气候变化领域集成服务门户

AimsIn this study, we investigated the effects of reduced snow depth on plant phenology, productivity, nitrogen (N) cycling, and N use in canopy and understory vegetation. We hypothesized that decreased snow depth would hasten the timing of leaf flushing and N uptake in understory vegetation, increasing its N competitive advantage over canopy trees.ResultsSnow removal did not directly affect the phenology of either canopy or understory vegetation. Understory vegetation took up more N in the snow removal plots than in the control plots, particularly in the mid- to late-growing season. Leaf production and N uptake in canopy trees also did not differ between the control and snow removal plots, but N resorption efficiency in the snow removal plots (57.6%) was significantly higher than those in control plots (50.0%).ConclusionsIncreased N uptake by understory plants may induce N limitation in canopy trees, which in turn may cause canopy trees to increase their N use efficiency. Such competitive advantage of understory vegetation over canopy trees against snow reduction may affect N cycling via litter quality and quantity not only just after the growing season but also in subsequent seasons.