• 目录 •

### 宁夏荒漠草原沙漠化过程中土壤粒径分形特征

1. 宁夏大学西北土地退化与生态恢复省部共建国家重点实验室培育基地/西北退化生态系统恢复与重建教育部重点实验室, 银川 750021
• 收稿日期:2017-03-20 修回日期:2017-07-27 出版日期:2017-10-18 发布日期:2017-10-18
• 作者简介:阎欣,女,1992年生,硕士研究生.主要从事植物生态学研究.E-mail:yanxinyx92@163.com
• 基金资助:

本文由宁夏高等学校科学研究项目(NGY2017006)资助

### Fractal features of soil particle size in the process of desertification in desert grassland of Ningxia, China.

YAN Xin, AN Hui*

1. Breeding Base for State Key Laboratory of Land Degradation and Ecological Restoration in Northwest China/Ministry of Education Key Laboratory for Restoration and Reconstruction of Degraded Ecosystem in Northwest China, Ningxia University, Yinchuan 750021, China
• Received:2017-03-20 Revised:2017-07-27 Online:2017-10-18 Published:2017-10-18
• Supported by:

This work was supported by the Scientific Research Project in Higher Education of Ningxia (NGY2017006).

Abstract: The variation of soil properties, the fractal dimension of soil particle size, and the relationships between fractal dimension of soil particle size and soil properties in the process of desertification in desert grassland of Ningxia were discussed. The results showed that the fractal dimension (D) at different desertification stages in desert grassland varied greatly, the value of D was between 1.69 and 2.62. Except for the 10-20 cm soil layer, the value of D gradually declined with increa-sing desertification of desert grassland at 0-30 cm soil layer. In the process of desertification in de-sert grassland, the grassland had the highest values of D, the volume percentage of clay and silt, and the lowest values of the volume percentage of very fine sand and fine sand. However, the mobile dunes had the lowest value of D, the volume percentage of clay and silt, and the highest value of the volume percentage of very fine sand and fine sand. There was a significant positive correlation between the soil fractal dimension value and the volume percentage of soil particles <50 μm, and a significant negative correlation between the soil fractal dimension value and the volume percentage of soil particles >50 μm. The grain size of 50 μm was the critical value for deciding the relationship between the soil particle fractal dimension and the volume percentage. Soil organic matter (SOM) and total nitrogen (TN) decreased gradually with increasing desertification of desert grassland, but soil bulk density increased gradually. Qualitative change from fixed dunes to semi-fixed dunes with the rapid decrease of the volume percentage of clay and silt, SOM, TN and the rapid increase of volume percentage of very fine sand and fine sand, soil bulk density. Fractal dimension was significantly correlated to SOM, TN and soil bulk density. Fractal dimension 2.58 was a critical value of fixed dunes and semi-fixed dunes. So, the fractal dimension of 2.58 could be taken as the desertification indicator of desert grassland.