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中国沙漠 ›› 2022, Vol. 42 ›› Issue (6): 44-52.DOI: 10.7522/j.issn.1000-694X.2022.00040

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青藏高原东缘玛曲沙化高寒草地土壤理化性质

李世龙()   

  1. 中铁第一勘察设计院集团有限公司,陕西 西安 710043
  • 收稿日期:2022-04-06 修回日期:2022-04-21 出版日期:2022-11-20 发布日期:2023-01-09
  • 作者简介:李世龙(1984—),男,甘肃武威人,工程师,主要研究方向为铁路路基工程及生态环境效应。E-mail: slli21@163.com
  • 基金资助:
    中铁第一勘察设计院集团有限公司科研(软件)项目“西成铁路高原湿地路基绿色生态防护体系研发及应用”

Soil physicochemical properties of alpine grasslands under different desertification degrees in MaquGansuChina

Shilong Li()   

  1. China Railway First Survey and Design Institute Group Co. ,Ltd. ,Xi'an 710043,China
  • Received:2022-04-06 Revised:2022-04-21 Online:2022-11-20 Published:2023-01-09

摘要:

沙漠化是青藏高原东缘高寒草地退化的重要指征,土壤理化性质是反映草地沙化过程的重要特征参数。以青藏高原东缘玛曲县为例,分析天然草地和轻度、中度、重度、极重度沙化草地土壤粒度组成、温湿度、有机碳和养分等因子的差异特征,旨在阐明高寒草地沙化过程中土壤理化性质的变化。结果表明:草地土壤黏土和粉沙含量随着沙化的发展显著减小,而沙颗粒含量(细沙和中沙)随着沙化程度的增加而增大;5—8月生长季,重度沙化土壤相比轻度沙化土壤温度明显升高,土壤含水量明显降低;随着沙化程度的增加,土壤有机碳含量显著降低,轻度沙化减少50%以上,中度至极重度沙化草地减少91%—99%;土壤全氮(TN)、碱解氮(AN)、全磷(TP)、有效磷(AP)等含量在轻度以上沙化草地中显著降低,而全钾(TK)变化不明显,速效钾(AK)仅在中度至极重度沙化草地中含量降低。高寒草地沙化进程中,随着植被盖度的不断降低,表层细颗粒物逐渐风蚀、土壤养分流失,粗颗粒物质保留下来,土壤含水量降低,在风的分选作用下不断堆积形成流动性沙丘。

关键词: 高寒草地, 沙漠化, 土壤理化性质, 玛曲

Abstract:

Desertification is one of the important indicators of alpine grassland degradation in the eastern margin of the Qinghai-Tibet Plateau, and soil physical and chemical properties are important characteristic parameters reflecting grassland desertification process. Taking Maqu County in the eastern margin of the Qinghai-Tibet Plateau as an example, the differences of soil grain size, temperature and humidity, organic carbon and nutrients in natural, light desertification, moderate desertification, severe desertification, and very severe desertification grasslands were compared and analyzed in order to clarify the change process of soil physical and chemical properties during the desertification process of alpine grassland. The results showed that the contents of clay and silt decreased significantly with the development of desertification, while the contents of sand increased with the increase of desertification. During the growing season from May to August, the temperature of severe desertification soil was significantly higher than that of light desertification soil, and the soil water content was significantly lower. With the increase of desertification degree, the soil organic carbon content decreased significantly, the light desertification decreased by more than 50%, and moderate to very severe desertification decreased by 91%-99%. The contents of soil total nitrogen (TN), alkali-hydrolyzable nitrogen (AN), total phosphorus (TP) and available phosphorus (AP) decreased significantly in light and over light desertification grasslands, while total potassium (TK) did not change significantly, and available potassium (AK) decreased only in moderate to very severe desertification grassland. The results indicate that in the process of alpine grassland desertification, with the continuous decrease of vegetation coverage, the surface fine particles are gradually eroded by wind, resulting in the loss of soil nutrient, while coarse particles retain, and soil water content decreases; under the action of wind sorting, continuous accumulation of sand particles forms mobile dunes. The results can provide theoretical basis for alpine desertification grassland management and grassland ecosystem restoration.

Key words: alpine grassland, desertification, soil physicochemical properties, Maqu

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