巨桉纯林皆伐迹地营建混交林对林下灌草物种多样性的影响  

Effects of constructing mixed forests on understory shrub and herb species diversity after clear-cutting of Eucalyptus grandis pure forest

作　　者：蒋璐 张辟芳 王军 秦晓鹏 汪海伦 周世兴[1] 黄从德[1] JIANG Lu;ZHANG Pifang;WANG Jun;QIN Xiaopeng;WANG Hailun;ZHOU Shixing;HUANG Congde(College of Forestry,Sichuan Agricultural University,Chengdu 611130,China;Natural Resources Bureau of Shawan,Leshan 614900,China;Shawan State-owned Forest Farm,Leshan 614900,China)

机构地区：[1]四川农业大学林学院,成都611130 [2]乐山市沙湾区自然资源局,乐山614900 [3]乐山市沙湾区国营林场,乐山614900

出　　处：《应用与环境生物学报》2024年第3期477-484,共8页Chinese Journal of Applied and Environmental Biology

基　　金：世界银行贷款长江上游森林生态系统恢复项目科研课题项目子专题(510201202038467);四川省自然科学基金青年基金项目(2022NSFSC-1134)资助。

摘　　要：林下植物多样性是反映森林群落结构和功能的重要指标.然而,混交林对林下灌草物种多样性的影响还存在不确定性.在四川省乐山市沙湾区巨桉纯林可持续经营改造示范区,选择巨桉(Eucalyptus grandis)人工纯林皆伐后营建的红叶碧桃(Prunus persica‘Atropurpurea’)+西府海棠(Malus×micromalus)混交林、杉木(Cunninghamia lanceolata)+桢楠(Phoebezhennan)+红叶碧桃混交林和香樟(Cinnamomumcamphora)+水杉(Metasequoia glyptostroboides)混交林为对象,并以巨桉纯林为对照,研究相同种植年限的混交林对林下灌草多样性的影响.研究发现:与巨桉纯林相比,混交林林下植被物种数量明显增加,以杉木+桢楠+红叶碧桃混交林林下植物群落组成最为丰富;3种混交林灌木层的物种丰富度(R)、Simpson优势度指数(D)、Shannon-Wiener多样性指数(H)及Pielou均匀度指数(Jsw)均显著高于巨桉纯林,而草本层则无显著差异;在3种混交林中,灌木层和草本层植物多样性分别以香樟+水杉混交林和杉木+桢楠+红叶碧桃混交林最高;营建混交林在一定程度上提高了土壤pH值、含水量、全氮、全磷、全钾和有机质含量,降低了土壤容重和孔隙度;冗余分析(RDA)表明,土壤有机质含量是影响灌草层植物多样性的主要因素.综上可见,巨桉纯林转换成混交林后在初期提高了林下植物多样性,土壤有机质含量是影响混交林林下植物多样性的主要因子.Understory plant diversity is an important indicator of forest community structure and function.However,the impact of understory plant diversity in pure artificial forests after clear-cutting into mixed forests remains unclear.Therefore,in this study,the replacement and transformation demonstration site of Eucalyptus grandis pure forest in the Shawan District of Leshan City,Sichuan Province,China,was investigated.To study the effect of mixed forests on the diversity of understory shrub and grass plants,we selected 5-year-old mixed forests of Prunus persica‘Atropurpurea’+Malus×micromalus,Cunninghamia lanceolata+Phoebe zhennan+Prunus persica‘Atropurpurea’,and Cinnamomum camphora+Metasequoia glyptostroboides as well as pure forest of E.grandis.All forests were recently constructed after clear-cutting the E.grandis.The results showed that the number of understory vegetation species increased significantly in mixed forests compared to pure forest of E.grandis,with C.lanceolata+P.zhennan+P.persica‘Atropurpurea’forest being the richest in understory plant community composition.The species richness(R),Simpson(D),Shannon-Wiener diversity(H),and Pielou evenness indices(JSW)were significantly higher in the shrub layer of the three mixed forests than in the pure E.grandis forest,whereas no significant differences were observed in the herb layer.Among the three mixed forests,the highest plant diversity in the shrub and herb layers was found in the C.camphora+M.glyptostroboides and C.lanceolata+P.zhennan+P.persica‘Atropurpurea’forests,respectively.Soil pH,soil water content,total nitrogen,total phosphorus,total potassium,and organic matter content of mixed forests showed increasing trends,whereas soil bulk density and porosity showed decreasing trends.The redundancy analysis results showed that the soil organic matter content was the main factor affecting the understory diversity of vegetation.In conclusion,understory plant species diversity increased in the initial stage after the conversion of pure E.grandis

关 键 词：植物多样性 混交林 巨桉人工林 土壤理化性质 冗余度分析(RDA) 

分 类 号：S718.54[农业科学—林学]