Events hidden in winter warming: Effects of recurrent soil freeze-thaw cycles on ecosystem functions in the temperate zone

持续的全球变暖预计将增加寒温带地区土壤冻融循环（FTC）的重现，因为冬季积雪减少和气温变异性增加。目前，北半球一半以上的地区都出现了联邦贸易委员会，因此，探讨气候变化对其制度改变的生态影响是很重要的。尽管植物可能是控制生态系统功能（如养分保留）的决定性因素，但关于FTC对植物群落影响的知识很少。有证据表明，FTC改变了植物生产力、碳分配和竞争。FTC频率和时间的变化能够改变生态系统稳定性和生态系统服务、植被组成和物种分布。养分循环通过物理破坏和微生物活动的变化而改变，导致养分浸出和微量气体损失。这些过程间接影响人类利益（例如生产力、水质、温室气体排放）。我们希望通过田间试验分析冬季强化FTC对草地和健康草地生物量生产的影响，从而探索FTC对植物氮营养、光合活性、根系损伤以及植物竞争和根菌根化等生物相互作用的影响过程。

Ongoing global warming is expected to increase the recurrence of soil freeze-thaw cycles (FTC) in cool-temperate regions due to decreases in snow cover and increased variability of air temperature in winter. FTC currently occur in more than half of the northern hemisphere, therefore it is important to explore the ecological implications of their altered regimes due to climate change. Knowledge of FTC effects on plant communities is scarce, although plants may be the decisive factor in controlling ecosystem functions such as nutrient retention. Evidence suggests that FTC alter plant productivity, carbon allocation and competition between. Shifts in frequency and timing of FTC are capable of altering ecosystem stability and ecosystem services, vegetation composition and species distributions. Nutrient cycling is altered via physical disruption and changes in microbial activity, leading to nutrient leaching and trace gas loss. These processes indirectly affect human interests (e.g. productivity, water quality, greenhouse gas emissions). We want to analyze effects of intensified FTC in winter for the biomass production of grassland and heath in a field experiment, thereby also exploring processes behind effects of FTC on plants addressing N-nutrition, photosynthetic activity, root injury, and biotic interactions such as plant competition and root mycorrhization.