In order to identify a harvesting model which is beneficial for broadleaf-Korean pine mixed forest （BKF） sustainability, we investigated four types of harvested stands which have been logged with intensities of 0 （...In order to identify a harvesting model which is beneficial for broadleaf-Korean pine mixed forest （BKF） sustainability, we investigated four types of harvested stands which have been logged with intensities of 0 （T0, control）, 15% （T1, low intensity）, 35% （T2, moderate intensity）, and 100% （T3, clear-cutting）, and examined the impacts of logging intensity on composition and structure of these stands. Results showed that there were no significant differences between To and T1 for all structural characteristics, except for density of seeding and large trees. The mean diameter at breast height （DBH, 1.3 m above the ground）, stem density and basal area of large trees in T2 were significantly lower than in To, while the density of seedlings and saplings were significantly higher in T2 than in To. Structural characteristics in T3 were entirely different from To. Dominant tree species in primary BKF comprised 93%, 85%, 45% and 10% of the total basal area in T0, T1, T2 and T3, respectively. Three community similarity indices, the Jaccard＇s similarity coefficient （Cj）; the Morisita-Hom index （CMH）; and the Bray-Curtis index （CN）, were the highest for T0 and T1, followed by T0 and T2, and T0 and T3, in generally. These results suggest that effects of harvesting on forest composition and structure are related to logging intensities. Low intensity harvesting is conductive to preserving forest structure and composition, allowing it to recover in a short time period. The regime characterized by low logging intensity and short rotations appears to be a sustainable harvesting method for BKF on the Changbai Mountains.展开更多
The study is based on the i^dea of intersection of two current trends： The increasing importance of social networking services on the one hand, and on the other hand, the increase in the high schools＇ need to be suc...The study is based on the i^dea of intersection of two current trends： The increasing importance of social networking services on the one hand, and on the other hand, the increase in the high schools＇ need to be successful on the （school） market. Facebook, the most popular social networking service currently, is gradually transforming its form from the leisure and entertainment media towards the more serious media suitable for many traditional types of messages. At the same time, high schools, in addition to traditional forms of reaching out the public, are trying to find and use new forms of communication media, including social networking services. In this study, the author will focus on the current status of the social networking service----Facebook, used as a communication tool of high schools in Slovakia. The presented data are based on exploratory research followed by discursive analysis.展开更多
基金National Key Technologies Research and Development Program of China(No.2012BAD22B04)
文摘In order to identify a harvesting model which is beneficial for broadleaf-Korean pine mixed forest （BKF） sustainability, we investigated four types of harvested stands which have been logged with intensities of 0 （T0, control）, 15% （T1, low intensity）, 35% （T2, moderate intensity）, and 100% （T3, clear-cutting）, and examined the impacts of logging intensity on composition and structure of these stands. Results showed that there were no significant differences between To and T1 for all structural characteristics, except for density of seeding and large trees. The mean diameter at breast height （DBH, 1.3 m above the ground）, stem density and basal area of large trees in T2 were significantly lower than in To, while the density of seedlings and saplings were significantly higher in T2 than in To. Structural characteristics in T3 were entirely different from To. Dominant tree species in primary BKF comprised 93%, 85%, 45% and 10% of the total basal area in T0, T1, T2 and T3, respectively. Three community similarity indices, the Jaccard＇s similarity coefficient （Cj）; the Morisita-Hom index （CMH）; and the Bray-Curtis index （CN）, were the highest for T0 and T1, followed by T0 and T2, and T0 and T3, in generally. These results suggest that effects of harvesting on forest composition and structure are related to logging intensities. Low intensity harvesting is conductive to preserving forest structure and composition, allowing it to recover in a short time period. The regime characterized by low logging intensity and short rotations appears to be a sustainable harvesting method for BKF on the Changbai Mountains.
文摘The study is based on the i^dea of intersection of two current trends： The increasing importance of social networking services on the one hand, and on the other hand, the increase in the high schools＇ need to be successful on the （school） market. Facebook, the most popular social networking service currently, is gradually transforming its form from the leisure and entertainment media towards the more serious media suitable for many traditional types of messages. At the same time, high schools, in addition to traditional forms of reaching out the public, are trying to find and use new forms of communication media, including social networking services. In this study, the author will focus on the current status of the social networking service----Facebook, used as a communication tool of high schools in Slovakia. The presented data are based on exploratory research followed by discursive analysis.
