Effects of aeolian processes on soil nutrient loss in the Gonghe Basin, Qinghai–Tibet Plateau: an experimental study
Effects of aeolian processes on soil nutrient loss in the Gonghe Basin, Qinghai–Tibet Plateau: an experimental study
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DOI：
10.1007/s11368-017-1734-0
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发表时间：
2017
影响因子：
3.6
通讯作者：
Xunming Wang;L. Lang;Ting Hua;Hui Li;Caixia Zhang;Wenyong Ma
中科院分区：
文献类型：
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作者：
Xunming Wang;L. Lang;Ting Hua;Hui Li;Caixia Zhang;Wenyong Ma
目的青藏高原东北部共和盆地受到风沙过程、土壤养分流失和沙漠化的威胁，近几十年来人类活动急剧增加。然而，风沙过程和土壤养分流失之间的相互作用仍然知之甚少。材料与方法通过野外调查、风洞实验和实验分析，研究了人类活动(植被遭到大规模破坏)和风沙过程对共和盆地土壤养分流失和沙化的影响。结果与讨论草原土壤表层分解后，高风沙强度(≥16 mm、S−1)对土壤养分流失和沙化的影响范围为294.02~1012.73 g/m−2，风蚀深度为4.09~11.27 mm。高风速使土壤有机质和全氮损失分别为7.5 6和0.38万kg/ha−1。在极高风速下(≥22m和S−1)，土壤有机质和全氮损失分别为26.99g/ha和1.41g/ha−1。风洞试验表明，共和盆地土壤有机质和全氮的去除与风速的相关性不显著，而与总磷和全钾的去除呈正相关。结论风沙过程使土壤表面的全磷和全钾去除，对植被有潜在的影响，因为K和P是植物生长所必需的营养物质。此外，大部分养分在土壤的细粒级中被富集。因此，风沙作用造成的养分流失可能导致农田和草地退化，从而可能引发共和盆地的荒漠化。
PurposeThe Gonghe Basin of northeastern Qinghai–Tibet Plateau is threatened by aeolian processes, soil nutrient loss, and desertification, where human activities have greatly increased over recent decades. However, the interactions between aeolian processes and soil nutrient loss remain poorly understood. Therefore, in this study, we employed a wind tunnel to simulate aeolian processes and soil nutrient loss affected by human activities such as tillage and trampling by livestock.Materials and methodsField investigations, wind tunnel experiments, and experimental analyses were conducted to assess the impacts of human activity (wholesale destruction of vegetation) and aeolian processes on soil nutrient loss and desertification in the Gonghe Basin.Results and discussionAfter grassland soil surface was disaggregated, sediments removed by high aeolian intensity (≥16 m s−1) ranged from 294.02 to 1012.73 g m−2, and wind erosion depths varied from 4.09 to 11.27 mm. High wind velocities resulted in losses of total soil organic matter (SOM) and total nitrogen (TN) by 7.56 and 0.38 kg ha−1, respectively. Under very high wind velocities (≥22 m s−1), losses of SOM and TN were 26.99 and 1.41 kg ha−1, respectively. Wind tunnel experiments indicate that in the Gonghe Basin, there were no significant correlations between wind velocity and the removal of SOM and TN; however, positive correlations were observed between wind velocity and total phosphorus (TP) and total potassium (TK).ConclusionsAeolian processes remove TK and TP from the soil surface, which has a potential impact on vegetation because that K and P are essential nutrients for plant growth. In addition, most nutrients are enriched within fine particle fraction of soil. Nutrient loss caused by aeolian processes may therefore result in the degradation of farmland and grassland, which consequently may have triggered desertification in the Gonghe Basin.