Crown's dimension and factors related with those in 30...40 year old stands on abandoned agricultural lands
1997
Reisner, Ue. (Estonian Agricultural Univ., Tartu (Estonia). Dept. of Silviculture)
Seven sample plots were established in stands on abandoned fields to describe the relations between tree's crown dimensions and other characteristics of stand or tree. There are very good conditions for tree growth in these lands. The site index in all stands is I b. The stand age in sample plots was from 28 to 42 years. Two stands are pine stands, two pine-larch mixed stands and three are pine-birch mixed stands. The dimensions of crowns of different tree species are significantly different. The height of crown's base in stand depends on tree diameter at breast height (DBH) and class of height, the crown diameter depends on DBH. Both functions are exponential and positive. Average grown dimensions in stands are well described by linear models using average DBH and height as independent variables. The average height of crown base in pine stands is well predicted by stand age. The differences between the crown variables of forest and abandoned fields were not significant
显示更多 [+] 显示较少 [-]