In the process of pruning,the saw-cutting force of a tall tree pruner is changing constantly,and meanwhile the forces applied on the circular saw blades,gear pairs and control levers are changing all the time.

Under branch height has direct impact on woods growth and trunks form,so dynamic model established with under branch height can reflect the growth of woods and stands.

Estimation of total carbon-containing gas emission from main tree species in forest fires in Daxing an Mountains;

And there were 177 species of trees among them,which are subdivided into 111 genera and 47 families.

The Zhifanggou watershed in Ansai county is an example of a Loess Hilly Region and the characteristics of nutrient cycling and balance of 1 tree,4 shrub,and 9 herbage vegetation types have been systematically studied during a period of vegetation stabilization and rehabilitation.