Soil Moisture Dynamics of Artemisia ordosica Communities in the Mu Us Sandy Land
Received date: 2013-11-27
Revised date: 2014-03-14
Online published: 2015-05-20
Soil moisture content of the 5, 15, 30, 50 and 70 cm soil layers was continuously measured at 10-min intervals for four sites: shifting dune (I), Artemisia ordosica community in semi-fixed dune (II), A. ordosica community with biological soil crusts (III), and A. ordosica + Stipa bungeana community (IV), in the Mu Us Sandy land of Inner Mongolia, to determine soil moisture dynamics during the growing season under different land coverage. The results indicated that: (1) Soil moisture storage capacity was largest for all sites in autumn, while the capacity of the A. ordosica+ Stipa bungeana community was the largest of all the sites, at least 30 mm larger than that of the other sites. (2) Influenced by soil evaporation and lacking the replenishment of small rainfall in spring, soil moisture content of the 20-60 cm soil layer in the shifting dune was only 4% and showed substantial variation during the whole growing season, while the soil moisture contents of the 0-20 cm and 60-80 cm layers were much more stable. Soil moisture content of the 0-60 cm soil layer in the A. ordosica community in semi-fixed dune was about 6% for the majority of the study period and was unimodal. Soil moisture content of the 60-80 cm layer was bimodal, showing minimum moisture content in spring and replenishment of moisture content in summer and autumn. Average soil moisture content of the 0-10 cm layer in A. ordosica community with biological soil crusts was more than for the 10-20 cm soil layer. With the influence of the biological soil crusts, soil moisture content of the 0-10 cm layer was bimodal, while the moisture content in the 10-60 cm layer was stable and unimodal. Soil moisture content of the 60-80 cm soil layer was bimodal and lowest in spring. Water holding capacity of A. ordosica+S. bungeana community was significantly increased compared with the other sites. Soil moisture content of the 0-60 cm soil layer was 12% to 14% for most of the summer and autumn, and showed a distinct bimodal pattern during the growing season. Because of a lack of adequate replenishment from precipitation, soil moisture content of the 60-80 cm soil layer was unimodal and steady at about 4%. (3) Soil moisture content after individual precipitation was different by about 30 mm in sites of different land coverage. Precipitation could influence soil water down to 70, 50, 30, and 40 cm for shifting dune, A. ordosica community in semi-fixed dune, A. ordosica community with biological crusts, and A. ordosica+S. bungeana community, respectively. Extreme precipitation could rapidly affect the soil layer down to 70 cm in all sites.
Li Engui , Huang Yongmei , Yu Xiaona , Li Xiaoyan . Soil Moisture Dynamics of Artemisia ordosica Communities in the Mu Us Sandy Land[J]. Journal of Desert Research, 2015 , 35(3) : 674 -682 . DOI: 10.7522/j.issn.1000-694X.2014.00035
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