广西主要树种热值研究

探讨树种不同器官间的植物热值规律,可为这些树种的能量特征和生态效率研究提供基础资料和科学依据。通过对广西12个主要树种不同器官的热值测定,结果表明：各主要树种的加权平均干重热值和去灰分热值分别在18.56～20.41 kJ/g和19.11～20.57 kJ/g;树种各器官热值表现为叶片含量最高,各器官热值含量顺序一般为叶〉枝〉皮〉干,或叶〉皮〉枝〉干;树种各器官的灰分含量在0.18%～14.48%,树种各器官灰分含量一般表现为叶〉皮〉枝〉干。     

新疆8年生银新杨热值与含碳率特征分析研究

对新疆克拉玛依地区的乔木银新杨的茎、枝、根的热值、灰分、化学组分、含碳率进行研究。结果表明:不同器官的热值为主干皮(19.701 kJ.g-1)>主干干(18.653 kJ.g-1)>侧枝皮(18.512 kJ.g-1)>侧枝干(18.135 kJ.g-1)>根干(18.075 kJ.g-1)>根皮(17.106 kJ.g-1);干的灰分含量在0.80%～1.69%之间,皮的灰分含量在8.05%～9.63%之间;相关性分析结果表明,干的热值与灰分含量之间没有显著的相关性;而皮的热值与灰分之间存在极显著的负相关性(P<0.01),相关系数为-0.58;木质素和纤维素与热值之间并没有显著的相关性(P>0.05);热值与含碳率之间存在显著的负相关关系(P<0.05),相关系数为-0.856。     

新疆6年生白榆热值与含碳率特征分析研究

经对新疆克拉玛依地区的乔木白榆的茎、枝、根热值、灰分、化学组分、含碳率进行研究,结果表明:6年生白榆乔木不同器官的热值变化是各组分干的热值均大于皮的热值.不同器官的热值为主干干(19.272 kJ·g<'-1>)>根干(18.881 kJ·g<'-1>)>侧枝干(18.738 kJ·g<'-1>)>主干皮(17.145 kJ·g<'-1>)>侧枝皮(16.021 kJ·g<'-1>)>根皮(15.326 kJ-g<'-1>);不同器官的干的灰分含量在0.94%～1.36%之间,皮的灰分含量为9.78%～10.91%,白榆的热值与灰分含量呈显著的负相关关系(P<0.05),相关系数为-0.908,这与大多数研究结论相同;木质素和纤维素可能是影响热值变化的重要因素,相关分析结果表明,二者与热值之间并没有显著的相关性(P>0.05);热值与含碳率之间存在极显著的正相关关系(P<0.01),相关系数为0.947.     

南方马尾松碳素含量与热值分析

以中国南方马尾松为研究对象,对南方马尾松不同器官的碳素含量、灰分含量与去灰分热值的分布特征进行研究。结果表明：①南方马尾松林分的平均碳素含量、灰分含量与去灰分热值分别为50.55%,1.02%,21.74 kJ.g-1;枝、叶、干、皮、根相互之间的平均碳素含量、灰分含量、去灰分热值都具有显著性差异;②认为将树干（去皮）中部位（3.5/10树高处）碳素含量,皮的上、中、下部位的平均去灰分热值,枝的中、下部位的平均灰分含量可分别作为整株碳素含量、去灰分热值、灰分含量是可行的;③马尾松碳素含量、去灰分热值、灰分含量三者之间均存在较强的相关性,其中去灰分热值与灰分含量的相关性系数达0.668;④马尾松碳素含量比较稳定,与林木起源、胸径、年龄等因子相关不显著,而去灰分热值、灰分含量与胸径、年龄、冠幅、树高相关性显著,与起源、坡度、海拔等因子相关性不明显。     

四种杨属植物的热值及灰分含量的比较

对新疆克拉玛依地区的胡杨(P.euphraticaOliv.)、俄罗斯杨(Populus.Russkii)、新疆杨(P.albavar.pyramidalis)、银×新杨(Populus alba×Populus bolleana),茎、枝、根热值和灰分含量进行研究。结果表明:(1)4种杨属植物不同组分灰分含量变化趋势没有一定的规律性,但各组分皮的灰分含量均大于木质的灰分含量;(2)4种杨属植物不同组分的干质量热值和去灰分热值变化相同,均为枝茎根;(3)4种杨属植物不同部位木质的干重热值和灰分含量没有显著的线性相关(P0.01),不同部位皮的干重热值和灰分含量具有显著的线性相关(P0.01);(5)4种杨属植物热值各组分木质和皮的差异不显著(P0.01)。     

2种桉树不同林龄生物量与能量的研究

对广东廉江市石岭林场2种桉树不同林龄的生物量和能量进行了研究。结果表明:2种桉树各器官生物量及林分生物量都随林龄的增大而增大,各器官生物量都以干的最大,叶的最小。4.5年生雷林1号桉和尾巨桉林分生物量分别为77.13、80.03 t·hm^-2。不同器官间灰分含量、干质量热值、去灰分热值差异很大,排序分别为:皮>叶>根>枝>干,叶>枝或干>根>皮,叶>枝或根>干>皮。叶、枝、根、干的灰分含量随林龄的增大有减小的趋势,而干质量热值则相反;皮的灰分含量和干质量热值随林龄的变化与前者相反。植     

浙江大盘山香果树群落各层优势种叶片热值研究

对浙江大盘山国家级自然保护区香果树群落各层优势植物不同季节叶的灰分含量和热值进行了比较,结果表明:(1)不同种类植物叶的灰分含量变化较大,介于3.60%～17.55%之间;不同季节植物叶的灰分含量不同,夏秋两季较高,春季较低,经检验,春季植物叶片灰分含量与夏秋两季相比,其差异达到了显著水平(p＜0.05).群落各层植物叶的平均灰分含量由高到低依次为:草本层(10.42±3.24)%、藤本层(8.56±2.22)%、乔木层(8.80±2.69)%和灌木层(6.16±1.78)%,经检验,仅草本层和灌木层差异显著(p＜0.05).(2)不同季节之间植物叶片干重热值和去灰分热值均以秋季为最高;各层植物叶的干重热值和去灰分热值由高到低均依次为灌木层(32.15±1.61)kJ/g、乔木层(30.92±1.15)kJ/g、藤本层(30.24±2.33)kJ/g和草本层(30.59±1.63)kJ/g,但各层次之间差异均未达到显著水平(p＞0.05).(3)为了探讨生境片断化的影响,对保护较为完好的生境(H1)和破坏较严重的生境(H2)下共有的6种植物叶的热值和灰分含量进行了比较研究,结果显示,植物叶的热值为H2＞H1,而灰分含量为H1＞H2.     

尾巨桉不同器官热值影响因素研究

对广东廉江石岭林场5年生尾巨桉不同器官的燃烧特性因子、物质组成成分和营养元素等指标进行了研究,并做了相关性分析。结果表明:5种器官去灰分热值在18.57~21.09 kJ·g~(-1)间,排序为叶片树枝树根树干树皮;去灰分热值和干质量热值、灰分相关显著,和粗纤维、粗蛋白、粗脂肪、全氮都显著相关,尾巨桉不同器官的热值受其物质成分及营养元素的影响。     

5年生刺槐4个无性系的枝干生物量及热值对比分析

对河南省陕县5年生的3-I、豫刺槐1号、匈牙利四倍体、一般刺槐(CK)4个刺槐无性系的生物量、灰分含量、干质量热值和去灰分热值进行分析。结果表明:无性系间单位干质量热值和去灰分热值差异显著,分别在3750～3950kcal·kg-1与3800～4000kcal·kg-1之间,高低排序均为3-I>CK>豫刺槐1号>匈牙利四倍体;部位间单位干质量热值和去灰分热值差异显著,分别在3800～3960kcal·kg-1与3840～4000kcal·kg-1之间,高低排序均为树干中部>树枝>树干上部>树干下部;无性系间单株枝干干质量热值和去灰分热值差异显著,分别在10900～35000kcal与11000～35500kcal之间,无性系间单株枝干热值排序与枝干总生物量排序一致,均为豫刺槐1号>3-I>CK>匈牙利四倍体。综合热值、灰分含量和生物量分析,对刺槐进行能源林经营的品种选择是有效的,无性系豫刺槐1号选做能源刺槐树种栽培最为理想,3-I次之;树干中部为理想能量部位,树枝次之。     

毛竹叶片灰分含量及热值月动态变化规律研究

在福建省永春县,对毛竹(Phyllostachys pubescens)叶片的灰分含量、干重热值、去灰分热值月动态变化规律进行研究。结果表明:①毛竹成熟叶、老叶的灰分含量月变化趋势相似,毛竹成熟叶、老叶的灰分含量在秋季的10月至翌年春季的3月灰分含量较高,而春夏季相对较低;毛竹成熟叶的灰分含量在7.56%～15.91%之间,老叶的灰分含量在7.46%～16.67%,老叶的灰分含量显著高于成熟叶(P=0.0199)。②毛竹成熟叶、老叶的干重热值月变化趋势相似;成熟叶的干重热值在18.166～20.923 kJ.g-1之间,老叶的干重热值在18.581～20.249 kJ.g-1,老叶的干重热值与成熟叶接近;成熟叶的干重热值与灰分含量相关性不显著,老叶的干重热值与灰分含量具有显著的线性负相关。③毛竹成熟叶、老叶的去灰分热值月变化趋势相似;成熟叶的去灰分热值在20.061～22.962 kJ.g-1之间,平均为(21.670±0.720)kJ.g-1;老叶的去灰分热值在20.793～23.053 kJ.g-1之间,平均为(21.779±0.584)kJ.g-1;成熟叶的去灰分热值与老叶接近。     

Calorific values and ash contents of different parts of Masson pine trees in southern China

Calorific value of plants is an important parameter for evalu- ating and indexing material cycles and energy conversion in forest eco- systems. Based on mensuration data of 150 sample sets, we analyzed the calorific value （CV） and ash content （AC） of different parts of Masson pine （Pinus massoniana） trees in southern China using hypothesis testing and regression analysis. CV and AC of different tree parts were almost significantly different （P〈0.05）. In descending order, ash-free calorific value （AFCV） ranked as foliage 〉 branch 〉 stem bark 〉 root 〉 stem wood, and AC ranked as foliage 〉 stem bark 〉 root 〉 branch 〉 stem wood. CV and AC of stem wood from the top, middle and lower sections of trees differed significantly. CV increased from the top to the lower sections of the tnmk while AC decreased. Mean gross calorific value （GCV） and AFCV of aboveground parts were significantly higher than those of belowground parts （roots）. The mean GCV, AFCV and AC of a whole tree of Masson pine were 21.54 kJ/g, 21.74 kJ/g and 0.90%, re- spectively. CV and AC of different tree parts were, to some extent, cor- related with tree diameter, height and origin.     

桉树、厚荚相思和马占相思树种热值比较分析

充分利用木质能源对于缓解我国能源危机,减轻生态负荷有很大作用。为此,对广西省北海市合浦县内桉树、厚荚相思和马占相思三种速生树种的热值进行试验研究。结果表明,桉树的热值为19.782kJ/g,马占相思的热值为20.640kJ/g,厚荚相思的的热值为20.978kJ/g;桉树、厚荚相思和马占相思三树种的各器官中,热值由高到低的顺序大致为树叶和树枝、树干边材、树干心材和树皮,其中,马占相思树皮的发热量界于树叶与树枝之间。     

南方马尾松不同器官的含碳系数分析

为了应对全球气候变化,森林碳储量监测日益受到重视,而含碳系数是一项重要的基础计量指标.以南方马尾松为对象,利用假设检验和回归分析方法,对不同器官的含碳系数进行系统分析.结果表明:马尾松不同器官的含碳系数存在显著差异,从大到小依次为树叶>干材>树根>树枝>干皮;树干不同高度干材和干皮的含碳系数也存在明显差异,但不同层次树...     

Evaluation of fuelwood quality of indigenous and exotic tree species of India's semiarid region

The fuelwood potential of indigenous (Acacia nilotica, Azadirachta indica, Casuarina equisetifolia, Dalbergia sissoo, Prosopis cineraria andZizyphus mauritiana) and exotics (Acacia auriculiformis, A. tortilis, Eucalyptus camaldulensis andE. tereticornis) trees were studied. Calorific value variations for components, such as, stump, main stem, treetop, branches, foliage and bark, were determined. Tree components differed highly significantly (P<0.01) among groups (indigenous and exotics) and within species. The calorific means ranged from 18.7 to 20.8 MJ/kg for indigenous tree species and 17.3 to 19.3 MJ/kg for exotics. Besides calorific values, other fuelwood characteristics, such as, density, ash, biomass/ash ratio, moisture and nitrogen content were also studied. It was observed that indigenous tree species are better suited as fuelwood species as they contain high density wood, low ash content and low N percentage. The fuelwood value index (FVI) was found to be high of indigenous tree species and was maximum forCasuarina equisetifolia (2815). The most promising tree species were in the order ofC. equisetifolia, A. nilotica andZ. mauritiana.     

人工林樟子松发热量与碳氢含量的关系分析

对东北林业大学哈尔滨实验林场人工林樟子松发热量和碳氢含量进行试验研究,结果表明,人工林樟子松发热量平均值为20.03 kJ/g,碳含量平均值为47.63%,氢含量平均值为6.39%;人工林樟子松各器官中,发热量和碳氢含量呈现出一致的变化趋势,即树叶各项值最高,树干木质部次之,其它依次为树枝木质部、树枝皮和树干皮;人工林樟子松各器官中,发热量与碳氢含量存在显著的相关关系。     

Fuel quality of Norway spruce stumps – influence of harvesting technique and storage method

Abstract

The interest in using stump biomass as a biofuel has recently increased in Sweden. The uneven consumption of wood fuel during the year creates a need for storage. This study examined the properties of stump biomass and how they vary at two sites in Sweden depending on harvesting technique, storage method and storage period. Norway spruce stumps, extracted using three different stump harvesting heads (Pallari, Rotary Cutter and Aalto), were stored in windrows or heaps. After 3 months, stumps stored in heaps were gathered into windrows. The fuel quality parameters moisture content (MC), ash content (AC) and calorific value (CV) were evaluated on five occasions in the period May 2008–September 2009. After 16 months of storage, the MC in all treatments had decreased to <25% (wet basis). Average AC decreased from 3.8% to around 1% (dry basis), whereas CV marginally increased. Stumps split during harvesting dried better than those harvested in one piece. The influence of storage method was minimal, although initial storage in heaps allowed better drying in the stumps harvested in one piece. In general, fuel quality improved in all treatments after storage.     

Net calorific values and mineral concentration of thirteen tree and shrub species in Ghana

Obtaining accurate and reliable information on biomass characteristics of tree species is important as it aids in selecting plant species that optimize fuel production for bioenergy. In this study, the net calorific value (NCV) and mineral concentration of 13 plant species selected from the Guinea savanna ecological zone of Ghana were investigated. Significant variation in NCV across the species components was found, with branch wood from most of the species exhibiting higher values compared to stem wood or the bark tissues. Accurate and reliable information on plant biomass could therefore be obtained through plant partitioning. High mobility of Zn and Pb after uptake was observed in the studied species. Apart from Cd whose concentrations in the species exceeded the recommended levels, no toxic levels were observed for the rest of the heavy metals. Thus, the major drawbacks in the use of the species as biomass resource are their higher concentrations of Cd and to some extent, higher ash contents. On account of the relatively high NCV, low ash content and low mineral concentrations, D. microcarpum, and C. febrifuga were found to be most suitable candidates for biomass production and subsequent bioenergy optimization in the Guinea savanna of Ghana.     

Energy dynamics ofPinus taiwanensis community in the Wuyi Mountains, Fujian, China

Based on the measurement of biomass and productivity, the calorific values of plant samples, the total amounts of energy, annual net energy fixation and energy conversion efficiency of 29-year-oldPinus taiwanensis community in the Wuyi Mountains were determined. There were some differences in calorific values among the various components ofP. taiwanensis community, in which the calorific value of trunk bark was the highest and that of dead roots was the lowest. The total amounts of energy in 29-year-oldP. taiwanensis community was 379.82 MJ/m², in which that accumulated in the aboveground biomass was 275.48 MJ/m², accounting for 72.53% of the total; that of below-ground was 104.34 MJ/m², 27.47% of the total. Net energy fixation for this community was 20.66 MJ/m²·yr in 1993. The energy conversion efficiency of the photosynthetic active radiation on the stand was 1.00%. This research was supported by Fujian Nature Science Foundation and The Administrative Bureau of Wuyi Mountains Nature Reserve.