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1.
西双版纳热带次生林生物量的初步研究   总被引:22,自引:4,他引:18       下载免费PDF全文
 本文采用“空间代替时间”和维量分析的方法研究了西双版纳热带次生林4块不同年龄林分的生物量,并详细分析了热带次生林在演替初期阶段生物量的变化趋势。结果表明:林分总生物量随林龄而增加,5年生林分的总生物量为41.932t·hm-2,10年生林分的总生物量为52.116t·hm-2,14年生林分的总生物量为88.284t·hm-2,22年生林分的总生物量为113.743t·hm-2。林分生物量的层次分配比例以乔木层所占的比例最大,占4/5以上,随林龄而增加;灌木层增长到14年生林分后又下降,草本层随林龄而递减,层间植物则上升。生物量的器官分配比例以干材所占的比例最大,占1/2以上,随林龄而递增;而枝、根和叶的生物量分配比例则随林龄而下降。并建立了4个林分主要优势种及乔木层器官生物量的回归模型。  相似文献   

2.
云南松林的净第一性生产量研究   总被引:5,自引:0,他引:5  
本文研究了云南省易门县海拔1600—1700m的云南松中幼龄林分的净第一性生产量。3个林分的净生产量总量依次为:11年生林分是1201.0g/(m~2·a),23年生林分是1060.3g/(m~2·a),4年生林分是530.4g/(m~2·a)。各林分乔木层器官净生产量的分配比例均以针叶为最高,其次是干材。针叶净生产量的比例随林龄的增加而下降,干材、树枝和根的比例则随林龄的增加而上升。  相似文献   

3.
不同林龄尾细桉人工林的生物量和能量分配   总被引:5,自引:0,他引:5  
对广东省遂溪县北坡林场1~4年生尾细桉人工林的生物量和能量进行研究.结果表明:林龄对林分现存生物量影响极显著(P0.01),1~4年生林分生物量在10.61~147.28t.hm-2,随林龄增加,各组分和林分的生物量均增加,叶片、枝、树皮生物量占林分总生物量的比例逐年减小,而树干则呈逐年升高趋势.4个林龄阶段各组分生物量的分布规律,1~2年生为树干枝树皮根叶片,3~4年生为树干根枝树皮叶片.不同林龄各组分的平均灰分含量在0.47%~5.91%,以树皮的灰分含量最高、树干最低.各组分的平均干质量热值和去灰分热值分别为17.33~20.60kJ.g-1和18.42~21.59kJ.g-1,均以叶片数值最高、树皮最低.林龄对枝、树干、树皮的干质量热值及对叶片、树干、树皮的去灰分热值有显著影响(P0.05),对叶片和根的干质量热值、枝和根的去灰分热值及植物体热值的影响不显著(P0.05).1~4年生尾细桉的林分能量现存量在199.98~2837.20GJ.hm-2,林龄对其的影响达极显著水平(P0.01),随林龄增长,各组分和林分能量现存量增加,且各组分能量分配比例的变化趋势与生物量相同.  相似文献   

4.
西双版纳橡胶林的生物量及其模型   总被引:1,自引:0,他引:1  
利用30株不同年龄和径阶的橡胶树样木数据,建立了以胸径(D)和胸径的平方乘以树高(D2H)为自变量的生物量回归模型.根据所建立的生物量回归模型,推算了15个1000 m2不同林龄橡胶林的生物量,并分析了其组成和分配特征及不同林龄生物量的变化趋势.林分的总生物量随林龄而增加,7、13、19、25和47年生橡胶林生物量分别为23.98、66.90、150.37、171.12和250.21 t·hm-2.生物量的器官分配以干材所占的比例最大,占50%以上,并随林龄而递增;枝生物量所占比例也随着林龄的增加而增大;叶和根的生物量所占比例则随林龄呈下降趋势.橡胶林生物量远低于本地区的热带季节雨林和石灰山季雨林,但高于本地区的热带次生林及其他热带地区年龄相近的人工林.  相似文献   

5.
林龄和竞争对日本落叶松各组分生物量异速关系的影响   总被引:1,自引:0,他引:1  
基于7-、17-、30-和40年生日本落叶松生物量测定数据,应用方差分析和多重比较分析了林龄和林分内树木竞争类型(优势木、平均木和被压木)对各组分生物量分配比例和异速关系的影响,构建了含林龄和树木竞争类型作为哑变量的生物量异速方程,为准确估算日本落叶松人工林生物量和碳储量提供依据。结果表明:(1)林龄显著影响生物量分配比例的异速关系。随林龄增加干生物量比例增大,枝叶生物量比例减小,根生物量逐渐稳定。加入林龄的干、枝和叶生物量方程显著改善。年龄效应在幼龄林阶段作用最显著,需单独构建生物量模型。(2)树木竞争类型对生物量分配的影响小于林龄。立地条件一致下,虽然相同胸径的优势木比劣势木积累更多的枝叶生物量和少的干生物量,但它们分配生物量到不同器官的比例和方式是基本相同的,林内竞争不会导致生物量分配规律由"异速关系理论"向"环境优先理论"转化。因此,常规采用平均木法估算各组分生物量是可行的。(3)在近成熟林分中不同竞争类型树木的根生物量分配比例均较为稳定,采用根茎比比值来估算根生物量是可行的。  相似文献   

6.
桂东不同林龄马尾松人工林的生物量及其分配特征   总被引:8,自引:0,他引:8       下载免费PDF全文
根据5a、15a、21a、32a、60a生的5个不同林龄的15块1 000m2样地(3次重复)调查资料,利用21株不同年龄和径阶的马尾松样木数据,建立以胸径(D)为单变量的生物量回归方程.采用样木回归分析法(乔木层)和样方收获法(灌木层、草本层、地上凋落物)获取不同林龄马尾松人工林的生物量,并分析了其组成、分配特征及不同林龄生物量的变化趋势.结果表明:(1)林分的总生物量随林龄而增加,5a、15a、21a、32a和60a生马尾松人工林生物量分别为15.03、125.93、183.51、191.53、405.31 Mg/hm2,其中活体植物占75.01%~94.19%,地上凋落物占0.86%~24.99%.(2)层次分配方面乔木层占绝对优势,占90.20%~98.35%,且随林龄的增加而增大,其次为地上凋落物,占0.86%~24.99%;草本层和灌木层生物量较小,分别占0.47%~34.85%和0.32%~27.00%,均随林龄的增加呈递减趋势.(3)乔木层器官分配以干所占比例最高,占49.93%~83.10%,且随林龄而增加;根相对比较稳定,占6.97%~12.82%;枝、叶分别占11.75%~14.83%、1.33%~23.65%,均随林龄增大而下降.灌木层器官分配除幼龄林为根>枝>叶,其余的均呈枝>根>叶的趋势.草本层中龄林和近熟林生物量地下>地上,其他林龄生物量地上>地下.(4)各林龄凋落物生物量在3.48~6.68Mg/hm2,规律性不强.(5)马尾松人工林乔木层各器官及林分生物量具有良好的优化增长模型,其32a生林分生物量高于同林龄的楠木人工林,低于热带雨林,是一种速生丰产、固碳潜力大的优良造林树种.  相似文献   

7.
为了清楚了解不同林龄杉木(Cunninghamia lanceolata)组织迁移养分(氮、磷、钾、钙、镁)再利用特征, 为人工林丰产的经营管理提供科学依据, 该文利用湖南会同杉木林不同林龄段的活的枝叶与枯死枝叶养分浓度及其差异和枝叶枯死量, 估算枝叶枯死前的养分迁移量。用某林龄段开始和结束时的杉木器官的养分浓度差异, 估算那些在某林龄段开始前林分生产的, 在林龄段结束时仍存活的器官(干、皮、枝、叶、根), 即仍存活物质, 在该林龄段的养分迁移量。将枝叶枯死前迁移的养分和这些仍存活物质中转移的养分与从土壤中吸收的养分相结合, 根据森林生产的生物量, 综合分析森林物质生产的养分利用特征。研究表明: 1-7年生林分, 利用枝叶枯死前迁移的养分生产的生物量及占总生产生物量的比例, 分别为217 kg·hm -2·a -1和3.52%; 20-25年生林分则分别上升到2 540 kg·hm -2·a -1和17.50%。枝叶枯死前迁移的养分生产的生物量及占总生产生物量的比例都随林龄增加而增大。林分在12-16、17-20、21-25年林龄段, 由这些仍存活物质中迁移出的养分生产的生物量分别为385、561和450 kg·hm -2·a -1, 分别占总生产生物量的3.40%、3.40%和3.11%。这些仍存活物质中迁移出的养分量随林龄增加呈现先上升后下降的变化, 由这些养分生产的物质量占总生产物质量的比例随林龄增加呈下降趋势。结果显示, 只要有枝叶枯死发生, 就有枝叶枯死前迁移出养分用于物质再生产。林分郁闭后, 才会发生这些仍存活物质中迁移出的养分再利用。杉木体内养分再分配及贮备机制、杉木生长规律和不同生长发育阶段对养分的需求和利用效率等, 共同调节控制着枝叶枯死前迁移的和这些仍存活物质中迁移出的养分再利用的年变化。  相似文献   

8.
北京松山自然保护区拥有华北地区唯一的天然油松林,通过对松山8块不同林龄天然油松林样地生物量分配格局进行调查,利用RDA分析和方差分解的方法探究环境因子对各器官生物量分配格局的影响,研究发现:(1)乔木层生物量随着林龄增大而增加,40、55、70、95年生林分乔木层生物量分别为116.96、132.31、144.86、170.82 t·hm-2,各器官(根、叶、干材、枝条)生物量随着林龄的增大也呈现增长趋势,但各器官的生物量分配比在各个林龄无明显差异(P0.05);(2)林龄与乔木层各器官生物量之间两两呈显著线性正相关。(3)环境因子前两个主成分对乔木层、灌木层、草本层生物量分配格局方差解释程度分别为:96.79%、46.04%、86.80%。在乔木层、草本层生物量分配格局的方差解释上,土壤因子模型的独立作用要远大于地形模型,在灌木层生物量分配格局的方差解释上,地形因子模型的独立作用要远大于土壤因子模型。  相似文献   

9.
杉木人工林生物量及其分配的动态变化   总被引:4,自引:0,他引:4  
根据5个年龄(6、16、23、32和50年生)共15块1000 m2样地的调查资料,利用15株不同年龄和径阶的杉木样木数据,建立以胸径(D)为单变量的生物量回归方程.采用样木回归分析法(乔木层)和样方收获法(灌木层、草本层、地上凋落物)获取不同林龄杉木人工林的生物量,并分析了其组成、分配特征及不同林龄生物量的变化趋势.结果表明:林分总生物量除16 ~23年生因间伐略有下降外均随林龄而增加,6、16、23、32和50年生杉木人工林生物量分别为62.73、172.51、141.65、192.30、247.32 Mg·hm-2,其中活体植物占95.76% ~98.39%;层次分配方面乔木层占绝对优势,为89.77% ~96.55%,其随林龄的变化与总生物量一致,其次为地上凋落物,占1.61% ~4.24%,灌木层和草本层生物量较小,分别占0.01% ~4.26%和0.27% ~4.07%,分别以6和23年生最大;乔木层器官分配以干所占比例最高,占54.89% ~75.97%,根占11.91% ~ 12.66%,均随林龄而增加,枝、叶分别占11.86%~15.19%和4.80%~13.17%,均随林龄而下降;灌木层器官分配除50年生杉木人工林枝相对生物量小于叶,23和50年生杉木人工林根相对生物量大干枝外,其大小顺序为枝>根>叶;草本层分配以6和23年生杉木人工林地上相对生物量最大,其他林龄相反;杉木人工林乔木层各器官、各层次及总生物量具有良好的优化增长模型,其32年生人工林总生物量与其他森林类型相比,处于中上等,是一个光合效率高、固碳潜力大的速生丰产优良造林树种.  相似文献   

10.
樟子松人工林蒸腾耗水量的初步研究   总被引:4,自引:1,他引:3  
樟子松(Pinus sylvestris L.var.mongolicaLitv.)于1955年开始在辽宁省彰武县章古台沙地上引种栽培,表现出适应性强,生长迅速,防风固沙效果好等特性。27年生林分平均树高达10米,胸径16厘米,材积105立方米/公顷,生物量84.1吨/公顷。但20年生以后松林沙土  相似文献   

11.
Aboveground tree biomass of Korean pine (Pinus koraiensis Sieb. et Zucc.) was determined for a natural forest of Korean pine and mixed deciduous trees and seven age classes of plantation forests in central Korea. Regression analyses of the dry weights of stem wood, stem bark, branches, and needles versus diameter at breast height were used to calculate regression equations of the form of log Y = a + b log X. Biomass of Korean pine in the mixed forest was 118 Mg ha(-1), and biomass in the plantations was linearly related to stand age, ranging from 52.3 Mg ha(-1) in 11 to 20-year-old stands to 317.9 Mg ha(-1) in 71 to 80-year-old stands. The proportions of stem wood and stem bark in the total aboveground biomass decreased with stand age while those of branch and needle increased. Specific leaf area of Korean pine ranging from 35.2 to 52.1 cm2 g(-1) was significantly different among crown positions and needle ages; in general, lower crown position and current needles had the greatest surface area per unit dry weight.  相似文献   

12.
The pattern of carbon (C) allocation across different stages of stand development of Chinese pine (Pinus tabulaeformis) forests is poorly documented. In order to understand the effects of stand age on the C pool of the Chinese pine forest ecosystem, we have examined the above- and belowground C pools in three differently aged stands of Chinese pine in the northern mountains of Beijing, China, by plot-level inventories and destructive sampling. Our results suggest that tree branch and foliage biomass should be estimated by age-specific equations. Reasonably accurate estimates of tree stem, tree root, aboveground, and total tree biomass in a Chinese pine forest at different development stages were obtained using age-independent allometric equations from tree diameter only. The ratio of belowground to aboveground tree biomass was relatively constant with stand aging, remaining around 21?%. The contribution of aboveground tree biomass C increased from 21?% of the total ecosystem C in a 25-year-old stand to 44?% in a 65-year-old stand, subsequently falling to 41?% in a 105-year-old stand, while the contribution of mineral soil C decreased from 64?% of the total ecosystem C in 25-year-old stand to 38?% in a 65-year-old stand, subsequently increasing to 41?% in a 105-year-old stand. The C stock of the total ecosystem and its aboveground tree, tree root, forest floor, and mineral soil components continuously increased with stand ageing, whereas the C stock of the understory showed a declining trend and contributed little to the total site C pool.  相似文献   

13.
The biomass and net primary productivity (NPP) of 5- to 15-year-old Shisham (Dalbergia sissoo Roxb.) forests growing in central Himalaya were estimated. Allometric equations were developed for all above- and below-ground components of trees and shrubs for each stand. Understorey forest floor biomass and litter fall were also estimated in forest stands. The biomass (dry matter), forest floor biomass (standing crop litter), tree litter fall and NPP of trees and shrubs increased with increasing age of the forest stand, whereas the dry matter and herb NPP decreased significantly (P < 0.001) with increasing age of the forest. Total forest biomass and NPP ranged from 58.7 (5-year-old stand) to 136.1 t ha(-1) (15-year-old stand) and 12.6 (5-year-old stand) to 20.3 t ha(-1) year(-1) (15-year-old stand), respectively. Of these values, tree biomass accounted for 85.7 (5-year-old stand) to 90.1% (15-year-old) of total forest biomass, and tree NPP for 72.2 (5-year-old) to 82.3% (15-year-old) of total forest NPP. The biomass accumulation ratio (BAR) of the bole component (bole wood + bole bark) increased with increasing age of the forest stand. The bole BAR was 5.8 (5-year-old stand) to 7.9 (15-year-old stand). However, total BAR of the forest stand ranged from 5.5 (5-year-old) to 7.5 (15-year-old).  相似文献   

14.
Exotic pine plantations constitute a significant landscape feature in the North Island of New Zealand but their conservation value for native plant species is not often documented. Pine stem density, height and basal area of nine plantations of Pinus radiata ranging in age from 6 to 67 years in Kinleith Forest was determined. Pines reached heights of 60 m, and stand basal areas up to 183 ± 14 m(2)ha(-1). The abundance of woody shrubs, tree ferns and ground ferns was assessed in each stand. Understorey composition of shrubs and ferns was reflected on the first two axes of DCA ordinations and correlated with the age of the pines. Adventive shrubs predominated in stands < 20 years old. Light-demanding native shrubs with bird dispersed fruits predominated in older stands, with more shade-tolerant species in the oldest site. Species richness increased rapidly in the first 11 years, but thereafter more slowly. Twelve native shrub species and 22 ferns were recorded from the most diverse stands. Richness and species composition were related to stand age, and probably also to topographical heterogeneity and aspect. Tree ferns reached densities of 2000—2500 ha(-1) and basal areas of 20—30 m(2)ha(-1) in the older stands. Initially the tree fern population was strongly dominated by Dicksonia squarrosa, which comprised 84% of individuals overall. Five species were present by 29 years. The faster growing Cynthea medullaris and C. smithii achieved greater heights than the Dicksonia spp., and their relative biomass was greatest in the oldest stands.  相似文献   

15.
Kurka  Anne-Marie  Starr  Michael 《Plant and Soil》1997,195(2):273-281
The relationship between the decomposition of cellulose placed on and buried in the forest floor and various tree stand characteristics was studied at sites with minimal anthropogenic influence. The 22 study sites, including both forested upland and peatland plots, were clustered in 4 catchments between 61°–69° N in Finland. The stands were 60 to 320 years old and composed of varying proportions of Scots pine (Pinus sylvestris L.), Norway spruce (Picea abies Karst.) and deciduous species (mainly t Betula spp.). Cellulose strips (softwood pulp) were placed on the forest floor surface and buried at four depths down to 5 cm for two 1-year periods and the weight loss measured. Decomposition did not significantly correlate with stand age, but was strongly and positively correlated with stand basal area, mean tree height and stem volume. This was valid at all depths, and even after differences due to climate between catchments had been taken into account. The stem volume of Scots pine dominated plots had the highest correlation. Our results showed that decomposition of organic matter on and in the forest floor is related to the stand characteristics. This relationship should be considered when comparing soil processes different stands, even when comparing stands of the same tree species composition.  相似文献   

16.
Curt  Thomas  Prévosto  Bernard 《Plant Ecology》2003,167(2):269-282
The natural establishment of shade-tolerant forest species such as beech (Fagus sylvatica L.) occurs in naturally regenerated Scots pine (Pinus sylvestris L.) woodlands that develop on former pastures and cultivated lands. To examine possible effects of underground competition in beech establishment, we studied the root biomass and the rooting profile of 53 mixed Scots pine-natural beech woodlands in French mid-elevation volcanic areas. Stands were arranged along a maturation gradient. Roots were sampled using the root-auger technique (0 to 75 cm depth every 15 cm). In addition, 23 young beeches were uprooted to study the entire root system. Total beech fine-root biomass was closely correlated with most beech aerial characteristics, (e.g., height, diameter and girth), and correlated moderately with tree age. However, it correlated poorly with basic competition indices such as stand density and basal area. Conversely, competition indices including vertical dimensions of competing trees were correlated with the underground biomass, probably as a result of redundancy with beech height. The rooting profile (fine roots, < 5 mm) of beech and pine were quite similar, and did not change significantly along the stand maturation gradient. Beech has a heart-shaped root system while pine is more plate-like and dimorphic. Beech fine-root biomass progressively surpassed pine biomass throughout the soil layers, thus confirming that it is dynamic and competitive in mature mixed stands. The coexistence of the root systems of beech and pine in the same soil layers presumably results in strong underground competition.  相似文献   

17.
采用空间代替时间的样地调查方法,利用异速生长方程和一元材积表计算不同林龄桦木林的生物量、生产力与材积,结果表明,桦木林乔木层及平均单株地上生物量均随林龄增加而增加,在50 a时达到最大;生产力则先增加而后逐渐减少,乔木层30 a时生产力为7.88 t.hm-.2a-1,到40 a和50 a时,分别下降到5.17 t.hm-.2a-1和1.19.thm-.2a-1;单株平均生产力在30 a时达到最大值1.13 kg.a-1,40 a时下降为0.96 kg.a-1,50 a时略有上升。林分蓄积量随林龄增加而增加,平均生长量在50 a达到最大值3.78 m.3hm-2,连年生长量在30 a时达到最大值6.07 m.3hm-2。平均单株材积增长速度随林龄增加而增加,50 a时平均生长量和连年生长量达到最大值。  相似文献   

18.
Abstract

Fine roots (<2 mm) are very dynamic and play a key role in forest ecosystem carbon and nutrient cycling and accumulation. We reviewed root biomass data of three main European tree species European beech, (Fagus sylvatica L.), Norway spruce (Picea abies L. Karst.) and Scots pine (Pinus sylvestris L.), in order to identify the differences between species, and within and between vegetation zones, and to show the relationships between root biomass and the climatic, site and stand factors. The collected literature consisted of data from 36 beech, 71 spruce and 43 pine stands. The mean fine root biomass of beech was 389 g m?2, and that of spruce and pine 297 g m?2 and 277 g m?2, respectively. Data from pine stands supported the hypothesis that root biomass is higher in the temperate than in the boreal zone. The results indicated that the root biomass of deciduous trees is higher than that of conifers. The correlations between root biomass and site fertility characteristics seemed to be species specific. There was no correlation between soil acidity and root biomass. Beech fine root biomass decreased with stand age whereas pine root biomass increased with stand age. Fine root biomass at tree level correlated better than stand level root biomass with stand characteristics. The results showed that there exists a strong relationship between the fine root biomass and the above-ground biomass.  相似文献   

19.
分布区西缘油松种群的生长特征   总被引:4,自引:0,他引:4       下载免费PDF全文
 在青海省互助北山林场和贵德东山林场的油松林内分别设置6个和5个样方,对分布区西缘的天然油松种群的生长特征进行了生态学研究。结果表明,两地的油松种群均为复层异龄结构;树高与胸径的关系揭示东山的油松种群其生长能力仅为北山的一半;种群内个体的树高直径比与个体的大小呈负相关,表明个体生长对被压的生态适应;两地个体的直径生长过程也差异很大,即东山油松的直径生长随年龄的增长呈下降趋势,而北山呈上升趋势或变化很小。上述差异导致两地的生产力差异很大:北山可望获得200t/ha的生物量,而东山仅约为100t/ha,但两地的生物量密度差异不大,为7一11t/ha.m,利用生物量密度与总胸高断面积之间的线性关系,可以建立良好的推算种群地上部生物量的方法。本文还对天然油松的种群密度与平均个体重之间的关系作了讨论。  相似文献   

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