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气候变化对高寒生态系统地气间水能循环过程产生强烈的影响,因此,气候变暖条件下的高寒生态系统水热过程和寒区流域水循环过程具有重要研究意义.采用开顶式温室(OTC)对长江源沼泽草甸进行模拟增温试验,分析了模拟增温对多年冻土活动层土壤水分的影响.结果表明:短期增温使得沼泽草甸生物量显著增加,使得多年冻土活动层土壤冻结起始时间推迟、融化起始时间提前,从而使融化期延长.室外对比样地在65 cm深度存在明显的干层,而OTC土壤水分随着深度加深不断降低.增温使得多年冻土浅层土壤具有更高的含水量,但并未导致表层土壤干化,这与沼泽草甸土壤浅层密集的根系层和具有较强的持水和保水能力的有机质层有关.
Therefore, it is of great significance to study the hydrothermal processes of alpine ecosystems and the water cycle processes in the cold regions of the cold climate system under the condition of climate warming.Using the open roof greenhouse (OTC) The effect of simulated warming on the soil moisture in the active layer of permafrost was analyzed by simulating the temperature increase of marsh meadow in the Yangtze River.The results showed that the biomass of the swamp meadow increased significantly under short-term warming, The onset of the thawing period was delayed and the thawing initiation time was advanced so as to prolong the thawing period.When the depth was 65 cm, there was obvious dry layer in the outdoor contrast sample, while the OTC soil moisture decreased with the depth deepening. Soil layers had higher water content, but did not result in the desiccation of topsoil, which was related to the shallow root layer of marsh meadow soil and the organic layer with strong water holding and water holding capacity.