桉树改造模式对土壤多功能性的影响

Effect of Eucalyptus robusta Transformation Patterns on Soil Multifunctionality

本研究以佛山市西岸林场6种桉树样地为研究对象,在2种套种模式(Ⅰ:5种山茶科树种,Ⅱ:5种山茶科树种和2种落叶阔叶树种)下对比3种桉树郁闭度(0%,15%,30%)混交林的土壤理化性质、酶活性和土壤多功能性的影响。结果表明,在套种模式Ⅱ下,0%郁闭度样地0~20 cm土层有机碳、碱解氮、酸性磷酸酶活性和土壤多功能性显著提高(P<0.05)。在两种模式下,0%郁闭度样地0~20 cm土层有机碳、全氮、碱解氮均显著高于30%郁闭度样地(P<0.05),30%郁闭度样地0~20 cm土层有效磷、酸性磷酸酶活性均显著高于0%和15%郁闭度样地(P<0.05)。套种模式与郁闭度处理对土壤物理性质基本无显著影响。土壤多功能性的影响主要集中在表层土壤,且在套种模式Ⅱ下,0%郁闭度样地土壤多功能性最高(1.17)。相关性分析显示,土壤含水量、土壤总孔隙度、土壤化学性质和酶活性均与土壤多功能性显著正相关。冗余分析显示,有机碳、土壤含水量、土壤总孔隙度和有效磷是样地土壤酶活性的主导因子。因此,适宜的套种模式和桉树郁闭度有利于土壤表层土壤养分的积累、土壤酶活性和土壤多功能性的提升,山茶科树种与落叶阔叶树种的混交模式可在今后桉树林分改造模式中提供参考。

We compared the soil physicochemical properties,enzyme activities and soil multifunctionality in six mixedstands with 3 canopy density of Eucalyptus robusta(0%,15%,30%)under two intercropping modes(I:5 species of Theaceae,II:5 species of Theaceae and 2 deciduous broad-leaved tree species)in the Xi’an Forest Farm in Foshan City.Theresults showed that under the II mode,the soil organic carbon(SOC),alkali-hydrolyzable nitrogen(AN),acid phosphataseactivity(ACP)and soil multifunctionality(SMF)of the 0~20 cm soil layer in the stand with 0%canopy density weresignificantly increased(P<0.05).Under the two modes,the SOC,total nitrogen(TN)and AN of the 0~20 cmsoil layer with0%canopy density were significantly higher than the data in the stand with 30%canopy density(P<0.05),and the availablephosphorus(AP)and ACP of the 0~20 cm soil layer with 30%canopy density were significantly higher than the data inthestands with 0%and 15%canopy density plots(P<0.05).Intercropping mode and canopy density treatments basically hadno significant effects on soil physical properties.The effect of SMF was mainly concentrated in the surface soil,and under the II mode,the SMF with 0%canopy density was the highest(1.17).According to correlation analysis,soil water content(SWC),soil total porosity(STP),soil chemical properties and enzyme activity were significantly positively correlated withSMF.Redundancy analysis showed that SOC,SWC,STP and AP were the dominant factors of soil enzyme activity.Therefore,the suitable interplanting mode and canopy density of E.robusta are conducive to soil nutrient accumulation,theimprovement of soil enzyme activity and soil versatility in the surface soil.The mixed mode of Theaceae tree species anddeciduous broad-leaved tree species can provide reference for the future stand transformation mode of E.robusta stand.