浙江天童常绿阔叶林石栎叶片昆虫取食状类型和取食强度研究

在浙江天童常绿阔叶林中随机选择10株石栎（Lithocarpus glaber）大树，每株选择冠层向阳枝条2枝，取其所有成熟叶片（2332片）对昆虫取食状类型和取食强度进行了分析。结果表明，石栎叶片昆虫取食状类型多样，计有15种，但出现频度有很大不同；顶食状和缘食状的频度分别在30％以上；切叶状、连续小孔状和大孔状的频度在10％～30％：小孔状、阴面食状、叶中脉、泡状的频度在6．4％～1．5％；其余6种类型的频度〈1％。对叶片的危害程度取决于取食面积和频度，顶食状等3种类型频度高、取食面积大，对叶片的危害重；而阴面食状等11种类型取食面积较小，频度低，对叶片的危害较小；连续小孔状尽管取食频度高，但取食面积小，对叶片的危害也小。连续小孔状和切叶状之间存在显著正相关，但连续小孔食状与阴面食状之间，切叶状、连续小孔食状与小孔食状之间则存显著负相关，其它取食状之间均没有显著相关性，反映出不同昆虫类型的取食生态位关系。石栎叶片昆虫取食率为13．6％，介于温带森林和热带森林之间；但石栎叶片的昆虫取食频率64％，小于辽东栎，可能是由于防御机制上的差异所至；此外，石栎叶片昆虫取食强度还受到植株本身因素和小生境等因素的影响。

Intensity and patterns of leaf area eaten of Lithocarpus glaber by insects, at Tiantong Forest Park, Zhejiang

Intensity and patterns of leaf area eaten of Lithocarpus glaber by insects were studied in the evergreen broadleaved forest at Tiantong Forest Park of Zhejiang Province, China. The results showed that the patterns of leaf area eaten were diverse with their frequencies greatly varied. Totally 15 patterns of leaf area eaten by insects were identified, among which the frequencies of the top and edge defoliations were more than 30 %, the cutting leaf, successive pinhole and big perforation 10 % - 30 %, the small perforation, lower epidermis defoliation, middle vein defoliation and bloth-shaped mine 1.5 % - 6.4 %, and the upper epidermis defoliation, rugate defoliation, excavating defoliation, spiral mine slender defoliation and striped defoliation less than 1%. The intensity of leaf damage depended on the pattern of leaf area eaten and its frequency. Because of the high frequencies and serous damage of leaves, the top defoliation, edge defoliation and cutting leaf were the most important types to damaged leaves of L. galber. There was significant positive correlation between successive pinhole and cutting leaf, while significant negative correlation between successive pinhole and lower epidermis defoliation, cutting leaf and small perforation, which indicated the difference of eating pattern of different insects in space and time. There was 64 % of leaves eaten and the rate of leaf damage was 13.6 %.