Abstract:

A comprehensive analysis was made on the 5 year's successive monitoring findings from the 62 fixed forest pest monitoring sites of newly established high yielding timber plantations of 15 main timber tree species,such as Larix kaempferi,Ulmus pumila,Robinia pseudoacacia,Paulownia sp,,Populus tomentosa,Populus×euramericana,Cunninghamia lanceolata,Pinus massoniana,Pinus taeda,Pinus elliottii,Pinus caribaea,Eucalyptus globulus,Eucalyptus urophylla,Eucalyptus grandis ×uraphylla and Eucalyptus ABL12,under the World Bank Loan Afforestation Project,which distributed in 16 provinces or autonomous regions in China. The analysis results showed following conclusions: a. At the forest pest monitoring sites with plantations of 15 tree species,the plantations of 14 species,except Larix kaempferi,occurred some insect pests and the plantations of 11 species,except Larix kaempferi,occurred some diseases. Comparatively,the plantations of Pinus massoniana,Pinus taeda,Populus tomentosa and Populus×euramericana had relatively frequent occurrence of insect pests and the plantations of Pinus massoniana,Pinus taeda,Populus tomentosa,Populus×euramericana,Eucalyptus ABL 12 and Eucalyptus globulus had relatively frequent occurrence of diseases. b. According to statistics on the percentage of the observations with occurrence of insect pest or disease occupying the total observations at the monitoring sites of given plantation species,i.e. the observation occurrence rate,and the percentage of the monitoring sites with occurrence of insect pest or disease occupying the total monitoring sites of given plantation species,i.e. the sites occurrence rate of each species or kind of insect pest or disease,the most frequently or frequently occurring insect pests or diseases of each given plantation species were identified,which provid clear target for the effective control of forest pests. c. Among all observations conducted at all monitoring sites,the observations with occurrence of insect pests occupied 77.7% while the observations with occurrence of diseases occupied 27.1%. The statistics of the damage degrees to the plantations caused by insect pests or diseases indicates that among all observations with insect pest occurrence,extremely few observations (2.5%) showed severe damage,few observations (8.86%) showed middle degree damage and most observations showed slight or no damage to the plantation stands,and among all observations with disease occurrence,still extremely few observations (6.08%) showed severe damage,few observations (11.6%) showed middle degree damage and most observations showed slight or no damage to the plantations. Therefore,the overall insect pest or disease damages to the project plantations were slight. However,for some plantation species the emphasis should be given to the prevention and control of the insect pests or diseases causing severe damages. It was suggested that the list of frequently occurring insect pests and diseases,especially,the severe damage causing insect pests or diseases should be paid much attention by the forest managers and the appropriate control strategy should be made for them.

Key words: High-yielding timber plantations, Fixed forest pest and disease monitoring, Most frequently occurring pests and diseases, Pest damage degree