短期增温对内蒙古大青山油松人工林土壤呼吸的影响

Effects of Short-term Warming on Soil Respiration of Pinus tabulaeformis Plantation in Daqingshan Mountains

在全球变暖的气候大背景下,为进一步明确增温对干旱半干旱区土壤呼吸的影响,于2020年6—11月采用开顶增温室(OTC)模拟增温,观测内蒙古呼和浩特市大青山乌素图林场内油松(Pinus tabuliformis)人工林土壤呼吸速率的变化,揭示大青山油松人工林土壤呼吸的变化趋势与土壤温湿度之间的关系。结果表明:土壤呼吸的昼夜变化及季节变化均呈单峰型变化趋势,且增温抑制内蒙古大青山油松人工林土壤呼吸速率;昼夜变化中,生长季土壤呼吸速率呈现白天高夜间低的趋势,峰值出现在11:00—15:00;季节变化中,8月土壤呼吸速率达到最高,6—11月增温与对照相比,增温使土壤呼吸速率平均降低了15.2%;土壤呼吸速率受土壤温湿度共同影响且与土壤湿度的相关性更高;增温使得不同土壤深度的Q_(10)值均降低。

In the context of global warming,in order to further clarify the influence of warming on soil respiration in arid and semi-arid areas,Open Top Chamber(OTC) was used to simulate warming and observe the changes of soil respiration rate of Pinus tabulaeformis plantation in Daqingshan Mountains Wusutu Forest Farm in Hohhot,Inner Mongolia from June to November 2020.The relationship between soil respiration and soil temperature and humidity in P.tabulaeformis plantation in Daqingshan Mountains was revealed.The diurnal and seasonal variations of soil respiration showed a unimodal trend,and increasing temperature inhibits soil respiration rate of P.tabulaeformis plantation in Daqingshan Mountains,Inner Mongolia.In the diurnal change,the soil respiration rate in the growing season was higher in the daytime and lower at night,and the peak rate appeared between 11:00 and 15:00.In the seasonal change,the soil respiration rate reached the highest in August.Compared with the control group,the soil respiration rate from June to November decreased by 15.2% on average due to the increasing temperature.Soil respiration rate was influenced by soil temperature and humidity with a higher correlation with soil humidity.The Q_(10)values of different soil depths were reduced by temperature increase.