Influence of grazing on hydraulic and mechanical properties of semiarid steppe soils under different vegetation type in Inner Mongolia, China
Influence of grazing on hydraulic and mechanical properties of semiarid steppe soils under different vegetation type in Inner Mongolia, China
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DOI：
10.1007/s11104-010-0405-3
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发表时间：
2011-03
期刊：
影响因子：
4.9
通讯作者：
A. Reszkowska;J. Krümmelbein;S. Peth;R. Horn;Ying Zhao;L. Gan
中科院分区：
文献类型：
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作者：
A. Reszkowska;J. Krümmelbein;S. Peth;R. Horn;Ying Zhao;L. Gan
在过去的几十年里，由于放牧强度的增加，动物践踏导致内蒙古土壤结构恶化。本文研究了两个不同的草原生态系统：羊草（Leymus chinensis, LCh）和大针茅（stipa grandis， SG），以及两个放牧强度：1979年以来未放牧（UG79）和放牧（连续放牧，CG，在大针茅地和冬季放牧，WG，在羊草）。对不同深度（4-8 cm、18-22 cm、30-34 cm和56-60 cm）的半干旱草原土壤团聚体、扰动和块状土样以及0-15 cm的团聚体进行了土壤力学和水力特性的测定。放牧导致团聚体抗拉强度和土体预压应力的显著增加，以及空气和饱和水力导电性的降低，与植被类型无关。此外，不放牧导致LCh场地土壤强度、孔隙连续性和水力传导性的恢复更为明显，但这也取决于场地的水分条件。在较湿的条件下以及反复冻融后，土壤强度下降。
Over the last few decades, due to increase in grazing intensity, animal trampling has led to soil structure deterioration in Inner Mongolia, China. We investigated two different steppe ecosystems:Leymus chinensis(LCh, characterized by relatively higher precipitation) andStipa grandis(SG) and two grazing intensities: ungrazed since 1979 (UG79) and grazed (continuously grazed, CG, at theStipa grandissite and winter grazed, WG, atLeymus chinensis). Soil mechanical and hydraulic properties of semiarid steppe soils from each site and treatment were determined for soil aggregates and disturbed and bulk soil samples from different depths (4–8, 18–22, 30–34 and 56–60 cm for disturbed and bulk samples and 0–15 cm for the aggregates). Grazing causes a significant increase in tensile strength of aggregates and in the precompression stress of the bulk soil as well as a decrease in air and saturated hydraulic conductivity, irrespective of the vegetation type. Furthermore, exclusion from grazing led to more pronounced recovery of soil strength and pore continuity and hydraulic conductivity at the LCh site but it also depended on the moisture conditions of the sites. Under wetter conditions as well as after repeated freezing and thawing the soil strength declined.