内蒙古草原典型植物对土壤微生物群落的影响

为了分析内蒙古草原不同植物物种对土壤微生物群落的影响, 采用实时荧光定量PCR (real-time PCR)以及末端限制性片段长度多态性分析(terminal restriction fragment length polymorphism, T-RFLP)等分子生物学技术, 测定了退化-恢复样地上几种典型植物的根际土壤和非根际土壤中细菌和真菌的数量及群落结构。结果表明, 不同植物物种对根际和非根际细菌及根际真菌数量均有显著影响。根际土壤中的细菌和真菌数量普遍高于非根际土壤, 尤其以真菌更为明显。对T-RFLP数据进行多响应置换过程(multi-response permutation procedures, MRPP)分析和主成分分析(principal component analysis, PCA), 结果表明, 大多数物种的根际细菌及真菌的群落结构与非根际有明显差异, 并且所有物种的真菌群落可以按根际和非根际明显分为两大类群。此外, 细菌和真菌群落结构在一定程度上存在按物种聚类的现象, 以细菌较为明显。这些结果揭示了不同植物对土壤微生物群落的影响特征, 对理解内蒙古草原地区退化及恢复过程中植被演替引起的土壤性质和功能的变化有一定的帮助。     

Soil and plant effects on microbial community structure

We investigated the effects of two different plant species (corn and soybean) and three different soil types on microbial community structure in the rhizosphere. Our working hypothesis was that the rhizosphere effect would be strongest on fast-growing aerobic heterotrophs, while there would be little or no rhizosphere effect on oligotrophic and other slow-growing microorganisms. Culturable bacteria and fungi had larger population densities in the rhizosphere than in bulk soil. Communities were characterized by soil fatty acid analysis and by substrate utilization assays for bacteria and fungi. Fatty acid analysis revealed a very strong soil effect but little plant effect on the microbial community, indicating that the overall microbial community structure was not affected by the rhizosphere. There was a strong rhizosphere effect detected by the substrate utilization assay for fast-growing aerobic heterotrophic bacterial community structure, with soil controls and rhizosphere samples clearly distinguished from each other. There was a much weaker rhizosphere effect on fungal communities than on bacterial communities as measured by the substrate utilization assays. At this coarse level of community analysis, the rhizosphere microbial community was impacted most by soil effects, and the rhizosphere only affected a small portion of the total bacteria.     

Contribution of above- and below-ground plant traits to the structure and function of grassland soil microbial communities

Background and Aims

Abiotic properties of soil are known to be major drivers of the microbial community within it. Our understanding of how soil microbial properties are related to the functional structure and diversity of plant communities, however, is limited and largely restricted to above-ground plant traits, with the role of below-ground traits being poorly understood. This study investigated the relative contributions of soil abiotic properties and plant traits, both above-ground and below-ground, to variations in microbial processes involved in grassland nitrogen turnover.

Methods

In mountain grasslands distributed across three European sites, a correlative approach was used to examine the role of a large range of plant functional traits and soil abiotic factors on microbial variables, including gene abundance of nitrifiers and denitrifiers and their potential activities.

Key Results

Direct effects of soil abiotic parameters were found to have the most significant influence on the microbial groups investigated. Indirect pathways via plant functional traits contributed substantially to explaining the relative abundance of fungi and bacteria and gene abundances of the investigated microbial communities, while they explained little of the variance in microbial activities. Gene abundances of nitrifiers and denitrifiers were most strongly related to below-ground plant traits, suggesting that they were the most relevant traits for explaining variation in community structure and abundances of soil microbes involved in nitrification and denitrification.

Conclusions

The results suggest that consideration of plant traits, and especially below-ground traits, increases our ability to describe variation in the abundances and the functional characteristics of microbial communities in grassland soils.     

Impact of the plant community composition on labile soil organic carbon, soil microbial activity and community structure in semi-natural grassland ecosystems of different productivity

Aims

The main objective was to describe the effects of plant litter on SOC and on soil microbial activity and structure in extensively managed grasslands in Central Germany that vary in biomass production and plant community composition.

Methods

The decomposition of shoot and root litter was studied in an incubation experiment. Labile C and N were isolated by hot water extraction (C_HWE, N_HWE), while functional groups of microbes were identified by PLFA analysis and microbial activity was measured using a set of soil exo-enzymes.

Results

The plant community composition, particulary legume species affected SOC dynamics and below-ground microbial processes, especially via roots. This was reflected in about 20% lower decomposition of root litter in low productivity grassland soil. The C_HWE soil pool was found to be a key driver of the below-ground food web, controlling soil microbial processes.

Conclusions

Below-ground responses appear to be related to the presence of legume species, which affected the microbial communities, as well as the ratio between fungal and bacterial biomass and patterns of soil enzyme activity. Low productivity fungal-dominated grasslands with slow C turnover rates may play an important role in SOC accumulation. The approach used here is of particular importance, since associated biological and biochemical processes are fundamental to ecosystem functioning.     

Long-term effects of nitrogen and phosphorus fertilization on soil microbial community structure and function under continuous wheat production

Soil microorganisms play a critical role in the biosphere, and the influence of cropland fertilization on the evolution of soil as a living entity is being actively documented. In this study, we used a shotgun metagenomics approach to globally expose the effects of 50-year N and P fertilization of wheat on soil microbial community structure and function, and their potential involvement in overall N cycling. Nitrogen (N) fertilization increased alpha diversity in archaea and fungi while reducing it in bacteria. Beta diversity of archaea, bacteria and fungi, as well as soil function, were also mainly driven by N fertilization. The abundance of archaea was negatively impacted by N fertilization while bacterial and fungal abundance was increased. The responses of N metabolism-related genes to fertilization differed in archaea, bacteria and fungi. All archaeal N metabolic processes were decreased by N fertilization, while denitrification, assimilatory nitrate reduction and organic-N metabolism were highly increased by N fertilization in bacteria. Nitrate assimilation was the main contribution of fungi to N cycling. Thaumarchaeota and Halobacteria in archaea; Actinobacteria, Alphaproteobacteria, Betaproteobacteria, Gammaproteobacteria and Deltaproteobacteria in bacteria; and Sordariomycetes in fungi participated dominantly and widely in soil N metabolic processes.     

高寒草甸连续围封与施肥对土壤微生物群落结构的影响

以放牧为对照,应用PLFA法分析研究了放牧、连续6年围封及围封内连续6年施肥后高寒草甸土壤微生物群落结构的变化.结果表明:围封和围封内施肥对不同土层各菌群和微生物总量均有显著影响,其对0 ～ 10 cm土层微生物的影响大于10～20 cm土层,不同土层的PLFA种类发生显著变化.围封和围封内施肥处理不同土层的革兰氏阴性菌(G-)含量均低于放牧;放牧0 ～10 cm土层中细菌、真菌、革兰氏阳性菌(G+)、微生物总量大干围封和围封内施肥处理,但其放线菌生物量均低于围封和围封内施肥处理;在10～20 cm土层中,各样地土壤中的G+无显著差异,围封土壤中的细菌、真菌、放线菌、微生物总量显著高于放牧,而围封内施肥后各菌群生物量及微生物总量明显下降.围封和围封内施肥不同土层的细菌/真菌均高于放牧;一般饱和脂肪酸/单烯不饱和脂肪酸(SAT/MONO)和革兰氏阳性菌/革兰氏阴性菌(G+/G－),围封处理均低于放牧,围封内施肥处理均高于放牧.连续围封和围封内施肥后降低了土壤微生物活性和土壤生态系统的稳定性.     

采煤塌陷地不同施肥处理对土壤微生物群落结构的影响

采用磷脂脂肪酸(PLFA)分析方法,对山西长治襄垣五阳煤矿采煤沉陷区复垦土壤的微生物群落结构进行了研究。结果表明:施肥处理能够不同程度的增加土壤微生物的PLFA总量、细菌PLFA量和真菌PLFA量,其中化肥+有机肥处理下的土壤微生物PLFA总量,细菌PLFA量和真菌PLFA量增加作用比较明显,差异显著于对照处理;对不同施肥处理的复垦土壤微生物群落PLFA进行主成分分析也可得出化肥+有机肥处理下的土壤微生物的群落结构变化比较大,从因子载荷图上进一步分析可知,化肥+有机肥处理下的土壤中代表真菌的不饱和脂肪酸C18∶2ω6t、C18∶3ω6、18∶1ω9t、18∶3ω3的含量较高,这些脂肪酸将化肥+有机肥处理与单施化肥和对照处理区分开来,产生了明显的优势种群。土壤PLFA总量与土壤有机质、碱解氮、速效磷和速效钾含量都有很好的相关性,相关系数分别为0.76,0.85,0.67和0.67。     

Effects of grassland species on decomposition of litter and soil microbial communities

Decomposition of litter is greatly influenced not only by its chemical composition but also by activities of soil decomposers. By using leaf litter from 15 plant species collected from semi-natural and improved grasslands, we examined (1) how interspecific differences in the chemical composition of litter influence the abundance and composition of soil bacterial and fungal communities and (2) how such changes in microbial communities are related to the processes of decomposition. The litter from each species was incubated in soil of a standard composition for 60 days under controlled conditions. After incubation, the structure of bacterial and fungal communities in the soil was examined using phospholipid fatty-acid analysis and denaturing gradient gel electrophoresis. Species from improved grasslands had significantly higher rates of nitrogen mineralization and decomposition than those from semi-natural grasslands because the former were richer in nitrogen. Litter from improved grasslands was also richer in Gram-positive bacteria, whereas that from semi-natural grasslands was richer in actinomycetes and fungi. Nitrogen content of litter also influenced the composition of the fungal community. Changes in the composition of both bacterial and fungal communities were closely related to the rate of litter decomposition. These results suggest that plant species greatly influence litter decomposition not only through influencing the quality of substrate but also through changing the composition of soil microbial communities.     

施肥梯度对高寒草甸群落结构、功能和土壤质量的影响

在三江源区研究了不同施肥梯度对高寒矮嵩草草甸群落结构、功能;土壤全量养分、速效养分;土壤有机碳和微生物生物量碳的影响,以揭示矮嵩草草甸群落特征;土壤养分和土壤微生物活性对施肥梯度的响应.结果表明:1)随着施肥量的增加,不同功能群的盖度响应各异,其中禾本科植物的响应较大,而豆科和杂类草植物盖度明显降低,莎草科盖度变化不明显;施肥量增加到一定程度,如施氮40 g/m2时,各功能群植物的盖度逐渐降低.生物量随施肥梯度呈单峰曲线变化,不施肥时生物量最低,施肥20 g/m2或32 g/m2时生物量最高.2)土壤全量养分和速效养分在施肥量为20 g/m2或32 g/m2时较高,施肥量增加到40 g/m2时土壤资源逐渐降低.3)不同施肥梯度矮嵩草草甸土壤有机碳和微生物生物量碳在0-10 cm土层明显较高,且随着施肥量的增加,分布在0-40 cm土层的土壤有机碳含量呈单峰曲线变化.施肥20 g/m2或32 g/m2时土壤有机碳和微生物量碳含量最高.4)30 g/m2施肥量可作为高寒草甸最佳施氮水平.施肥梯度下土壤有机碳和微生物量碳含量可作为衡量土壤肥力和土壤质量变化的重要指标.高施肥量(≥40 g/m2)视为影响高寒草甸生态系统结构与功能、土壤养分及土壤微生物活性的阈值.     

Changes in soil microbial community structure and function following degradation in a temperate grassland

温带草原退化后土壤微生物群落结构和功能的变化 草原退化是草原生产力维持面临的一个重大挑战,这一过程显著影响着草原生态系统的能量流动和土壤养分变化过程,进而直接或间接地影响着土壤微生物。我们的研究目的首先是调查不同草原退化程度(即未退化、中度退化和严重退化)如何影响着内蒙古温带草原的土壤微生物组成、多样性和功能,其次是阐明哪些生物和非生物因素导致了这些变化。我们的研究主要通过高通量测序技术分析土壤微生物的群落组成,并且采用FAPROTAX工具和FUNGuild工具分别预测细菌群落和真菌群落的功能。研究发现：草原退化显著降低了土壤细菌的多样性,但对真菌多样性影响不大。地下生物量、土壤有机碳和总氮与细菌的多样性变化呈显著正相关关系。草原退化显著增加了绿弯菌门的相对丰度(由2.48%提高到8.40%),降低了厚壁菌门的相对丰度(由3.62%降低到1.08%)。其次,草原退化也显著增加了球囊菌门的相对丰度(从0.17%提高到1.53%),降低了担子菌门的相对丰度(从19.30%降低到4.83%)。致病菌的相对丰度在草原退化过程中显著下降。此外,草原退化对土壤细菌群落的功能有显著的影响,尤其是与土壤碳氮循环相关的土壤细菌群落。我们的结果表明,土壤细菌群落对草原退化的响应比真菌群落更敏感。     

Changes in soil microbial biomass and community structure with addition of contrasting types of plant litter in a semiarid grassland ecosystem

Aims Elevated atmospheric CO₂ has the potential to enhance the net primary productivity of terrestrial ecosystems. However, the role of soil microorganisms on soil C cycling following this increased available C remains ambiguous. This study was conducted to determine how quality and quantity of plant litter inputs would affect soil microorganisms and consequently C turnover.Methods Soil microbial biomass and community structure, bacterial community-level physiological profile, and CO₂ emission caused by different substrate C decomposition were investigated using techniques of biological measurements, chemical and stable C isotope analysis, and BIOLOG-ECO microplates in a semiarid grassland ecosystem of northern China in 2006 and 2007 by mixing three contrasting types of plant materials, C₃ shoot litter (SC 3), C₃ root litter (RC 3), and C₄ shoot litter (SC 4), into the 10- to 20-cm soil layer at rates equivalent to 0 (C 0), 60 (C 60), 120 (C 120) and 240 g C m ?2 (C 240).Important findings Litter addition significantly enriched soil microbial biomass C and N and resulted in changes in microbial structure. Principal component analysis of microbial structure clearly differentiated among zero addition, C₃ -plant-derived litter, and C₄ -plant-derived litter and among shoot- and root-derived litter of C₃ plants; soil microorganisms mainly utilized carbohydrates without litter addition, carboxylic acids with C₃ -plant-derived litter addition and amino acids with C₄ -plant-derived litter addition. We also detected stimulated decomposition of older substrate with C₄ -plant-derived litter inputs. Our results show that both quality and quantity of belowground litter are involved in affecting soil microbial community structure in semiarid grassland ecosystem.     

The effects of plant roots on microbial community structure in aerated wastewater-treatment reactors

Hydroponic reactors are aerated tanks on top of which emergent macrophytes are grown with their roots developing freely into the wastewater, thus providing a support medium for attached microbial growth. The community structures of biofilms derived from the roots of two macrophyte species, Typha domingensis and Cyperus alopcuroides, were compared. The macrophytes were grown, hydroponically, in reactors treating public kitchen wastewater. Tuff particles served as a control. Microbial community structure was determined through community level physiological profiling using BIOLOG Ecoplates. The experimental system consisted of six parallel treatment trains, each composed of four consecutive aerated tanks inhabited by one plant species or unplanted. Retention time was 80 h. Biofilm samples were taken from the first and last reactors of each treatment train. Water analyses were also conducted. Wastewater treatment removed 97.7, 98.6, 99.98 and 73.1% of BOD, TSS, coliforms and TN, respectively. Support-medium type had no significant effect on any of these parameters. Ordination analyses showed a significant effect of support-medium type, treatment stage and reactor age on the physiological profile of biofilms. The effect of support-medium type on community structure remained significant across different treatment stages and reactor ages. Richness of well response was higher in the first reactors than in the last ones. Differences in richness between support-medium types were minor.     

长期施肥对新疆灰漠土土壤微生物群落结构与功能多样性的影响

以20a新疆国家灰漠土土壤肥力与肥料效益长期定位试验为平台,采用常规培养法,结合Biolog技术对可培养微生物、生理菌群数量和碳源利用进行测定分析,研究撂荒(CK0)、耕作不施肥(CK)、不同化肥(N、NK、NP、PK、NPK)、化肥配施低量高量有机肥(NPKM1和NPKM2)和秸秆还田(NPKS)等10种处理土壤微生物特征,揭示长期施肥对土壤微生物群落结构与功能多样性的影响。结果表明:(1)可培养微生物:与CK处理相比,CK0处理显著提高了细菌、放线菌和真菌的数量(P0.05),NPKS处理微生物数量则显著降低(P0.05);不同化肥处理的细菌(除PK处理外)、放线菌(除PK和N处理外)数量也有所增加,增幅在8.14%—135.70%和15.30%—44.78%之间;真菌数量(除NK处理外)则有一定幅度的降低;NPKM1和NPKM2处理,微生物数量最高,细菌分别增加了162.20%和173.75%,放线菌增加了34.39%和39.37%,真菌增加了63.33%和488.33%;(2)生理菌群:与CK0相比,CK处理显著提高了自生固氮菌和亚硝化细菌数量(P0.05),显著降低了氨化细菌和纤维素分解菌数量(P0.05);与CK相比,NPKM1和NPKM2处理显著提高土壤中与氮素转化有关的生理菌群数量(P0.05),不同化肥处理和NPKS处理的影响不相同,NPK处理显著高于其余处理(P0.05);(3)微生物碳源利用:微生物活性表现为NK、NPKM1、NPKM2N、NPK、CKPK、NPKSCK0、NP;CK0处理3个多样性指数以及NPKM1、NPKM2和NK处理Shannon(H)指数最高,其余施肥处理差异不显著;糖类、氨基酸类、羧酸类和胺类是微生物利用的主要碳源。(4)聚类分析表明,除NP处理外,施氮处理土壤有较为相似的碳源利用,细菌和真菌与养分之间有较好的相关性,可培养微生物和生理菌群与微生物碳源利用的相关性较差。因此,长期不同施肥对新疆灰漠土土壤微生物群落结构和功能多样性产生了显著的影响,长期耕作不施肥降低了土壤微生物群落结构和功能多样性,不同化肥配合施用对微生物群落的影响不同,NPK及NPK配施有机肥可提高土壤微生物多样性。     

放牧和刈割对大针茅草原土壤微生物群落结构及多样性的影响

放牧和刈割是内蒙古草原的两种主要利用方式,然而,长期放牧和刈割对大针茅草原土壤微生物群落的影响知之甚少,因此,以内蒙古大针茅草原为研究对象,设置放牧和刈割两种利用方式,以围封不利用为对照,基于高通量测序技术,研究大针茅草原在不同利用方式下土壤微生物组成及多样性的变化,并结合土壤理化因子进一步探究土壤微生物群落组成的主要影响因素。研究结果表明：不同利用方式下土壤细菌α多样性指数无显著差异,而刈割显著提高了土壤真菌Observed＿species、Chao1和ACE指数;土壤细菌群落的优势菌门是变形菌门(Proteobacteria)和放线菌门(Actinobacteria),土壤真菌群落的优势菌门是子囊菌门(Ascomycota)和被孢霉门(Mortierellomycota),不同利用方式下部分微生物类群的相对丰度差异显著,放牧显著提高了细菌群落的变形菌门、疣微菌门(Verrucomicrobia)和芽单胞菌门(Gemmatimonadetes)的相对丰度,刈割显著提高了真菌群落的担子菌门(Basidiomycota)相对丰度,此外,放牧和刈割均显著降低了厚壁菌门(Firmicutes...     

Interactive effects of fertilization and disturbance on community structure and resource availability in an old-field plant community

Summary The interactive effects of fertilization and disturbance on plant community structure and resource availability were studied by supplying four levels of nitrogen and applying four intensities of tilling to a 30 year old field in a factorial design for 2 year. Live above-ground biomass, root biomass, and litter generally increased with nitrogen supply and decreased with disturbance. Species composition varied significantly, with annuals increasing with both nitrogen and disturbance, but with perennials unaffected by nitrogen and decreased by disturbance. Species diversity decreased with disturbance, but decreased with nitrogen only in undisturbed vegetation. Root: shoot ratios decreased with added nitrogen, leaf allocation decreased with disturbance, and flowering allocation increased. Surprisingly, stem allocation was unaffected by disturbance. This result reflected a shift from vertical stems to horizontal stems as disturbance increased. Resource measurements suggested that the vegetation responded to interactions between the treatments as well as to direct treatment effects. Variation in light penetration was reduced by fertilization in undisturbed vegetation but not in tilled plots; variability was not directly affected by disturbance. The availability of nitrogen, the limiting soil nutrient, increased with fertilization but was not significantly affected by disturbance. In contrast, the ratio of ammonium to nitrate was significantly reduced by disturbance but unaffected by supply rates, suggesting that nitrogen may have had different effects under different disturbance regimes, even though its total availability was constant. While many community responses to fertilization and disturbance conformed to those reported earlier, resource and allocation measurements indicated that their interactions are not always predictable from their separate effects.     

长期施肥和增水对半干旱草地土壤性质和植物性状的影响

本文对内蒙古多伦退化草地2005年建立的长期野外控制试验中施肥和增水对土壤性质和植物群落特征的影响进行了总结和综合评述.结果表明:加氮导致了表土酸化并降低酸缓冲容量,提高了表土中碳氮磷硫有效性及DTPA-浸提态铁锰铜含量,导致盐基离子钙镁钾钠总量的消耗,降低了土壤微生物群落多样性,促进了优势植物物种叶片对氮磷硫钾及锰铜锌的吸收,抑制植物叶片对铁的吸收,而对钙镁吸收无显著影响,增加了植物地上净初级生产力(ANPP),降低了植物物种多样性和群落稳定性.单独加磷增加了表土全磷和Olsen-P含量及真菌丰度,促进了植物叶片对氮、磷、硫的吸收,但对其他土壤基本化学性质及ANPP、物种多样性无显著影响.增水提高了植物群落对干旱的抵抗力,但对ANPP增长的贡献受到土壤氮有效性的限制.增水对于加氮导致的土壤酸化、植物和微生物多样性降低等具有一定的缓冲作用;加氮增水和加磷增水下,土壤微生物多样性及功能受地上植物群落结构及功能变化的影响.长期野外控制试验对于深入理解草地生态系统结构和功能对环境变化的响应具有重要意义,但单点的研究结果仍需与不同区域多点控制试验的联网研究相结合,深入开展地上与地下生态过程的关联研究,才能深入理解草地生态系统生态学的相关机制.     

植物、土壤及土壤管理对土壤微生物群落结构的影响

土壤微生物是土壤生态系统的重要组成部分,对土壤微生物群落结构多样性的研究是近年来土壤生态学研究的热点。本文综述了有关植物、土壤类型以及土壤管理措施对土壤微生物群落结构影响的最新研究结果,指出植物的作用因植物群落结构多样性、植物种类、同种植物不同的基因型,甚至同一植物不同根的区域而异;而土壤的作用与土壤质地和有机质含量等因素有关;植物和土壤类型在对土壤微生物群落结构影响上的作用存在互作关系。不同的土壤管理措施对土壤微生物群落结构影响较大,长期连作、大量的外援化学物质的应用降低了土壤微生物的多样性;而施用有机肥、免耕可以增加土壤微生物群落结构多样性,有利于维持土壤生态系统的功能。     

The effects of water- and nitrogen-induced stresses on plant community structure in a semiarid grassland

Summary A replicated factorial experiment was designed to test the hypothesis that manipulating inputs of water and mineral nitrogen to a semiarid grassland would disrupt existing interactions resulting in alteration of the structure of the primary producer community. Alteration of community structure was measured as either changes in growing season average biomass of 6 functional groups of plants or their relative contribution to total biomass.Additions of water greatly increased total biomass and resulted in the replacement of one of the dominant functional groups by a subordinate group. The water plus nitrogen treatment resulted in large biomass increases in two of the dominant functional groups, elimination of succulents as an important component of community structure, and establishment of several introduced weedy species. Continuation of the experiment will likely result in complete dominance of the water plus nitrogen treatment by these introduced species.Despite the large changes in community structure observed as a result of water- and nitrogen-induced stresses we conclude that the shortgrass prairie in northcentral Colorado is asymptotically stable with respect to these influences.     

应用PLFA方法分析长期不同施肥处理对玉米地土壤微生物群落结构的影响

土壤微生物群落被认为是土壤生态系统变化的预警及敏感指标,指示土壤质量变化,决定着土壤的生态功能.为了探讨长期施肥处理(1987～2004年)对土壤微生物群落结构的影响,采用磷脂脂肪酸(PLFA)法测定了沈阳农业大学棕壤长期定位试验站玉米地不同施肥土壤微生物生物量的活性部分及群落结构的变化情况.结论:长期施肥处理都能提高土壤微生物总生物量、细菌生物量及真菌生物量,特别是有机肥和有机无机肥配施在整个生育期对微生物总生物量的增加作用比较明显.真菌的生长与季节变化和玉米生育的关系较为密切,各施肥处理土壤真菌含量在抽雄期都明显降低.长期不同施肥处理可以改变土壤微生物群落结构,单施氮肥处理土壤微生物群落结构与长期不施肥处理较为相似,没有明显的优势种群.施用有机肥和有机无机配施的土壤微生物群落均以含a15:0, i15:0, cy17:0, i16:0, 16:1w7t,10Me18:0和15:0的微生物为优势种群.土壤有机质、碱解氮、速效磷和速效钾是微生物生长和活性的主要能源和营养因子.