To investigate the effect of reduced snow cover on fine root dynamics in a cool-temperate forest in northern Japan because of decreases in snowfall at high latitudes due to global warming, we monitored root length, production, and mortality before and after snow removal with an in-ground root scanner. We measured root dynamics of both overstory deciduous oak (Quercus crispula) and understory evergreen dwarf bamboo (Sasa nipponica), the two major species in the forest. Snow removal advanced the timing of peak root production by a month both in total and in Sasa, but not in oak. There was a significant interaction between snow removal and plant form on root production; this indicates that enhanced Sasa root production following snow removal might increase its ability to compete with oak. In contrast, snow removal did not enhance root mortality, suggesting that the roots of these species tolerate soil freezing. The earlier snow disappearance in the snow removal plot expanded the growing season in Sasa. We speculate that this change in the understory environment would advance the timing of root production by Sasa by extending the photosynthetic period in spring. We propose that different responses of root production to reduced snow cover between the two species would change the competitive interactions of overstory and understory vegetation, influencing net primary production and biogeochemistry (e.g., carbon and nitrogen cycles) in the forest ecosystem.

为了研究由于全球变暖导致高纬度地区降雪导致降雪量减少的日本北部凉爽森林中积雪减少对精细根系动态的影响，我们使用除草剂监测了除雪前后的根长，产量和死亡率。地下根扫描仪。我们测量了森林中的两个主要树种—落叶乔木栎（Quercus crispula）和林下常绿矮竹（Sasa nipponica）的根系动态。除雪使Sasa的根总产高峰时间提前了一个月，但在橡树中却没有。除根与植物形态在根系生产上存在显着的相互作用。这表明增强的Sasa除雪后的根系生产可能会增强其与橡树竞争的能力。相反，除雪并不能提高根系死亡率，这表明这些物种的根系可以容忍土壤冻结。除雪场中较早的积雪消失扩大了Sasa的生长期。我们推测，林下环境的这种变化将延长春季的光合作用时间，从而加快Sasa根系生产的时机。我们认为，两个物种之间根系减少对积雪减少的不同反应将改变上层和下层植被的竞争性相互作用，影响森林生态系统的净初级生产力和生物地球化学（例如碳和氮循环）。