竹林立竹度和竹龄结构与螨危害的关系

Relationship between stocking & age structure and mite damage in bamboo forest

对毛竹害螨 (南京裂爪螨、竹缺爪螨、竹针刺瘿螨 )在毛竹林中的危害程度与竹林立竹度和竹龄结构的关系 ,以及害螨对竹林产竹量、产笋量的影响进行了调查。调查表明 ,当竹林立竹度为2 70 0～ 30 0 0株 /hm2 ,竹林内 度以上竹少于 1 0 %时 ,竹林轻度受害 ;当竹林立竹度为 2 2 0 5～ 2 70 0株 /hm2 ,竹林内 度以上竹占 1 0 %～ 30 %时 ,竹林中度受害 ;当竹林立竹度为 1 2 0 0～ 2 1 0 0株 /hm2 ,竹林内 度以上竹比例大于 30 %时 ,竹林重度受害。毛竹害螨危害对竹林产量、产值的影响是 :轻、中、重度受害林比未受害林 ,度产竹量分别下降 1 3.7%、35 .6%、61 .9% ;度产笋量分别下降1 6.1 %、38.7%、61 .3% ;产值每公顷分别减少 1 0 1 4元、2 4 87.8元、40 4 7.9元。

The investigation sho wed that b amboos were injured slightly when the st oc king was 2700-3000/hm2 and the six to seven- year-old bamboos were less than 10%.Medi um damage occurred when the stocking was 2205-2700/hm2 and six to seven-year-old bamboos reached 10%-3 0 %.Bamboos were injured badly when the st oc king was 1200-2100/hm2 and six to seven- y ear-old bamboos were more than 30%.Accordi ngly,the influence of the harmful mite d amage on bamboos was also divided into t hree degrees.Compared with the uninjure d bamboos,the output of bamboo decreased by 13.7%,35.6% and 61.9% respectively;t he output of bamboo shoots decreased by 1 6.1%,38.7% and 61.3% respectively,and th e output value decreased by 1014,24 87.8 and 4047.9 yuan per hectare respectively.