年平均生长量 meaning in Chinese

mean annual precipitation

This paper gives a survey on experimental forestland . 25 tree species were selected , and arranged in order by average diameter at breast height , average height , average individual volume and annual average volume increment in a unit area in this experiment
摘要简要介绍了试验林地的概况，选择了25个树种进行试验，并按各树种林分平均胸径、平均树高、平均单株材积和平均单位面积蓄积的年平均生长量进行排序。