水中痕量金属元素的方法。用ICP—AES研究了该吸附材料对某些痕量元素的吸附和解吸性能；考察了共存元素的影响。方法应用于湖水中Fe、Cu、Mn、Y和Sc的测定，检出限为ng／ml级，RSD为1．9％～4．4％，加入回收率81％～101％间，试样分析结果满意。     

活性炭水处理技术应用

本文综述了活性炭水处理的特点，主要影响因素，活性炭的再生及活性炭吸附法在水处理中的应用，从而论证了活性炭吸附法应用于水处理的可行性和有效性。     

Accounting for time in Mitigating Global Warming through land-use change and forestry

Many proposed activities formitigating global warming in the land-use change and forestry(LUCF) sector differ from measures to avoid fossilfuel emissions because carbon (C) may be held out ofthe atmosphere only temporarily. In addition, thetiming of the effects is usually different. Many LUCFactivities alter C fluxes to and from the atmosphereseveral decades into the future, whereas fossil fuelemissions avoidance has immediate effects. Non-CO₂ greenhouse gases (GHGs), which are animportant part of emissions from deforestation inlow-latitude regions, also pose complications forcomparisons between fossil fuel and LUCF, since themechanism generally used to compare these gases(global warming potentials) assumes simultaneousemissions. A common numeraire is needed to expressglobal warming mitigation benefits of different kindsof projects, such as fossil fuel emissions reduction,C sequestration in forest plantations, avoideddeforestation by creating protected areas and throughpolicy changes to slow rates of land-use changes suchas clearing. Megagram (Mg)-year (also known as`ton-year') accounting provides a mechanism forexpressing the benefits of activities such as these ona consistent basis. One can calculate the atmosphericload of each GHG that will be present in each year,expressed as C in the form of CO₂ and itsinstantaneous impact equivalent contributed by othergases. The atmospheric load of CO₂-equivalent Cpresent over a time horizon is a possible indicator ofthe climatic impact of the emission that placed thisload in the atmosphere. Conversely, this index alsoprovides a measure of the benefit of notproducing the emission. One accounting methodcompares sequestered CO₂ in trees with theCO₂ that would be in the atmosphere had thesequestration project not been undertaken, whileanother method (used in this paper) compares theatmospheric load of C (or equivalent in non-CO₂GHGs) in both project and no-project scenarios.Time preference, expressed by means of a discount rateon C, can be applied to Mg-year equivalencecalculations to allow societal decisions regarding thevalue of time to be integrated into the system forcalculating global warming impacts and benefits. Giving a high value to time, either by raising thediscount rate or by shortening the time horizon,increases the value attributed to temporarysequestration (such as many forest plantationprojects). A high value for time also favorsmitigation measures that have rapid effects (such asslowing deforestation rates) as compared to measuresthat only affect emissions years in the future (suchas creating protected areas in countries with largeareas of remaining forest). Decisions on temporalissues will guide mitigation efforts towards optionsthat may or may not be desirable on the basis ofsocial and environmental effects in spheres other thanglobal warming. How sustainable development criteriaare incorporated into the approval and creditingsystems for activities under the Kyoto Protocol willdetermine the overall environmental and social impactsof pending decisions on temporal issues.