广西典型喀斯特地区不同林地土壤粒度分布的单重与多重分形特征  

Fractal and multifractal characteristics of soil particle-size distribution in different forest types in typical karst regions of Guangxi

作　　者：孙哲 马雄忠 陈宇航 Sun Zhe;Ma Xiongzhong;Chen Yuhang(School of Geographical Science and Planning,Nanning Normal University,Nanning,Guangxi 530001,China)

机构地区：[1]南宁师范大学地理科学与规划学院,广西南宁530001

出　　处：《水土保持通报》2025年第1期10-19,共10页Bulletin of Soil and Water Conservation

基　　金：广西科技基地和人才专项“广西喀斯特地区典型人工林区土壤结构及水分输运分形特征研究”(桂科AD23026075),“南流江河岸带典型乡土物种根系特征及其对岸坡稳定性影响研究”(桂科AD22080050);广西自然科学基金项目(2024GXNSFBA010295;2024GXNSFBA010098);广西高校中青年教师科研基础能力提升项目(2022KY0386;2024KY0398)。

摘　　要：[目的]揭示广西典型喀斯特地区不同林地土壤粒度分布的分形特征及其与土壤性质的关系,为石漠化地区林业可持续发展提供科学指导。[方法]测定桉树、马尾松人工林及天然次生林土壤的粒度分布与性质。采用分形模型计算各类林地土壤的单重与多重分形维数,同时探讨土壤分形维数与土壤性质的关联。[结果]相较于天然次生林,桉树与马尾松人工林的容重小23%和15%,总孔隙度增大27%和17%,黏粒含量分别减少58%与42%,砂粒增多24%与14%,单重分形维数(D_(s))下降6%与4%,且有效磷、速效钾和全钙含量均减少(前者分别减少68%,49%,6%,后者分别减少42%,40%,25%)。[容量维度(D_(0))-关联维数(D_(2))],D_(q)值域的跨度(ΔD),奇异谱宽(Δα)是反映土壤粒度分布不同维度上异质性的多重分形参数。这3个参数数值上桉树(0.13,1.29,1.52)与马尾松(0.13,0.99,1.18)人工林均大于天然林(0.08,0.83,1.02)。此外,人工林土壤的多重分形参数与土壤养分含量存在更显著的相关性(p<0.05)。[结论]喀斯特地区的人工林的种植与经营不当,可能促使土壤细颗粒的流失和关键养分的枯竭,导致土壤粒度分布集中于小概率密集区,增加土壤粒度分布的异质性,进一步加速石漠化的过程。单重分形维数(D_s)能够反映喀斯特林区土壤肥力的退化程度,而多重分形参数还能精细揭示土壤粒径在微观层面上的非均匀分布特征,表明分形维数可作为喀斯特地区人工林土壤质量精准评价的潜在指标。[Objective]The relationship between the fractal characteristics of soil particle size distribution and properties in different forest types in the typical karst regions of Guangxi Zhuang Autonomous Region(GZAR)was investigated in order to provide scientific guidance for sustainable forestry development in rocky desertification areas.[Methods]The particle size distribution and properties of soil in Eucalyptus spp.,Pinus massoniana,and natural secondary forests were determined.Single and multiple fractal dimensions of soil from different forest types were calculated using fractal models,and the their correlations with soil properties were explored.[Results]Compared to natural secondary forests,the bulk densities of Eucalyptus spp.and P.massoniana plantations were 23% and 15%lesser,respectively.However,the total porosities of Eucalyptus spp.and P.massoniana plantations were greater by 27%and 17%,respectively,than that of natural secondary forests.The clay contents in Eucalyptus spp.and P.massoniana plantations were lower(58%and 42%,respectively)whereas the sand contents were higher(24%and 14%,respectively),than that of natural secondary forests.Additionally,the single fractal dimensions(Ds)were 6%and 4%lesser in Eucalyptus spp.and P.massoniana plantations,respectively,than that of secondary natural forests.Furthermore,the available phosphorus,readily available potassium,and total calcium contents for Eucalyptus spp.were 68%,49%,and 6%lower,and,those for P.massoniana were 42%,40%,and 25%lower,respectively,than those of secondary natural forests.D_(0)-D_(2),ΔD andΔαwere the multifractal parameters that reflect the heterogeneity of soil particle size distribution across different dimensions;for Eucalyptus spp.(0.13,1.29,1.52)and P.massoniana(0.13,0.99,1.18)plantations these values were higher than those for natural forests(0.08,0.83,1.02).Furthermore,there was a significant correlation between multifractal parameters and soil nutrient content in the different plantations.[Conclusion]Improper cultivation and manageme

关 键 词：喀斯特地区 人工林 土壤粒度分布 单重和多重分形维数 土壤养分 

分 类 号：S714.5[农业科学—林学]