为认知叶片呼吸(<em>R</em><sub>L</sub>)的季节变化格局及其影响因子,以东北东部山区3个主要树种(红松 <em>Pinus koraiensis</em>、樟子松 <em>P.sylvestris</em> var. <em>mongolica</em>和白桦 <em>Betula platyphylla</em>)为对象,采用红外气体分析法在2011年生长季(常绿树4月至10月;落叶树6月至9月)测定了自然条件下叶片气体交换及其相关生理特征的季节变化,探索了<em>R</em><sub>L</sub>与空气温度(<em>T</em><sub>air</sub>)和相关叶片特征之间的关系。结果表明:红松和樟子松基于叶面积的<em>R</em><sub>L</sub>(<em>R</em><sub>L-area</sub>)表现为生长季初期和末期较大,而白桦<em>R</em><sub>L-area</sub>则随生长季进程而逐渐减小。在生长季中,<em>R</em><sub>L-area</sub>与叶片总光合之比的时间动态明显。红松、樟子松<em>R</em><sub>L-area</sub>与<em>T</em><sub>air</sub>关系显著,而白桦<em>R</em><sub>L-area</sub>与<em>T</em><sub>air</sub>关系不显著;但3种树种基于叶质量的<em>R</em><sub>L</sub>(<em>R</em><sub>L-mass</sub>)与<em>T</em><sub>air</sub>均呈显著的指数函数关系。叶片特征(包括可溶性糖、淀粉、氮、比叶面积等参数)也有明显的季节变化。影响<em>R</em><sub>L</sub>的叶片特征参数因树种而异,其中可溶性糖浓度对3种树种的<em>R</em><sub>L</sub>均有显著影响。可见,<em>R</em><sub>L</sub>的季节变化格局受树木的生长节律、温度和叶片特征的联合控制。;To understand the factors influencing seasonal variation in leaf respiration (<em>R</em><sub>L</sub>), the leaf gas exchange characteristics and related leaf traits were examined for three tree species in northeastern China. The species were Korean pine (<em>Pinus koraiensis</em>), Mongolian pine (<em>P. sylvestris</em> var. <em>mongolica</em>) and white birch (<em>Betula platyphylla</em>). The <em>R</em><sub>L</sub>, net photosynthetic rate, and air temperature (<em>T</em><sub>air</sub>) were measured <em>in situ</em> with an infrared gas exchange analyzer (LI-6400 IRGA) twice per month throughout the growing season in 2011 (from April to October for the pines; from June to September for the birch). Specific leaf area (<em>SLA</em>) was calculated from oven-dried leaf weight and projected leaf area; nonstructural carbohydrates (<em>NSC</em>) concentrations were determined by a modified phenol-sulfuric acid method; and leaf nitrogen concentrations were measured by the Kjeldahl method. A stepwise multiple regression procedure was applied to explore the relationships between <em>R</em><sub>L</sub> and leaf traits. The area-based <em>R</em><sub>L</sub> (<em>R</em><sub>L-area</sub>) of Korean pine and Mongolian pine peaked in early and late growing seasons, while the <em>R</em><sub>L-area</sub> of white birch declined gradually with the growing season proceeding. The ratio of <em>R</em><sub>L-area</sub> to total photosynthesis and leaf trait parameters (i.e., soluble sugar concentration, starch concentration, <em>SLA</em>, leaf nitrogen concentration) also exhibited seasonal variations for the three species. The <em>R</em><sub>L-area</sub> of pines were positively correlated with <em>T</em><sub>air</sub>, while that of the birch was not. The mass-based <em>R</em><sub>L</sub> (<em>R</em><sub>L-mass</sub>) of the three tree species, however, were all positively related with <em>T</em><sub>air</sub> in an exponential function. The leaf trait parameters affecting the <em>R</em><sub>L</sub> varied with species, and the soluble sugars concentration significantly influenced the <em>R</em><sub>L</sub> for all the species. These results suggest that seasonal variation in <em>R</em><sub>L</sub> jointly controlled by growth rhythm, temperature and leaf traits.