阔叶红松混交林立地因子和林分因子对松梢象甲发生及危害的影响

抽样调查黑龙江省伊春地区上甘岭林业局2013年度阔叶红松混交林遭受松梢象甲危害的24个林班、59个小班内177块样地的立地和林分因子、受灾情况等,计算有虫株率、虫口密度、Simpson多样性指数,分析阔叶红松混交林立地因子和林分因子对松梢象甲发生及危害的影响。结果表明:在上甘岭林业局阔叶红松混交林中,南坡受松梢象甲的危害较北坡严重,南坡虫害发生数是北坡的189.80%,占总有虫样方的52.54%,为主要受灾区域;将受灾样地的有虫株率与郁闭度值进行一元二次方程拟合,y=–12.689x~2–11.713x+27.843,R~2=0.666 4;将受灾样地的有虫株率与Simpson指数进行一元二次方程拟合,y=0.001 3x~2–0.060 4x+1.084 1,R~2=0.720 8;随着Simpson多样性指数的增加和郁闭度的增加,有虫株率有明显降低的趋势。松梢象甲虫口密度与受灾林地的乔木平均树高和平均胸径呈显著相关。

Influence of the site factors and stand factors of broad-leaved Korean pine mixed forest on its resistance to Pissodes nitidus Roelofs

To analyze the influence of site factors and stand factors on the occurrence of Pissodes nitidus and the damage caused by Pissodes nitidus, the site factors,stand factors and the damage caused by Pissodes nitidus in 177 sample plots (with 24 compartments,59 sub-compartments)in broad-leaved Korean pine mixed forest were investigated,and the percentage of insect-infected trees, population density, Simpson diversity index were calculated. The result showed that the damage of P. nitidus on broad-leaved Korean pine mixed forest at the south slope was more serious than that in the north slope and the disease incidence of the south slope was 189.80% as much as that of the north slope. The disease incidence of the south slope accounts for 52.54% of the total samples, thus the south slop is the main morbidity region. When the percentage of insect-infected trees in the damaged area and the canopy density were fitted , the equation y =–12.689x2 – 11.713x + 27.843 was obtained,and the correlation coefficient R2=0.666 4. When the percentage of insect-infected trees in the damaged area and Simpson diversity index were fitted, the equation y = 0.001 3x2 – 0.060 4x +1.084 1 was obtained,and the correlation coefficient R2=0.720 8. The results indicated that with the increase of the Simpson diversity index and canopy density, the infection rate of pests was obviously decreased. The P. nitidus population density is significantly correlated with the average tree height and diameter at breast height of the arbor.