加拿大一枝黄花入侵对杭州湾湿地围垦区土壤酶活性的影响

为了阐明加拿大一枝黄花(Solidago canadensis)入侵对土壤养分循环产生的影响及机理,以杭州湾滨海湿地围垦区内分布的加拿大一枝黄花群落与3种土著植物群落:束尾草(Phacelurus latifolius)群落、芦苇(Phragmites australis)群落和白茅(Imperata cylindrica)群落为研究对象,研究了外来植物入侵对土壤酶活性的影响及其与土壤养分关系的影响.结果表明:加拿大一枝黄花群落0~10cm土层土壤脲酶活性显著高于束尾草、白茅和芦苇(P0.001),分别提高了91.49%、116.97%和334.88%;加拿大一枝黄花入侵也显著提高了土壤蔗糖酶活性和碱性磷酸酶活性(P0.01).相关性分析表明:土壤碱解氮、硝态氮和铵态氮含量和脲酶活性呈显著正相关(P0.01),土壤全磷含量与碱性磷酸酶活性呈显著正相关(P0.05),土壤全磷、碱解氮、铵态氮和全氮含量与蔗糖酶活性呈显著正相关关系(P0.05),土壤全磷、碱解氮和全氮含量都与β-淀粉酶活性呈显著的正相关关系(P0.05),土壤全磷、碱解氮、硝态氮、铵态氮、全氮和有机质含量都与β-葡萄糖苷酶活性呈显著的正相关关系(P0.05).加拿大一枝黄花入侵显著提高了部分土壤酶的活性.这些土壤酶活性的变化可能加速了土壤养分转化,有利于其进一步入侵.     

上海崇明东滩加拿大一枝黄花根际部分可培养细菌的多样性分析

加拿大一枝黄花（Solidago canadensis L．）是一种外来引进后逃逸造成危害的新入侵杂草,以上海市崇明东滩不同时期围垦地为研究地点,采用微生物培养技术,对生长于上海崇明东滩不同时期围垦地的加拿大一枝黄花根际微生物进行分离筛选和菌种鉴定,结果表明：加拿大一枝黄花根际可培养微生物种类随入侵时间的延长而增多,根际微生物多样性随入侵时间的延长而增加;根际可培养微生物种类随季节的变化有所不同,夏季的根际微生物种类总体比冬季多,另外具有解磷和分解尿素的微生物较多,推测这些细菌的存在与加拿大一枝黄花可以在入侵地成功繁殖并且速度惊人有一定关系．     

金针虫添加对冬小麦根际土壤线虫群落的影响

通过室内盆栽实验研究沟金针虫(Pleonomus canaliculatus)处理下冬小麦(Triticum aestivum)根际土壤线虫群落的变化.结果显示，添加金针虫显著增加了冬小麦根际土壤线虫的总属丰富度、总土壤线虫的丰富度以及食细菌类和食真菌类线虫的丰富度，原因主要是金针虫添加提高了冬小麦根际土壤有机碳含量以及冬小麦苗和根中的类黄酮含量.主成分分析(PCA)结果表明，添加金针虫可以改变冬小麦根际土壤线虫群落的组成.冗余分析(RDA)证实冬小麦苗和根中的类黄酮含量、土壤有机碳含量分别解释土壤线虫群落变异的35.80%、16.40%和12.52%.上述结果表明，金针虫添加通过间接作用影响冬小麦根际土壤线虫群落，即通过增加冬小麦苗和根中的类黄酮含量对根际土壤线虫的丰富度和多样性产生影响.     

苯菌灵添加对植物种间竞争的影响：以加拿大一枝黄花与野大豆为例

共生微生物在植物的种间竞争与植物入侵过程中起到重要作用,而人类活动的干扰会破坏植物与土壤微生物间的共生关系,进而影响植物的种间竞争.为了探究干扰导致的共生关系破坏对植物种间竞争的影响及其可能的生态学后果,本研究选取土著植物野大豆(Glycine soja)与外来入侵植物加拿大一枝黄花(Solidago canadensis)为研究对象,使用苯菌灵抑制植物与土壤微生物之间的相互作用强度.结果显示,苯菌灵的添加主要抑制了植物与土壤微生物(菌根真菌、根瘤菌)的互利共生.对于苯菌灵导致的共生作用破坏,两种植物产生了不同的生长响应(野大豆叶根比不变,加拿大一枝黄花叶根比上升).这导致种间竞争条件下,野大豆的地下及地上竞争能力降低,植物的种间竞争平衡发生变化.本研究的结果表明,干扰导致的共生关系破坏对土著植物野大豆的影响大于对加拿大一枝黄花的影响,进而间接促进了外来植物加拿大一枝黄花的入侵.     

芦苇修复新疆石油污染土壤效果

考察芦苇对新疆污染土壤石油烃的处理效能、石油烃对芦苇生长的影响及不同石油污染度条件下芦苇根际微生物数量的变化。研究结果表明:经过123 d的芦苇修复,石油烃去除率可到41.21%～62.14%,明显高于空白样(19.75%～37.92%),其中饱和烃去除效果最好,可达60.52%～73.11%;芦苇对原油污染具有较好的耐受性,在土壤石油污染率低于1.25%情况下能够有效促进土壤中石油烃的去除;芦苇根际土壤中微生物数量与原油降解率呈正相关关系,芦苇根际效应促进原油降解菌数量的增加和活性的增强;芦苇的修复以根际效应为主,芦苇根际恰当的微生物类群为土壤原油降解提供有利保障。     

玉米不同生长时期潮土固氮细菌nifH基因的丰度和多样性

为了探究潮土环境下植物生长对土壤固氮细菌群落结构和数量的影响,采集中国北方潮土玉米不同生长时期的根际和非根际土壤,利用荧光定量PCR和末端片段长度多态性分析方法,研究了北方潮土玉米不同生长时期固氮细菌nif H基因丰度和多样性的变化.结果表明,根际土和非根际土固氮细菌nif H基因丰度随玉米生长时期的推进均呈现先升高后降低的趋势,乳熟期最高,根际土的在拔节期最低,而非根际土的在完熟期最低.相关分析结果表明,土壤有机质是驱动土壤固氮细菌nif H基因丰度变化的关键因子,非根际土固氮细菌nif H基因丰度同时受含水量的显著影响.根际土和非根际土固氮细菌优势种群结构在玉米各生长时期均相同,但所占比例有所差异.PCA分析也表明,土壤固氮细菌群落结构受玉米生长时期和土壤采样区域的影响均不显著.玉米不同生长时期土壤固氮细菌nif H基因的Shannon指数变化明显,根际土和非根际土均呈先增高后降低的趋势,根际土的在抽雄期最高,拔节期最低,非根际土的在乳熟期最高,完熟期最低;不同生长时期间的Evenness指数则无显著差异,且根际土和非根际土之间也没有显著差异.RDA分析结果显示,土壤硝态氮含量对固氮微生物群落结构有显著影响.     

加拿大一枝黄花入侵对杨树人工林土壤呼吸的影响

【目的】杨树是我国重要的人工林栽培树种,近年大量的加拿大一枝黄花(Solidago canadensis L.)入侵杨树人工林生态系统,研究加拿大一枝黄花对杨树人工林土壤呼吸的影响,有助于进一步认识陆地人工林生态系统的地下碳(C)循环对植物入侵的响应及其机制。【方法】2018年11月以江苏省东台林场内加拿大一枝黄花入侵和未入侵的8年生相同立地条件下杨树人工林群落为研究对象并建立固定样地,采用长期野外试验监测的研究方法对土壤呼吸以及土壤温度和湿度进行监测,同时钻取土芯测定样地土壤理化性质,对比加拿大一枝黄花入侵与未入侵条件下杨树人工林群落土壤呼吸的变化规律,探讨加拿大一枝黄花入侵杨树人工林后各个非生物因子变化对土壤呼吸的影响。【结果】加拿大一枝黄花的入侵显著增加了杨树人工林的土壤呼吸(P <0.001),且主导这种变化的非生物因子是入侵导致的土壤湿度的变化。加拿大一枝黄花入侵会通过改变土壤理化性质来影响土壤呼吸,显著增加杨树人工林的土壤湿度(P <0.001),同时显著增加土壤总氮含量(P <0.05),降低土壤碳氮比(P <0.05),但对于土壤总碳含量的增加并不显著(P >0.05),对土壤温度和pH的影响也不显著(P >0.05)。【结论】加拿大一枝黄花的入侵增加了杨树人工林土壤系统二氧化碳的排放量,增加了土壤系统的C损失,改变了杨树人工林土壤的C交换过程。     

一枝黄花属三种欧洲入侵种的生态学研究概况

北美一枝黄花(Solidago altissima)、巨大一枝黄花(Solidago gigantean)和狭叶一枝黄花(Solidago graminifolia)原产北美,于19世纪中叶在欧洲归化并成为外来入侵种。简述这3个种的种群扩张动态、侵占速率的基本模型、当前分布区域及潜在生长域的预测等种群生态学方面的研究内容,并介绍一枝黄花属入侵种在中国的分布情况及基本生物学特性。以借鉴国外对一枝黄花属植物的研究方法和手段,帮助我们理解该植物成功入侵的原因并预言一枝黄花属在我国的入侵植物的未来扩张趋势,对开展它们的综合治理有重要的意义。     

不同海拔珙桐群落乔木物种多样性与土壤因子关系研究

 为探讨珙桐(Davidia involucrata)生长的最适海拔高度及其与土壤性质的关系,研究了四川卧龙自然保护区白泥岗地带不同海拔高度的珙桐群落的植物多样性及其根际土壤性质.结果表明,海拔1700 m的珙桐群落的物种多样性最高,1500~1700 m是适宜珙桐生长的海拔高度.珙桐根际土壤速效磷、速效氮、速效钾、有机质和含水量在3个土层深度上差异显著;整个地区土壤pH值变化范围小.腐殖质层土样1500~1700m 3个海拔土壤养分含量显著高于1800 m和1850 m 2个海拔;淀积层、母质层土壤养分在5个海拔间的变化规律性不强.相关分析表明,速效磷、速效钾和pH值与群落物种多样性无显著相关性,只有淀积层有机质、腐殖质层含水量与群落物种多样性显著相关,母质层速效氮和淀积层、母质层含水量甚至与群落物种多样性显著负相关.     

芦苇根际土壤可培养真菌多样性的季节变化

以稀释平板法和形态学、分子生物学鉴定法对芦苇(Phragmites australis)进行了根际土壤可培养真菌的分离鉴定及季节变化对其种群结构影响的分析.结果表明:春、夏、秋、冬四季芦苇根际土壤可培养真菌菌落总数分别是5243、5003、6388和4970,种类数分别为9属21种、8属18种、11属22种和6属21种;真菌的多样性指数、丰富度指数值,从大到小的次序均为秋春夏冬,而均匀度指数为春夏冬秋,多样性指数和丰富度指数在秋季表现最高,但数值波动较大,均匀度指数差别较小.芦苇根际土壤中的真菌资源丰富,共分离出15属54种真菌,优势属为曲霉属(Aspergillus)、青霉属(Penicillium)、拟青霉属(Paecilomyces)、木霉属(Trichoderma)和链格孢属(Alternaria);金孢属(Chrysosporium)、伏革菌属(Corticium)、粘帚霉属(Gliocladium)、踝节菌属(Talaromyces)和根霉属(Rhizopus)是无植被土壤中没有的菌属.芦苇对土壤真菌多样性具有较强的保护作用,其根际土壤真菌的种类是无植被土壤的1.2倍,数量是无植被土壤的4倍.     

黄河三角洲自然保护区植物与土壤因子关系及生态位分析

以黄河三角洲自然保护区36个样地22个植物种的重要值(IV)为基础, 使用双向指示种分析法(TWINSPAN)将其分为6个群落类型: 翅碱蓬群落、柽柳?翅碱蓬群落、柽柳?芦苇+碱蓬群落、芦苇群落、旱柳?芦苇群落、人工林群落(刺槐林和白腊林)。在群落演替梯度上, 土壤pH逐渐增加, 土壤盐分呈下降趋势, 土壤含水量最大和最小值分别出现在芦苇群落和人工林群落, 土壤有机碳和总氮总体逐渐增加, 土壤碳氮比呈下降趋势。通过典范对应分析(CCA)发现, 影响黄河三角洲植物种分布的关键土壤环境因子是土壤盐分和pH, 植物物种多样性与土壤盐分呈显著负相关, 与土壤pH有正相关关系。在土壤pH和盐分梯度上的生态 位分析发现, 优势种柽柳、芦苇和翅碱蓬的生态位宽度较大, 植物种之间的生态位重叠一般较小, 说明物种在土壤pH和盐分梯度上出现了生态位分化。     

Species-diversified plant cover enhances orchard ecosystem resistance to climatic stress and soil erosion in subtropical hillside

Naturally occurring plants in agroecosystem evidently play an important role in ecosystem stability. Field studies on the ecological effects of native plants conserved in orchard and their resistance to adverse climatic stress, and soil erosion were conducted from 1998 to 2001 in a newly developed Changshan-huyou (Citrus changshan-huyou Y.B. Chang) orchard. The experimental area covered 150 ha in typical red soil hilly region in southeastern China. The experimental design was a randomized complete block with six combinations of twelve plant species with four replications. All species used were native in the orchard. Plots were 15 x 8 m2 and separated by 2 m buffer strips. Precipitation, soil erosion in rainstorm days and aboveground biomass of plant community when rainstorm days ended, soil temperature and moisture under various plant covers during seasonal megathermal drought period, antiscourability of soil with different root density under various simulated rainfalls were measured. Plant cover significantly decreased the daily highest and mean soil temperature and its daily variation in hot-drought season, but there was no significant difference of the alleviation among various plant covers. Plant covers significantly increased the soil moisture in seasonal megathermal drought period. Better moisture maintenance and soil erosion reduction was found when the plant species numbers in cover plant communities increased from one to eight. Higher root density in plant communities with higher species richness increased significantly the antiscourability of the soil. It was suggested that conserving plant communities with diversified native species could produce the best positive ecological effects on citrus orchard ecosystem stability.     

Soil biota and exotic plant invasion

Invasive plants are an economic problem and a threat to the conservation of natural systems. Escape from natural enemies might contribute to successful invasion, with most work emphasizing the role of insect herbivores; however, microbial pathogens are attracting increased attention. Soil biota in some invaded ecosystems may promote 'exotic' invasion, and plant-soil feedback processes are also important. Thus, relatively rare species native to North America consistently demonstrate negative feedbacks with soil microbes that promote biological diversity, whereas abundant exotic and native species demonstrate positive feedbacks that reduce biological diversity. Here we report that soil microbes from the home range of the invasive exotic plant Centaurea maculosa L. have stronger inhibitory effects on its growth than soil microbes from where the weed has invaded in North America. Centaurea and soil microbes participate in different plant-soil feedback processes at home compared with outside Centaurea's home range. In native European soils, Centaurea cultivates soil biota with increasingly negative effects on the weed's growth, possibly leading to its control. But in soils from North America, Centaurea cultivates soil biota with increasingly positive effects on itself, which may contribute to the success of this exotic species in North America.     

A new mechanism of invader success： Exotic plant inhibits natural vegetation restoration by changing soil microbe community

Since the 1950s of the last century, the exotic plant, Eupatorium adenophorum, has spread rapidly across southwest China, damaging native ecosystems and causing great economic losses. We examined the pH, N, P, K, and organic matter concentrations, and the bacterial community character (by Biolog EcoPlateTM) in soils from sites heavily and lightly invaded by this exotic species. Also, soil from the lightly invaded site was treated with a water extract of E.adenophorum roots to examine the effect of the plant on soil properties. We grew three plant species, one native and two exotic, in pot experiment using soil from heavily invaded site to examine the effects of the soil on these plants growth. The soil analysis demonstrated that the pH, organic matter, total N, total P and total K in soils from the heavily invaded site were only slightly different from those of the lightly invaded site, but concentrations of NH4^ , NO3^- and available P and K in the heavily invaded site were greater than those in the lightly invaded site. The catabolic activity of soil bacterial community in the heavily invaded site was different from that in the lightly invaded site. The catabolic activity of bacterial community in soils treated by the water extract of E.adenophorum roots changed and became similar to that in soils from the heavily invaded site. The pot experiment showed that the exotic plants growth in heavily invaded soil were not different from in lightly invaded soil; however, the native plant biomass decreased dramatically when grown in soil from the heavily invaded site as compared to soil from the lightly invaded site; and the same phenomenon was found when any potential allelopathic effects by E. adenophorum were eliminated by added activated carbon to those soils. Difference in soil nutrient availability and allelopathy could not explain this phenomenon of the native plant in the soils from the heavily and lightly invaded sites. Changes observed in the soil bacterial community were obviously related to native plant growth in those tow soils. Those results suggest that changing soil microbial community may be an important part of E. adenophorum invasion process. Since the soil microbial community serves as bridge in connection of exotic and natural plants, the exotic plant could inhibit the natural plant growth and reproduction by changing the soil microbial community in invaded site.     

互花米草与芦苇叶片化感物质对两者种子胚芽生长的影响

研究入侵植物互花米草叶片化感物质对土著植物芦苇种子胚芽生长的影响,对探讨其入侵机制具有重要意义.采用培养皿滤纸法,分析了用10,20,30,40,50g/L互花米草叶片化感物质提取液对芦苇种子胚芽,以及芦苇叶片化感物质提取液对互花米草种子胚芽生长的影响.结果表明:低浓度互花米草叶片化感物质提取液对芦苇胚芽生长无明显影响,30g/L时才有明显的抑制作用,且浓度越高,对芦苇胚芽生长抑制作用越强;而芦苇叶片化感物质提取液对互花米草的胚芽生长无明显影响.互花米草可能通过分泌某些次生代谢物质抑制土著植物芦苇种子萌发,而土著植物对入侵植物并无明显影响,这可能是互花米草成功入侵的主要原因之一.     

生态补水对黄河三角洲盐沼地土壤微生物群落分布特征的影响

为探究生态补水对盐沼湿地土壤微生物群落的影响，以黄河三角洲国家级自然保护区内人工围坝、实施“引淡压咸”淡水补给工程的湿地土壤为研究对象，以潮汐区天然盐沼湿地土壤为参照，使用磷脂脂肪酸（PLFA）法对比研究0~30 cm土层中4种土壤微生物群落（细菌、真菌、放线菌和丛枝菌根真菌等）在2类湿地中的分布特征，同时区别不同植被条件下（芦苇群落、盐地碱蓬群落和裸滩）的差异。结果表明:供试土壤的PLFA总量在4.25~32.71nmol.g-1之间，微生物群落组成均以细菌为主，表征4种微生物类群的PLFA含量由高到低依次为细菌(（8.47±4.66) nmol.g-1）、真菌（（1.28±2.21 ）nmol.g-1）、放线菌（（0.98±0.68） nmol.g-1）、丛枝菌根真菌（（0.29±0.27） nmol.g-1）。表征4种微生物类群的PLFA的含量均表现为生态补水区高于天然盐沼区，其中细菌平均高出39.63% ，真菌平均高出63.56% ，放线菌平均高出65.14% ，丛枝菌根真菌平均高出69.22% ，这可能是由补水引起的土壤pH减小、有机碳含量增加而导致的；从3种植被条件的对比来看，土壤PLFA含量由高到低依次为芦苇群落（7.43~32.71 nmol.g-1）、盐地碱蓬群落（4.87~16.58 nmol.g-1）、裸滩（4.25~7.54 nmol.g-1）。6种样地土壤PLFA总量排序为:补水区芦苇群落（17.70~32.71 nmol.g-1）、补水区盐地碱蓬群落（10.71~15.44 nmol.g-1）、潮汐区芦苇群落（7.43~12.23 nmol.g-1）、补水区裸滩（5.93~7.54 nmol.g-1）、潮汐区盐地碱蓬群落（4.87~6.50 nmol.g-1）、潮汐区裸滩（4.25~5.02 nmol.g-1）。补水区芦苇湿地土壤PLFA总量和真菌PLFA相对含量的增幅较大，这与补水区土壤适宜芦苇生长，而芦苇生物量的大量增加又导致土壤有机质的大幅增多和pH的下降密切相关；真菌与其他3类微生物相比，对补水和植被的响应幅度最大，尤其在恢复区芦苇群落土壤中，这进一步证实了土壤真菌在植物枯落物分解、植物碳转化为土壤碳方面的重要作用。从当前PLFA含量增加的角度来看，补水显著提升了芦苇群落土壤中微生物的生物量，然而盐沼湿地土壤微生物生物多样性及盐沼湿地生态过程、生态系统结构和功能在补水后的变化有待进一步系统综合地研究和评估。      

上海九段沙国家级湿地自然保护区昆虫多样性及其影响因素研究

在九段沙不同沙体和不同等级潮沟梯度下的5种主要植物群落中,在科和目层次上开展了昆虫多样性及其影响因素研究.调查区域共采集昆虫35444头,隶属于13目64科,按所含种数多少,主要的科有杆蝇科（42）、姬小蜂科（29）、金小蜂科（24）、茧蜂科（22）、姬蜂科（15）和缘腹细蜂科（12）;主要的目有膜翅目（137）、双翅目（85）、鞘翅目（32）和半翅目（10）.分析表明：（1）夏季昆虫的物种种数明显高于其他3个季节;（2）在上沙芦苇群落（夏季）,低潮滩的昆虫个体数最多,其次是高潮滩,中潮滩的最小.低潮滩中杆长蝽科、秆蝇科、瓢虫科和蚁形甲科的个体数极明显地多于中潮滩和高潮滩;随着由低潮滩向高潮滩高程的变化,杆长蝽科和飞虱科的昆虫个体数由少变多趋势明显.中潮滩与低潮滩相比,与高潮滩的昆虫组成更相似;（3）在中沙（夏季）,与芦苇群落相比,互花米草群落中昆虫个体数多,出现科数也多,互花米草群落中主要是啮虫目的种类和杆蝇科,两者占了互花米草群落昆虫总个体数的86.83%,而在芦苇群落中,以杆蝇科、蚁形甲科、瓢虫科3科为主,占芦苇群落昆虫总个体数的79%;在江亚南沙,藨草（海三棱藨草）群落中的昆虫主要是管蓟马科、叶蝉科、杆蝇科、茧蜂科和摇蚊科等5个科的昆虫,个体总数占了该类群落昆虫总个体数的96.82%,而菰群落中同样的5个科的昆虫个体数仅占菰群落昆虫总个体数的31.53%;（4）多样性指数以中生化群落最高,其次为芦苇和互花米草群落,最小为菰群落,物种丰富度则芦苇群落最高,其次为互花米草和中生化,最小为菰群落;（5）排序分析表明,植物群落中昆虫科的组成相似性反映了植物群落的演替方向,即菰群落、藨草/海三棱藨草群落的昆虫组成较相似,其次是互花米草与芦苇群落的,与中生化群落类型中的差异最大.     

鄱阳湖南矶湿地6种优势植物群落植被碳储量分布特征

在春季生长期,在鄱阳湖南矶湿地典型区内沿水位梯度采集6种优势植物群落样品,进一步区分植物地上部分茎叶和地下根系,以及优势种和伴生种.通过测定群落不同组分的全碳含量和生物量分析了鄱阳湖湿地植被碳分配与碳储量特征.结果表明:植物地上部分全碳含量的波动范围为37.12%～47.30%,地下根系全碳含量的波动范围为24.32%～38.33%,地上部分大于地下根系.总碳储量在不同群落间的变化范围为229.29～581.37 gC·m^-2,表现为灰化苔草群落最高,菰群落最低.不同群落物种的碳分配策略存在显著差异:灰化苔草和狗牙根地下根系碳分配远高于地上部分,虉草和芦苇则将更多的碳分配至地上部分,菰和南荻地上和地下碳分配较为均衡.碳储量在种间分配上主要集中于群落优势种.     

冰雪灾害对韶关地区3类典型植物群落的影响调查

运用群落样方调查方法,对韶关典型受灾地区3类典型植物群落的影响进行了调查。结果表明,公路人工边坡植物紫穗槐、百喜草以及野生乡土植物类芦生长旺盛,对华南边坡的植被修复有较好的应用价值;乡土植物种抗寒性普遍比外来植物种强,人工种植马尾松纯林受损严重,森林火灾和浅薄的石灰岩土不利于马尾松恢复生长;著名珍稀植物南方红豆杉的枝条受冰雪重力压断,但未出现冻死现象,在开阔地带生长的南方红豆杉比山地的有更强抗寒能力,并发现红豆杉伴生植物灰叶杉木和桃叶石楠生长良好。     

Changes in soil microbial community and enzyme activity along an exotic plant Eupatorium adenophorum invasion in a Chinese secondary forest

The exotic plant,Eupatorium adenophorum,has invaded rapidly across southwest China,damaging native ecosystems and causing great economic losses.Soil microbes,as an important component of belowground community,can drive nutrient cycling and regulate plant competition in terrestrial ecosystems.Therefore,knowledge of the soil microbial community and function will enhance our understanding of the mechanism of exotic plant invasive process in natural ecosystems.In this study,we examined the soil microbial community,soil enzyme activity,soil property and plant community along an invasive gradient of E.adenophorum in a southwest Chinese secondary forest.The soil analysis demonstrated that heavy invasion significantly increased the total P and NO3–-N contents,whereas it significantly decreased the total N and soil organic matter contents.The available P content was significantly decreased by moderate invasion.The E.adenophorum invasion significantly decreased the biomass of total soil microbes,as well as Gram-negative bacteria,actinomycetes,arbuscular mycorrhizal(AM)fungi and non-AM fungi.However,E.adenophorum invasion significantly increased the activities of soil urease,acid phosphatase,polyphenol oxidase and peroxidase.Non-metric multidimensional scaling showed that soil microbial composition and soil enzyme composition were significantly different in the three E.adenophorum invaded sites.Partial Mantel tests indicated that plant composition was the most important factor for structuring soil microbial and enzyme compositions.The results suggest that changes in soil microbial community structure and enzyme activity may play an important role in the process of E.adenophorum invasion in a Chinese secondary forest ecosystem.