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草业学报 ›› 2023, Vol. 32 ›› Issue (7): 1-11.DOI: 10.11686/cyxb2022310

• 研究论文 •    

内蒙古荒漠草原地表风沙活动对放牧强度的响应

刘欣雷1,2(), 杜鹤强1(), 刘秀帆1,2, 范亚伟1,2   

  1. 1.中国科学院西北生态环境资源研究院,沙漠与沙漠化重点研究室,甘肃 兰州 730000
    2.中国科学院大学,北京 100049
  • 收稿日期:2022-08-02 修回日期:2022-10-19 出版日期:2023-07-20 发布日期:2023-05-26
  • 通讯作者: 杜鹤强
  • 作者简介:E-mail: dilikexue119@163.com
    刘欣雷(1999-),女,山西长治人,在读硕士。E-mail: liuxinlei@nieer.ac.cn
  • 基金资助:
    国家自然科学基金项目(42271016);国家重点研发项目(2020YFA0608402)

Response of aeolian activity to grazing intensities in the desert steppe, Northern China

Xin-lei LIU1,2(), He-qiang DU1(), Xiu-fan LIU1,2, Ya-wei FAN1,2   

  1. 1.Key Laboratory of Desert and Desertification,Northwest Institute of Eco-Environment and Resources,Chinese Academy of Sciences,Lanzhou 730000,China
    2.University of Chinese Academy of Sciences,Beijing 100049,China
  • Received:2022-08-02 Revised:2022-10-19 Online:2023-07-20 Published:2023-05-26
  • Contact: He-qiang DU

摘要:

研究放牧强度对草地风沙活动的影响对深入理解风沙动力过程、准确评估和防治风沙灾害具有重要意义。本研究依托中国科学院乌拉特荒漠草原研究站,以内蒙古荒漠草原为研究区,设置两种草地类型(以草本为主的针茅草地和以灌木为主的灌丛草地)和3种放牧强度(禁牧为对照、中度和重度放牧强度),开展了近地表风速廓线、粒径分布、风沙流结构等相关参数的测量和研究。结果表明:1)放牧强度对不同草地类型地表的空气动力学粗糙度有显著影响,且对草本区的影响大于对灌木区的影响。2)草地类型和放牧强度对地表土壤可蚀性颗粒含量的影响均达到显著水平(P<0.05),且随着放牧强度的增加,草本区地表可蚀性颗粒含量逐渐减少,土壤质地逐渐粗化。3)放牧区的风沙流拟合函数均为幂函数,R2为0.78~0.97。草本中度(6.468 g·m-1·d-1)和重度放牧区(9.294 g·m-1·d-1)的水平通量分别是草本对照区(0.907 g·m-1·d-1)的7.13和10.25倍。灌木区的输沙高度和放牧强度对输沙率的影响均小于草本区。以上研究结果表明:草本区风沙活动受放牧扰动的影响远大于灌木区,即使是中度放牧强度的水平输沙通量也远远大于禁牧区。因此,仅仅依据载畜量制定的放牧策略尚存在严重不足,为了防止草地退化,促进牧业的持续发展,在制定放牧策略时应将地表风沙活动强度作为重要指标进行综合考虑。

关键词: 放牧强度, 荒漠草原, 风沙活动, 粒度特征, 风沙流结构

Abstract:

In this research we studied the effect of grazing intensity on aeolian sand movement in order to develop greater understanding the aeolian dynamic process and techniques for more accurately evaluating and preventing wind-blown sand disasters. The research was conducted at the Urat Desert-Grassland Research Station of the Chinese Academy of Sciences and the desert grassland of Inner Mongolia was the subject of our investigation. Two grassland types were studied: Shrub dominated grassland (SDG) and grass dominated grassland (GDG) and there were three grazing intensities: Prohibiting grazing as control (CK), moderate grazing intensity (MG) and heavy grazing intensity (HG). The near-surface wind speed profile, particle size distribution, wind-sand flow structure and other related parameters were measured and analyzed. It was found that: 1) The surface aerodynamic roughness length of the two grassland types was significantly influenced by grazing intensity and the effect of grazing intensity on the aerodynamic roughness length of GDG was greater than that on SDG. 2) Grassland type and grazing intensity had significant effects on soil erodible particle content (P<0.05). With increase in grazing intensity, the content of soil erodible particles progressively decreased and the soil texture became coarser. 3) The aeolian sand flow functions in grazing areas all followed power functions, and the correlation coefficients ranged from 0.78 to 0.97. The horizontal sand fluxes in MG plots (6.468 g·m-1·d-1) and HG plots (9.294 g·m-1·d-1) were 7.13 and 10.25 times higher than those in CK plots (0.907 g·m-1·d-1), respectively. The impacts of sand transport height and grazing intensity on sediment transport rate in SDG were less than in GDG. The above results showed that the influence of grazing disturbance on aeolian sand activity in GDG was much greater than that in SDG, and the horizontal sediment flux under grazing was much more than that of CK, even for MG. Therefore, decisions on grazing strategy based solely on vegetation carrying capacity are still seriously inadequate. In order to maintain the sustainable development of animal husbandry, the intensity of surface aeolian sand activity should be considered as an important index when developing grazing strategy.

Key words: grazing intensity, desert steppe, aeolian activity, soil particle size, aeolian sand structure