杨桦

杨桦作品

Works From Yang Hua

杨桦次生林群落是冀北山区最为常见的林分类型，其原生树种为华北落叶松林。

Polar-Birch secondary forest stands is the most common type of forest stands in northern mountain of Hebei province , the native species there is larch .

在森林覆被率上没有多大变化，杨桦的比重增加，但平均每公顷蓄积量却大大降低。

It had no much change on forest coverage . The proportion of poplar and birch increased . But the average volume per hectare decreased a lot .

杨桦次生林中白桦等阳性树种的株数所占比例较大，云冷杉针阔混交林的红松、云杉和冷杉在树种组成中表现较大成数。

In polar-birch secondary forest , Betula platyphylla had larger abundance than other species ', while Pinus koraiensis , Picea koraiensis , Abies nephrolepis were showed great number in species composition of broadleaved mixed forests .