【摘要】 树干呼吸是森林生态系统碳平衡的重要组成部分,它每年消耗碳同化总量(NPP)的11%～33%。本文采用Li-6400-09土壤呼吸气室于2010年5月测定了帽儿山地区4个主要树种(白桦、落叶松、山杨、红松)在不同高度、不同方位的树干呼吸速率,同时监测了树干表面温度。研究结果表明:树干呼吸速率随树干表面温度的升高而升高,随树干表面温度的降低而降低,它们之间呈现幂指数关系;各树种的树干呼吸速率差异性显著,树干呼吸的最高值因树种而异;不同方位的树干呼吸速率差异性显著,大多数东北树种的呼吸速率最高值出现在北向和东向,南向基本没有;所有树种在D10和DBH高度的呼吸速率与温度均显著相关,相关程度因树种和高度而异;不同树种在不同高度的呼吸速率均存在极显著差异(P<0.01),且差异程度因树种和高度而有所不同。更多还原

【Abstract】 Trunk respiration is an important component of carbon balance of forest ecosystems,which consume 11% to 33% total annual carbon assimilation(NPP).In this paper,Li-6400-09 soil respiration chamber was used in May 2007 in the Mao’er mountain,to measure trunk respiration rate of four major species(Betula platyphylla,Larix gmelinii,Populus davidiana,Pinus koraiensis) at different height and different position.The temperature on trunk surface was also monitored.The results showed that: 1) the trunk respiration rates positively related with the surface temperature,and a power function was found;2) the variation of trunk respiration rates was significant among different tree species,the highest respiration rate was tree species-specific;3) the trunks respiration rate were significantly different among different orientation of tree.The highest respiration rate mostly occurred at north and east orientation,and no respiration rate was detected at south orientation;4) the respiration rate was related with temperature for all species at D10 and DBH height,and the correlated coefficients varied among tree species and height;5) there were significant difference of respiration rate at different height for each species(P <0.01) and the differences degree was species-specific.更多还原