林业有害生物预警等级指标

摘要

A study was conducted to determine the hierarchical index of forest pests for early warning by means of size of unbroken infested area and potential direct economic loss. The hierarchical index consists of four hierarchies, great watch ( red early-warning signal) , severe watch (orange) , more watch (yellow) and ordinary watch (blue). The size of unbroken infested area ranged from 3 000 to 100 000 hm2, and the potential direct economic loss from 3 million to 100 million yuan, with a geometric ratio of 3 between every two neighboring hierarchies.%通过研究选取预测的有害生物连片发生面积、可能造成的林木直接经济损失来确定林业有害生物预警等级,并将其划分为四级:特大等级(Ⅰ级,红色预警信号),重大等级(Ⅱ级,橙色预警信号),较大等级(Ⅲ级,黄色预警信号),一般等级(Ⅳ级,蓝色预警信号).预警等级指标结果表明:可能造成的林木直接经济损失为300～10000万元以上,预测的有害生物连片发生面积3 000～100 000 hm2以上,等比级差为3.