Effects of Stand Factors and Plant Diversity on the Damage Degree of Dioryctria sylvestrella
The stand factor and under forest vegetation diversity of Pinus sylvestris var.mongolica plantation in Qiqihar area of Heilongjiang Province were investigated from 2017 to 2019,and the effects of each factor on the dam-age degree of Dioryctria sylvestrella were analyzed.The results showed that the correlation between stand factors and damage degree was different in stands with large difference of tree age within patch(stand type Ⅰ)and stands with small difference of tree age within patch(stand type Ⅱ).Tree height,age and crown density could better reflect the damage degree of stand type Ⅰ,while DBH,tree age and crown density could better reflect the damage degree of stand type Ⅱ,and crown density had opposite correlation with the plant damage rate in the two stand types.Due to the continuous damage of D.sylvestrella,the increase of wind break rate of young forest might lead to more serious occurrence of pest.The plant diversity of P.sylvestris var.mongolica plantation was low,with a total record of 154 species of 113 genera of 58 families.Shannon-Weiner index and Simpson index of herbaceous plants could better reflect the damage degree of the 8-25 a stands,while Shannon-Weiner index and Simpson index of woody plants could better reflect the damage degree of the 36-51 a stands,and the greater the plant diversity index was,the greater the damage degree was.The Pielou index of the whole understory plants could better reflect the damage degree of the 26-35 a stands,and the greater the diversity index was,the greater the damage degree was.
万方数据
维普
