Aboveground biomass stocks and net primary production of three primeval European beech forests in eastern Slovakia

The study took place in three primeval European beech forest reserves in eastern Slovakia and in three close by production forests with similar site conditions. Three compartments of aboveground biomass stocks (live woody tree biomass, litter biomass, regeneration biomass, coarse and fine woody debris) and two compartments of aboveground net primary production (anual woody biomass increment and litter production) were inventoried.
Stand structural data (tree diameter, coordinates, height and more) was inventoried on 40 500 m^2 plots per primeval forest and on 10 plots of the same size per production forest (low intensity plots - 150 LIPs in total). This data was used to estimate live woody biomass on basis of allometric equations. The structural data of the plots were used to classify the primeval forest plots into three stages of the natural development cycle (growth, optimal, terminal). The classification was used as a basis to select four plots per development stage and four plots per production forest for the recording of the remaining biomass and productivity compartments (high intensity plots - 48 HIPs in total). Litter biomass and production was estimated using litter traps. Regeneration biomass was recorded by counting regeneration trees on sub-plots of the 48 HIPs. Coarse woody debris was estimated by measuring dimensions of all downed logs with base diameters >= 20 cm. Fine woody debris was estimated with line intersect sampling on 4 6.5 m long transects per plot. Annual woody biomass was estimated by taking repeated readings of permanent increment tapes. Upscaling to tree level was done with allometric equations.

本研究选取斯洛伐克东部的三处原始欧洲山毛榉林保护区，以及三处立地条件相近的邻近经营性森林作为研究区域。地上生物量库的3类组分（涵盖活木本树木生物量、枯落物生物量、更新层生物量、粗木质残体与细木质残体）以及地上净初级生产力的2类组分（木本生物量年增量与枯落物生产量）均完成了清查。
针对每处原始林设置40个500平方米的样地，每处经营性森林设置10个相同面积的样地，共计150个低强度样地（Low Intensity Plots，LIPs），完成了林分结构数据（树木胸径、坐标、树高等）的清查工作。基于异速生长方程，利用该数据估算活木本树木生物量。
利用样地结构数据将原始林样地划分为自然发育周期的3个阶段：生长阶段、最优阶段与末期阶段。以此分类结果为依据，从每个发育阶段选取4个样地、每处经营性森林选取4个样地，共计48个高强度样地（High Intensity Plots，HIPs），用于剩余生物量与生产力组分的调查记录。
枯落物生物量与生产量通过枯落物收集器（Litter Traps）进行估算；更新层生物量通过在48个高强度样地的副样地内统计更新幼树数量完成测定。粗木质残体通过测量所有基径≥20厘米的倒木尺寸进行估算；细木质残体采用线截抽样法，在每个样地内设置4条长6.5米的样线完成估算。木本生物量年增量通过重复读取永久增量测带的数值完成估算，最终通过异速生长方程将样地尺度的估算结果上推至单木水平。