晋西刺槐和油松人工林密度效应规律

根据刺槐和油松人工林59株解析木资料,分析林分密度效应随年龄变化特征,拟合了单株胸径生长模型和密度效应模型.研究表明,随林龄增长,林木胸径生长与密度负相关系数增大,密度影响逐渐显著.但达一定林龄后,相关系数增幅变小,位于方山县阳坡刺槐林林龄为13 a,半阳坡为10a；位于吉县半阳坡刺槐林林龄为8a；位于方山县半阳坡和阴...

Plantation density effect characteristics of black locust and pitch pine plantation in the West Shanxi Province

According to data of 59 sample trees of black locust and pitch pine plantations in the west Shanxi,the variation characteristics of density effect with stand age were investigated to draft growth model of DBH of single and density effect model by fitting.The results showed as folliws the density effect became more and more obvious with the increase of forest age,while breast diameter in growth progress and negative correlation coefficient of density increased.When the forest age reached a certain standard,the correlation coefficient growth rate declined.The forest ages were 13 years old Robinia pseudoacacia on the north-facing slope;10 years old on the semi-north-facing slope;8 years old R.pseudoacacia on the semi-north-facing slope in Ji County;13 years old Pinus tabulaeformis Carr on the semi-north-facing slope and south-facing slope in Fangshan County.Different slopes gave different responses for density.The correlation coefficient of north-facing slope R.pseudoacacia Linn in Fangshan County was smaller than that of semi-north-facing slope;the correlation coefficient of south-facing slope of P.tabulaeformis Carr in Fangshan County was smaller than that of semi-north-facing slope.Plantation in different slope aspect had different first artificial afforestation density and tending management.