The Tibetan forest is one of the most important national forest zones in China. Despite the potentially important role that Tibetan forest will play in the Earth?s future carbon balance and climate regulation, few all...The Tibetan forest is one of the most important national forest zones in China. Despite the potentially important role that Tibetan forest will play in the Earth?s future carbon balance and climate regulation, few allometric equations exist for accurately estimating biomass and carbon budgets of this forest. In the present study, allometric equations,both species-specific and generic, were developed relating component biomass(DW) to diameter at breast height(DBH) and tree height(H) for six most common tree species in Tibetan forest. The 6 species were Abies georgei Orr., Picea spinulosa(Griff.)Henry, Pinus densata Mast., Pinus yunnanensis Franch., Cypresses funebris Endl. and Quercus semecarpifilia Smith.. The results showed that, both DBH-only and DBH2 H based species-specific equations showed a significant fit(P<0.05) for all tree species and biomass components. The DBH-only equations explained more than 80% variability of the component biomass and total biomass, adding H as a second independent variable increased the goodness of fit, while incorporating H into the term DBH2 H decreased the goodness of fit. However, not all DBH-H combined equations showed a significant fit(P<0.05) for all tree species and biomass components. Hence, the suggested species-specific allometric equations for the six most common tree species are of the form ln(DW) = c + αln(DBH). The generalized equations of mixed coniferous component biomass against DBH, DBH2 H and DBH-H also showed a significant fit(P<0.05) for all biomass components. However, due to significant species effect, the relative errors of the estimates were very high. Hence, generalized equations should only be used when there are too many different tree species, or there is no species-specific model of the same species or similar growth form in adjacent area.展开更多
Sanjiangyuan Area is located in Tibetan Plateau in Qinghai Province in China. It＇s the source of Yangtze River, Huanghe River and Lancangiiang River. Since the ecological environment became worse in recent decades, Q...Sanjiangyuan Area is located in Tibetan Plateau in Qinghai Province in China. It＇s the source of Yangtze River, Huanghe River and Lancangiiang River. Since the ecological environment became worse in recent decades, Qinghai government conducted an environmental migration project to move the herdsman out of Sanjiangyuan Area to protect the environment. Using the data we collected in five environmental migration resettlement villages in 2009 and the basic information of the nonmigrants, this paper calculated the index of migration differences to examine the selectivity between migrants and nonmigrants. The policy implication will also be discussed in this paper.展开更多
基金supported by the “Strategic Priority Research Program” of the Chinese Academy of Sciences (Grant No. XDA05050207)the National Natural Science Foundation of China (Grant No. 31300416)
文摘The Tibetan forest is one of the most important national forest zones in China. Despite the potentially important role that Tibetan forest will play in the Earth?s future carbon balance and climate regulation, few allometric equations exist for accurately estimating biomass and carbon budgets of this forest. In the present study, allometric equations,both species-specific and generic, were developed relating component biomass(DW) to diameter at breast height(DBH) and tree height(H) for six most common tree species in Tibetan forest. The 6 species were Abies georgei Orr., Picea spinulosa(Griff.)Henry, Pinus densata Mast., Pinus yunnanensis Franch., Cypresses funebris Endl. and Quercus semecarpifilia Smith.. The results showed that, both DBH-only and DBH2 H based species-specific equations showed a significant fit(P<0.05) for all tree species and biomass components. The DBH-only equations explained more than 80% variability of the component biomass and total biomass, adding H as a second independent variable increased the goodness of fit, while incorporating H into the term DBH2 H decreased the goodness of fit. However, not all DBH-H combined equations showed a significant fit(P<0.05) for all tree species and biomass components. Hence, the suggested species-specific allometric equations for the six most common tree species are of the form ln(DW) = c + αln(DBH). The generalized equations of mixed coniferous component biomass against DBH, DBH2 H and DBH-H also showed a significant fit(P<0.05) for all biomass components. However, due to significant species effect, the relative errors of the estimates were very high. Hence, generalized equations should only be used when there are too many different tree species, or there is no species-specific model of the same species or similar growth form in adjacent area.
文摘Sanjiangyuan Area is located in Tibetan Plateau in Qinghai Province in China. It＇s the source of Yangtze River, Huanghe River and Lancangiiang River. Since the ecological environment became worse in recent decades, Qinghai government conducted an environmental migration project to move the herdsman out of Sanjiangyuan Area to protect the environment. Using the data we collected in five environmental migration resettlement villages in 2009 and the basic information of the nonmigrants, this paper calculated the index of migration differences to examine the selectivity between migrants and nonmigrants. The policy implication will also be discussed in this paper.
