梯度增温对青藏高原高寒草甸生态系统碳交换的影响

发布时间：2018-03-22 02:31

  本文选题：增温　切入点：高寒草甸　出处：《草业科学》2017年12期 　论文类型：期刊论文

【摘要】：高寒草甸是青藏高原主要的草地生态系统类型,对气候变化非常敏感,研究高寒草甸生态系统碳交换对升温的响应具有重要的理论和现实意义。在青藏高原中部地区的高寒草甸,使用开顶箱法(open-top chambers,OTCs)设置不增温对照(T_0)以及4个不同程度的增温处理(T_1、T_2、T_3、T_4),采用CO_2红外分析仪对生长季期间的碳交换进行连续3年的观测。结果表明,4个增温处理的5cm土壤温度较之于不增温对照分别增加1.73(T_1)、1.83(T_2)、3.03(T_3)以及3.53℃(T_4);土壤水分没有发生梯度变化。观测期间,净生态系统碳交换(net ecosystem carbon exchange,NEE)基本为负值,因此高寒草甸表现为碳汇。增温小于2℃促进总生态系统生产力(gross ecosystem productivity,GEP),但对生态系统呼吸(ecosystem respiration,ER)影响较小,因而促进NEE,即促进高寒草甸的碳吸收;但增温大于3℃则抑制GEP,对ER影响较小,因而总体上对NEE产生抑制作用。综上所述,在高寒草甸生态系统,适度增温促进碳吸收,增温过度则降低碳吸收。
[Abstract]:Alpine meadow is the main grassland ecosystem in the Qinghai-Tibet Plateau and is very sensitive to climate change. It is of great theoretical and practical significance to study the response of carbon exchange in alpine meadow ecosystem to temperature rise. Using open-top chambersOTCs) to set up a non-warming control (T _ S0) and four different degrees of heating treatment, the CO_2 infrared analyzer was used to observe the carbon exchange during the growing season for three consecutive years. The results showed that the 5cm treated by the four warming treatments had been used to observe the carbon exchange during the growing season for three consecutive years with the help of the CO_2 infrared analyzer to observe the carbon exchange during the growth season by using the CO_2 infrared analyzer to observe the carbon exchange during the growing season. The soil temperature was increased by 1.73 T1 / T _ 1 / T _ (1.83) / T _ 3 / T _ 3) and 3.53 鈩，

本文编号：1646691