为研究西南喀斯特山地不同林下经济模式与土壤水分渗透性之间的关系, 以不同空白林地作为对照, 对重庆荣昌县6种不同林下经济模式土壤渗透性及其影响因子进行研究。结果表明: 不同林地和同一林地不同层次土壤渗透各指标存在很大差异, 0~10 cm土壤总渗透量在麻竹林下种菌模式中最强, 达到449 mL; 其次是黄葛树林下种草模式, 为427.5 mL; 再次是麻竹林下养禽模式, 为389.4 mL; 以桉树林下种菌模式最差, 仅有241.5 mL。各林地土壤渗透能力随土层深度的增加而减弱。在3种模拟土壤水分入渗过程的模型中, 通用经验方程拟合效果最优, Kostiakov方程次之, Philip方程效果最差。土壤渗透性评价得分显示: 麻竹林下种菌模式土壤渗透性最好, 其次是黄葛树林下种草模式, 再次是麻竹林下养禽模式, 以桉树林下种菌模式最差。土壤渗透性能与土壤理化性质相关性分析显示: 土壤渗透与土壤有机质、含水率、总孔隙度和0.005~0.01 mm颗粒含量呈极显著正相关(P<0.01), 与土壤容重和0.05~0.25 mm颗粒含量呈极显著负相关(P<0.01)。结合相关分析, 筛选出8个极显著或显著影响土壤渗透性能的土壤理化性质因子, 通过主成分分析, 得到表征土壤渗透性能综合参数α和表征显著影响土壤渗透性的理化性质指标的综合参数β, 并构建了土壤渗透性各指标及其综合参数α与β的线性回归模型, α=0.249 初入渗率+0.254 稳渗率+0.252 平均渗透速率+0.254 渗透总量, β=0.167 有机质+0.183 含水率+0.200 总孔隙度+0.174 非毛管孔隙度 0.145 P0.05~0.25+0.131 P0.005~0.01+ 0.106 P0.001~0.005 0.200 容重(P0.05~0.25、P0.005~0.01、P0.001~0.005分别表示0.05~0.25 mm、0.005~0.01 mm和 0.001~0.005 mm颗粒含量)。
This study aimed to determine the relationship between different under-forest economy modes and soil moisture permeability in the karst mountain of Southwest China. Soil infiltration and the influence factors of six different under-forest economy modes in Chongqing City were studied, with the pure forest as the control. The study showed significant differences in soil infiltration among different under-forest economy modes and soil layers. Infiltration was highest (449 mL) in 0 10 cm soil layer under the mode of fungi cultivation in Dendrocalamus latiflorus forest. The second highest (427.5 mL) was under the mode of grass cultivation in Ficus lacor forest, followed the soil under the mode of poultry feeding in D. latiflorus forest (389.4 mL). Soil infiltration was poorest (241.5 mL) under the mode of fungi cultivation in Eucalyptus robusta forest. Soil infiltration in each under-forest economy mode decreased with increasing soil depth. The common infiltration model was the most suitable for simulating soil infiltrating processes in the study area, followed by the Kostiakov equation, and then the Horton equation. Soil infiltration evaluation via correlation analysis showed that the strongest soil infiltration capacity was of the mode of fungi cultivation in D. latiflorus forest. This was fol-lowed by the mode of grass cultivation in F. lacor forest and then poultry feeding in D. latiflorus forest. Fungi cultivation in E. robusta forest performed the least in terms of soil infiltration. Correlation analysis between soil infiltration and physiochemical properties showed significant positive correlation between soil infiltration and organic matter (β1), moisture content (β2), total soil porosity (β3) and the 0.005 0.01 mm soil particle content (β6) (P < 0.01). Also significant negative correlation existed between soil infiltration and soil bulk density (β8) and 0.05 0.25 mm particle content (β5) (P < 0.01). According to the correlation analysis, eight indexes of soil physiochemical properties (which significantly influenced soil infiltration) were noted. Comprehensive parameters of soil infiltration (a) and soil physiochemical properties (β) were obtained by the Principal Component Analysis. Then linear regression models of the indicators of soil infiltration and comprehensive parameters (a and β) were built as α= 0.249a1+0.254a2+0.252a3+0.254a4, β=0.167β1+0.183β2+0.200β3+0.174β4 0.145β5+0.131β6+0.106β7 0.200β8. In the models, a1 was initial infiltration rate, a2 was stable infiltration rate, a3 was average infiltration rate, a4 was total infiltration; β4 was non-capillary porosity, β7 was content of 0.001 0.005 mm soil particles.