Abstract: The crown characteristics of eleven five years old black poplar hybrid clones were explored.No significant difference of crown characteristics was found among clones, but great difference existed among different layers and parts within the crown.The difference of the vertical distribution of foliage was greatly attributed to leaf size, while for the horizontal variation of foliage, the leaf number played a great part.The general distribution pattern of crown in population was that the leaf area increased from upper to lower and from inner to outer within the crown.

Key words: Crown characteristics, Spatial distribution, Poplar clones, mortality model, effects of thinning, Logistic regression, Larix olgensis plantation, generalized estimating equation