Effects of checkerboard barriers on the distribution of aeolian sandy soil particles and soil organic carbon
Effects of checkerboard barriers on the distribution of aeolian sandy soil particles and soil organic carbon
复制标题
棋盘屏障对风积沙土颗粒及土壤有机碳分布的影响
DOI：
10.1016/j.geomorph.2019.04.016
复制
发表时间：
2019-08-01
期刊：
影响因子：
3.9
通讯作者：
Guo, Jianying
中科院分区：
文献类型：
--
作者：
Dai, Yujie;Dong, Zhi;Guo, Jianying
设置沙障是防止表土风蚀的重要措施。毛乌素桑迪广泛采用沙柳方格沙障，以保障群众生命安全和农业生产。为研究不同年限（7 a和2 a）的沙障对土壤结构和质量的影响，以未设置沙障的沙丘为对照，研究了风成桑迪土壤颗粒组成和土壤有机碳（SOC）分布特征。利用多重分形参数对野外采集和室内测试的表层土样进行分析，结果表明：表层土颗粒以细砂、中粗砂和粘粒为主，粉砂和极细砂含量随屏障时间的延长而增加，分布范围更广，分散程度更大，土壤颗粒的非均质性更强。风沙桑迪颗粒，特别是细颗粒，由于障碍物的阻挡作用，在沙丘底部和顶部沉积和堆积，其粒度分布（PSD）的不均匀性在7年生障碍沙丘中最高，在无障碍沙丘中最低。7年沙障沙丘的D-0（容量维）、无沙障沙丘的D-1（熵维）和2年沙障沙丘的D-1/D-0的平均值最大。随着沙障持续时间的延长，沙障土壤的PSD幅度和分布均增大，多重分形谱的形状Δ f（偏导数）和宽度Δ f（偏导数）也随之增大;土壤有机碳含量随着沙障持续时间的延长和D-1/D-0的减小而增加。7年生有障沙丘土壤有机碳含量最高，无障沙丘土壤有机碳含量最低，差异显著（P < 0.05）。在PSD和SOC的分布上，7年障壁的效果均优于2年障壁和无障壁，7年障壁和2年障壁沙丘的SOC含量与PSD多重分形参数的相关性差异显著（P< 0.01）。多重分形参数可用于表征土壤养分含量，为评价桑迪生态系统土壤质量和结构恢复的生态工程效果提供基础知识。沙柳方格沙障能增加表层沙丘土壤细颗粒含量和土壤有机碳含量，有利于毛乌素沙地生态系统的恢复。因此，建议尽早使用沙障。(C)2019爱思唯尔B. V.保留所有权利。
Sand-barrier setup is an important measure to protect the topsoil against wind erosion. Salix psammophila checkerboard barriers are used widely in the Mu Us Sandy Land in order to ensure the safety of life and agricultural production. To measure variations in soil structure and quality caused by barriers with different duration (7 years and 2 years), the composition of aeolian sandy soil particles and the soil organic carbon (SOC) distributions are studied; the dunes with no barrier are used as controls (CK). Analyzed by multi-fractal parameters, the topsoil samples are collected in the field and tested in the laboratory.The predominant soil particles are fine sand, medium coarse sand and clay, and the contents of silt and very fine sand increase with extending barrier duration, which shows a wider distribution range, greater dispersion degree and larger soil particle heterogeneity. The aeolian sandy particles, particularly fine granular grains, are deposited and accumulate at the bottom and top of dunes because of the barrier blocking effect.The particle size distribution (PSD) heterogeneity is the highest in 7-year barrier dunes and the lowest in the no barrier dunes. The mean values of D-0 (Capacity dimension) of 7-year barrier dunes, D-1 (entropy dimension) of the no barrier dunes and D-1/D-0 of 2-year barrier dunes are maxima. In addition, the PSD range and distribution increased with prolonged dune barrier duration, as well as the changes of Delta f (partial derivative) (shape of the multi-fractal spectrum) and Delta partial derivative (width of multi-fractal spectrum).SOC content increased with increasing barrier duration and decreasing D-1/D-0. The average SOC contents of 7-year barrier dunes were the maximum and one of no barrier dunes had the minimum SOC content, and their difference was significant (P < 0.05). In both the PSD and SOC distribution, the 7-year barrier showed better results on the topsoil than that of 2-year and no barrier situation.Correlations between the SOC content and the PSD multi-fractal parameters of both 7-year and 2-year barrier dunes are significantly different (P< 0.01). The multi-fractal parameters can be used to indicate soil nutrient contents, which provide fundamental knowledge for evaluating the effectiveness of ecological engineering to restore soil quality and structure to sandy ecosystems. Salix psammophila checkerboard sand barriers play a role in increasing the fine particles and soil organic carbon in surface dune soil, which is helpful in restoring the Mu Us sand ecosystem. The early use of sand barriers is therefore recommended. (C) 2019 Elsevier B.V. All rights reserved.