Interactive effects of hydrological conditions on soil respiration in China's Horqin sandy land: An example of dune-meadow cascade ecosystem.
Interactive effects of hydrological conditions on soil respiration in China's Horqin sandy land: An example of dune-meadow cascade ecosystem.
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DOI：
10.1016/j.scitotenv.2018.10.198
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发表时间：
2019-02
期刊：
影响因子：
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通讯作者：
Chunxue Han;R. Yu;Xixi Lu;L. Duan;V. Singh;Ting-xi Liu
中科院分区：
文献类型：
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作者：
Chunxue Han;R. Yu;Xixi Lu;L. Duan;V. Singh;Ting-xi Liu
Soil moisture (Ms) strongly influences dynamic changes in soil respiration (Rs) and is thus an important factor when predicting soil carbon emissions. However, the various sources ofMs(rainfall, groundwater, and condensation) exert complicated and uncertain effects onRs. This study examined the growth seasonal variation (from April to October) ofRsand the diurnal variation in a cascade ecosystem consisting of sandy bare ground, a transitional artificialPopulusforest, and a meadowPhragmites communiscommunity in China's Horqin sandy land. Simultaneous measurements of the 0–10 cm depth soil temperature (Ts) andMs, rainfall, the surface air relative humidity and the groundwater depth were collected. The results revealed that in sandy bare ground withMsbelow field capacity,Mshad a greater impact onRsthanTs, and rainfall could increaseRs.The effect of condensation onRsduring periods of continuous drought could not be ignored. In the meadowlands withMsabove field capacity, the groundwater affectedRsindirectly by regulatingMsand the relationship withTs, and rainfall had an adverse effect onRs. The effects of rainfall,MsandTsonRswere minimum asMsapproached the saturation water content. In the transitional forest,MsandTswere the main factors controllingRs. The most favorableMsforRswas close to the field capacity. The results emphasize that field capacity and saturation water content are the demarcation points of a soil carbon emissions prediction model, and the effect of different hydrological conditions andTsonRsat each segment are reconsidered accordingly. Ultimately, the carbon emission patterns of the cascade ecosystems in arid and semi-arid areas are extremely complicated and have to be considered specially for estimating terrestrial carbon emissions.
