Evapotranspiration of a natural secondary white birch (Betula populifolia)forest in Maoershan Ecological Station was determined by water balance method, heat balance method and water and heat combination method. Resul...Evapotranspiration of a natural secondary white birch (Betula populifolia)forest in Maoershan Ecological Station was determined by water balance method, heat balance method and water and heat combination method. Results showed that the total evapotranspiration of the forest in the growing season was 3. 6mm/d. of which evapotrans piration from canopy xvas 2. 91 mm/d and that from forest floor was 0. 57 mm/d. and that in the non-growing season was 0. 8 mm/d.展开更多
Data from a survey in the Hasi Mountain areas of Jinyuan County in Gansu province of China showed that 83.3% white birch(Betula platyphylla) stand was infested by the Asian longhorned beete,Anoplophroa glabripennis.Th...Data from a survey in the Hasi Mountain areas of Jinyuan County in Gansu province of China showed that 83.3% white birch(Betula platyphylla) stand was infested by the Asian longhorned beete,Anoplophroa glabripennis.The longevity of the beetles was(41.2±11.5) days for a male and(39.1±13.1) days for a female when twigs of white birch were used as a sole source of food for the adult beetles.The area of twig barks consumed by a pair of beetles in their life time was(9.93±8.15) cm2.A female can make(12.4±12.1) egg pits in average during the period when they were alive and caged.If removal of the infested tree is used as a management measure,it must be excuted consecutively for two years to be effective.Field tests were conducted in 2005 and 2006 to treat infested trees with imidacloprid through trunk injection,soil injection,and soil drench.The results showed that the number of dead adults under the treated trees was 6.3 times for trunk injection,5.1 times for soil injection,and 4.9 times for soil drench more than that under the untreated control.The number of live larvae decreased by 95.8% for trunk injection,83.3% for soil injection,and 85.5% for soil drench in comparison with larva mortality in control.The number of egg pits made on tree trunks by an adult was decreased by 87.1%、77.4%and 82.6%for imidacloprid trough trunk injection,soil injection,and soil drench,respectively,compared with the untreated control.展开更多
Four wood rot fungi were used to decay 300 mature trees of white birch in Liangshui experiment stations,and the mass loss of the samples was measured to study bio-degradability of the wood by the fungi. The decaying s...Four wood rot fungi were used to decay 300 mature trees of white birch in Liangshui experiment stations,and the mass loss of the samples was measured to study bio-degradability of the wood by the fungi. The decaying susceptible and resistant populations in 10 trees each with the highest and lowest mass loss were selected,in which some main chemical components in decayed and non-decayed wood such as lignin and cellulose and so on was tested. The result showed that the decomposing power of Coriolus versicolor to wood samples was better,and then were Fomes fomentarius,Irpex lacteus and Pholiota adiposa were poor. 1%NaOH extraction in decayed wood was significant higher than that in non-decayed control. Benzene-alcohol extraction in the wood decayed by Coriolus versicolor and Fomes fomentarius was significant higher than that in non-decayed control,but much lower than the control in the wood decayed by Irpex lacteus. The lignin decomposing rate by Irpex lacteus,Pholiota adipose and Fomes fomentarius were faster than the cellulose decomposing rate,the contrary result was achieved by Coriolus versicolor. This paper would provide some useful information in future study in the course and mechanism of wood decaying by rot fungi,and select engineering fungi for paper-making industry and pollution control.展开更多
文摘Evapotranspiration of a natural secondary white birch (Betula populifolia)forest in Maoershan Ecological Station was determined by water balance method, heat balance method and water and heat combination method. Results showed that the total evapotranspiration of the forest in the growing season was 3. 6mm/d. of which evapotrans piration from canopy xvas 2. 91 mm/d and that from forest floor was 0. 57 mm/d. and that in the non-growing season was 0. 8 mm/d.
文摘Data from a survey in the Hasi Mountain areas of Jinyuan County in Gansu province of China showed that 83.3% white birch(Betula platyphylla) stand was infested by the Asian longhorned beete,Anoplophroa glabripennis.The longevity of the beetles was(41.2±11.5) days for a male and(39.1±13.1) days for a female when twigs of white birch were used as a sole source of food for the adult beetles.The area of twig barks consumed by a pair of beetles in their life time was(9.93±8.15) cm2.A female can make(12.4±12.1) egg pits in average during the period when they were alive and caged.If removal of the infested tree is used as a management measure,it must be excuted consecutively for two years to be effective.Field tests were conducted in 2005 and 2006 to treat infested trees with imidacloprid through trunk injection,soil injection,and soil drench.The results showed that the number of dead adults under the treated trees was 6.3 times for trunk injection,5.1 times for soil injection,and 4.9 times for soil drench more than that under the untreated control.The number of live larvae decreased by 95.8% for trunk injection,83.3% for soil injection,and 85.5% for soil drench in comparison with larva mortality in control.The number of egg pits made on tree trunks by an adult was decreased by 87.1%、77.4%and 82.6%for imidacloprid trough trunk injection,soil injection,and soil drench,respectively,compared with the untreated control.
文摘Four wood rot fungi were used to decay 300 mature trees of white birch in Liangshui experiment stations,and the mass loss of the samples was measured to study bio-degradability of the wood by the fungi. The decaying susceptible and resistant populations in 10 trees each with the highest and lowest mass loss were selected,in which some main chemical components in decayed and non-decayed wood such as lignin and cellulose and so on was tested. The result showed that the decomposing power of Coriolus versicolor to wood samples was better,and then were Fomes fomentarius,Irpex lacteus and Pholiota adiposa were poor. 1%NaOH extraction in decayed wood was significant higher than that in non-decayed control. Benzene-alcohol extraction in the wood decayed by Coriolus versicolor and Fomes fomentarius was significant higher than that in non-decayed control,but much lower than the control in the wood decayed by Irpex lacteus. The lignin decomposing rate by Irpex lacteus,Pholiota adipose and Fomes fomentarius were faster than the cellulose decomposing rate,the contrary result was achieved by Coriolus versicolor. This paper would provide some useful information in future study in the course and mechanism of wood decaying by rot fungi,and select engineering fungi for paper-making industry and pollution control.
