Effects of Different Numbers of Seedlings Left in the Seedbed on Diameter Grade of Robinia pseudoacacia
In the semi-arid areas of western Liaoning Province,taking 1-year-old Robinia pseudoacacia as obj ects, the effects of Robinia pseudoacacia seedlings with different densities on their qualities were studied.Result shows that GradeⅠemerged the largest number (60 000-90 000 ?hm-2 )while the density being 120 000-200 000 trees ? hm-2;seedlings of GradeⅠ and Grade Ⅱ occupied more than 90% of the total seedlings left in the seedbed ;when the densities of seedlings left in the seedbed are less than 1 2 trees ?hm-2 ,seedlings with GradeⅠand GradeⅡoccu-pied above 90% of the total seedlings left in the seedbed,but the number of seedlings with Grade Ⅰ reduced;when density of seedlings left in the seedbed are greater than 20 trees ?hm-2 ,seedlings with GradeⅠand GradeⅡoccupied less than 90% of the total seedlings left in the seedbed,the number of seedlings with GradeⅠreduced.
Robinia pseudoacaciadensity of seedlings left in the seedbedground diameterseedling quality
NETL
NSTL
万方数据
维普
