Total and root-severed soil respiration rates for five plots set up 50 m apart in a Betula ermanii Cham.-dark coniferous forest ecotone on a north-facing slope of the Changbai Mountains, China, were measured to evalua...Total and root-severed soil respiration rates for five plots set up 50 m apart in a Betula ermanii Cham.-dark coniferous forest ecotone on a north-facing slope of the Changbai Mountains, China, were measured to evaluate the seasonal variations of soil respiration, to assess the effect of soil temperature and water content on soil respiration, and to estimate the relative contributions of root respiration to the total soil respiration. PVC cylinders in each of 5 forest types of a B. ermanii-dark coniferous forest ecotone were used to measure soil respirations both inside and outside of the cylinders. The contribution of roots to the total soil respiration rates ranged from 12.5% to 54.6%. The mean contribution of roots for the different plots varied with the season, increasing from 32.5% on June 26 to 36.6% on August 3 and to 41.8% on October 14. In addition, there existed a significant (P < 0.01) logarithmic relationship between total soil respiration rate and soil temperature at 5 cm soil depth. Also, a similar trend was observed for the soil respiration and soil water content at the surface (0-5 cm) during the same period of time.展开更多
ABSTRACT: Based on catalogue of biology and geochemistry of chemical elements, content characteristics and variation law of the large nutrient elements, the needful trace elements, the uncertain needful elements, the ...ABSTRACT: Based on catalogue of biology and geochemistry of chemical elements, content characteristics and variation law of the large nutrient elements, the needful trace elements, the uncertain needful elements, the non-needful elements and the toxic elements in Betula ermanii trees are analyzed. The result shows that the content of the large nutrient elements in Betula ermanii trees is higher than that of other kinds of element; the contents of all kinds of elements in foliage with vigorous metabolism are higher than those in other parts; the content variations of the large nutrient elements and the needful trace elements with similar chemical property, geochemical property and biological function in different parts of Betula ermanii trees show the similar laws; but the other three kinds of elements variations are without laws. It is indicated that the variation of the needful elements in the plant follows a certain law, they are in relative equilibrium under undisturbed condition.展开更多
为了解树轮生长与气候间的关系是否受到海拔因素的影响,运用树木年代学方法,研究了长白山北坡沿海拔梯度岳桦径向生长与气候因素间的关系.响应分析结果显示,岳桦在其低海拔林线处(1 700 m a.s.l.)径向生长与当年1月月平均温度负相关,与...为了解树轮生长与气候间的关系是否受到海拔因素的影响,运用树木年代学方法,研究了长白山北坡沿海拔梯度岳桦径向生长与气候因素间的关系.响应分析结果显示,岳桦在其低海拔林线处(1 700 m a.s.l.)径向生长与当年1月月平均温度负相关,与上年9月月总降水量正相关(P<0.05).在中海拔森林内部(1 850 m a.s.l.)径向生长与上年6月、7月月平均温度负相关(P<0.05),与降水之间的响应关系不明显.高海拔林线处(2 000 m a.s.l.)岳桦径向生长与上年7月月平均温度负相关,与上年9月月平均温度正相关,与当年3月温度负相关,与当年7月温度呈正相关(P<0.05),此外,与当年6月降水量呈正相关(P<0.05).因此,随海拔梯度升高,岳桦年表中包含的气候信息量增加,岳桦径向生长对气候的敏感性增强.展开更多
基金Project supported by the Knowledge Innovation Program of Chinese Academy of Sciences (No. KZCX1-SW-01) and theNational Natural Science Foundation of China (No. 30070158).
文摘Total and root-severed soil respiration rates for five plots set up 50 m apart in a Betula ermanii Cham.-dark coniferous forest ecotone on a north-facing slope of the Changbai Mountains, China, were measured to evaluate the seasonal variations of soil respiration, to assess the effect of soil temperature and water content on soil respiration, and to estimate the relative contributions of root respiration to the total soil respiration. PVC cylinders in each of 5 forest types of a B. ermanii-dark coniferous forest ecotone were used to measure soil respirations both inside and outside of the cylinders. The contribution of roots to the total soil respiration rates ranged from 12.5% to 54.6%. The mean contribution of roots for the different plots varied with the season, increasing from 32.5% on June 26 to 36.6% on August 3 and to 41.8% on October 14. In addition, there existed a significant (P < 0.01) logarithmic relationship between total soil respiration rate and soil temperature at 5 cm soil depth. Also, a similar trend was observed for the soil respiration and soil water content at the surface (0-5 cm) during the same period of time.
基金Under the auspices of the Natural Science Foundation of the Chinese Academy of Sciences.
文摘ABSTRACT: Based on catalogue of biology and geochemistry of chemical elements, content characteristics and variation law of the large nutrient elements, the needful trace elements, the uncertain needful elements, the non-needful elements and the toxic elements in Betula ermanii trees are analyzed. The result shows that the content of the large nutrient elements in Betula ermanii trees is higher than that of other kinds of element; the contents of all kinds of elements in foliage with vigorous metabolism are higher than those in other parts; the content variations of the large nutrient elements and the needful trace elements with similar chemical property, geochemical property and biological function in different parts of Betula ermanii trees show the similar laws; but the other three kinds of elements variations are without laws. It is indicated that the variation of the needful elements in the plant follows a certain law, they are in relative equilibrium under undisturbed condition.
文摘为了解树轮生长与气候间的关系是否受到海拔因素的影响,运用树木年代学方法,研究了长白山北坡沿海拔梯度岳桦径向生长与气候因素间的关系.响应分析结果显示,岳桦在其低海拔林线处(1 700 m a.s.l.)径向生长与当年1月月平均温度负相关,与上年9月月总降水量正相关(P<0.05).在中海拔森林内部(1 850 m a.s.l.)径向生长与上年6月、7月月平均温度负相关(P<0.05),与降水之间的响应关系不明显.高海拔林线处(2 000 m a.s.l.)岳桦径向生长与上年7月月平均温度负相关,与上年9月月平均温度正相关,与当年3月温度负相关,与当年7月温度呈正相关(P<0.05),此外,与当年6月降水量呈正相关(P<0.05).因此,随海拔梯度升高,岳桦年表中包含的气候信息量增加,岳桦径向生长对气候的敏感性增强.
