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1.
长期种植毛竹林土壤丛枝菌根真菌群落演变趋势 总被引：1，自引：0，他引：1
为揭示长期种植毛竹林土壤丛枝菌根（Arbuscular mycorrhizae, AM）真菌群落演变特征,通过磷脂脂肪酸（Phospholipid fatty acid, PLFA）和Illumina Miseq测序平台研究了AM真菌生物量及群落结构的演变趋势。结果表明,长期种植毛竹林土壤养分含量总体呈下降趋势,球囊霉素相关土壤蛋白（Glomalin-related soil protein, GRSP）含量及AM真菌生物量也显著降低（p<0.05）,其中易提取态球囊霉素相关土壤蛋白含量与有机质、速效钾、碱解氮显著正相关（p<0.05）,而AM真菌菌丝生物量（16:1ω5 PLFA）与碱解氮极显著正相关（p<0.01）。长期种植毛竹林显著降低了土壤2~0.25 mm大团聚体比例（p<0.05）,且与AM真菌菌丝生物量极显著正相关（p<0.01）。测序结果表明,毛竹林土壤AM真菌以球囊霉属（Glomus）为优势种群,其次是无梗囊霉属（Acaulospora）,长期种植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（p<0.05）。非度量多维尺度转换排序（NMDS）分析显示,对照马尾松林与不同种植年限毛竹林土壤AM真菌群落显著区分（p=0.001）,土壤含水量（p=0.005）、有效磷（p=0.014）、碱解氮（p=0.001）对AM真菌群落结构变异具有重要贡献。长期种植毛竹显著降低了AM真菌生物量、球囊霉素相关土壤蛋白含量以及2~0.25 mm大团聚体比例,并改变了AM真菌群落结构,不利于土壤碳固存和维持生态系统稳定。 相似文献
2.
为明确丛枝菌根(AM)真菌对促进绿化苗木镉(Cd)吸收的影响,通过盆栽试验比较接种不同AM真菌对12种绿化苗木Cd吸收的差异,并进一步分析接种对金叶六道木根际微生物数量和AM真菌群落结构的影响。结果表明,12种绿化苗木,加Cd处理6个月后,其叶片浓度的变化范围为0.25~2.59 mg·kg-1。接种AM真菌处理组的叶片Cd含量均高于不接菌处理组。相比未接种,接种AM2摩西球囊霉(BGCAM00164)后金叶六道木叶片中Cd含量增加147.9%,故选择金叶六道木进行后续研究。接种AM212个月后,金叶六道木的根、枝、叶Cd浓度分别为164.7、22.86和10.57 mg·kg-1,为不接菌处理的2.64倍、2.06倍和1.76倍,全株总Cd含量达5078μg·株-1,显著高于不接菌对照(1745μg·株-1)。相比不接菌对照,接种AM2后降低了转移系数,将其更多吸收的Cd固定在根内,从而减少对植株的损害。接种AM真菌增加了AM真菌PLFA生物量,但降低了根际土壤微生物细菌和真菌PLFA生物量。所有样本中丰度较高的AM真菌为球囊霉科(Glomus)、类球囊霉科(Paraglomus)和原囊霉科(Archaeospora)。球囊霉科占总AM真菌的55%以上,是金叶六道木根际的主要优势种群。接种AM2后球囊霉丰度显著增加,由对照的61.8%上升至77.4%,但AM真菌的整体多样性和丰富度则表现为下降。接种AM1后类球囊霉科丰度显著增加,由对照的13.1%上升至17.8%,但球囊霉丰度无显著变化。主成分分析结果表明Cd和AM真菌接种可以改变金叶六道木根际AM真菌群落结构。总体而言,接种AM真菌(摩西球囊霉)能提高金叶六道木对土壤重金属Cd污染的修复效率,其联合修复技术可扩展Cd污染土壤植物修复的应用范围。 相似文献
3.
冬小麦免耕覆盖与有机栽培对土壤微生物群落组成的影响 总被引：2，自引：0，他引：2
为揭示农业管理活动对土壤微生物群落结构及AM真菌多样性的影响,以农田土壤生态系统为研究对象,选取免耕覆盖+施有机肥（NF）、免耕覆盖+不施有机肥（NC）、传统耕作不覆盖+施有机肥（TF）和传统耕作不覆盖+不施有机肥（TC）4种处理,采用Illumina Miseq高通量测序及磷脂脂肪酸（phospholipid fatty acids,PLFAs）分析方法,研究持续冬小麦免耕覆盖有机栽培3年后,土壤微生物群落结构组成、AM真菌及其多样性与土壤环境因子间的关系。结果表明,持续免耕覆盖有机栽培能增加以PLFA表征的土壤微生物群落的生物量,传统耕作显著提高了土壤革兰氏阳性菌（G+）、阴性菌（G-）的生物量（P<0.05）。且随免耕栽培管理年限增加,土壤AM真菌生物量呈显著上升趋势;以16：1ω5c中性脂（NLFA）与16：1ω5c磷脂（PLFA）表征的AM真菌生物量比值显著升高（P<0.05）。免耕覆盖措施下,有机肥的施用提高了土壤AM真菌丰富度指数（Chao1指数和ACE指数）,但降低了土壤AM真菌的多样性（香农指数、辛普森指数）。主成分分析结果显示,AM真菌孢子（16：1ω5c中性脂）的生物量与土壤有机质、土壤易提取球囊霉素含量呈正相关关系,AM真菌丰富度指数与土壤有机质含量呈正相关,AM真菌多样性指数与土壤全氮含量、脲酶活性呈正相关。受农业管理措施导致的土壤理化性状及土壤生物学差异等综合因素影响,土壤微生物生物量及AM真菌多样性和丰富度改变。免耕覆盖措施提高了土壤AM真菌多样性指数,有机肥施用显著影响了AM真菌NLFA/PLFA生物量的比例,改变了AM真菌孢子和菌丝间生物量碳的分配关系。 相似文献
4.
为揭示凤阳山毛竹入侵杉木林后土壤真菌群落结构组成和多样性的变化,采用Illumina Miseq 测序技术,分析杉木纯林、毛竹纯林及毛竹入侵后的杉木林真菌群落结构特征。结果表明:3 种林型的土壤真菌类群为26 门60 纲113 属415 OTU,子囊菌门和担子菌门是绝对优势的两个菌门。两者的丰度占真菌总量80.80% ～ 83.92%,在3 种林型间均不存在显著差异。识别出的1% 以上的优势菌纲有8 个,为古根菌纲、伞菌纲、粪壳菌纲、锤舌菌纲、银耳纲、球囊菌纲、散囊菌纲和酵母菌纲。古根菌纲和伞菌纲占真菌总量的50.82% ～ 75.40%。古根菌纲在毛杉混交林的相对丰度显著高于毛竹纯林(P<0.05),与杉木纯林无显著差异。Archaeorhizomyces 为优势菌属(20.07% ～ 51.51%)且在毛杉混交林中最高、在毛竹纯林最低,毛杉混交林中全氮、碱解氮和速效钾含量均显著低于杉木纯林和毛竹纯林。土壤真菌优势菌属水平丰度与土壤环境因子的斯皮尔曼相关性分析表明,全磷与Meliniomyces、毛壳菌属、Hodophilus、瓶霉属、Heterocephalacria 呈显著正相关(P<0.05),与Wickerhamomyces 呈极显著正相关(P<0.01)。毛竹入侵杉木林后土壤理化性质变化显著,全磷、有效磷、pH、速效钾和碳磷比是影响土壤真菌群落结构的主要环境因子,研究结果可为控制毛竹扩张,维护生态稳定和多样性提供科学依据。 相似文献
5.
马铃薯连作栽培对土壤微生物多样性的影响 总被引：3，自引：1，他引：3
为阐明马铃薯连作对土壤微生物群落结构和功能多样性的影响,揭示马铃薯连作障碍机制,本试验采用BIOLOG技术结合丛枝菌根真菌(AMF)形态学鉴定方法,就连作0(迎茬)、2 a、4 a、6 a、10 a的马铃薯田块土壤进行研究。结果表明:土壤养分含量随马铃薯连作年限增加有一定程度下降,其中,连作10 a马铃薯根际土壤的全磷、速效磷、速效钾和碱解氮与连作4 a相比分别下降61.32%、26.86%、26.87%和17.24%,但没有明显的养分亏缺和不均衡现象。土壤微生物群落结构发生了较大变化,放线菌、真菌数量显著随连作年限的延长先增加后减少,呈单峰型变化趋势;细菌数量随连作年限的延长呈逐步减少趋势,但差异不显著。连作4~6 a土壤微生物群落依然有较强的功能多样性,培养120 h后,连作6 a较迎茬AWCD值提高3.89%;群落组成中随连作年限的延长以碳水化合物、氨基酸类为碳源的微生物类群代谢能力明显下降,但代谢功能多样性趋于一致。连作马铃薯土壤AM真菌优势种发生改变,迎茬土壤为沙漠球囊霉(Glomus deserticola),连作2 a土壤为扭形球囊霉(Glomus delhiense)和福摩萨球囊霉(Glomus formosanum),连作10 a土壤为球泡球囊霉(Glomus globiferum)。多元分析结果表明,土壤微生物结构与功能多样性、AM真菌多样性变化受土壤p H、全磷含量、放线菌数量、细菌数量及土壤中以碳水化合物、氨基酸类等为碳源基质的微生物类群影响。说明长期连作栽培会影响土壤真菌、放线菌的数量,使真菌群落中AM真菌种的多样性显著下降,优势种发生改变,打破了微生物群落结构与功能平衡,引起土壤微生物群落结构与功能的失调。 相似文献
6.
为揭示冬麦免耕覆盖栽培管理措施对土壤丛枝菌根真菌多样性的影响,以农田土壤生态系统为研究对象,利用Illumina MiSeq平台通过高通量测序的方法,对连续免耕覆盖栽培及有机肥管理下冬麦土壤丛枝菌根真菌群落组成及其与土壤环境因子间的相互关系进行研究。结果表明,丛枝菌根(AM)真菌在97%相似度下共获得4 515个AM真菌的操作分类单元(OTUs),分属于1门3纲4目8科10属155种。不同处理中,类球囊霉属(Paraglomus),球囊霉属(Glomus)和近明球囊霉(Claroideoglomus)为优势属,受农业综合管理措施中有机肥施用、免耕覆盖因子的影响,近明球囊霉、有隔球囊霉属相对丰度在不同处理间存在显著差异(P<0.05)。与耕作、不覆盖相比,免耕、覆盖措施提高了AM真菌多样性指数,但降低了AM真菌属的丰富度;与无肥条件相比,有机肥施用提高了AM真菌丰富度指数,但降低了AM真菌多样性指数。多元分析结果表明,土壤全磷及速效磷含量是影响AM真菌群落组成中优势属丰度变化的主要因素。免耕覆盖、有机栽培改变了土壤AM真菌的多样性及丰富度,土壤中丰度较低的AM真菌菌属更容易受到有机肥施用的影响;有机肥与免耕、覆盖管理的交互作用对AM真菌近明球囊霉属相对丰度有显著影响(P<0.05)。AM真菌群落对耕作覆盖、有机肥施用管理活动的响应受到农业综合管理活动及其相关因素交互作用的影响。本研究结果为合理农作物免耕覆盖、有机栽培管理提供了理论依据。 相似文献
7.
球囊霉素或球囊霉素类相关蛋白(glomalin-related soil protein,GRSP)是丛枝菌根真菌(AMF)分泌的一种疏水性蛋白。为研究氮沉降对土壤GRSP的影响,选取了黄土高原典型地带性植物白羊草(Bothriochloa ischaemum)为研究对象,采用小车模拟小区试验,通过氮添加来模拟氮沉降,共设置3个氮添加浓度N_1(2.5g/m~2)、N_2(5g/m~2)和N_3(10g/m~2),以裸地(LD)和不添加氮处理CK(0g/m~2)为对照。结果表明:不同浓度氮添加后,土壤中总球囊霉素(Total glomalin,T-GRSP)含量呈现先增加后降低的趋势,但变化未达到显著水平,而易提取球囊霉素(Easily extractable glomalin,EE-GRSP)的含量变化在N_3时显著降低(p0.05)。冗余分析表明SOC,C/N、地下地上生物量是影响土壤GRSP的主要因素。研究从土壤GRSP角度分析了氮添加对土壤活性物质的影响,有利于揭示未来全球氮沉降背景下土壤质量的变化,加深对土壤生态变化过程的认识。 相似文献
8.
通过温室盆栽试验,研究接种苏格兰球囊霉(Glomus caledonium)条件下添加不同比例发酵牛粪(0.33%、0.50%和1.00%)对苏丹草(Sorghum sudanense)根系丛枝菌根(AM)真菌侵染率、土壤孢子密度、植株生物量与根冠比及根系磷(P)吸收效率的影响。结果发现,与对照相比,接种AM真菌处理植株地上部生物量趋于下降、根冠比显著提高(p<0.05),在此基础上添加0.33%或0.50%发酵牛粪处理土壤孢子密度、植株根系生物量和AM真菌侵染率均趋于升高,根冠比没有明显变化,根系P吸收效率显著提高(p<0.05);添加1.00%发酵牛粪显著提高土壤孢子密度、植株生物量和根系AM真菌侵染率(p<0.05),根冠比与仅接种AM真菌处理相同,根系P吸收效率则达到仅接种AM真菌处理的1.83倍。结果表明,添加1.00%发酵牛粪对苏格兰球囊霉扩繁及其宿主植物P吸收均具有突出促进作用。 相似文献
9.
长期秸秆覆盖对免耕稻-麦产量、土壤氮组分及微生物群落的影响 总被引：3，自引：0，他引：3
为探究长期秸秆覆盖对免耕区作物产量、土壤氮素组分及微生物群落特征的影响,以稻–麦定位免耕试验为研究对象,选取了其中免耕且秸秆移除和免耕且秸秆覆盖2个处理,于试验开展第12年 (2018年) 小麦收获后,统计分析近五年产量数据,并采集各处理0~5、5~10、10~20、20~30 cm的土壤样品,测定土壤全氮及活性氮组分,利用磷脂脂肪酸 (PLFA) 方法表征土壤微生物群落。结果表明： (1) 秸秆覆盖显著提高了小麦产量 (增幅为6.49%),对水稻产量影响不显著。 (2) 秸秆覆盖对土壤氮组分的影响略有差异：它显著提高了土壤0~5 cm 全氮、硝态氮和铵态氮以及0~10 cm 颗粒有机氮、0~5 cm和10~20 cm 可溶性有机氮含量,对微生物生物量氮无显著影响;它提高了0~5 cm 和10~20 cm 可溶性有机氮占全氮的比例,对其他组分占全氮比例无显著影响。 (3) 秸秆覆盖显著提高了土壤微生物总PLFA和细菌PLFA丰度,对真菌PLFA和放线菌PLFA无影响,降低了土壤真菌/细菌比;微生物生物量氮、土壤全氮、颗粒有机碳/颗粒有机氮比是显著影响土壤微生物群落组成的关键土壤环境因子。 (4)无论秸秆覆盖与否,土壤全氮、活性氮组分含量和微生物组分均表现出显著的深度效应。综上所述,秸秆还田提升了土壤氮素含量,提高了小麦产量,增加了土壤微生物总量,可在四川免耕稻–麦轮作区推广应用。 相似文献
10.
对贵州务川汞矿区不同水平汞污染植物根际土壤丛枝菌根(Arbuscular Mycorrhizal,AM)真菌资源分布及多样性进行分析，结果发现：本研究选取的务川汞矿区3个样地土壤汞含量在94.1～268.0 mg/kg，远高于国家规定的土壤汞含量，汞污染极其严重。随着汞含量增加，AM真菌侵染率、孢子密度显著降低，AM真菌群落丰富度、多样性及均匀度均有所降低，但差异未达显著水平，而仍有部分对汞污染耐受性较强的AM真菌有较高的分布。另外，管柄囊霉属AM真菌在5个样品中均有较高丰度，球囊霉属AM真菌在火棘根际的相对丰度随着汞含量升高而升高，因此，火棘–管柄囊霉属AM真菌或火棘–球囊霉属AM真菌联合进行汞污染修复，有一定的应用价值。 相似文献
11.
利用原位微宇宙试验将丛枝菌根(Arbuscular mycorrhiza,AM)真菌菌丝与根系区分,设置菌根室(RA)和菌丝室(AH)两个分室处理,以粗放经营(extensive management,EM)毛竹林为对照,研究集约经营(Intensive management,IM)条件下毛竹林土壤丛枝菌根共生体对氨氧化微生物群落的影响及其响应机理。结果表明,无论集约经营还是粗放经营AH处理土壤pH均显著降低,且集约经营毛竹林AH处理土壤碱解氮显著降低;不同分室处理对硝化势没有显著影响,但集约经营毛竹林RA处理土壤硝化势显著高于粗放经营;集约经营之后氨氧化古菌(Ammonia-oxidizing archaea,AOA)基因丰度显著降低,而氨氧化细菌(Ammonia-oxidizing bacteria,AOB)基因丰度则在两种经营强度的AH处理中显著降低。不同经营强度和分室处理并未对氨氧化微生物群落组成结构产生显著影响,但网络分析显示集约经营毛竹林氨氧化微生物之间的互作和共生关系优于粗放经营,粗放经营毛竹林氨氧化微生物之间的竞争更为激烈。研究结果为更好地理解毛竹林AM真菌与氨氧化微生物之间的互作关系提供了理论基础。 相似文献
12.
Stefano Bedini Luciano Avio Paolo Bazzoffi Manuela Giovannetti 《Soil biology & biochemistry》2009,41(7):1491-1496
Arbuscular mycorrhizal (AM) fungi are key organisms of the soil/plant system, influencing soil fertility and plant nutrition, and contributing to soil aggregation and soil structure stability by the combined action of extraradical hyphae and of an insoluble, hydrophobic proteinaceous substance named glomalin-related soil protein (GRSP). Since the GRSP extraction procedures have recently revealed problems related to co-extracting substances, the relationship between GRSP and AM fungi still remains to be verified. In this work the hypothesis that GRSP concentration is positively correlated with the occurrence of AM fungi was tested by using Medicago sativa plants inoculated with different isolates of Glomus mosseae and Glomus intraradices in a microcosm experiment. Our results show that (i) mycorrhizal establishment produced an increase in GRSP concentration - compared to initial values - in contrast with non-mycorrhizal plants, which did not produce any change; (ii) aggregate stability, evaluated as mean weight diameter (MWD) of macroaggregates of 1-2 mm diameter, was significantly higher in mycorrhizal soils compared to non-mycorrhizal soil; (iii) GRSP concentration and soil aggregate stability were positively correlated with mycorrhizal root volume and weakly correlated with total root volume; (iv) MWD values of soil aggregates were positively correlated with values of total hyphal length and hyphal density of the AM fungi utilized.The different ability of AM fungal isolates to affect GRSP concentration and to form extensive and dense mycelial networks, which may directly affect soil aggregates stability by hyphal enmeshment of soil particles, suggests the possibility of selecting the most efficient isolates to be utilized for soil quality improvement and land restoration programs. 相似文献
13.
Jue Dai Junli Hu Xiangui Lin Anna Yang Rui Wang Jiabao Zhang Ming Hung Wong 《Journal of Soils and Sediments》2013,13(1):1-11
Purpose
Arbuscular mycorrhizal (AM) fungi are crucial for ecosystem functioning and can contribute to the formation and maintenance of soil aggregates through the exudation of glomalin by extraradical hyphae. Monitoring fertilization effects on AM fungi may help us to develop sound management strategies. The objectives of this study were to investigate the impacts of long-term fertilization on AM fungal parameters and to find out the key factor that affects the diversity and function of AM fungi.Materials and methods
A long-term fertilization experiment established in a sandy loam soil at northern China has received continuous fertilization treatments for 21 years, including control; mineral fertilizers of NK, PK, NP, and NPK; organic manure (OM); and half organic manure N plus half mineral fertilizer N (1/2 OMN). Top soil samples (0–15 cm) from three individual plots per treatment were collected for the analysis of chemical properties and fungal parameters. The population size of soil AM fungi was determined by real-time PCR, and the community composition was analyzed using PCR-denature gradient gel electrophoresis (DGGE), cloning, and sequencing techniques. The external mycelium of AM fungi was assessed using the grid-line intersect method, and the glomalin-related soil protein (GRSP) was extracted with citrate solution using bovine serum albumin as a standard.Results and discussion
Long-term fertilization significantly increased (P?<?0.05) soil organic C content, AM fungal population, species richness (R), Shannon–Wiener index (H), and GRSP content, except for the P-deficiency (NK) fertilization treatment. OM had a significantly greater (P?<?0.05) impact on AM fungal population and GRSP content compared to mineral fertilizers but significantly decreased the length of external mycelium compared to the control (P?<?0.05). Fertilization also changed the community composition of AM fungi, and the P-deficiency treatment again had the slightest influence. In addition, most species recovered from the DGGE profiles belonged to three genera, Glomus, Diversispora, and Archaeospora. Redundancy analysis showed that the population size and species richness of AM fungi and the GRSP content all significantly correlated to soil organic C content (P?<?0.05).Conclusions
Long-term P-containing fertilization, especially the application of OM, greatly increased the population size, species richness, and species diversity of AM fungi, as well as the contents of GRSP and soil organic C, but tended to decrease the length of external mycelium, while the P-deficiency fertilization had no such effect, suggesting that P was the key factor to maintain soil fertility as well as soil AM fungal diversity in this sandy loam soil. 相似文献14.
Effects of Organic Amendments on Soil Physical Attributes and Aggregate-Associated Phosphorus Under Long-Term Rice-Wheat Cropping 总被引：1，自引：0，他引：1
Tarik MITRAN Pabitra Kumar MANI Prasanta Kumar BANDYOPADHYAY Nirmalendu BASAK 《土壤圈》2018,28(5):823-832
The quantification of phosphorus(P) in bulk soil and P distribution in different size fractions of water-stable aggregates(WSAs)are important for assessing potential P loss through runoff. We evaluated available and total P distribution within WSAs of a sitty clay to clay soil in a long-term fertility experiment of a rice-wheat cropping system in India. Surface soil samples were collected from seven plots amended with NPK fertilizers in combination with or without organic amendments, farmyard manure(FYM), green manure(GM), and paddy straw(PS). The plot with no NPK fertilizers or organic amendments was set as a control. The soil samples were separated by wet sieving into four soil aggregate size fractions: large macroaggregates( 2.0 mm), small macroaggregates(0.25–2.0 mm), fine microaggregates(0.05–0.25 mm), and a silt + clay-sized fraction( 0.05 mm). Structural indices were higher in the soil receiving organic amendments than in the soil receiving inorganic fertilizer alone. Organically amended soil had a higher proportion of stable macroaggregates than the control and the soil receiving inorganic fertilizer alone, which were rich in microaggregates. Total and available P contents within WSAs were inversely related to the aggregate size, irrespective of treatment. The distribution of available and total P in the soil aggregate size fraction was as follows: silt + clay-size fraction small macroaggregates fine microaggregates large macroaggregates. Within a size class, aggregate-associated available and total P contents in the organically amended soil were in the following order: FYM PS ≥ GM. The available P content of the microaggregates( 0.25 mm) was 8-to 10-times higher than that of the macroaggregates( 0.25 mm), and the total P content of the microaggregates was 4-to 5-times higher than that of the macroaggregates. Cultivation without organic amendments resulted in more microaggregates that could be checked by the application of organic amendments such as FYM and GM, which increased the proportion of water-stable macroaggregates by consolidating microaggregates into macroaggregates. 相似文献
15.
16.
降水变化和氮沉降是影响植物、微生物和土壤环境变化的两个重要方面。尽管丛枝菌根（AM）真菌在陆地生态系统中起着至关重要的作用，但人们对降水变化和氮添加如何交互影响AM真菌群落仍知之甚少。本研究以短花针茅荒漠草原为研究对象，采用裂区设计，主区为自然降雨(CK)、增雨30%(W)和减雨30%(R)三个水分梯度，副区为0(N0)，30(N30)，50(N50)和100(N100) kg?hm-2?a-1 四个氮素梯度共12个处理，通过高通量测序分析了土壤中AM真菌群落的多样性和组成。结果发现，水分处理对土壤AM真菌的Alpha多样性有促进作用，氮素处理抑制了土壤AM真菌的Alpha多样性，水分增加和氮素添加的交互作用促进了AM真菌的Alpha多样性增加，并改变了土壤AM真菌群落组成。水分和氮素刺激了各功能型植物生物量的增加，氮添加使多年生杂草和半灌木、小半灌木生物量显著增加，多年生禾草生物量显著减少。此外，多型孢子菌科的相对丰度与一二年生植物和半灌木、小半灌木生物量呈显著正相关，一二年生植物和半灌木、小半灌木生物量在氮添加和增雨处理下增加。本研究证明了AM真菌群落在短期气候变化下的稳定性。此外，AM真菌在科水平上的丰度与各生活型植物地上生物量的相关性证明了地上和地下生态系统的连通性。 相似文献
17.
The carbon storage in moso bamboo plantation and its spatial variation in Anji County of southeastern China 总被引：1，自引：0，他引：1
Weijun Fu Peikun Jiang Keli Zhao Guomo Zhou Yongfu Li Jiasen Wu Huaqiang Du 《Journal of Soils and Sediments》2014,14(2):320-329
Purpose
Forest ecosystems play an important role in sequestering carbon in their biomass and soils. Moso bamboo plantations, as a special forest type, are mainly distributed in southern China. There is little information about the carbon storage in moso bamboo plantations, it is now important to better understand the moso bamboo’s carbon sequestration. The main objectives of this study were to investigate the spatial variation of aboveground biomass carbon (AGC) and soil organic carbon (SOC) in moso bamboo plantations and to compare carbon storage in moso bamboo plantations under different management options.Materials and methods
A total of 73 moso bamboo plots were selected in Anji County, which is a famous “bamboo town” in northwest Zhejiang province, China. The diameter at breast height and the age of each moso bamboo in the selected plots were measured in order to calculate the AGC. SOC was analyzed using sulfuric acid–potassium dichromate solution. One-way ANOVA was applied to analyze the significant difference of AGC and SOC under different management options. Geostatistics and geographical information were used to study the spatial dependence characteristics of AGC and SOC.Results and discussion
The AGC values were very variable, ranging from 9.92 to 38.70 Mg?ha?1, with an average of 20.85 Mg?ha?1. The SOC values were from 34.8 to 176.17 Mg?ha?1. Both the AGC and SOC values were followed normal distributions. Moso bamboo plantations contributed about 16.5 % of total forest biomass carbon in Zhejiang Province, indicating its important influence on regional carbon budget. Geostatistical analysis revealed that the AGC had moderate spatial autocorrelation. A nested model (a spherical model with a Gaussian model) was chosen to describe the variogram. Spatial patterns for AGC were found in Anji County, with relatively high AGC values were found in the southwestern part of Anji County, and low values were located in the eastern and central parts of the county. While no clear spatial autocorrelation trend was observed in the semivariogram of SOC, indicating a random distribution pattern for SOC in the study area. Meanwhile, the Pearson’s correlation between AGC and SOC in bamboo plantation was weak (r?=?0.064, p?=?0.496), due to moso bamboo’s special growth process and different management options by human beings.Conclusions
In this study, moderate spatial dependency was found for AGC, while the spatial autocorrelation of SOC was poor. In moso bamboo forest ecosystem, SOC was mainly stored at the top 40 cm layer. Management options were proved to be an important factor for carbon sequestration. Extensive management is an efficient way to increase carbon stock, compared to moderate and intensive management. With the rapid increase of plantation area, moso bamboo ecosystem will continue to play an important role in regional carbon budget. 相似文献18.
The conversion of pasture to cropland leads to a decline of aggregation in topsoils and to a decrease of aggregate-binding agents such as carbohydrates and glomalin-related soil protein (GRSP). Till now, studies on soil aggregation focused either on carbohydrates or on GRSP as a binding agent in aggregates. In this study we analyse the development of the relationship between carbohydrates, GRSP, TOC and aggregate-stability following land-use change. Furthermore, we discuss the contents of carbohydrates, GRSP and TOC in each of the aggregate fractions. For these purposes, a chronosequence of sites, which were converted from pasture to cropland at different periods in history, was established. To get further insight into the impact of different types of land-use, also soils under forest, either afforested or permanent, were studied. The mean-weight diameter (MWD) of water-stable aggregates, the carbohydrate, and the GRSP content were determined in 49 soils. It was found that the MWD of the water-stable aggregates decreased monoexponentially (R2 = 0.66) by 66% during the first 46 years after conversion of the soils from pasture to cropland. During the same period, the carbohydrate content decreased very rapidly after the land use change by 64% and the GRSP content decreased more slowly by 57%. The MWD of the forest soils were in the same range as those of the permanent pasture soils although they exhibit significantly higher TOC contents, which indicate that other stabilization mechanisms are dominant in forest soils, less important in the chronosequence soils. TOC, carbohydrates and the GRSP contents were sigmoidally correlated with the MWD. Among the four water-stable aggregate fractions TOC and carbohydrates exhibited high contents in the macroaggregates and were less present in the microaggregates. GRSP, in contrast, was more equally distributed among the four water-stable aggregate fractions. 相似文献
19.
Zhang Wenyuan Liu Shun Zhang Manyun Li Yinan Sheng Keyin Xu Zhihong 《Journal of Soils and Sediments》2019,19(7):2913-2926
Purpose
Rhizosphere and fertilization might affect soil microbial activities, biomass, and community. This study aimed to evaluate the impacts of Phyllostachys edulis (moso bamboo) rhizospheres on soil nutrient contents and microbial properties in a moso bamboo forest with different fertilizer applications and to link soil microbial activities with abiotic and biotic factors.
Materials and methodsThe experiment included three treatments: (1) application of 45% slag fertilizer (45%-SF); (2) application of special compound fertilizer for bamboos (SCF); and (3) the control without any fertilizer application (CK). Simultaneously, bulk soils and 0.5, 2.5, 4.5, and 6.5-year-old (y) bamboo rhizosphere soils were selected. Soil nutrient contents were analyzed. Microbial activities were evaluated based on the activities of soil enzymes including β-glucosidase, urease, protease, phosphatase, and catalase. The total microbial biomass and community were assessed with the phospholipid fatty acids (PLFAs) method.
Results and discussionIn the CK and SCF treatments, organic matter contents of rhizosphere soils were significantly higher than those of bulk soils. Soil β-glucosidase, urease, protease, phosphatase, and catalase activities in rhizosphere soils were higher than those of bulk soils, with the sole exception of β-glucosidase of 0.5 y rhizosphere soil in the 45%-SF treatment. Compared with the CK treatment, fertilizer applications tended to increase soil total PLFAs contents and changed soil microbial community. Moso bamboo rhizospheres did not significantly increase the total microbial biomass. In the SCF treatment, the Shannon index of bulk soil was significantly lower than those of rhizosphere soils.
ConclusionsOur results suggested that both rhizospheres and fertilizer applications could change the soil microbial community structures and that moso bamboo rhizosphere could increase microbial activity rather than biomass in the forest soils with different fertilizer applications.
相似文献20.
【目的】五爪金龙(Ipomoea cairica)、 南美蟛蜞菊(Wedelia trilobata)已入侵我国华南地区并造成严重危害。本文研究了五爪金龙入侵群落、 南美蟛蜞菊入侵群落与土著植物类芦(Neyraudia reynaudiana)群落内的土壤养分、 土壤微生物量、 土壤酶活性以及微生物群落代谢活性、 碳源利用特征与功能多样性的变化规律,探讨两种外来植物入侵对土壤生态系统的影响,为揭示其野外入侵机制提供科学依据。【方法】采用野外样方法于2010年1月在广州市东郊的火炉山森林公园设置五爪金龙入侵区、 南美蟛蜞菊入侵区和土著植物类芦区3类样地,测定土壤养分、 土壤酶活性、 土壤微生物量与微生物功能多样性。【结果】1)与土著植物区相比,五爪金龙入侵区土壤有机碳、 全氮、 全磷以及速效氮、 速效磷、 速效钾含量显著提高,增幅达到60.38%~230.01%; 南美蟛蜞菊入侵区土壤有机碳、 全氮、 速效氮、 速效磷含量亦显著提高,增幅达到50.54%~145.52%; 两种外来植物入侵区土壤C/N比显著降低,但对全钾含量的影响不明显。2)两种外来植物能够显著提高入侵地的土壤微生物量,其中五爪金龙、 南美蟛蜞菊入侵区的土壤微生物量碳(Cmic)、 氮(Nmic)、 磷(Pmic)含量分别比土著植物区增加105.00%~152.15%和61.51%~138.27%,但土壤微生物量在两个入侵区之间的差异不明显; 对于土壤微生物熵,南美蟛蜞菊入侵区的Cmic/Corg值显著高于土著植物区,但Nmic/Nt、 Pmic/Pt值3类样地之间差异不显著。3)两种外来植物入侵显著提高土壤脲酶、 蛋白酶、 蔗糖酶和纤维素酶的活性,其中南美蟛蜞菊入侵区的土壤脲酶、 蛋白酶和纤维素酶活性最高,分别比土著植物区增加70.35%、 21.51%和227.86%; 对于蔗糖酶活性,五爪金龙、 南美蟛蜞菊入侵区的增幅则分别达到322.58%和157.14%; 过氧化氢酶活性各处理间的差异较小,差异均不显著。4)两种外来植物入侵能够提高土壤微生物群落的代谢活性,平均孔颜色变化率(AWCD)在整个培育周期内均表现为五爪金龙入侵区＞南美蟛蜞菊入侵区＞土著植物区,其中72 h的AWCD值分别为1.18、 0.88和0.56,差异显著。与土著植物区相比,五爪金龙入侵区6种类型碳源的利用效率显著提高,其增幅高达75.00%~162.86%; 南美蟛蜞菊入侵区碳水化合物类、 羧酸类和聚合物类碳源的利用率亦显著提高,其增幅分别为87.72%、 41.18%和83.72%; 两种入侵植物对不同类型碳源的利用程度存在一定差异,五爪金龙对羧酸类、 胺类碳源的利用率显著高于南美蟛蜞菊。主成分分析显示,PC1与PC2能够解释不同入侵区土壤微生物群落碳源利用数据71.89%的总体变异,其中PC1主要受碳水化合物类、 氨基酸类与聚合物类碳源的影响,PC2则主要受碳水化合物类与羧酸类碳源的制约。两种外来植物入侵对土壤微生物群落的功能多样性产生重要影响,其中入侵地土壤微生物群落的Shannon-Wiener指数(H)、 Mc Intosh指数(U)、 丰富度指数(S)和Simpson优势度指数(Ds)显著高于土著植物区,但两个入侵区之间的差异较小; 三个处理区的Pielou均匀度指数(E)差异不明显。【结论】五爪金龙、 南美蟛蜞菊两种外来植物能够改善入侵地的土壤营养环境,提高土壤肥力水平,形成对自身生长、 竞争有利的微环境,从而加快入侵扩散。 相似文献