毛乌素沙地樟子松人工林恢复过程中土壤粒径演变特征

目的]研究土壤颗粒分形维数与樟子松人工林恢复时间的关系，为评价毛乌素沙地植被恢复对土壤颗粒特征的影响提供数据支撑。方法]以自然荒草地为对照，选择不同恢复年限樟子松人工林土壤为研究对象，分析了不同林龄樟子松林下土壤基本理化性质、颗粒粒径含量和分形维数，开展毛乌素沙地樟子松人工林恢复过程中土壤粒径演变特征研究。结果] 3种不同林龄樟子松土壤中细砂粒含量最多，极粗砂粒含量最少，并且随着土层深度的增加细砂粒含量和粗砂粒含量呈增加的趋势，而黏粒含量、粉粒含量以及极细砂粒含量呈现减少的趋势。随着土层深度的增加土壤中全氮、全磷、有机质以及土壤含水率均呈现减小的趋势。不同林龄下樟子松土壤颗粒分形维数范围为2.27～2.71,均值大小顺序表现为50 a>60 a>40 a>CK;全氮含量和土壤含水率的均值大小顺序均表现为60 a>50 a>CK>40 a;全磷含量和有机质含量的均值大小顺序均表现为60 a>50 a>40 a>CK。全氮、全磷和土壤有机质含量与分形维数间呈正相关关系，相关系数分别为0.391,0.418,0.522。结论]樟子...

Characteristics of Soil Particle Size Evolution During Restoration of Pinus sylvestris var. mongolica Plantation in Mu Us Sandy Land

Objective] The aim of this study is to study the relationship between the fractal dimension of soil particles and the restoration time of Pinus sylvestris var. mongolica plantation and provide data support for evaluating the effects of vegetation restoration on soil particle characteristics in Mu Us Sandy Land. Methods] This paper took the natural wasteland as a contrast, and selected the soil of Pinus sylvestris var. mongolica plantation with different restoration years as the object. The basic physical and chemical properties, particle size content and fractal dimension were analyzed, and the characteristics of soil particle size evolution during the restoration of Pinus sylvestris var. mongolica plantation in Mu Us Sandy Land were studied. Results] The content of fine sand is the most, and very coarse sand was the least in the soil of three different forest ages. With the increase of soil depth, the contents of fine sand and coarse sand increase, while the contents of clay, silt and very fine sand decrease. Meanwhile, with the increase of soil depth, total nitrogen, total phosphorus, organic matter and soil water content also show a decreasing trend. The fractal dimensions of soil particles under different age range from 2.27 to 2.71, and the order of mean size is 50 a>60 a>40 a>CK. The average order of total nitrogen content and soil moisture content is 60 a>50 a>CK>40 a. The average order of total phosphorus content and organic matter content is 60 a>50 a>40 a>CK. The contents of total nitrogen, total phosphorus and soil organic matter are positively correlated with the fractal dimension, and the correlation coefficients are 0.391, 0.418 and 0.522, respectively. Conclusion] The restoration of Pinus sylvestris var. mongolica plantation significantly affects the fractal characteristics of soil particle size and the fractal dimension of soil particles, and the maximum recovery time is 50 years.