Top executive succession is one of the most crucial events in the life of any firm. Based on the database of Chinese Entrepreneur Survey System, this research firstly reports new factors that influence the likelihood ...Top executive succession is one of the most crucial events in the life of any firm. Based on the database of Chinese Entrepreneur Survey System, this research firstly reports new factors that influence the likelihood of succession in Chinese corporations, which may not exist in western companies, then tests previous western research result in Chinese information technology （IT） industry and traditional industry. The results are hopefully to enlighten the reform of corporations during the period of China transitional economy.展开更多
Analyzing and understanding the structure and growth dynamics of forests at different stages is helpful to promote forest succession, restoration and management. Three spots representing three succession stages of spr...Analyzing and understanding the structure and growth dynamics of forests at different stages is helpful to promote forest succession, restoration and management. Three spots representing three succession stages of spruce-fir mixed forest(SF: polar-birch secondary forest, MF: spruce-fir mixed forest and PF: spruce-fir near primary forest) were established. Structure, growth dynamics during two growth seasons for dominant tree species, regeneration were examined, and a univariate O-ring function statistic was used to analyze the spatial patterns of main regeneration tree species. Results showed that,(1) composition of tree species, periodic annual increment(PAI) of the diameter at breast height(DBH), basal area for overstory trees and of ground diameter(DGH) for saplings, were significantly different with the succession;(2) the current species composition and regeneration dynamics of SF suggested a development towards spruce-fir mixed forests. Pioneer species like Betula platyphyllaa will gradually disappear while climax species, such as Abies nephrolepis, Pinus koraiensis, Picea koraiensis and Tilia amurensis will dominate forest stands;(3) Despite the highest volume occurring in PF, and saplings in it grew better than in the others, this forest type is unstable because of its unsustainable structure of DBH class and insufficient regeneration; and(4) MF had the most reasonable distribution of DBH class for adult trees(DBH > 5.0 cm) and DGH class for saplings(H ≥30 cm and DBH ≤5 cm), as well as an optimal volume increment. Limiting canopy opening size can lessen the physiological stress and promote the growth and competitive status of regeneration. Management implications for increasing the gaps and thus creating better growth conditions for understory saplings and facilitating forest succession were discussed.展开更多
Insights into the microbial communities in municipal wastewater treatment plants(WWTPs)are critical for the optimization of biological nutrient removal process.However,our understanding about the spatiotemporal charac...Insights into the microbial communities in municipal wastewater treatment plants(WWTPs)are critical for the optimization of biological nutrient removal process.However,our understanding about the spatiotemporal characteristics of the microbial communities in WWTPs remains limited.In the present study,264 samples were collected biweekly from four spatially independent corridors in a typical municipal WWTP.The annual compositional and metagenomic characteristics were investigated based on multiple ecological indicators using statistical tests.The results revealed that the microbial community compositions from the four corridors showed significantly high similarities,as revealed by the statistical analysis at the operational taxonomic unit(OTU)level.Consistent with the OTU level results,the functionality of the microbial communities in the four independent corridors also showed significant similarity.In comparison,the dynamics of the microbial community over the year showed two successional peaks of the microbial communities with the spatial similarity,and this resulted in three alternative stable states of the microbial communities in a calendar year.The microbial communities only drifted in July and November,suggesting an uneven community succession pattern driven by seasonal variation in environmental conditions.The functional characteristics were found to be relatively conservative compared to the microbial community succession,which revealed the decoupling between the composition and functionality of the microbial community in the municipal WWTP.The present study provides an in-depth overview of the microbial communities in a municipal WWTP and will be useful for the establishment of the connection between ecological characteristics and the operational stability of WWTPs.展开更多
文摘Top executive succession is one of the most crucial events in the life of any firm. Based on the database of Chinese Entrepreneur Survey System, this research firstly reports new factors that influence the likelihood of succession in Chinese corporations, which may not exist in western companies, then tests previous western research result in Chinese information technology （IT） industry and traditional industry. The results are hopefully to enlighten the reform of corporations during the period of China transitional economy.
基金co-supported by the "948" Project of the State Forestry Administration of China (Grant No. 2013-4-66)"The Twelfth Five-Year-Plan" of National Science and Technology for Rural Development in China (Grant No. 2012BAD22B0203)
文摘Analyzing and understanding the structure and growth dynamics of forests at different stages is helpful to promote forest succession, restoration and management. Three spots representing three succession stages of spruce-fir mixed forest(SF: polar-birch secondary forest, MF: spruce-fir mixed forest and PF: spruce-fir near primary forest) were established. Structure, growth dynamics during two growth seasons for dominant tree species, regeneration were examined, and a univariate O-ring function statistic was used to analyze the spatial patterns of main regeneration tree species. Results showed that,(1) composition of tree species, periodic annual increment(PAI) of the diameter at breast height(DBH), basal area for overstory trees and of ground diameter(DGH) for saplings, were significantly different with the succession;(2) the current species composition and regeneration dynamics of SF suggested a development towards spruce-fir mixed forests. Pioneer species like Betula platyphyllaa will gradually disappear while climax species, such as Abies nephrolepis, Pinus koraiensis, Picea koraiensis and Tilia amurensis will dominate forest stands;(3) Despite the highest volume occurring in PF, and saplings in it grew better than in the others, this forest type is unstable because of its unsustainable structure of DBH class and insufficient regeneration; and(4) MF had the most reasonable distribution of DBH class for adult trees(DBH > 5.0 cm) and DGH class for saplings(H ≥30 cm and DBH ≤5 cm), as well as an optimal volume increment. Limiting canopy opening size can lessen the physiological stress and promote the growth and competitive status of regeneration. Management implications for increasing the gaps and thus creating better growth conditions for understory saplings and facilitating forest succession were discussed.
基金financially supported by the National Natural Science Foundation of China(Grant Nos.52122005 and U23A20675).
文摘Insights into the microbial communities in municipal wastewater treatment plants(WWTPs)are critical for the optimization of biological nutrient removal process.However,our understanding about the spatiotemporal characteristics of the microbial communities in WWTPs remains limited.In the present study,264 samples were collected biweekly from four spatially independent corridors in a typical municipal WWTP.The annual compositional and metagenomic characteristics were investigated based on multiple ecological indicators using statistical tests.The results revealed that the microbial community compositions from the four corridors showed significantly high similarities,as revealed by the statistical analysis at the operational taxonomic unit(OTU)level.Consistent with the OTU level results,the functionality of the microbial communities in the four independent corridors also showed significant similarity.In comparison,the dynamics of the microbial community over the year showed two successional peaks of the microbial communities with the spatial similarity,and this resulted in three alternative stable states of the microbial communities in a calendar year.The microbial communities only drifted in July and November,suggesting an uneven community succession pattern driven by seasonal variation in environmental conditions.The functional characteristics were found to be relatively conservative compared to the microbial community succession,which revealed the decoupling between the composition and functionality of the microbial community in the municipal WWTP.The present study provides an in-depth overview of the microbial communities in a municipal WWTP and will be useful for the establishment of the connection between ecological characteristics and the operational stability of WWTPs.
