青冈栎解析木分析及人工林生物量调查

Analytical wood analysis and biomass investigation of Cyclobalanopsis glauca plantation

为了掌握青冈栎人工林生长及生物量分配规律,为青冈栎人工林经营管护提供科学依据和技术指导,对50年生青冈栎人工林随机设置5个面积为400 m^2(20 m×20 m)的标准地进行生物量调查,并在每个标准地内各选取6株不同径级的平均木伐倒进行树干解析。结果表明:(1)青冈栎树高、胸径和材积的连年生长量范围分别在0.15～0.45 m、0.09～0.56 cm和0.000 4～0.01 m^3之间。(2)树高、胸径和材积的连年生长量高峰值分别出现在12 a、15 a和40 a,高峰值分别为0.45 m、0.56 cm和0.010 0 m^3·a^(-1)。(3)材积的连年生长量和平均生长量相交于50 a,林分达到数量成熟,可以确定为主伐年龄。(4)50年生青冈栎人工林单株总生物量高达936.22 kg·株^(-1),各组分生物量排布从大到小依次为:树干(426.95 kg)>大枝(201.44 kg)>根蔸(134.19 kg)>树皮(41.23 kg)>小枝(36.83 kg)>叶(35.02 kg)>粗根(32.40 kg)>枯枝(15.71 kg)>中根(9.69 kg)>细根(2.76 kg)。(5)青冈栎人工林乔木层的总生物量为595.11 t·hm^(-2),占林分总生物量的98.33%,其中地上部分与地下部分分别为481.32 t·hm^(-2)和113.80 t·hm^(-2),占乔木层比重为80.88%和19.12%。(6)50年生青冈栎林分的总生产力为18.57 t·hm^(-2)a^(-1),3个植被层生产力大小为:乔木层(15.91 t·hm^(-2)a^(-1))>灌木层(1.85 t·hm^(-2)a^(-1))>草本层(0.82 t·hm^(-2)a^(-1));分别占总生产力的85.65%、9.94%、4.41%。青冈栎人工林主伐年龄为50 a。合理调整密度、科学间伐和改善林下环境是促进青冈栎人工林健康生长的必要手段。

The study was carried out to understand the growth and biomass allocation pattern of Cyclobalanopsis glauca plantation in order to scientifically and technically guide the management operation of Cyclobalanopsis glauca plantation.In this trial,5sample plots with area of400m^2(20m×20m)were randomized set to investigate the biomass and6average trees with different diameter grades in each sample pot were cut down to do the stem analysis in50a Cyclobalanopsis glauca plantation.[Result](1)The range of current annual increment of tree height,DBH and volume of timber was0.15m^0.45m,0.09cm^0.56cm and0.0004m^3~0.01m^3respectively.(2)The peak of current annual increment of tree height,DBH and volume of timber occurred in12a,15a and40a,with peak value of0.45m,0.56cm and0.0100m^3·a^-1respectively.(3)In curve gragh,the current annual increment and average increment of volume of timber intersected at50a,when the plantation matured quantitatively and could be identified as the final felling age.(4)The total individual biomass of50a Cyclobalanopsis glauca plantation reached936.22kg·tree^-1.The ranking order of biomass of components was as follows:stem(426.95kg)>limb(201.44kg)>root stump(41.23kg)>undershoot(36.83kg)>leaf(35.02kg)>large root(32.40kg)>dead branch(15.71kg)>middle size root(9.69kg)>fine root(2.76kg).(5)The total biomass of tree layer in50a Cyclobalanopsis glauca plantation was595.11t·hm^-2,as98.33%of the toal biomass of the plantation.The biomass of aboveground and underground of tree layer was481.32t·hm^-2and113.80t·hm^-2,as80.88%and19.12%of the biomass of tree layer respectively.(6)The gross productivity of50a Cyclobalanopsis glauca plantation was18.57t·hm^-2a^-1,among which the ranking order of productivity of3vegetation layers was tree layer(15.91t·hm^-2a^-1)>shrub layer(1.85t·hm^-2a^-1)>herb layer(0.82t·hm^-2a^-1),as85.65%,9.94%and4.41%of the gross productivity respectively.The final felling age of Cyclobalanopsis glauca plantation is50a.It is necessary to adjust the idensity reasonably,thin scientifically and improve the underforest environment for the healthy growth of Cyclobalanopsis glauca plantation.