荒漠草原人工柠条引入后土壤大孔隙拓扑结构演变特征  

Evolution of Soil Macropore Topological Structure After the Artificial Introduction of Caragana korshinskii in Desert Steppe

作　　者：杨志强 孟晨[2,3,4] 王兴 朱志昊[2,3,4] 宋乃平[2,3,4] 杜灵通 Yang Zhiqiang;Meng Chen;Wang Xing;Zhu Zhihao;Song Naiping;Du Lingtong(College of Agriculture,Ningxia University,Yinchuan 750021,China;State Key Laboratory of Land Degradation and Ecosystem Restoration in Northwest China,Ningxia University,Yinchuan 750021,China;Key Laboratory of Restoration and Reconstruction of Degraded Ecosystem in Northwest China,Ministry of Education,Yinchuan 750021,China;College of Ecology and Environment,Ningxia University,Yinchuan 750021,China)

机构地区：[1]宁夏大学农学院,银川750021 [2]宁夏大学西北土地退化与生态系统恢复国家重点实验室培养基地,银川750021 [3]西北退化生态系统恢复与重建教育部重点实验室,银川750021 [4]宁夏大学生态环境学院,银川750021

出　　处：《水土保持研究》2024年第2期92-100,共9页Research of Soil and Water Conservation

基　　金：宁夏重点研发计划项目(2021BEB04012,2022BEG02003,2019BFG02010);宁夏自然科学基金(2022AAC03012,2021AAC05005)。

摘　　要：[目的]认识人工柠条种植对土壤生态过程的影响,从而为人工植被的管理提供科学依据。[方法]以宁夏盐池县典型荒漠草原区风沙土生境的草地(0 a)及9,14,24,35 a生人工柠条林为对象,分别进行原状土柱采集、CT扫描及图像处理分析,获取土壤大孔隙几何分布特征,量化大孔隙表面积、等效直径和连接度等拓扑结构参数,研究了柠条生长过程中土壤大孔隙演变特征。[结果]通过三维图像可以看出,和0 a样地相比,随着林龄增加,各样地在0—200 mm土层大孔隙数量明显增多且结构更加复杂。定量分析表明,和0 a样地相比,不同林龄柠条林地在同一土层,大孔隙数量密度、长度密度、等效直径、连接度之间差异显著(p<0.05),而表面积密度、体积密度无显著差异(p>0.05)。具体表现为在0—100 mm和100—200 mm土层大孔隙数量密度、长度密度均显著增加(p<0.05),且随着林龄增加,表层土壤(0—100 mm)增幅要大于深层土壤(100—200 mm);等效直径在0—100 mm土层显著减小,在100—200 mm土层显著增加(p<0.05),而连接度变化规律恰好相反。进一步分析发现,林龄与大孔隙数量密度、长度密度、表面积密度呈显著正相关(p<0.05),与大孔隙等效直径呈显著负相关(p<0.01),与大孔隙体积密度差异不显著(p>0.05)。[结论]人工柠条林的引入会促进土壤大孔隙致密网络状结构形成,改善大孔隙表面积、连接度等拓扑结构,且随着林龄增加,对土壤改良效果越明显。[Objective]The aims of this study are to understand the effects of planted Caragana korshinskii on soil ecological processes,and to provide a scientific basis for the management of artificial vegetation.[Methods]This study focused on the planted C.korshinskii forest with ages ranging from 9 years to 35 years in a typical desert grassland area of Yanchi County,Ningxia.The changes in the geometric distribution and topological structure of macropores in soil after the introduction of C.korshinskii were studied.Computed tomography(CT)scanning and image processing were applied to soil samples collected from the undisturbed soil column to identify the geometric distribution of soil macropores and their topological parameters.These parameters included macropore surface area,equivalent diameter,and connectivity.[Results]The three-dimensional(3D)CT images indicated a relatively small number of macropores in the 0—200 mm soil layer of plots 0 a,whereas those in the 0—200 mm layer of other plots were significantly higher and showed a more complex structure with stand age.Quantitative analysis showed the significant differences in the quantities,lengths,equivalent diameters,and connectivity of macropores of the same soil layers between different ages of C.korshinskii forest(p<0.05),although there were no significant differences in surface area density and volume density(p>0.05).The quantity density and length density of macropores in the 0—100 mm and 100—200 mm soil layers significantly increased(p<0.05)with the increase of forest age,with that in surface soil(0—100 mm)exceeding that in deep soil(100—200 mm).The equivalent macropore diameters for different ages of C.korshinskii forest decreased and increased significantly in 0—100 mm and 100—200 mm soil layers,respectively(p<0.05).In contrast,macropore connectivity increased and decreased significantly in the 0—100 mm and 100—200 mm soil layers,respectively(p<0.05).Further analysis showed positive correlations between stand age and the number density,leng

关 键 词：荒漠草原 人工柠条 土壤大孔隙 拓扑结构 CT扫描 

分 类 号：S152.5[农业科学—土壤学]