细根(直径≤ 2 mm)的生长和死亡动态及其影响因子是森林生态系统能量流动和物质循环的重要研究内容,但因受到研究方法的限制而了解甚少。于2010年5-10月采用微根管技术对东北东部山区5种温带森林生态系统的细根生长量(FRP)和死亡量(FRM)进行了动态跟踪测定,并同步测定了土壤温度(<em>T</em>s)、土壤湿度(<em>M</em>s)、叶面积指数(LAI)等相关因子。结果表明: 不同林型和取样时间的FRP和FRM均差异显著(<em>P</em> < 0.001)。杨桦林、硬阔叶林、兴安落叶松林、红松林、蒙古栎林的FRP和FRM分别为:(13.34±0.90) μm·cm<sup>-2</sup>·d<sup>-1</sup>(平均值±标准误)和(5.02±0.36) μm·cm<sup>-2</sup>·d<sup>-1</sup>、(13.04±0.82) μm·cm<sup>-2</sup>·d<sup>-1</sup> 和(6.85±0.32) μm·cm<sup>-2</sup>·d<sup>-1</sup>、(8.74±1.44) μm·cm<sup>-2</sup>·d<sup>-1</sup>和(5.05±0.61) μm·cm<sup>-2</sup>·d<sup>-1</sup>、(8.02±2.27) μm·cm<sup>-2</sup>·d<sup>-1</sup>和(3.88±0.35) μm·cm<sup>-2</sup>·d<sup>-1</sup>、(7.59±0.82) μm·cm<sup>-2</sup>·d<sup>-1</sup>和(3.88±0.61) μm·cm<sup>-2</sup>·d<sup>-1</sup>。所有林型生长季期间FRP的时间变化均呈现明显的单峰型,但峰值出现的时间却因林型而异。FRM随生长季的进程而逐渐增加,杨桦林和硬阔叶林FRM在8月初出现峰值,而红松林、兴安落叶松林和蒙古栎林的FRM峰值均出现在生长季末期。<em>T</em>s、<em>M</em>s和LAI对FRP和FRM均存在显著的正效应(<em>P</em> < 0.05),3个因子的综合作用对各个林型FRP和FRM变异性的解释率分别达68%和53%以上,表明这些温带森林生态系统细根生长和死亡的时间动态主要受土壤温湿度和叶面积变化的联合影响。;Production and mortality of fine roots (diameter ≤ 2mm) and influencing factors are important to energy flow and nutrient cycling in forest ecosystems, but remain poorly understood mainly due to the limitation of methodology. In this study, we used a minirhizotron technique to investigate the temporal dynamics in fine root length production (FRP) and mortality (FRM) of five representative forest ecosystems in Northeast China during the period between May and October of 2010. Soil temperature (<em>T</em>s), soil moisture (<em>M</em>s), and leaf area index(LAI)were simultaneously measured for each stand. The stands were aspen-birch forest dominated by <em>Populus davidiana</em> and <em>Betula platyphylla</em>, hardwood forest dominated by <em>Fraxinus mandshurica</em> and <em>Juglans mandshurica</em>, Mongolian oak forest dominated by<em> Quercus mongolica</em>, Korean pine (<em>Pinus Koraiensis</em>) plantation, and Dahurian larch (<em>Larix gmelinii</em>) plantation. The experimental design included five forest types, three 20 m×30 m replicate plots in each forest type. The results showed that the FRP and FRM were significantly (<em>P</em> < 0.001) affected by forest types, sampling times and their interactions. The FRP was (13.34±0.90) μm·cm<sup>-2</sup>·d<sup>-1 </sup>(mean±SE), (13.04±0.82) μm·cm<sup>-2</sup>·d<sup>-1</sup>, (8.74±1.14) μm·cm<sup>-2</sup>·d<sup>-1</sup>, (8.02±2.77) μm·cm<sup>-2</sup>·d<sup>-1</sup>, and (7.59±0.82) μm·cm<sup>-2</sup>·d<sup>-1</sup> for the aspen-birch, hardwood, larch, pine, and oak stands, respectively; and the FRM was (5.02±0.36) μm·cm<sup>-2</sup>·d<sup>-1</sup>, (6.85±0.32) μm·cm<sup>-2</sup>·d<sup>-1</sup>, (5.05±0.61) μm·cm<sup>-2</sup>·d<sup>-1</sup>, (3.88±0.35) μm·cm<sup>-2</sup>·d<sup>-1</sup>, and (3.88±0.61) μm·cm<sup>-2</sup>·d<sup>-1</sup>, correspondingly. The FRP showed a unimodal seasonal pattern with peaks varying with forest types. The FRM increased gradually as the growing season proceeded, and reached its maximum at the end of the growing season for all the stands except for the aspen-birch and hardwood stands where it peaked in early August. <em>T</em>s, <em>M</em>s, and LAI all exerted significant positive effects on FRP and FRM (<em>P</em> < 0.05), which, together, explained more than 68% and 53% of variability in FRP and FRM, respectively. These results illustrated that the temporal dynamics of fine root production and mortality in these temperate forest ecosystems were jointly influenced by changes in soil temperature, moisture and leaf area index.