Permafrost changes in the Nanwenghe Wetlands Reserve on the southern slope of the Da Xing'anling‒Yile'huli mountains, Northeast China

• Published in: Advances in Climate Change Research
• Main Authors: Rui-Xia He, Hui-Jun Jin, Dong-Liang Luo, Xiao-Ying Li, Chuan-Fang Zhou, Ning Jia, Xiao-Ying Jin, Xin-Yu Li, Tao Che, Xue Yang, Li-Zhong Wang, Wei-Hai Li, Chang-Lei Wei, Xiao-Li Chang, Shao-Peng Yu
• Format: Article in Journal/Newspaper
• Language: English
• Published: KeAi Communications Co., Ltd. 2021
• Subjects: Nanwenghe wetland reserve; Permafrost; Climate change; Active layer thickness; Ground thermal state; Thermal offset; Meteorology. Climatology; QC851-999; Social sciences (General); H1-99; permafrost
• Online Access: https://doi.org/10.1016/j.accre.2021.06.007; https://doaj.org/article/ccc018f1b75c44cbaa3c18376ff9b3c7

The Nanwenghe Wetlands Reserve in the Yile'huli Mountains is a representative region of the Xing'an permafrost. The response of permafrost to climate change remains unclear due to limited field investigations. Thus, longer-term responses of the ground thermal state to climate change since 2011 have been monitored at four sites with varied surface characteristics: Carex tato wetland (P1) and shrub-C. tato wetland (P2) with a multi-year average temperatures at the depth of zero annual amplitude (TZAA) of −0.52 and −1.19 °C, respectively; Betula platyphylla-Larix gmelinii (Rupr.) Kuzen mixed forest (P3) with TZAA of 0.17 °C, and; the forest of L. gmelinii (Rupr.) Kuzen (P4) with TZAA of 1.65 °C. Continuous observations demonstrate that the ecosystem-protected Xing'an permafrost experienced a cooling under a warming climate. The temperature at the top of permafrost (TTOP) rose (1.8 °C per decade) but the TZAA declined (−0.14 °C per decade), while the active layer thickness (ALT) thinned from 0.9 m in 2012 to 0.8 m in 2014 at P1. Both the TTOP and TZAA increased (0.89 and 0.06 °C per decade, respectively), but the ALT thinned from 1.4 m in 2012 to 0.7 m in 2016 at P2. Vertically detached permafrost at P3 disappeared in summer 2012, with warming rates of +0.42 and + 0.17 °C per decade for TTOP and TZAA, respectively. However, up to date, the ground thermal state has remained stable at P4. We conclude that the thermal offset is crucial for the preservation and persistence of the Xing'an permafrost at the southern fringe.