赤腹松鼠在人工林中的危害特征

Damage of Callosciurus erythraeus in Planted Forests

2008年3月～2009年3月,设置15个固定样地每月监测,对四川省洪雅县柳杉Crypotomeria fortunei和杉木Cunninghami lanceolata人工混交林中赤腹松鼠Callosciurus erythraeus的危害特征进行调查研究,结果表明:1)2～7月是危害的主要时期,其中3、4月最高;柳杉的年平均危害株率高于杉木,但两者的年平均危害程度区别不大;2)不同龄林的危害情况不同,月平均危害株率:中林显著高于成林和幼林(P<0.05);月平均危害程度:幼林高于中林,中林高于成林,三者差异显著(P<0.05);3)林木被危害的部位主要集中在上部和中部;不同龄林危害部位的分布不同,成林和中林的危害部位比例为上部>中部>下部,而幼林是中部>上部>下部;4)啃剥树皮类型以包含木栓、木栓形成层和次生韧皮部的树皮为主,同时有少数外周皮;啃剥外周皮的现象出现在2～4月和7～11月。

From March 2008 to March 2009,damage inflicted on Crypotomeria fortunei and Cunninghami lanceolata by Callosciurus erythraeus was observed monthly in 15 fixed sample plots in Hongya County,Sichuan Province. Our results showed：1） February to July was the main period of damage,among which the most serious damage occurred in March and April. Crypotomeria fortunei showed a higher annual average rate of damaged trees than Cunninghami lanceolata,but the difference of the annual average degree of damage between them was not significant. 2） Different aged forests showed diversity in damage. Middle aged forests had significantly higher monthly average rates of damaged trees than mature forests and young forests （P0.05）; Young forests had a higher monthly average damage degree than middle aged forests,and middle aged forests had a higher monthly average damage degree than mature forests. The difference between the three was significant （P0.05）. 3） Damage mainly occurred in the upper and middle part of trees. The location of the damage was different in forests of different ages. The ratio of damage locations in mature forests and middle aged forests was uppermiddlelower,whereas in young forests the proportion was middleupperlower. 4） Bark-stripping types mainly consisted of bark that included phellem,cork cambium and secondary phloem,as well as few external periderm. Bark-stripping of external periderm occurred in February to April and July to November.