乌兰布和沙漠不同灌丛土壤颗粒多重分形特征及其与有机碳分布的关系

发布时间：2018-12-20 08:06

【摘要】：w(SOC)(SOC为土壤有机碳,soil organic carbon)及其分布状况显著受到土壤PSD(particle-size distribution,粒径分布)和有机质相互胶结方式的差异影响,而w(SOC)可反映土壤结构优劣程度,表征土壤肥力状况及碳库饱和度.以乌兰布和沙漠沙冬青、花棒、猫头刺、白刺和梭梭灌丛下0~100 cm深度风沙土为研究对象,通过野外分层采样与室内测试,采用多重分形理论探讨土壤特性和w(SOC)分布特征及其相互关系,反映土壤结构及肥力状况.结果表明:(1)不同灌丛下的土壤均具有良好的分形特征,并且灌丛可通过降低风速,使≤50μm的优质颗粒在周围表层土壤沉降,而优质颗粒数量与w(SOC)、D_0(粒径分布范围)及D_1(分布均匀程度)极显著正相关(P0.01),与D_1/D_0(分布离散程度)极显著负相关(P0.01);(2)各灌丛下w(SOC)的大小关系与D_1、D_0相似但与D_1/D_0完全相反,即w(SOC)可表征PSD状况进而反映土壤结构优劣程度,并且在沙冬青灌丛的20~30、60~80 cm土层出现两次峰值,分别为11.958、11.928 g/kg;(3)对D_0的扩大及D_1/D_0的降低程度以沙冬青灌丛最为明显,但对D_1的降低程度则以花棒灌丛最为明显.研究显示,多重分形理论可很好地描述乌兰布和沙漠风沙土性质,并且适生灌丛中沙冬青及花棒可更好地改善土壤颗粒及SOC特征,故可通过种植二者局部改良土壤及增加碳库饱和度.
[Abstract]:W (SOC) (SOC was soil organic carbon, soil organic carbon) and its distribution was significantly affected by the difference of soil PSD (particle-size distribution, particle size distribution) and organic matter cementation mode, while w (SOC) could reflect the degree of soil structure. Soil fertility and carbon pool saturation were characterized. In this paper, the depth of 100 cm sandy soil under the scrub of Wu Lan and Desert Holly, Flower stick, Cat head, Nitraria and Haloxylon ammodendron shrub was studied. Field stratified sampling and laboratory test were carried out. The multifractal theory was used to study the characteristics of soil and the distribution of w (SOC) and their relationship, which reflected the soil structure and fertility. The results are as follows: (1) the soil under different shrub has good fractal characteristics, and the shrub can reduce the wind speed and make the fine particles less than 50 渭 m settle in the surrounding surface soil, and the number of high quality particles and w (SOC), can be reduced. D0 (particle size distribution range) and D01 (distribution uniformity) were significantly positively correlated (P0.01), and negatively correlated with D_1/D_0 (P0.01). (2) the size relationship of w (SOC) under various shrubs is similar to that of D1D _ 0, but is completely opposite to that of D_1/D_0, that is, w (SOC) can characterize the PSD status and reflect the degree of soil structure. There were two peaks in the soil layer of 20 ~ (30) ~ 60 ~ (-80) cm (11.958 ~ 11.928 g 路kg ~ (-1); (3) the expansion of D _ 0 and the decrease of D_1/D_0 were the most obvious in Holly thicket, but the decrease degree of D _ (1) was the most obvious in flower rod thicket. The results show that the multifractal theory can well describe the properties of Wu Lan Buhe desert sandy soil, and the characteristics of soil particles and SOC can be improved better by holly and flower stick in the suitable shrub. Therefore, the soil can be improved and the saturation of carbon pool can be increased by planting both of them.
【作者单位】：山东农业大学林学院山东省土壤侵蚀与生态修复重点实验室泰山森林生态站;水利部牧区水利科学研究所;
【基金】：国家自然科学基金项目(41301303) 水利部公益性行业科研专项经费(201401084) 中国水科院科研专项项目(MK2016J03)
【分类号】：S714

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