With both field investigation and pure culture experiments, the occurrence and optimal essential growth of mycorrhizal fungi with oaks in Dandong Region of Liaoning Province, China were investigated from 1997-2002. A ...With both field investigation and pure culture experiments, the occurrence and optimal essential growth of mycorrhizal fungi with oaks in Dandong Region of Liaoning Province, China were investigated from 1997-2002. A total of 36 species of mycorrhizal fungi associated with oaks were observed. The results showed that the occurrence of mycorrhizal fungi was related to tree species, tree ages, and months of the year, with at least 20 fungi species being associated with more than two oak species. The highest Simpson index (SI) and Shannon index (H') values, 0.95 and 4.44 respectively, were found in the 15-25 year-old age group. The optimum month for fungal occurrence was August, when the SI and H' values were 0.97 and 5.16, respectively. Additionally, the cultivated mycorrhizal fungus grew best at temperature of 25-30 ℃ and at pH of 5-6. The results also indicated that the association between mycorrhizal fungi and oaks was common.展开更多
Natural regeneration of tree species is important to the sustainability of native forest ecosystems in the temperate zone of north- east China. This study compared the densities and heights of seedlings and the divers...Natural regeneration of tree species is important to the sustainability of native forest ecosystems in the temperate zone of north- east China. This study compared the densities and heights of seedlings and the diversities of shrubs and herbs on three sites of logging op- erations: log-skidding trails (LST), logging gaps (LG) and log landing sites (LLS). Sites undisturbed by logging gaps operations were sam- pled as control. The species, counts and height of tree seedlings and the species, counts, height and percentage coverage of shrubs and herbs were recorded in the field. The highest density and greatest height of regeneration trees were observed at LG and LST. The effects of LST on the densities of broadleaved trees were greater than those of coniferous trees. The difference in seedling density between LLS and control was significant (p=0.05). There was no significant difference in average seedling height for all the tree species between the disturbed sites and control. There were more shrub and herb species at the disturbed sites than at control. The diversity of understory plants at LG was the highest among all the sites. LST and LLS were different in shrub diversity, so were LLS and control. Both LG and LLS were different from control in herb diversity. Active measures need to be taken on the operation sites to protect the coniferous trees and the diversities of under- story plants for sustaining the structure and composition of the broadleaved-Korean pine mixed forest on Changbai Mountain of China. Since different operation sites have different effects on different tree species, site-dependent actions must be taken to assure the regeneration of ecologically important tree species.展开更多
基金Project supported by the National Natural Science Foundation of China (No. XSFC70373044) the Knowledge Innovation Program of the Chinese Academy of Sciences (No. C12SD)
文摘With both field investigation and pure culture experiments, the occurrence and optimal essential growth of mycorrhizal fungi with oaks in Dandong Region of Liaoning Province, China were investigated from 1997-2002. A total of 36 species of mycorrhizal fungi associated with oaks were observed. The results showed that the occurrence of mycorrhizal fungi was related to tree species, tree ages, and months of the year, with at least 20 fungi species being associated with more than two oak species. The highest Simpson index (SI) and Shannon index (H') values, 0.95 and 4.44 respectively, were found in the 15-25 year-old age group. The optimum month for fungal occurrence was August, when the SI and H' values were 0.97 and 5.16, respectively. Additionally, the cultivated mycorrhizal fungus grew best at temperature of 25-30 ℃ and at pH of 5-6. The results also indicated that the association between mycorrhizal fungi and oaks was common.
文摘Natural regeneration of tree species is important to the sustainability of native forest ecosystems in the temperate zone of north- east China. This study compared the densities and heights of seedlings and the diversities of shrubs and herbs on three sites of logging op- erations: log-skidding trails (LST), logging gaps (LG) and log landing sites (LLS). Sites undisturbed by logging gaps operations were sam- pled as control. The species, counts and height of tree seedlings and the species, counts, height and percentage coverage of shrubs and herbs were recorded in the field. The highest density and greatest height of regeneration trees were observed at LG and LST. The effects of LST on the densities of broadleaved trees were greater than those of coniferous trees. The difference in seedling density between LLS and control was significant (p=0.05). There was no significant difference in average seedling height for all the tree species between the disturbed sites and control. There were more shrub and herb species at the disturbed sites than at control. The diversity of understory plants at LG was the highest among all the sites. LST and LLS were different in shrub diversity, so were LLS and control. Both LG and LLS were different from control in herb diversity. Active measures need to be taken on the operation sites to protect the coniferous trees and the diversities of under- story plants for sustaining the structure and composition of the broadleaved-Korean pine mixed forest on Changbai Mountain of China. Since different operation sites have different effects on different tree species, site-dependent actions must be taken to assure the regeneration of ecologically important tree species.
