浙江天童主要树种含碳率分析

[目的]为准确估算区域森林碳储量,研究分析浙江天童主要树种含碳率.[方法]应用干烧法对天童地区主要针叶、阔叶乔灌木树种和毛竹不同器官的含碳率进行测定.[结果]不同树种器官含碳率范围在36％ ～51％,针叶树种器官平均含碳率最高,均在48％以上,常绿灌木或小乔木的器官含碳率相对较低,50个乔灌木树种器官平均含碳率的大小顺序为干、枝、叶、根.[结论]结合实测的标准木器官生物量数据,各树种含碳率加权平均值为47％,适用于天童乃至宁波地区森林碳储量估算.     

土地复垦视角的低排放控制研究

随着经济社会的高速发展,生态环境逐步恶化,土地资源正面临严峻挑战,为实现土地资源持续利用和土地生态的健康发展,新一轮土地整治工作正全面展开.在此背景下,该研究结合国家新颁布的《土地复垦条例》以及多年来土地复垦工作所取得的成效和存在的问题,重点研究当前土地复垦中低排放控制的关键技术与方法.结果表明:土地复垦作为土地资源可持续发展的必要保障措施,目前缺乏相关低排放控制研究;现行土地复垦模式在当前社会经济发展的新形势、新要求下,其传统的复垦模式具有一定的局限性、缺乏新理念;通过文献综述法,结合土地复垦的内容与特征,总结归纳了边坡治理低排放、自然灾害损毁土地低排放、矿区固体废弃物和水污染低排放、土壤与和植被固碳减排等关键技术;低碳排放与土地复垦息息相关,做好土地复垦与低碳排放工作,对我国碳排放控制目标具有积极贡献.     

Biochemistry of hexose and pentose transformations in soil analyzed by position-specific labeling and 13C-PLFA

Microbial transformations are key processes of soil organic matter (SOM) formation, stabilization and decomposition. Combination of position-specific ¹³C labeling with compound-specific ¹³C-PLFA analysis is a novel tool to trace metabolic pathways. This combination was used to analyze short-term transformations (3 and 10 days after tracer application) of two key monosaccharides: glucose and ribose in soil under field conditions. Transformations of sugars were quantified by the incorporation of ¹³C from individual molecule positions in bulk soil, microbial biomass (by CFE) and in cell membranes of microbial groups classified by ¹³C-PLFA.The ¹³C incorporation in the Gram negative bacteria was higher by one order of magnitude compared to all other microbial groups. All of the ¹³C recovered in soil on day 3 was allocated in microbial biomass. On day 10 however, a part of the ¹³C was recovered in non-extractable microbial cell components or microbial excretions. As sugars are not absorbed by mineral particles due to a lack of charged functional groups, their quick mineralization from soil solution is generally expected. However, microorganisms transformed sugars to metabolites with a slower turnover. The ¹³C incorporation from the individual glucose positions into soil and microbial biomass showed that the two main glucose utilizing pathways in organisms – glycolysis and the pentose phosphate pathway – exist in soils in parallel. However, the pattern of ¹³C incorporation from individual glucose positions into PLFAs showed intensive recycling of the added ¹³C via gluconeogenesis and a mixing of both glucose utilizing pathways. The pattern of position-specific incorporation of ribose C also shows initial utilization in the pentose phosphate pathway but is overprinted on day 10, again due to intensive recycling and mixing. This shows that glucose and ribose – as ubiquitous substrates – are used in various metabolic pathways and their C is intensively recycled in microbial biomass.Analyzing the fate of individual C atoms by position-specific labeling deeply improves our understanding of the pathways of microbial utilization of sugars (and other compounds) by microbial groups and so, of soil C fluxes.     

Impacts of organic residue management on the soil C dynamics in a tropical eucalypt plantation on a nutrient-poor sandy soil after three rotations

Harvest residue management is a key issue for the sustainability of short rotation plantations of fast growing tree species established on poor soils and for potential carbon (C) accretion in many soils. By measuring the C isotope composition (δ¹³C) of different soil organic matter fractions and microbial respiration, we examined the effects of organic residue management at harvest on soil C dynamics in a tropical eucalypt plantation established on a savannah at the end of the third rotation on three treatments repeated at each harvest. We compared plots where the standard harvesting method in Congolese commercial plantations was applied (SWH; only removing the debarked commercial-sized boles) with plots where all the aboveground biomass and the litter layer from the previous rotations were removed at harvest (R) and plots where the residues from a whole tree harvest treatment were added (double slash, DS). Organic residue removal decreased the accretion of eucalypt-derived C in coarse and fine particulate organic matter (POM) fractions and in the organo-mineral fraction, resulting in 44% less total soil C in the top soil (0–0.05 m) but did not affect the amount of savannah-derived C in any SOM fraction. In contrast, increasing the amount of harvest residue by 36% in comparison with the reference practice did not increase the amount of C stored in the soil nor the accretion of eucalypt-derived C in any soil organic matter fractions, but the amount of savannah-derived C remaining in the coarse POM fraction was higher. We concluded that carbon accretion may be limited by the low C saturation level of these sandy-structured soils but that higher rates of residue retention may reduce priming on older savannah-derived C.     

碱液与超声波联用再生活性炭技术中碱液种类和浓度对再生和利用率的影响

[目的]考察在碱液与超声波联用技术中,不同碱液种类和浓度对活性炭再生效率的影响.[方法]以邻苯二甲酸氢钾标准溶液和污水处理厂二级出水分别进行饱和吸附后,采用碱液与超声波联用技术进行再生,通过测定消耗碱液量、碳损失量,研究碱液种类和浓度对再生效率和利用率的影响.[结果]对于二级出水和人工配制的邻苯二甲酸氢钾标准溶液,NaOH、Mg(OH)2、Ca(OH)2使用量依次增加,再生后碳损失量依次减小;随碱液浓度的增加,相同条件下处理饱和的活性炭,任一碱液消耗量均减小,碳损失量增加.在相同试验条件下控制相同的有机物浓度,发现人工配制的邻苯二甲酸氢钾标准溶液碱液消耗量低于二级出水,人工配制的邻苯二甲酸氢钾标准溶液碳损失量高于二级出水.[结论]该研究为活性炭再生技术提供了参考.     

干巴菌仿野生栽培菌种培养基碳源氮源筛选

配制不同碳源氮源培养基接种干巴菌菌种,研究不同配方碳源、氮源培养基对干巴菌母种、栽培种菌丝长势、生长速度、满袋时间的影响。结果表明,干巴菌母种培养基用松针水配制,栽培种培养基中添加40%的松针,其菌丝生长速度均较快。干巴菌母种培养基菌丝最适合的主要碳源是马铃薯,菌丝生长速度最快（4.53mm/d）,最适合的主要氮源是蛋白胨与酵母粉1:1的混合物,菌丝生长速度快（5.06mm/d）、菌丝长势强。干巴菌栽培种碳源以糯米最好,生长速度快（5.89mm/d）、菌丝长势强,菌丝满袋时间短（39d）;栽培种氮源以麸皮最好,生长速度快（5.75mm/d）、菌丝长势强,菌丝满袋时间短（40d）。     

基于森林资源连续清查的森林碳储量估算1）--以内蒙古呼伦贝尔地区为例

基于森林资源清查数据,采用联合国政府间气候变化专门委员会（ IPCC）提供的方法对内蒙古呼伦贝尔地区森林碳储量进行核算。结果表明：呼伦贝尔地区森林碳储量5．39×108t;用材林碳储量最大,占区域总碳储量的85％;其次是防护林,占区域总碳储量的11％。不同优势树种森林碳储量差异较大,兴安落叶松和白桦占11个优势树种总碳储量的88％。用材林不同龄组碳储量中,中龄林最大;但在不同龄组间,其碳密度随林龄的增大而增大,成过熟林表现出较大的碳汇能力。应通过森林资源培育保护工程,加强中幼林抚育和经营管理,提高森林质量和碳汇能力,更好地应对气候变化。     

广东碳汇林评价指标体系构建研究

国内对于森林生态系统的价值评价进行了诸多研究,产生了系列研究成果,但对碳汇林价值评价的研究尚不多。为了弥补这一缺陷,对广东碳汇林所产生的价值进行了研究,运用频度分析法、德尔菲法和层次分析法等方法建立广东碳汇林价值评价指标体系,包括目标层、状态层和指标层等3个层次,共计有碳汇价值、生态价值、经济价值和社会价值等4类19项指标。在此基础上,利用专家评分的方法确定指标重要程度,按照9标度法构造判断矩阵,从而计算出各指标的权重以及在在总体评价中的权重,其中碳汇价值、生态价值、经济价值和社会价值所占权重分别为0.5240、0.2620、0.1070和0.1070。     

Modelling spatial exclusion of a vulnerable native fish by introduced trout in rivers using landscape features: a new tool for conservation management

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Evaluation of full-scale carbon dioxide stripping columns in a coldwater recirculating system

The objective of this research was to evaluate the dissolved carbon dioxide stripping efficiency of two types of 1-m tall structured plastic packing (tubular NORPAC and structured block CF-3000 Accu-Pac media) that were placed separately in two full-scale forced-ventilation cascade columns that were located within a coldwater recirculating aquaculture system at the Freshwater Institute. These two structured packing types were selected because they both provide large 4–5 cm void spaces that are either vertically-continuous (e.g. the tubular NORPAC) or an open structure with zigzagging but continuous void spaces (e.g. the blocks of cross-corrugated sheet media), which should reduce the likelihood of plugging with biosolids. Water flow rates were adjusted so that each cascade column was loaded with either 87, 136 and 187 m³/h water flow per m² of cascade column plan area (i.e. 35, 56 and 76 gpm/ft²). Air:water loading rates of 2.2:1 to 3.4:1, 5.1:1 to 5.6:1, and 9.5:1 to 9.9:1 were produced by setting the water flow rates through each column at 1.62, 2.54 and 3.48 m³/min, respectively, and then measuring the resulting air flow rate through the column under these conditions. As expected, the dissolved carbon dioxide removal efficiencies of both structured packing tested were found to depend on the volumetric air:water loading rate applied. The lowest volumetric air:water loading rate (i.e. 2.2:1 to 3.4:1) resulted in only 21–24% dissolved carbon dioxide removal. However, the dissolved carbon dioxide removal efficiencies rose to 32.4–33.6 and 35.8–37.2% for the medium and high air:water loading rates, i.e. 5.1:1 to 5.6:1 and 9.5:1 to 9.9:1, respectively. A second objective of this research was to determine if either packing would plug with biosolids after long-term operation. At the end of approximately 1 year of operation, both of the plastic packing materials were examined from the top of the packing to determine if potential fouling or plugging problems were apparent. A thin layer of brown biofilm covered both packings, but the biofilm did not appear to threaten water or airflow through the packing. In addition, no large mats of biosolids were visible from the top of either column. However, flooding at the interface of the support screen and the tubular NORPAC was suspected to have reduced air flows measured at the highest hydraulic loading rate tested (i.e. at 187 m³/h per m²), which coincided with the lowest air:water loading rates tested.