[1]WEI Yingxin,ZHOU Lijun,BU Chongfeng,et al.Monthly Variation Characteristics and Key Influencing Factors of Carbon Fluxes in Two Typical Desert Crusts[J].Research of Soil and Water Conservation,2021,28(06):153-161.
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Research of Soil and Water Conservation[ISSN 1005-3409/CN 61-1272/P] Volume:
28
Number of periods:
2021 06
Page number:
153-161
Column:
Public date:
2021-10-10
- Title:
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Monthly Variation Characteristics and Key Influencing Factors of Carbon Fluxes in Two Typical Desert Crusts
- Author(s):
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WEI Yingxin1,2,ZHOU Lijun3,BU Chongfeng1,2,LUO Han1,2,JU Mengchen1,WANG Chun1,LI Yahong1,GUO Qi1,LI Bingyin4
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(1.Institute of Soil and Water Conservation,Northwest A&F University,Yangling,Shaanxi 712100,China; 2.Institute of Soil and Water Conservation,CAS & MWR,Yangling,Shaanxi 712100,China; 3.Central Station of Soil and Water Conservation Monitoring in the Yangtze River Basin,Changjiang Water Resources Commission,Wuhan 430010,China; 4.Upper and Middle Yellow River Bureau,Yellow River Conservancy Commission,Xi'an 710021,China)
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- Keywords:
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Mu Us Sandy Land; moss crust; algal crust; soil carbon flux; monthly variation characteristics; environmental factors
- CLC:
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S154.3
- DOI:
-
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- Abstract:
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In order to clarify the characteristics of monthly changes in carbon fluxes of soil covered with biological crust in desert ecosystem and its key influencing factors,the respiration rates(DR)and net carbon fluxes(NCF)of soils covered with moss crust(M),algal crust(AL)and bare land set as the control were observed in situ dynamically(during the growing period,June-November)in Mu Us Sandy Land,and the photosynthetic rate(Pn)was calculated. The corresponding environmental index data were recorded simultaneously. The results showed that:(1)DR and Pn of both types of crusts first increased and then decreased,with DR peaking in August [1.96,1.66 μmol/(m2·s)for M and AL,respectively]; and with Pn peaking in September 2.75,1.39 μmol/(m2·s)for M and AL,respectively]; NCF first increased,then decreased and increased later,with peaking in July [1.38,1.43 μmol/(m2·s)for M and AL,respectively],and reached a trough value in September [-1.24,-0.18 μmol/(m2·s)for M and AL,respectively];(2)temperatures of soil depths of 2 cm,5 cm and 10 cm and soil water contents of soil depths of 2 cm and 5 cm were the key influencing factors on moss crust cover soil carbon flux,temperatures of soil depths of 2 cm,5 cm and 10 cm,light intensity and near-surface air humidity were the key influencing factors on algal crust cover soil carbon flux;(3)the soil moisture threshold of net carbon fixation by moss crust(8.9%)was lower than that of algal crust(11.4%),and the temperature threshold(13.5℃)was higher than that of algal crust(7.3℃). The above results indicated that the monthly changes of carbon fluxes of soils covered by moss crust and algal crust were similar,but the key influencing factors were different,and the risk of carbon loss in algal crust was higher than that in moss crust in the context of warming and rainfall reduction caused by future climate change.