多梯度增温对青藏高原高寒草甸温室气体通量的影响
发布时间：2019-01-12 12:10
【摘要】：高寒草甸是青藏高原重要的草地类型之一。目前增温对高寒草甸温室气体通量影响的研究较少,尤其在不同尺度的增温条件下,温室气体通量的响应尚不明确。因此,设置多梯度增温实验,模拟未来不同幅度增幅情况,对预测高寒草甸温室气体通量的变化具有重要意义。为深入地认识气候变暖对高寒草甸温室气体通量的影响,假设高寒草甸温室气体通量的周转速率在增温条件下随增温梯度而加快。在青藏高原纳木错地区高寒草甸,采用开顶箱法(Open-top chambers,OTCs)设置对照(T0,不增温)以及4个不同程度的增温处理(T1、T2、T3、T4,分别增温1、2、3、4℃),结合静态箱-气相色谱法对增温处理后的CO_2、CH_4和N_2O通量进行同步观测。对3个生长季(2013—2015年)进行连续观测发现:(1)地下5 cm土壤3年的平均温度相对于对照处理分别增加1.73℃(T1)、1.83℃(T2)、3.03℃(T3)和3.53℃(T4);(2)高寒草甸生长季平均呼吸(CO_2)为(42.6±9.11)mg·m~(-2)·h~(-1),同时具有较强的CH_4吸收能力,达到(-47.96±8.76)μg·m~(-2)·h~(-1),其N_2O通量维持在较低水平,为(0.3±0.46)μg·m~(-2)·h~(-1);(3)在高寒草甸生长季,温室气体通量与温度以及水分均具有显著的相关关系,但增温未能显著改变生长季温室气体平均通量。以上结果表明,增温所引起的其他环境因素的改变(如伴随不同梯度增温下土壤水分变化的不确定性),导致高寒草甸在短期内进行内部调节,并维持温室气体通量稳定。
[Abstract]:Alpine meadow is one of the important grassland types in Qinghai-Tibet Plateau. At present, the effect of warming on greenhouse gas flux in alpine meadow is less studied, especially in different scales, the response of greenhouse gas flux is not clear. Therefore, it is of great significance to predict the change of greenhouse gas flux in alpine meadow by setting up multi-gradient warming experiment and simulating the future increase of different amplitude. In order to understand the effect of climate warming on greenhouse gas flux in alpine meadow, it is assumed that the turnover rate of greenhouse gas flux in alpine meadow is accelerated with the increase of temperature gradient. In the alpine meadow of Namuco area, Qinghai-Xizang Plateau, the open top box method (Open-top chambers,OTCs) was used to set up the control (T0, no temperature increase) and four different degrees of warming treatment (T1OT2T2T3T4, respectively). The flux of CO_2,CH_4 and N2O after heating treatment was observed synchronously by static box gas chromatography. Continuous observation of three growing seasons (2013-2015) showed that: (1) the average temperature of 3 years of underground 5 cm soil increased by 1.73 鈩，
本文编号：2407759
[Abstract]:Alpine meadow is one of the important grassland types in Qinghai-Tibet Plateau. At present, the effect of warming on greenhouse gas flux in alpine meadow is less studied, especially in different scales, the response of greenhouse gas flux is not clear. Therefore, it is of great significance to predict the change of greenhouse gas flux in alpine meadow by setting up multi-gradient warming experiment and simulating the future increase of different amplitude. In order to understand the effect of climate warming on greenhouse gas flux in alpine meadow, it is assumed that the turnover rate of greenhouse gas flux in alpine meadow is accelerated with the increase of temperature gradient. In the alpine meadow of Namuco area, Qinghai-Xizang Plateau, the open top box method (Open-top chambers,OTCs) was used to set up the control (T0, no temperature increase) and four different degrees of warming treatment (T1OT2T2T3T4, respectively). The flux of CO_2,CH_4 and N2O after heating treatment was observed synchronously by static box gas chromatography. Continuous observation of three growing seasons (2013-2015) showed that: (1) the average temperature of 3 years of underground 5 cm soil increased by 1.73 鈩，
本文编号：2407759
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