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林木细根生物量具有一定的空间异质性,因此采用合理的细根取样策略对精确估算细根生物量十分重要。通过在福建省三明杉木人工林林内采用土钻法随机选取100个取样点,分析不同细根类型(杉木、林下植被、总细根)生物量的空间变异特征,并对细根生物量所需的取样数量进行估计。结果表明:不同细根类型单位面积生物量随径级(0—1、1—2 mm)及土层深度的增加变异增大,所需的取样数量也相应增加。Shapiro-Wilk检验表明,仅0—2 mm杉木细根和总细根单位面积生物量符合正态分布,其余各个细根类型不同径级不同土层单位面积生物量均不符合正态分布,均呈明显的右偏分布。蒙特卡罗统计模拟分析表明:在置信水平为95%、精度为80%的条件下,直径为0—1 mm、1—2 mm和0—2 mm的细根,杉木采集95、96、32个样品可以满足测定单位面积生物量的需要,林下植被分别采集98、98、63个样品可以满足测定单位面积生物量的需要,而总细根分别采集93、93、18个样品可以满足测定单位面积生物量的需要。
Fine root biomass of forest has certain spatial heterogeneity, so it is very important to adopt fine root sampling strategy to accurately estimate fine root biomass. The spatial variability of biomass of different fine root types (fir, understory vegetation and total fine root) was analyzed by using the soil drilling method to select 100 sampling points at random in the forest of Sanming Cunninghamia lanceolata plantation in Fujian Province. The number of samples needed to be estimated. The results showed that the biomass per unit area of different fine roots increased with the increase of diameter (0-1, 1-2 mm) and soil depth, and the number of samples required increased accordingly. Shapiro-Wilk test showed that the biomass per unit area of fine roots and total fine roots of 0-2 mm only accorded with the normal distribution, and the biomass of unit area of different fine-grained types and different soil layers did not fit the normal distribution Obviously right-sided distribution. Monte Carlo statistical simulation analysis showed that fine roots with diameter of 0-1 mm, 1-2 mm and 0-2 mm were collected under the confidence level of 95% and the precision of 80%. Chinese fir collected 95, 96, 32 The samples can meet the need of measuring biomass per unit area. 98, 98 and 63 samples can be collected by undergrowths, which can meet the need of measuring biomass per unit area, while 93,93 and 18 samples of total fine roots can meet the needs of determination The need for biomass per unit area.