林地生长数据 Forest Growth Data
图1. 林地生长数据
Image 1. Forest Growth Data
林地保存率非常稳定，尤其是近三年。从保存率看，林木的保存情况不如同期林地好，但没有发生明显的林木损失。该林地栽植的全部为杨树，杨树是速生树种，生长速度较快。主要体现在树高、地径、胸径等生长指标上。从树高均值变化看，林地增长趋势明显。林地地径均值始终保持增长。胸径均值出现下滑。由于胸径测量比例几乎未发生变化，胸径均值的下滑也就不是由保存情况或采样量增大等因素导致的了。这主要是由于采样的系统误差导致的。
The plot’s preservation rate was very steady, particularly in recent three years. The preservation rate was slightly lower than the trees in other plots, but there was no obvious loss in the amount. This plot was planted with poplars. As poplars are fast-growing trees, the fast growth was featured in the indicators such as height, basal diameter, diameter at breast height etc. The growing trend was very obvious when looking at the variation of average height. The average basal diameter kept increasing as well, but there was a decline in the average DBH. Since the measurement percentage of DBH was almost the same, the decline was not caused by the preservation situation or the sample size. This was merely caused by systematic errors.林地情况说明 Forest Description
图2. 林地树行（2020年10月25日）
Image 2. Tree Rows, October 25, 2020
图3. 林地北部（左）和南部（右）区域（2020年10月25日）
Image 3. Northern Part (Left) and Southern Part (Right) of the forest site, October 25, 2020
