Chin J Plant Ecol ›› 2020, Vol. 44 ›› Issue (9): 916-925.DOI: 10.17521/cjpe.2020.0018

• Research Articles • Previous Articles     Next Articles

Effects of simulated warming on biological soil crust-soil system respiration in alpine sandy lands

ZHAO He-Ju1,2, YUE Yan-Peng1,2, JIA Xiao-Hong1,2,*(), CHENG Long1,2, WU Bo1,2, LI Yuan-Shou3, ZHOU Hong1,2, ZHAO Xue-Bin4   

  1. 1Institute of Desertification Studies, Chinese Academy of Forestry, Beijing 100091, China
    2Key Laboratory of Desert Ecosystem and Global Change, State Administration of Forestry and Grassland, Beijing 100091, China
    3Chinese Academy of Meteorological Sciences, Beijing 100081, China
    4 Qinghai Gonghe Desert Ecosystem National Positioning Research Station, Gonghe, Qinghai 813000, China
  • Received:2020-01-17 Revised:2020-06-15 Online:2020-09-20 Published:2020-07-31
  • Contact: JIA Xiao-Hong
  • Supported by:
    Supported by the National Key R&D Program of China(2016YFC0500801);the Special Survey on Science and Technology Basic Resources(2017FY100206);the National Natural Science Foundation of China(41471096);the National Natural Science Foundation of China(41371093)

Abstract:

Aims Biological soil crust is an important type of surface cover in alpine sandy lands. Understanding of the effect of warming on respiration from the biological soil crust-soil system in alpine regions can provide theoretical reference to the assessment of the response and feedback of biological soil crusts to climate changes.
Methods The moss and algae crusts in the artificial vegetation restoration areas were taken as the research objects. The open top chamber (OTC) was used as a passive warming device to simulate warming. The daily and growing season dynamics of respiration rates in two types of biological soil crust-soil systems were measured. The effects of warming on CO2 emission and its temperature sensitivity were discussed.
Important findings Both the daily and the growing season dynamics of respiration rate of the moss and algae crust-soil system showed “single-peak” curves and were not affected by warming. The daily peaks appeared around 13:00, and the growing season peaks appeared around August. Warming changed the daily peak value of respiration rate of the biological soil crust-soil system. In the relatively dry year (2017), moderate warming increased cumulative CO2 emission from the two types of biological soil crust-soil system during growing season, but the increase declined under excessive warming. In the relatively wet year (2018), as warming got greater, CO2 emission from the two types of biological soil crust-soil system increased more. The relationship between respiration rate and temperature of two types of biological soil crust-soil system followed the exponential function. In the relatively dry year, more increase of temperature induced smaller temperature sensitivity of CO2 emission, and the temperature sensitivity varied from 1.47 to 1.61 and 1.60 to 1.95 in the moss and algae crust soil system respectively. In the relatively wet year, with the increase of temperature, temperature sensitivity of system respiration increased, and the temperature sensitivity varied from 1.44 to 1.68 and 1.44 to 1.76 in the moss and algae crust soil system respectively. This study shows that global warming has greatly increased the respiration of biological soil crust-soil system in alpine ecosystems. Therefore, we should fully consider the impact of climate warming on the wide spread biological soil crusts in this area for better evaluation of carbon cycling processes in alpine ecosystems.

Key words: alpine sandy area, biological soil crust, warming, respiration, temperature sensitivity