青藏高原高寒草甸不同放牧方式下土壤粒径分形特征  

Characteristics of Soil Particle Size Fractals under Different Grazing Regimes in Alpine Meadows of the Tibetan Plateau

作　　者：安海涛 孙彩彩 董全民 杨晓霞[1,2] 刘文亭 王晓丽 赵新全 AN Hai-tao;SUN Cai-cai;DONG Quan-min;YANG Xiao-xia;LIU Wen-ting;WANG Xiao-li;ZHAO Xin-quan(State Key Laboratory of Plateau Ecology and Agriculture in the Three River Head Waters Region,Qinghai University,Xining,Qinghai Province 810018,China;Animal Science and Veterinary Medicine of Qinghai University,Xining,Qinghai Province 810016,China)

机构地区：[1]青海大学省部共建三江源生态与高原农牧业国家重点实验室,青海西宁810016 [2]青海大学畜牧兽医科学院青海省高寒草地适应性管理重点实验室,青海西宁810016

出　　处：《草地学报》2025年第4期1106-1113,共8页Acta Agrestia Sinica

基　　金：青海省“帅才科学家负责制”项目(2024-SF-102);国家自然基金联合基金项目(U20A2007)资助。

摘　　要：为研究放牧方式对青藏高原高寒草甸土壤粒径的影响,本研究基于分形理论,选取青藏高原高寒草甸区4种放牧方式(牦牛单独放牧、藏羊单独放牧、牦牛和藏羊混牧、无放牧)为研究对象,利用激光粒度仪测定了土壤粒径体积分数,研究了土壤颗粒组成和分形特征对不同放牧方式的响应,揭示了不同放牧方式下土壤颗粒尺寸的空间分布规律。结果表明:各样地土壤颗粒组成均以粉粒、细砂粒和极细砂粒为主,且砂粒体积分数最高(49.3%~67.2%),其次为粉粒(26.1%~40.8%),黏粒体积分数最低(5.0%~10.0%)。牦牛藏羊混牧样地表层土壤细颗粒含量和单重分形维数均高于牦牛和藏羊单独放牧,而土壤容重却显著低于其他处理。相关性和主成分分析表明,单重分形维数与黏粒、粉粒和有机碳显著正相关,与砂粒极显著负相关。综上,在中度放牧强度下,青藏高原高寒草甸牦牛和藏羊混牧方式可以促进土壤颗粒的均匀分布,维持稳定的土壤结构,改良土壤质地。To evaluate the impact of grazing practices on soil particle size distribution in alpine meadows of the Qinghai-Tibet Plateau based on fractal theory,four grazing practices were carried out:yak grazing,Tibetan sheep grazing,mixed yak and Tibetan sheep grazing,and no grazing.Soil particle size distribution was measured using a laser particle size analyzer,and the responses of soil particle composition and fractal characteristics to various grazing practices were analyzed to reveal spatial distribution patterns of soil particle sizes under different grazing regimes.The results showed that soil particle composition in all sample plots was primarily composed of silt,fine sand,and very fine sand,with sand particles accounting for the highest volume fraction(49.3%-67.2%),followed by silt(26.1%-40.8%),and clay representing the lowest fraction(5.0%-10.0%).Surface soils in mixed grazing plots of yak and Tibetan sheep displayed higher fine particle content and single fractal dimension but significantly lower bulk density compared to other treatments.Correlation and principal component analysis revealed that the single fractal dimension was significantly positively correlated with clay,silt,and organic carbon,while exhibiting a significant negative correlation with sand.In conclusion,at moderate grazing intensity,mixed yak and Tibetan sheep grazing in alpine meadows of the Qinghai-Xizang Plateau can promote uniform soil particle distribution,maintain stable soil structure,and improve soil texture.

关 键 词：青藏高原 放牧方式 土壤颗粒组成 单重分形维数 

分 类 号：S812.2[农业科学—草业科学]