A systematic general survey of quarantine objects (diseases and pests)of main tree species of various forest types in Heilongjiang Province was carried out during 1988-1989 by the forestry Department of Heilongjiang P...A systematic general survey of quarantine objects (diseases and pests)of main tree species of various forest types in Heilongjiang Province was carried out during 1988-1989 by the forestry Department of Heilongjiang Province. By which the species, distribution and damage of quarantine diseases and pests have been broght to light, the epidemic regions and protecting regions have been divided. The scienific basis for the controlling of the quarantine objectS spreading and the protecting of forest resources has been provided by this work.展开更多
文摘A systematic general survey of quarantine objects (diseases and pests)of main tree species of various forest types in Heilongjiang Province was carried out during 1988-1989 by the forestry Department of Heilongjiang Province. By which the species, distribution and damage of quarantine diseases and pests have been broght to light, the epidemic regions and protecting regions have been divided. The scienific basis for the controlling of the quarantine objectS spreading and the protecting of forest resources has been provided by this work.
