White Spruce NPP: average NPP per tree by age cohort for 4 time periods between 1993 and 2008

This data set is derived from BNZ LTER inventory plots, where DBH of all trees is measured every 3 to 4 years, and increment changes in AG biomass are derived from allometric equations. Data included in this file were obtained from 1993, 1997, 2000, 2004 and 2008 inventories, generating 4 growth increments between 1997 and 2008. Data are reported by age cohort, and include NPP increments (averaged across all trees within each landscape and successional stage) for all trees of known age (determined from coring).

本数据集源自BNZ长期生态研究（Long-Term Ecological Research, LTER）样地的清查数据，该样地内所有林木的胸径（Diameter at Breast Height, DBH）每3至4年测定一次，地上生物量（Aboveground Biomass, AG biomass）的增量变化通过异速生长方程推导得到。本文件收录的数据来自1993、1997、2000、2004及2008年的五次清查，其中1997至2008年间共生成4组生长增量数据。数据按年龄组进行统计，包含所有通过钻芯法确定年龄的林木的净初级生产力（Net Primary Productivity, NPP）增量，该增量为各景观与演替阶段内所有林木的平均值。