Preliminary Study On Population Dynamics Of Anoplophora Glabripennis(Motschulsky) In The Stands Of Multi-tree Species Disposal

27 representative plots of disposal model with different tree were sampled in Ningxia for the study on population dynamics of Anoplophora glabripennis (Motschulsky) (Asian Longhorned Beetle, ALB). The integrated damage index (IDI) reflecting the general damage status of ALB was offered. Furthermore, the dynamic models for ALB's damage were established. Spatial pattern and dispersal rules of damage indexes in different forest stands were educed. The results were described as follows:1. The conclusions were drawn in the experiment of stem analysis that the total growth of timber volume of individual P. alba var. pyramidalis and that of per ha. were both the largest in the mixed forest of Populus alba var. pyramidalis and Acer negundo in the ratio of 17:1, which indicated that forests disposalling luring trees in a certain proportion were more resistant to ALB. Luring trees protected Populus alba var. pyramidalis from the damage by ALB, and increased their growth to certain extent.2. Study on the relationship between the height & DBH of different tree species and the damage by ALB in stands of different disposal showed that when the DBH of luring trees and target trees were over 3 cm and the height of them over 3 m, they could be damaged by ALB.3. The IDI reflecting the general damage by ALB was put forward for the first time, and the disposal model was evaluated by the IDI. The less the IDI was, the better the disposal model was.4. Models reflecting the growth and the damage dynamics of P. alba var. pyramidalis and Populus opera were established, and it offered a method to forecast the growth and damage status of P. alba var. pyramidalis and Populus opera of different disposal in the same conditions and at the same ages.5. Comparing the variograms at different grid size, it was found that the dependence range did not change with grid side length within some limit. The range and the sill both reduced with grid size, while the intensity of local spatial continuity enhanced with grid size.6. Study on the omnidirectional spatial variance of ALB in stands (8-year-old) of different disposal indicated that the numbers of incisions, frass holes and emergence holes presented the same spatial distribution in the same stand, while the spatial dependence range and local spatial continuity were different. The ALB populations presented aggregation distribution in both the pure stand of Populus opera and the mixed stand of P. alba var. pyramidalis and A. negundo, however, they showed random or uniform distribution in the mixed forest of Populus opera and P. alba var. pyramidalis in the ratioof 1:1. Study on spatial variance pattern of ALB in different directions showed that incisions and frass holes were of the same spatial pattern in 45 and 90 directions(Set east as 0, counterclockwisely ), while incisions and frass holes in other directions varied in spatial pattern. Additionally, the emergence holes in every direction are anisotropic.7. The spatial heterogeneity of IDI of ALB in different disposal stands (3-year-old) were studied and the results showed that in the mixed forest ofPopulus opera and P. alba var. pyramidalis in the proportion of 1:3, the intensity of local spatial continuity of IDI enhanced from August toOctober, but the spatial dependence range of IDI did not change. However, local spatial continuity and spatial dependence range of IDI of ALB were increased in the mixed stands of Acer negundo and Populus alba var. pyramidalis in the ratio of 1:9. Conclusion could be drawn that disposal model in the ratio of 1:3 is better than that in 1:9.