Five indices of species richness, species diversity and species evenness were used to assess a diversity of four types of coniferous forests undergone different artificial regeneration time. The study was based on the...Five indices of species richness, species diversity and species evenness were used to assess a diversity of four types of coniferous forests undergone different artificial regeneration time. The study was based on the vertical structure of forests, involving growth-forms of total plants as well as vertical layers of woody plants. The results showed that, except for the fourth layer of woody plants, the vertical structure of the four forests exhibited significant difference in terms of their species richness, species diversity and species evenness, suggesting that a species diversity index provided more detailed information and was a better index reflecting the regeneration processes in this region. It was recommended that silvicultural management of artificially regenerated forests should be strengthened to conserve the biodiversity of the forests, optimize forest structure and, in the long run, promote sustainable development of forest ecosystems.展开更多
Temperature of every month on both the upper and lower boundaries of sub-alpine dark conifer forests at various sites in China are estimated in terms of their distributions and temperature records. Based on these esti...Temperature of every month on both the upper and lower boundaries of sub-alpine dark conifer forests at various sites in China are estimated in terms of their distributions and temperature records. Based on these estimated data, the heat factors to influence and control the distribution and growth of subalpine dark conifer forests in China are discussed. It is found that the most important heat index to influence and control the distribution and growth of subalpine dark conifer forests is neither the mean temperature in the warmest month, nor the maximum or minimum temperatures, but monthly accumulated temperature of>0℃ or monthly effective accumulated temperature of>5℃.When monthly accumulated temperature of>0℃ is more than 40℃, or monthly effective accumulated temperature of>5℃ is over 50℃, sub-alpine dark conifer forests cannot grow well. When monthly accumulated temperature of>5℃ is less than 60℃, sub-alpine dark conifer forests can not grow at all. When monthly effective accumulated temperature of>5℃ is in the range 15℃-45℃, subalpine dark conifer forests in China can grow well. The ecological significance of temperature in May and September, and in summer half year are discussed.展开更多
文摘Five indices of species richness, species diversity and species evenness were used to assess a diversity of four types of coniferous forests undergone different artificial regeneration time. The study was based on the vertical structure of forests, involving growth-forms of total plants as well as vertical layers of woody plants. The results showed that, except for the fourth layer of woody plants, the vertical structure of the four forests exhibited significant difference in terms of their species richness, species diversity and species evenness, suggesting that a species diversity index provided more detailed information and was a better index reflecting the regeneration processes in this region. It was recommended that silvicultural management of artificially regenerated forests should be strengthened to conserve the biodiversity of the forests, optimize forest structure and, in the long run, promote sustainable development of forest ecosystems.
文摘Temperature of every month on both the upper and lower boundaries of sub-alpine dark conifer forests at various sites in China are estimated in terms of their distributions and temperature records. Based on these estimated data, the heat factors to influence and control the distribution and growth of subalpine dark conifer forests in China are discussed. It is found that the most important heat index to influence and control the distribution and growth of subalpine dark conifer forests is neither the mean temperature in the warmest month, nor the maximum or minimum temperatures, but monthly accumulated temperature of>0℃ or monthly effective accumulated temperature of>5℃.When monthly accumulated temperature of>0℃ is more than 40℃, or monthly effective accumulated temperature of>5℃ is over 50℃, sub-alpine dark conifer forests cannot grow well. When monthly accumulated temperature of>5℃ is less than 60℃, sub-alpine dark conifer forests can not grow at all. When monthly effective accumulated temperature of>5℃ is in the range 15℃-45℃, subalpine dark conifer forests in China can grow well. The ecological significance of temperature in May and September, and in summer half year are discussed.
