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以腾格里沙漠东南缘天然植被区藓类结皮和藻-地衣结皮-土壤为研究对象,利用开顶式生长室(OTC),采用Li-8150系统连续测定了冬季(2015年11月—2016年1月)低温环境下两类结皮-土壤呼吸的变化,分析了低温及模拟增温对两类结皮-土壤呼吸的影响.结果表明:观测期内,藓类结皮、藻-地衣结皮-土壤呼吸速率分别为-0.052~0.418、-0.032~0.493μmol·m~(-2)·s~(-1),且藓类结皮显著高于藻-地衣结皮-土壤系统.不同类型结皮-土壤呼吸速率与5 cm土壤温度和土壤体积含水量均呈显著线性正相关,增温主要是通过加速土壤水分蒸散而抑制生物结皮-土壤呼吸速率.在整个观测期,藓类结皮-土壤系统累计排放9.90 g C·m~(-2),显著高于藻-地衣结皮-土壤系统的7.00 g C·m~(-2).研究区生物结皮-土壤系统冬季累计排放7.40g C·m~(-2),是该荒漠生态系统全年碳收支的重要组成部分.
Taking the moss crusts and algal-lichen crust-soil in the natural vegetation area of the southeastern margin of the Tengger Desert as research objects, the open roof growth chamber (OTC) was used to determine the winter with the Li-8150 system (November 2015 January 2016) The changes of soil crust-soil respiration in two types of crusts at low temperature were analyzed, and the effects of hypothermia and simulated warming on two types of crust-soil respiration were analyzed.The results showed that during the observation period, - lichen crust-soil respiration rates were -0.052-0.418 and -0.032-0.493μmol · m -2 · s -1, respectively, and the moss crusts were significantly higher than those of algae-lichen crust-soil System.The different types of crust-soil respiration rate had a significant linear positive correlation with 5 cm soil temperature and soil volumetric water content, and the warming mainly inhibited the biological crust-soil respiration rate by accelerating soil water evaporation.In the whole observation period , And moss crust-soil system accumulated 9.90 g C · m -2, which was significantly higher than 7.00 g C m -2 of algal-lichen crust-soil system. In winter, soil system accumulated 7.40g C · m -2, which is an important part of the annual carbon budget of the desert ecosystem.