马尾松与不同阔叶树种混交种植对土壤微生物群落组成和多样性特征的影响

Effects of Mixed Plantation of Pinus massoniana with Different Broadleaf Species on Soil Microbial Community Compositionand Diversity

关键词:  南亚热带  马尾松人工林  树种混交  土壤微生物多样性  微生物群落组成

Key words:  south subtropical  Pinus massoniana plantation  tree species mixing  soil microbial diversity  microbial community composition

摘要:

为探究马尾松(Pinus massoniana)不同混交模式对土壤细菌、真菌群落组成和多样性特征的影响，本研究选取马尾松/红锥(Castanopsis hystrix)混交林(MPC)、马尾松/格木(Erythrophleum fordii)混交林(MPE)、马尾松/多树种[红锥、格木、火力楠(Michelia macclurei)、灰木莲(Manglietia glauca)、米老排(Mytilaria laosensis)](MPM)混交林为研究对象，并以马尾松纯林(PP)作为对照。结果表明：(1)混交种植均提高了细根生物量(FRB)和凋落物量(TL)，MPM表现最好且差异显著(P<0.05)；(2)MPC、MPE和MPM真菌群落物种多样性指数(Chao1)显著提高(P<0.05)，而细菌群落物种多样性指数变化不明显；(3)在细菌群落中，变形菌门(Proteobacteria)、酸杆菌门(Acidobacteria)、绿弯菌门(Chloroflexi)是优势菌门；在真菌群落中，子囊菌门(Ascomycota)、担子菌门(Basidiomycota)和接合菌门(Zygomycota)是优势菌门。与马尾松纯林相比，MPC拟杆菌门(Bacteroidetes)和接合菌门的相对丰度显著提高(P<0.05)，MPE拟杆菌门和装甲菌门(Armatimonadetes)的相对丰度显著提高，但变形菌门的相对丰度显著降低；(4)土壤有效磷(AP)、细根碳氮比(C_root∶N_root)、细根碳磷比(C_root∶P_root)与细菌群落物种多样性指数显著相关，而土壤有机碳(SOC)和pH值是影响细菌群落组成的最关键因素；土壤中的全氮(TN)、容重(BD)与真菌群落物种多样性指数显著相关，含水率(SWC)是影响真菌群落组成的主要因素。综上，马尾松与单一或多种阔叶树种混交种植5年后对土壤真菌群落的物种多样性产生显著影响，但对细菌群落物种多样性的影响不显著。

Abstract:

This study explored the effects of different mixing patterns on the community composition and diversity of soil bacteria and fungi in the Mixed Pinus massoniana/Castanopsis hystrix plantation (MPC),Mixed P.massoniana/Erythrophleum fordii plantation (MPE),and Mixed P.massoniana/(C.hystrix,E.fordii,Mytilaria laosensis,Michelia macclurei,and Manglietia glauca) plantation (MPM),with the P.massoniana Pure plantation (PP) as the control.The results were yielded as follows.(1)The mixed plantations all increased Fine Root Biomass (FRB) and Total Litterfall mass (TL),which were the highest in MPM(P<0.05).(2)MPC,MPE,and MPM increased the fungal diversity index Chao1(P<0.05),whereas they did not cause significant changes in the bacterial Chao1 compared with PP.(3)Proteobacteria,Acidobacteria,and Chloroflexi were the main dominant bacterial phyla,and Ascomycota,Basidiomycota,and Zygomycota were the dominant fungal phyla.Compared with PP,MPC increased the relative abundance of Bacteroidetes and Zygomycota (P<0.05),and MPE increased the relative abundance of Bacteroidetes and Armatimonadetes while decreasing the relative abundance of Proteobacteria (P<0.05).(4)Soil Available Phosphorus (AP),Carbon to Nitrogen ratio of fine root (C_root∶N_root) and Carbon to Phosphorus ratio of fine root (C_root∶P_root) were significantly correlated with the bacterial community diversity indices,while Soil Organic Carbon (SOC) and pH value were the most critical factors influencing bacterial community composition.Total Nitrogen (TN) and Bulk Density (BD) were significantly correlated with the fungal community diversity indices,and Soil Water Content (SWC) was the main factor influencing the fungal community composition.In conclusion,the mixed plantation of P.massoniana with a single or multiple broadleaf species for 5 years significantly affects the soil fungal diversity,while it does not have significant effect on the bacterial diversity.