毛竹入侵及经营方式对土壤丛枝菌根真菌群落的影响及其机理研究

发布时间：2018-04-10 08:02

本文选题：丛枝菌根真菌　切入点：毛竹入侵　出处：《浙江农林大学》2017年硕士论文

【摘要】：毛竹(Phyllostachys pubescens)入侵和人为经营导致毛竹林面积不断扩大,由此产生的生态问题已引起广泛关注。丛枝菌根(Arbuscular mycorrhiza,AM)真菌作为植物与土壤、微生物之间的桥梁,生态环境的变化对其群落结构及生态功能具有重要影响。本研究利用磷脂脂肪酸(Phospholipid fatty acid,PLFA)和高通量测序分析技术,研究毛竹入侵及不同经营模式对土壤AM真菌群落的影响并进一步阐明其作用机理,结果对于评估毛竹入侵和人为经营的生态风险、保护生态系统可持续发展具有重要意义,同时也为合理经营毛竹林、进一步明确AM真菌生态功能提供理论依据。结果如下:(1)毛竹入侵针阔叶林土壤AM真菌中性脂脂肪酸(Neutral lipid fatty acid,NLFA)生物量、易提取球囊霉素含量和水稳性团聚体数量均显著增加(P0.05)。AM真菌生物量对土壤团聚体和易提取球囊霉素有重要贡献作用,且易提取球囊霉素与土壤有机碳含量显著相关(P0.05)。毛竹入侵主要通过AM真菌生物量间接影响土壤有机碳。毛竹入侵显著影响AM真菌群落,森林类型(P=0.001)、p H(P=0.038)和有机碳(P=0.023)是主要影响因素。结果表明,毛竹入侵后土壤AM真菌群落结构变化显著且AM真菌生物量显著增加,促进了土壤大团聚体形成和有机碳固存。(2)长期粗放经营毛竹林土壤养分含量总体呈下降趋势,球囊霉素含量及AM真菌生物量也显著降低(P0.05),其中易提取球囊霉素含量与有机碳、碱解氮、速效钾显著正相关(P0.05),而AM真菌PLFA生物量与碱解氮含量和大团聚体百分比极显著正相关(P0.01)。长期粗放经营毛竹后土壤球囊霉属相对丰度显著增加而无梗囊霉属显著降低(P0.05)。马尾松林对照与不同粗放经营年限毛竹林土壤AM真菌群落显著区分(P=0.001),土壤含水量(P=0.005)、碱解氮(P=0.001)、有效磷(P=0.014)对AM真菌群落结构变异具有重要贡献。(3)长期集约经营显著降低了毛竹林土壤AM真菌NLFA生物量和总球囊霉素含量(P0.05);AM真菌群落结构变化显著(P=0.001),且主要影响因素为土壤速效钾(P0.001)、硝态氮(P0.01)、铵态氮(P0.05)和有效磷(P0.05)。集约经营15年土壤250-2000μm团聚体百分比下降20-29%,且团聚体百分比和土壤有机碳含量与AM真菌生物量和总提取球囊霉素含量显著相关(P0.05)。长期集约经营改变了毛竹林土壤AM真菌群落结构和生物量,长期来看对土壤有机碳固存具有负面影响。
[Abstract]:The invasion and artificial management of Phyllostachys pubescens led to the continuous expansion of the area of Phyllostachys pubescens.As a result, the ecological problems caused by the invasion of Phyllostachys pubescens have aroused widespread concern.Arbuscular mycorrhizal (AMN) fungi act as a bridge between plant and soil microbes. The changes of ecological environment have important influence on their community structure and ecological function.In this study, the effects of Phyllostachys pubescens invasion and different management models on soil AM fungal community were studied by using phospholipid fatty acidFa and high-throughput sequencing techniques.The results were significant for assessing ecological risk of bamboo invasion and artificial management, protecting sustainable development of ecosystem, and providing theoretical basis for rational management of Phyllostachys pubescens forest and further clarification of ecological function of AM fungi.The results were as follows: (1) the biomass of neutral fatty acid (NAFA) of AM fungi, Neutral lipid fatty acidine (NLFAs) of Phyllostachys pubescens invading the coniferous broadleaved forest,The content of readily extractable balloon mycin and the number of water stable aggregates significantly increased the biomass of P0.05. AM fungi contributed significantly to soil aggregates and easy extraction of balloon mycin, and the easy extraction of balloon mycin was significantly correlated with soil organic carbon content (P 0.05).Phyllostachys pubescens invasion indirectly affected soil organic carbon through AM fungi biomass.The invasion of Phyllostachys pubescens significantly affected AM fungal community, and the forest types P0. 001, P ~ (H ~ (+)) P ~ (0. 038) and P ~ (0. 023)) were the main influencing factors.The results showed that the community structure of AM fungi and the biomass of AM fungi increased significantly after invasion of Phyllostachys pubescens, which promoted the formation of soil macroaggregates and organic carbon sequestration.The content of balloon mycin and the biomass of AM fungi also decreased significantly, among which the content of balloon mycin and organic carbon, alkali-hydrolyzed nitrogen, available potassium were positively correlated with P0.05, while the biomass of AM fungi was positively correlated with the content of alkali-hydrolyzed nitrogen and the percentage of large aggregates.The relative abundance of Bleomyces in soil increased significantly after a long period of extensive management of Phyllostachys pubescens, while P0.05 decreased significantly.The soil AM fungi communities of Pinus massoniana forest and bamboo forest with different extensive operating years were significantly distinguished from that of Phyllostachys pubescens, soil water content, soil water content, alkali-lytic nitrogen, available phosphorus and P ~ (0.014)), which contributed significantly to the variation of AM fungal community structure.The NLFA biomass and total balloon mycin content of AM fungi were decreased in Phyllostachys pubescens forest soil. The community structure of AM fungi changed significantly (P 0.05). The main influencing factors were soil available potassium P 0.001N, nitrate N P 0.01N, ammonium N N P 0.05) and available phosphorus P 0.05.The percentage of soil aggregates from 250 to 2000 渭 m decreased by 20-29 in intensive management for 15 years, and the percentage of aggregates and the content of soil organic carbon were significantly correlated with the biomass of AM fungi and the content of total extracted balloon mycin (P0.05).Long-term intensive management changed the structure and biomass of AM fungi community in Phyllostachys pubescens forest soil, and had a negative effect on soil organic carbon sequestration in the long run.
【学位授予单位】：浙江农林大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：S795.7;S714.3

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