Annual tree productivity in permanent plots within the H.J. Andrews Experimental Forest

Tree cores were taken from trees in permanent plots within the H.J. Andrews Experimental Forest to estimate annual bole biomass increment. The purpose of measuring this was to determine how many trees need to be sampled within a stand in order to determine NPP accurately. Increment cores were extracted from all trees greater than 5 cm diameter at breast height in each site and measured for annual growth increment (cm). This data was used to explore a method for using increment cores in combination with long-term permanent plots and remeasurement records to estimate annual bole biomass increment.

研究从H.J. 安德鲁斯实验林（H.J. Andrews Experimental Forest）内永久样地的林木中采集树木生长芯（Increment core），以估算年树干生物量增量。本次测量的核心目的为确定单个林分（stand）内需采样的林木株数，以实现净初级生产力（Net Primary Productivity，NPP）的精准估算。研究人员从各样地内所有胸径（diameter at breast height）大于5 cm的林木中提取生长芯，并测量其年生长量（单位：cm）。本数据集被用于探索一种结合生长芯、长期永久样地与复测记录来估算年树干生物量增量的研究方法。