硬覆盖对城市街路行道树土壤呼吸的影响

采用静态气室法测定了长春市人民大街行道树与对照林地不同深度的土壤中CO₂含量。研究发现林地土壤呼吸作用可以用土壤中CO₂含量大小及其变化规律反映出来,而街路行道树土壤中的CO₂含量不能直接反映土壤呼吸速率大小。       

不同植被恢复模式对生物多样性及土壤有机质的影响

在陶瓷工业集中重酸污染区,设计不同空间配置格局"乔灌草、灌草、草本"三种植被恢复模式,研究分析不同植被恢复模式对提高生物多样性和改良土壤有机质的效应,试验结果表明,乔木、灌木和草本植物的合理配置格局,无论在增加地被覆盖、促进土壤动物类群的发展,还是在改善土壤质量方面都优于灌木-草本群落和草本群落。       

桑天牛危害对杨树次生物质含量的影响

通过室内分析方法研究桑天牛危害对杨树次生物质含量的影响。结果表明,受害植株与健康植株之间单宁、黄酮及总酚含量存在显著差异,其中受害植株单宁、黄酮含量增加,总酚含量减少。       

福贡县县城林业土壤理化性质对造林的影响

采集福贡县县城林业土壤,分析了其物理性质和速效养分含量。结果表明,福贡县县城林业土壤密度平均值为1.54g·cm-3,孔隙度平均值为40.12%,速效磷含量平均值为18.63 mg·kg-1,速效钾含量平均值为156.51 mg·kg-1,碱解氮含量平均值为25.73 mg·kg-1。数据表明,福贡县县城林业土壤密度和孔隙度偏低,速效钾和速效磷含量丰富,碱解氮缺乏。       

土壤钻孔通气法对行道树生长的改善

硬覆盖路面下绿化树根际土壤环境是影响树体生长势衰弱的主要原因。以改良土壤透气性、调节土壤含水量、增加土壤养分为目的,对绿化树根际土壤实施钻孔通气,补充养料。研究结果表明,治理后的植物叶片增厚、颜色加深、叶中保持相对较高含水量,新梢生长旺盛,病斑恢复较快;但是钻孔不是导致土壤气体浓度变化的主要因素。       

土壤与行道树的选择配置——以包头为例

土壤是影响行道树生长的重要环境因子。从土壤的物理化学特征如上层厚度、土壤容重和紧实度、土壤的水分供应、土壤有机质与养分含量、土壤酸碱度、土壤离子浓度等时论土壤对行道树成活及生长的影响,确定行道树的选择与配置。       

公路及其路网对生态环境的影响与对策

公路及其路网对开放空间及其中的各种自然生态过程产生了十分不利的影响。从沿线环境污染与侵扰、行动障碍与交通伤亡、区域生境碎化等几方面分析了公路生态环境影响,并结合国际上的一些先进经验论述了公路生态环境建设的基本方法框架、生态环境决策与生态工程措施。       

城市不同功能区对空气负离子水平的影响

本项研究在吉林市选择具有代表性的城市功能区,对其空气正负离子浓度进行了测定,结果表明:不同功能区空气负离子水平差异显著,城市绿地中空气负离子明显高于其它非绿地功能区。       

融雪剂对冷季型草坪草外观质量的影响

对冷季型草坪草早熟禾进行不同浓度和频次的融雪剂处理,观测草坪草外观质量的变化,研究对草坪草返青率及颜色、质地、均一性和盖度等外观性状的影响。结果表明,试验处理下的盐胁迫对草坪返青率和外观性状都有较大的影响,所有处理的返青率均极显著地低于对照处理;施盐浓度过大延迟草坪草春季返青,施盐次数的增加比施盐总量的增加对草坪返青影响更大;所有处理综合性状评分与对照均有显著差异。       

有机覆盖物对城市绿地土壤水分和温度的影响

为了解有机覆盖物对城市绿地土壤水分和温度的影响,文章选择城市公园绿地对地表分别进行了覆盖3cm、5cm有机覆盖物和未覆盖空白对照三种处理试验,研究了0~10cm、10~20cm、20~30cm和30~40cm不同土层的水分和温度变化。结果表明:(1)三种覆盖处理土壤含水量的季节变化趋势一致。土壤含水量在0~10cm波动最大,随着土壤深度的增加,这种波动表现得越来越弱。(2)覆盖3cm有机物处理在四个土壤层次均高于空白对照,而在10~20cm和20~30cm的增加量最多;覆盖5cm有机物处理只在0~10cm明显的高于空白对照。(3)不同覆盖处理的土壤温度的季节变化趋势一致。相对于空白对照,覆盖处理的土壤日温变化幅度要明显小于空白对照,其中覆盖3cm和5cm有机物的处理比对照区在炎热的夏季土壤温度分别降低了2.0℃和0.9℃,而在寒冷的冬季升高了0.9℃和1.4℃。同时,覆盖处理也减小了不同土层深度的温度变幅。       

稻草覆盖对果园土壤温度与含水量的影响

在洮南市北部半山区的果树试验场,按果树树冠垂直投影筑树盘,对树盘进行稻草覆盖处理,研究其对土壤温度与含水量的影响。结果表明：覆草处理能够有效地提高土壤含水量,年平均含水量比清耕地高出16．0％;经覆草处理的土壤,生长前期土温上升缓慢,后期土温下降缓慢,越冬前,土温高于清耕地2．00℃,可减少低温对根系的危害。     

Influence of soil organic matter contents on soil water characteristics of forests on east slope of Gongga Mountain

By testing soil organic matter （SOM） contents, soil water contents （SWC） within low suctions, and saturated infiltration rates of samples taken from east slope of Gongga Mountain of China, the enhancive effects of SOM contents on SWC within low suctions and saturated infiltration rates were quantified. The simulated functions might be applied on regional experience forest-hydrology model. The improving function of protecting forest floor and increasing SOM contents on forest ecosystem hydrological effects were also embodied.     

亚热带地区杉木人工林和阔叶林土壤活性有机质研究(英文)

土壤活性有机质对土壤养分如氮、磷、硫的生物化学循环具有作用,其含量和质量影响土壤的初级生产力。本试验在中国科学院会同森林生态实验站通过对第一代、第二代杉木纯林和地带性阔叶林土壤活性有机质组分的对比研究,发现杉木纯林土壤活性有机质的含量低于地带性阔叶林。第一代杉木纯林易氧化有机碳、微生物生物量碳、水溶性有机碳和水溶性碳水化合物的含量分别比第二代杉木纯林高35.9%、13.7%、87.8%和50.9%,比地带性阔叶林的低15.8%、47.3%、38.1%和30.2%。在调查的三种林地内,土壤微生物生物量碳和水溶性有机碳含量下降幅度较大,其次为水溶性碳水化合物,而易氧化有机碳的变化最小。同时,杉木纯林土壤养分等理化性质也比地带性阔叶林低。这表明在杉木纯林取代地带性阔叶林以及杉木纯林连栽后林地的土壤肥力降低。图3 表2参26。     

Modelling moisture content and dry matter loss during storage of logging residues for energy

Abstract

To achieve optimal utilisation of logging residues for energy, it is important to know how different handling and storage methods affect fuel properties. The aim of this study was to model how the moisture content and dry matter losses of logging residues develop during storage. Logging residues were collected from five different stands of spruce and pine during different seasons of the year and stored in the same location. The logging residues were stored in covered piles of bundled residues and loose residues. Only minor differences were found in the moisture content profiles between piles of bundles and loose residues. Logging residues located in the centre of both types of piles had considerably lower moisture content than the outer parts. The moisture content significantly affected dry matter loss, with the highest dry matter losses being found in the samples with the least favourable drying conditions. The dry matter losses varied between 1 and 3% per month. Significantly higher dry matter losses were found in the spruce bundles than in the pine bundles. Seasoned logging residues had the lowest dry matter loss, while the logging residues harvested and piled in the autumn had the highest loss.     

烘箱加热法测定森林土壤有机质的研究

采用烘箱加热法测定东北地区地带性土壤暗棕色森林土有机质含量,结果表明:测定最佳加热时间为30 min,最适宜加热温度为150℃,最适宜重铬酸钾浓度为1.2 mol·L~(-1)。烘箱加热法适宜测定有机质含量较高的土壤。     

晋西北不同植被类型土壤水分空间分异

采用土钻法对晋西北朔州地区杨树林、柳树林、草地3种植被类型0~600 cm土层土壤水分动态进行研究。结果表明:土壤平均含水量表现为草地杨树林地柳树林地。草地土壤平均含水量比杨树林地高1.25%,比柳树林地高1.9%。随着土壤深度的增加,土壤含水量先减小后上下波动,然后趋于稳定。0~100cm土层范围内,土壤水分变异系数大小为草地柳树林地杨树林地;在200~300 cm、400~500 cm土层范围内,变异系数表现为柳树林地草地杨树林地;300~400 cm、500~600 cm土层范围内,变异系数大小为柳树林地杨树林地草地。越靠近表层,土壤干化现象越严重,柳树林地干化现象最明显,含水量变化最剧烈,杨树林地次之,草地最稳定。     

沙棘根际土壤有机质特征及转化酶活性的初步研究

文章对沙棘根际和非根际的有机质特征和转化酶活性进行了初步的比较研究。结果表明，沙棘根际土壤有机质和活性有机质含量、可浸提腐殖酸及胡敏酸和富里酸含量、胡敏酸E4／E6比值都高于非根际土壤。根际土壤转化酶活性是非根际土壤的1．73倍。说明根际是树木和土壤相互作用最直接的区域，根际效应是树木改良土壤的重要机理。     

Impact of moisture content on dynamic mechanical properties and transition temperatures of wood

The dynamic shear modulus and the loss modulus of Betula alba, Ulmus parvifolia, Quercus robur, Acer platanoides, Tilia cordata, Fraxinus excelsior and Pinus sylvestris wood were measured using an inverted torsion pendulum within a wide temperature range. The glass transition temperature of the lignin–carbohydrate complex and the decomposition temperature of the wood cellulose were estimated. The temperature band from 170°C to 240°С shows the transition of the lignin–cellulose complex from the glassy to the rubbery state. Mechanical properties of different types of wood are affected by moisture and anatomical differences, but glass transition and decomposition temperatures are the same. More than 5% of moisture in the wood stored at normal conditions were found. After drying, the increase of dynamic shear modulus of wood over the entire region of the glassy state was observed. The intensity of maximum peak of dynamic loss modulus is also increased due to activation of the segmental motion of macromolecules of the ligno-carbon complex. The decomposition temperature of the cellulose crystallites was unchanged for specimens containing moisture and for dried specimens.     

Postharvest organic matter removal effects on FH layer and mineral soil characteristics in four New Zealand Pinus radiata plantations

The effects of three postharvest organic matter removal treatments on fermentation-humus (FH) layer and soil characteristics were compared in replicated trials in four second rotation New Zealand Pinus radiata plantation forests, planted 8–16 years prior to sampling. All sites were sampled in early 2002 and 2003. Increasing organic matter removal significantly decreased the mass of the FH layer in the treatment plots, the moisture content in the FH layer and mineral soil, the concentration of carbon in the FH layer and mineral soil, the pool of carbon stored in the FH layer, the concentration of nitrogen in the mineral soil and the pool of nitrogen stored in the FH layer. Mineral soil pH was significantly increased with increasing organic matter removal. The persistence of the significant differences in the FH layer and mineral soil characteristics strongly suggested that variations in organic matter removal have long-term effects on forest floor properties, and significantly influences carbon storage over the life of the rotation.