火烧对北亚热带杉木林土壤有机碳的影响

[Objective]To study the effect of burning on soil organic carbon and to provide references for post-fire vegetation regeneration. [Method]The changes of organic carbon and nutrient contents in post-fire Cunninghamia lanceolata stand with the soil depth of 0~50 cm in north subtropical areas were analyzed. [Result]The contents of soil total organic carbon (TOC), easily-oxidized carbon (EOC) and light fraction organic carbon (LFOM) were higher than those of contrast sample area, which increased by 1.7%~38.0%、6.6%~33.2% and 3.1%~45.7%, respectively. Significant differences were found in the soil layer with depth of 0~10 cm and 10~20 cm (P<0.01). Compared with the contrast sample area, the soil carbon storage in the layer with depth of 0~50 cm increased by 19.1% one year after burning. The TOC, EOC and LFOM were all significantly related to the soil nutrients (total N, hydrolyzable N and available K). After burning, the increase of TOC, EOC and LFOM were mainly concentrated on the surface of soil and the organic carbon contents increased by 9.22 g·kg^-1 in 010 cm layer. [Conclusion]Moderate intensity burning has a significant impact on organic carbon in the soil of C. lanceolata stand in the north subtropical area. Moderate burning can increase the soil organic carbon because the soil can mix the organic residues caused by incomplete combustion of vegetation layer. Replanting in the burned area could be adopted to promote the vegetation restoration.     

高效液相色谱-质谱联用技术测定毛榛中的紫杉醇含量

Established method by reverse phase HPLC and electrospray ionization mass spectrometry (HPLC-ESI-MS) analysis and hazelnut extract trace of taxol. Through the research, seven mass spectrum characteristics of taxol compounds were contested, and the taxanes database was initially established. It was found that the paciltaxel contents were 23.65 μg·mL^-1 and 4.09 μg·mL^-1 in leaves and stems respectively. The paciltaxel contents in different parts of hazelnut was slightly different, which were 0.61, 0.23 and 0.35 μg·mL^-1 in hazel branch, leaf and leather. With these data it can quickly identify the known paclitaxel compounds in hazelnut extract, and can perform the unknown structure analysis to certain degrees. This analysis method is confirmed sensitive, reliable and fast.     

4种山茶花营养成分及有害元素含量分析

The nutritional components and poisonous elements in flowers of Camellia chekiangoleosa, C. polydonta, C. semiserrata and C. azalea were studied. The results indicated that the soluble sugar content of the four Camellia flowers had no difference. The maximum protein content was 82.9 g·kg^-1, detected in the flower of C. semiserrata. And the minimum protein content was 56.8 g·kg^-1, found in C. azalea. Vitamin C and β-carotene contents in C. azalea and C. semiserrata were higher, and in C. polydonta and C. chekiangoleosa were lower. The total amino acid contents of the four Camellia were 68.41、67.26、50.77、66.87 g·kg^-1 respectively, the essential amino acid contents were 33.86、32.70、27.21、33.79 g·kg^-1 respectively, and the proportion of essential amino acid in total amino acid of the four Camellia were 49.50%, 48.62%, 53.59% and 50.53% respectively. The contents of Ca, Mn and Cu in C. chekiangoleosa were the highest. Zn and Se contents were the maximum and Ca was the minimum in C. polydonta. The contents of Fe and Se were the lowest in C. semiserrata. Fe content were the maximum and Mn, Zn and Cu the minimum in C. azalea. The trace element contents in the flower of the four Camellia species followed the order of Mn, Fe, Zn, Cu, Se, but the content of Fe was higher than that of Mn in C. azalea. The contents of Pb, Cd, As and Hg of the four Camellia flower were all lower than the permissible amount.     

Long-term charcoal-induced changes to soil properties in temperate regions of northern Iran

The long-term performance and benefits of charcoal application on the carbon sequestration and properties of forest soils in temperate or non-tropical regions has not been studied in detail in spite of its important role in global warming. This study was conducted to describe the long-term charcoal-induced changes in organic carbon (OC) content and other soil properties of temperate deciduous forests in Mazandaran province, northern Iran. Three sites were sampled to collect composite soil samples from two depths (0–20 and 20–40 cm) inside and outside of a plot of charcoal-enriched soils surrounding a historical charcoal production site (abandoned for more than 120 years). The presence of charcoal in soils for about 120 years elevated significantly the black carbon, total OC, natural soil OC, total nitrogen, dissolved organic matter, soil OC density, exchangeable bases, saturated hydraulic conductivity, available water capacity and available Fe, Mn and Zn compared to the adjacent reference soils. Cation exchange capacity (CEC) and pH were 15.5 cmolc kg^-1 and 0.5 units, respectively, higher than the adjacent reference soils at 0–20 cm soil depth. However, electrical conductivity (EC), bulk density and available Cu were higher in the adjacent reference soil. The aged charcoal had no significant effect on the microbial respiration rate of studied soils. The results of this study provide new insights and strong support for the long-term benefits of biochar application as a management strategy for improving soil productivity as well as sequestering large quantities of durable carbon in soils of the region and mitigating global warming.     

Soil carbon characterization along the profile of two forest soils under Quercus pyrenaica

In light of concerns over climate change and increasing levels of CO2 in the atmosphere,it is of importance to investigate soil organic matter in Mediterranean forests at a profile scale.In-depth studies of the organic fraction are also of interest to improve understanding of carbon balance and to facilitate modelling of carbon fixation in forest soils.This research evaluates the relationships between diverse parameters such as colour,content,and form of soil organic matter(SOM).Two Quercus pyrenica ecosystems with soils classified as inceptisols with a xeric or dry moisture regime,and developed under a Mediterranean climate in Spain,were used to characterize SOM through the complete sequence of layers of the soil profile.The differentiating factor between the two ecosystems was slope gradient.Characterization was done using characteristics of humic substances(HS)as indicators of SOM turnover in inceptisols.Infrared analysis was used to further characterize the humic acids.As soil colour measurements are a tool for soil type classification and soil organic carbon prediction,the relation between HS colour measured by reflection and by transmission was determined in order to establish a relationship between measurement techniques.Infrared analysis and colour provided evidence of a different level of stabilization of HS from both soils,and between the different horizons.Oxidation of humic acids was found to be greater in deeper horizons than in the surface layers.An inverse relationship between HS colour measured by reflection and by transmission was revealed.Both soils showed a clear trend in which horizons presenting lower absorbance numbers showed higher figures of hue and value.A more marked accumulation of humified compounds was found in pedons,(the smallest unit or volume of soil that contains all the soil types),in the less steep slope.This might be explained in terms of the physiographic position affecting infiltration behavior and exposure to runoff.     

Profile distribution and seasonal dynamics of water-extractable carbohydrate in soils under mixed broad-leaved Korean pine forest on Changbai Mountain

Carbohydrate represents an important part of the soil labile organic carbon pool. Water soluble carbohydrate drives the C cycle in forest soil by affecting microbial activity and hot water extractable carbohydrate is thought related to soil carbon sequestration due to the association with soil aggregation. In a temperate forest region of northeast China, Changbai Mountain, we investigated the abundance, spacial distribution, and seasonal dynamics of cool and hot-water extractable carbohydrate in soils under mixed broad-leaved Korean pine forest. The concentrations of cool-water extractable carbohydrate (CWECH) in three soil layers (0-5, 5-10, 10-20 cm) ranged from 4.1 to 193.3 g·kg-1 dry soil, decreasing rapidly with soil depth. On an annual average, the CWECH concentrations in soils at depths of 5-10 and 10-20 cm were 54.2% and 24.0%, respectively, of that in the 0-5 cm soil layer. CWECH showed distinct seasonal dynamics with the highest concentrations in early spring, lowest in summer, and increasing concentrations in autumn. Hot-water extractable carbohydrate (HWECH) concentrations in three soil layers ranged from 121.4 to 2026.2 g·kg-1 dry soil, which were about one order of magnitude higher than CWECH. The abundance of HWECH was even more profile-dependent than CWECH, and decreased more rapidly with soil depth. On an annual average, the HWECH concentration in soils 10-20 cm deep was about one order of magnitude lower than that in the top 0-5 cm soil. The seasonality of HWECH roughly tracked that of CWECH but with seasonal fluctuations of smaller amplitude. The carbohydrate concentrations in cool/hot water extracts of soil were positively correlated with UV254 and UV280 of the same solution, which has implications for predicting the leaching loss of water soluble organic carbon.     

脱硫石膏改良龟裂碱土对枸杞根际土壤理化性质及根系生长的影响

In this study, the rhizosphere soil properties of Takyr Solonetzs ameliorated with FGDG, and its effect on root growth of Lycium barbarum were studied. The results indicated that with increasing applications of FGDG, the contents of Na⁺, K⁺, Mg²⁺, Cl^-, and HCO₃^- in rhizosphere soil decreased gradually with the ratio of 51.9%, 16.7%, 42.7%, 44.7% and 28.2%, respectively, while the contents of Ca²⁺ and SO₄^2- showed an increasing trend and increased by 96.9% and 80.4% compared with those of the CK. As the content of exchangeable Na⁺ decreased with the increasing application of FGDG, the exchangeable sodium percentage (ESP) and soil pH values decreased from 32.2% and 10.5 to 18.1% and 7.82, respectively and thus the soil physical properties improved. However, the lowest total salt content (2.91 g·kg^-1) was found in T2 (2.5 t/(667m²)), and similarly, the highest values of taproot length (44.78 cm), root surface area(179.97 cm²) and root dry weight (17.53 g) were also found in T2, which suggested that applications of FGDG were not always positively correlated with soil reclamation, and excessive amount of FGDG would inhibit root’s growth. Overall, application of FGDG is effective in ameliorating Takyr Solonetzs, but high amount of FGDG would result in excess salts against root growth and subsequently influence production.     

土壤有机碳动态模型的研究进展

As the largest pool of terrestrial organic carbon, soils interact strongly with atmosphere composition, climate, and land change. Soil organic carbon dynamics in ecosystem plays a great role in global carbon cycle and global change. With development of mathematical models that simulate changes in soil organic carbon, there have been considerable advances in understanding soil organic carbon dynamics. This paper mainly reviewed the composition of soil organic matter and its influenced factors, and recommended some soil organic matter models worldwide. Based on the analyses of the developed results at home and abroad, it is suggested that future soil organic matter models should be developed toward based-process models, and not always empirical ones. The models are able to reveal their interaction between soil carbon systems, climate and land cover by technique and methods of GIS (Geographical Information System) and RS (Remote Sensing). These models should be developed at a global scale, in dynamically describing the spatial and temporal changes of soil organic matter cycle. Meanwhile, the further researches on models should be strengthen for providing theory basis and foundation in making policy of green house gas emission in China.     

Active organic carbon pool of coniferous and broad-leaved forest soils in the mountainous areas of Beijing

In order to explore the effects of different forest types on active soil carbon pool, the amounts and density of soil organic carbon (SOC) were studied at different soil horizons under typical coniferous and broad-leaved forests in the mountainous area of Beijing. The results showed that the amount of total SOC, readily oxidizable carbon and particulate organic carbon decreased with increasing depths of soil horizons and the amounts at depths of 0–10 cm and 10–20 cm in broad-leaved forest was clearly higher than that in coniferous forests. The trend of a decrease in SOC density with increasing depth of the soil horizon was similar to that of the amount of SOC. However, no regular trend was found for SOC density at different depths between coniferous forest and broad-leaved forests. The ratio of readily oxidizable carbon to total amount of SOC ranged from 0.36–0.45 and the ratio of particulate organic carbon to total amount of SOC from 0.28–0.73; the ratios decreased with increasing depths of soil horizons. Active SOC was significantly correlated with total SOC; the relationship between readily oxidizable carbon and particulate organic carbon was significant. A broad-leaved forest may produce more SOC than a coniferous forest.     

Above and below ground organic carbon stocks in a sub-tropical Pinus roxburghii Sargent forest of the Garhwal Himalayas

Accurate estimates of tree carbon,forest floor carbon and organic carbon in forest soils (SOC) are important in order to determine their contribution to global carbon (C) stocks.However,information about these carbon stocks is lacking.Some studies have investigated regional and continental scale patterns of carbon stocks in forest ecosystems;however,the changes in C storage in different components (vegetation,forest floor and soil) as a function of elevation in forest ecosystems remain poorly understood.In this study,we estimate C stocks of vegetation,forest floor and soils of a Pinus roxburghii Sargent forest in the Garhwal Himalayas along a gradient to quantify changes in carbon stock due to differences in elevation at three sites.The biomass of the vegetation changes drastically with increasing elevation among the three sites.The above-ground biomass (AGB) and below-ground biomass (BGB) were highest at site Ⅰ (184.46 and 46.386 t·ha-1 respectively) at an elevation of 1300 m followed by siteⅡ (173.99 and 44.057 t·ha-1 AGB and BGB respectively) at 1400 m and the lowest AGB and BGB were estimated at site Ⅲ(161.72 and 41.301 t·ha-1) at 1500 m.The trend for SOC stock was similar to that of biomass.Our results suggest that carbon storage (in both soil and biomass) is negatively correlated with elevation.     

黑龙江省森林碳库碳储量、碳密度及吸碳吐氧价值研究

根据2008年黑龙江省森林面积蓄积统计资料,按照18个森林类型的蓄积量,分别估算了黑龙江省森林碳库的生物碳储量、土壤碳储量,并分析了森林碳库生物碳密度的分布规律和影响因素,同时对黑龙江省森林吸碳吐氧价值进行了经济评价。结果表明,黑龙江省森林碳库生物碳储量为8.93亿 t,同时吸收二氧化碳32.93亿 t,释放氧气23.81亿 t;黑龙江省森林土壤碳储量为9.29亿 t,同时森林土壤吸收二氧化碳34.06亿 t,释放氧气24.77亿 t。     

木材固碳量与含碳率研究进展

木材碳学是近年来兴起的一门科学, 其主要研究内容包括木材碳素的储存量、木材储能、人工林木材固碳增汇与优质木材培育技术及木质产品固碳延伸等方面。文中简述了木材碳学研究中木材固碳量与含碳率、木材固碳量的影响因素、木材固碳量与木材热值的关系以及木质材料固碳量和固碳延伸等方面的研究现状, 并对今后的研究方向进行了展望。     

森林生态系统碳蓄积量与年净碳汇估算研究

文章简述了森林生态系统碳蓄积量几种研究方法,并通过分析森林生态系统年固碳量与年释放碳量,估算了森林生态系统年净碳汇量;同时指出我国森林生态系统碳蓄积和碳循环研究存在的不足之处和发展前景,为实现林业低碳提供理论依据。       

森林碳汇研究进展

评价森林的碳源、碳汇功能,认为森林是一个大的碳汇,但随着森林破坏、退化的加剧以及火灾等干扰因素的影响,森林生态系统就可能成为碳源.列举森林碳储量及固碳经济效益计算的方法.认为目前大多数相关研究尤其是国内学者仅限于对现存森林CO2吸收或排放的计算,未能阐明森林碳汇、碳源的分布格局,研究对象多为大尺度的,在森林固碳经济效益计算方面缺乏公认的方法.     

黑龙江省碳储量及碳汇潜力分析

通过研究分析证明,黑龙江省碳储量约为9.994×109t,其中,森林植物和林地土壤碳储量占52.31%;黑龙江省有机碳净增长约为每年9.381×107t,其中,森林碳汇净增长占88.89%;黑龙江省有机碳净增长价值合人民币为每年2.523×1010元,其中,森林碳汇价值净增长为每年2.242×1010元。     

森林碳库及碳汇监测概述

气候变化是全球未来发展所面临的巨大挑战,森林作为_陆地生态系统的重要组成部分,在减缓温室气体排放方面发挥着重要的作用。介绍了森林碳库和碳汇的研究背景、研究现状,分析了碳汇监测的重要意义;林业碳汇监测急需完善针对区域的植被生物量模型,建立森林土壤碳储量和碳汇监测体系。     

我国森林碳库特点与森林碳汇潜力分析

森林生态系统在稳定全球碳循环和缓解全球气候变暖方面发挥着重要的作用,合理发展林业,可以实现固碳增汇,是缓解全球气候变化的重要措施。综述了森林碳库的重要地位、我国森林生态系统碳库特点,分析了通过增加森林面积和提高森林经营水平来增加森林碳汇的潜力。     

湘乡市林地森林碳储量及碳密度研究

通过对湘乡市林地的森林碳储量、碳密度及碳储量的空间分布特征进行研究,得出:①在各优势树种组中,中生阔叶树组的碳储量和碳密度都是最大的,碳储量排序依次为:中生阔叶树组>马尾松组>杉木组>竹木组>国外松组>经济林组〉慢生阔叶树组>灌木组>速生阔叶树组,碳密度排序依次为:中生阔叶树组>国外松组>竹木组>马尾松组〉慢生阔叶树组>杉木组>经济林组>速生阔叶树组〉灌木组;②除马尾松组和中生阔叶树组外,各优势树种小班的碳储量主要集中分布在0~100t的区域内,且与人类活动呈负相关。     

湖北省区域碳排放强度和森林碳汇差异分析

核算湖北省各州市碳排放强度与森林碳汇,分析区域能源消耗与碳吸收现状,并采用聚类分析方法将各州市按其地区差异划分为4个类别。结果表明,湖北省大部分地区碳排放强度超过0.5t/万元GDP,其中黄石地区碳排放强度最高,随州地区最低;湖北省各地区森林碳汇差异较大,森林碳汇的总体分布格局为鄂西北>鄂东>鄂中;天门、仙桃、荆州、武汉、随州市属于低碳排放强度—低森林碳汇地区,潜江、荆门、鄂州市属于高碳排放强度—低森林碳汇地区,宜昌、黄石、咸宁、孝感、襄阳市和恩施州属于高碳排放强度—高森林碳汇地区,黄冈、神农架、十堰市属于低碳排放强度—高森林碳汇地区。提出加强造林与森林经营工作,加大木质产品与可再生能源的开发,完善碳汇交易市场等建议。     

土地利用方式对土壤有机碳和碳库管理指数的影响

土壤碳库管理指数反映土壤管理的科学性.对比研究了干热河谷新银合欢林、苏门答腊金合欢林、大叶相思林、印楝林、荒地和旱耕地土壤有机碳(SOC)、易氧化有机碳(ROC)含量和土壤碳库管理指数.结果表明:6种土地利用方式下SOC和ROC含量范围分别为4.22～5.92 g·kg-1和1.34～2.33 g·kg-1.各利用方式...