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气候变化引发的季节性雪被改变可能对高寒森林土壤氮循环产生深刻影响.以遮雪棚去除雪被,研究了雪被去除样方和对照样方在不同关键时期(雪被初期、深雪被期和雪被融化期)土壤氮库和矿化速率的变化.结果表明:季节性雪被对土壤具有良好的保温作用,雪被去除使得5 cm深度土壤平均温度和最低温度分别降低0.33和1.17℃,并明显增加了土壤冻结深度和冻融循环.土壤活性氮在不同雪被时期存在显著差异.雪被去除使得冬季土壤铵态氮、硝态氮和可溶性有机氮增加38.6%、23.5%和57.3%.此外,雪被去除也促进了融化期土壤硝化和矿化速率的增加.因此,未来气候变暖引起的雪被减少可能加快川西亚高山森林冬季土壤氮循环.
The change of seasonal snow caused by climate change may have a profound impact on the nitrogen cycle in alpine forest so as to remove the snow cover in the snow shelter and study the snow-removed quadrats and control quadrats at different critical periods The results showed that seasonal snow had a good heat preservation effect on the soil, and the snow was removed so that the average soil temperature and the minimum temperature at the depth of 5 cm decreased by 0.33 and 1.17, respectively ℃, and significantly increased soil freezing depth and freeze-thaw cycle.The soil active nitrogen was significantly different in different snow cover periods.The removal of snow increased the contents of ammonium, nitrate nitrogen and soluble organic nitrogen in winter soil by 38.6%, 23.5% and 57.3% .In addition, the removal of snow also promoted the increase of soil nitrification and mineralization in the thawing period, so the reduction of snow caused by future climate warming may accelerate the winter soil nitrogen cycle in sub-alpine forests in western Sichuan.