CollectHomepage AdvertisementContact usMessage

Arid Land Geography ›› 2020, Vol. 43 ›› Issue (3): 761-769.doi: 10.12118/j.issn.1000-6060.2020.03.22

Previous Articles     Next Articles

Characteristic of soil respiration and its influencing factors on the coastal of saline lake in arid region

LI Dian-peng1,YAO Mei-si1,SUN Tao1,LIUSUI Yun-hao1,JIA Hong-tao1,2   

  1. College of Grassland and Environmental Science,Xinjiang Agricultural University,Urumqi 830052,Xinjiang,China;Xinjiang Key Laboratory of Soil and Plant Ecological Processes,Urumqi 830052,Xinjiang,China

  • Received:2019-07-10 Revised:2019-11-27 Online:2020-05-25 Published:2020-05-25

Abstract:

Inland water ecosystems can act as greenhouse gas sinks through the photosynthetic uptake of carbon dioxide (CO2) and subsequent storage in longlived biomass or burial in soils.As one of the most important carbon sinks,the carbon sedimentation rate of lakes was related to the source and sink status of organic carbon content in coastal soils and their carbon emission rates.We investigated the characteristics of soil respiration rate(Rs),the temperature sensitivity of soil respiration (Q10) variability,and its influencing factors in a typical arid saline lake coastal area.In this study,we measured the soil respiration rate using a Li-8100 automated soil flux system (LI-COR,Lincoln,Nebraska,USA) from May to October 2015 and 2016  at Dabancheng and Barkol saline lakes,Xinjiang,China.The dynamics of seasonal soil respiration rate and Q10 value,the correlation between soil respiration and soil organic carbon (SOC),bulk density (BD),soil temperature (ST),soil moisture (M),plant biomass (BIO),and salt and pH were also evaluated.The results showed as follows:(1) the seasonal variation of soil respiration rate ranged from 0.07 to 11.59 μmol·m-2·s-1,and the monthly mean value was 2.45 μmol·m-2·s-1.The soil respiration rate peaked once in July with a maximum value of 4.69 μmol·m-2·s-1,while the lowest respiration rate was in October (1.01 μmol·m-2·s-1).(2) the monthly mean cumulative daily CO2 emission was 9.30 g·m-2·s-1,July cumulative emission rate reach peak (17.82 g·m-2·s-1) .(3) the negative correlation between soil respiration rate,soil temperature (5 cm ),and soil salt was significant (P < 0.05),and there was a positive correlation between soil respiration rate,soil organic carbon,and soil moisture.(4) the Q10 value presented a single peak trend from July to October,and there was no significant differences between the saline lakes,with minimum and maximum values of 2.25 and 3.52 in June and September,respectively.(5) the results of the linear model showed the best fitting model for soil respiration rate and SOC,ST5,M,and soil salt content.The singlefactor model could explain 41.7%-75.7% of soil respiration variability in the saline lakes coastal regions (P < 0.05),and the multifactor synthesis model Rs=0.001×SOC+0.039×M - 0.534×Salt-0.116×ST5+5.06 (P=0.05) could explain 80.4% of soil respiration variability.After eliminating SOC,ST5,SM,and Salt,the determinants of the three-factor regression equation (R2) were reduced to 0.024,0.027,0.104,and 0.269,respectively,indicating that the contribution rate of salt was the largest among the factors affecting the soil respiration rate.The results of singlefactor and multifactor synthesis models showed that soil salt had the greatest influence on soil respiration rate in the saline lakes coastal regions.Therefore,when considering the carbon budget and cycle of terrestrial ecosystems,we cannot ignore the soil carbon processes in saline lakes in arid regions and the effects of soil salt on the carbon emissions from saline lake ecosystems in arid regions.

Key words: carbon emission, soil salt, Dabancheng Saline Lake, Barkol Saline Lake, temperature sensitive of soil respiration (Q10)