The relevant factors for physiological chlorosis of Cinnamomum camphora L. in Pingdingshan were studied combining with references and production sur- vey. The resuhs showed that the disease was the integrated results ...The relevant factors for physiological chlorosis of Cinnamomum camphora L. in Pingdingshan were studied combining with references and production sur- vey. The resuhs showed that the disease was the integrated results of soil environment, planting situation, microenvironment construction and maintenance manage- ment. Therefore, the countermeasures of ＂prevention first, restore tree vigor; integrated control, enhance tree vigor＂ were proposed. Chlorosis of C. camphora had been basically controlled after four years, and the control effect was obvious.展开更多
Dendrolimus superans (Butler) occurred in the vast areas of Daxing'an Mountains forest. in Heilongjiang Province, in 1990. Stands damaged by D.Superans seriously, intermediately and lightly show patch shape dis...Dendrolimus superans (Butler) occurred in the vast areas of Daxing'an Mountains forest. in Heilongjiang Province, in 1990. Stands damaged by D.Superans seriously, intermediately and lightly show patch shape distribution within damaged area. By ordination analysis and correlation analysis between ordination factors and coordinate axis. It was found that occurrence of D. Superans in different extent is owing to the effect of forest age. composition and exposure. The tended young pure forests grown on the sunward slopes are most seriously damaged and non-tended middle-age mixing stands grown on the sunless slopes are most lightly damaged. Therefore, in order to prevent D.superans from seriously damaging larch forests. relatively large crown density (P>0. 7) should be kept,and broadleaftrees should be also properly preserved.展开更多
文摘The relevant factors for physiological chlorosis of Cinnamomum camphora L. in Pingdingshan were studied combining with references and production sur- vey. The resuhs showed that the disease was the integrated results of soil environment, planting situation, microenvironment construction and maintenance manage- ment. Therefore, the countermeasures of ＂prevention first, restore tree vigor; integrated control, enhance tree vigor＂ were proposed. Chlorosis of C. camphora had been basically controlled after four years, and the control effect was obvious.
文摘Dendrolimus superans (Butler) occurred in the vast areas of Daxing'an Mountains forest. in Heilongjiang Province, in 1990. Stands damaged by D.Superans seriously, intermediately and lightly show patch shape distribution within damaged area. By ordination analysis and correlation analysis between ordination factors and coordinate axis. It was found that occurrence of D. Superans in different extent is owing to the effect of forest age. composition and exposure. The tended young pure forests grown on the sunward slopes are most seriously damaged and non-tended middle-age mixing stands grown on the sunless slopes are most lightly damaged. Therefore, in order to prevent D.superans from seriously damaging larch forests. relatively large crown density (P>0. 7) should be kept,and broadleaftrees should be also properly preserved.
