Soil Fungal Community Composition Research Articles

Soil Acidification Under Long-Term N Addition Decreases the Diversity of Soil Bacteria and Fungi and Changes Their Community Composition in a Semiarid Grassland.

Soil microorganisms play key roles in terrestrial biogeochemical cycles and ecosystem functions. However, few studies address how long-term nitrogen (N) addition gradients impact soil bacterial and fungal diversity and community composition simultaneously. Here, we investigated soil bacterial and fungal diversity and community composition based on a long-term (17years) N addition gradient experiment (six levels: 0, 2, 4, 8, 16, 32 gN m-2year-1) in temperate grassland, using the high-throughput Illumina MiSeq sequencing. Results showed that both soil bacterial and fungal alpha diversity responded nonlinearly to the N input gradient and reduced drastically when the N addition rate reached 32gNm-2year-1. The relative abundance of soil bacterial phyla Proteobacteria increased and Acidobacteria decreased significantly with increasing N level. In addition, the relative abundance of bacterial functional groups associated with aerobic ammonia oxidation, aerobic nitrite oxidation, nitrification, respiration of sulfate and sulfur compounds, and chitinolysis significantly decreased under the highest N addition treatment. For soil fungi, the relative abundance of Ascomycota increased linearly along the N enrichment gradient. These results suggest that changes in soil microbial community composition under elevated N do not always support the copiotrophic-oligotrophic hypothesis, and some certain functional bacteria would not simply be controlled by soil nutrients. Further analysis illustrated that reduced soil pH under N addition was the main factor driving variations in soil microbial diversity and community structure in this grassland. Our findings highlight the consistently nonlinear responses of soil bacterial and fungal diversity to increasing N input and the significant effects of soil acidification on soil microbial communities, which can be helpful for the prediction of underground ecosystem processes in light of future rising N deposition.

Effects of microtopography on soil fungal community diversity, composition, and assembly in a subtropical monsoon evergreen broadleaf forest of Southwest China

Topography is a critical factor that determines the patterns and assemblages of species diversity in forest communities. Small-scale topography changes are defined as microtopography. Our understanding of the effects of microtopography on soil fungal communities is limited. The objective of this study was to explore the impact of microtopography on soil fungal community diversity, community composition, functional guild, and community assembly. The diversity, composition, and relative abundance of functional guilds were measured using Illumina high-throughput sequencing techniques in five microtopography types (steep slope, less-steep slope, valley, high plateau, and ridge). OTU and Chao1 indexes were the highest in the high plateau and were the lowest in the ridge. The Shannon index was the lowest in the valley, and the highest in the ridge. In the valley, soil fungal networks were more interconnected than they were in any of the other microtopography unit. At the class level, the relative abundance of Agaricomycetes, Eurotionmycetes, and Leotiomycetes were higher in the ridge unit. The relative abundance of ectomycorrhiza, the dominant functional guild, in the ecosystem was as follows: less-steep slope (71.31%), ridge (66.55%), valley (65.83%), steep slope (63.91%), and high plateau (60.09%). Microtopography influenced fungal community diversity and composition more than any other factor and had, varying degrees of influence on the different functional guilds. In every microtopography type, dispersal limitations and drift shaped fungal communities more than other ecological processes. Our findings suggest that microtopography affects soil fungal community diversity and composition, functional guilds, and the relative contributions of ecological processes to soil fungal communities in subtropical monsoon evergreen broadleaf forests.

Tree decline and mortality following pathogen invasion alters the diversity, composition and network structure of the soil microbiome

The loss of tree health is a global concern with many unknown cascading impacts on the diversity and function of forest ecosystems. Specifically, it is uncertain how the process of tree decline and mortality driven by exotic pathogens might alter the soil microbiome. Here we combined high-throughput sequencing, neighborhood models, and network analysis to explore the impacts of the decline of a Mediterranean tree species, Quercus suber, on the diversity, composition and network structure of soil fungal and bacterial communities in forests invaded by the exotic pathogen Phytophthora cinnamomi. The belowground footprint of pathogen-driven tree decline implied an increase in the taxonomic and phylogenetic diversity of both bacteria and fungi, but also a severe reduction of tree-symbiotic fungi and Proteobacteria known to have positive effects on plant growth and disease suppression. Moreover, we detected alterations of the topology of soil microbial networks in declining tree neighborhoods (lower connectivity, higher modularity), with implications for ecosystem function. Our findings reveal the large impacts that moderate levels of tree decline can have on the soil microbiome of invaded forests, and highlight the recovery of a functionally diverse and highly connected soil microbiome as a key target in the restoration of these disturbed systems.

Comparison of the Responses of Soil Fungal Community to Straw, Inorganic Fertilizer, and Compost in a Farmland in the Loess Plateau.

ABSTRACTThe Loess Plateau is located in the arid and semi-arid regions in northern China. The ecosystem is particularly sensitive to natural and anthropogenic disturbances. Fungi can produce extracellular enzymes, decompose a variety of organic matter, and regulate carbon and nutrient balance. We studied the changes of soil fungal community compositions in response to straw, inorganic fertilizer, and compost in a typical farmland in the Loess Plateau. Our results demonstrated that the addition of straw significantly reduces the Shannon index of the fungal community, in addition, the participation of straw significantly affects the composition of the fungal community. Functional prediction based on FUNGuild showed that straw significantly reduced the relative abundance of saprotrophs, pathotrophs, symbiotrophs, lichenized, ectomycorrhizal, and plant pathogens. Although fertilization practices destroyed the co-occurrence pattern among the fungal species, the addition of straw alleviated this affect. No significant effect of straw, compost, and inorganic fertilizers on the co-occurrence pattern among species in the soil fungal community was observed. Compared with compost and inorganic fertilizer, the addition of straw shaped the community composition by changing the relative abundance of fungal functional taxa. Thus, in the fragile Loess Plateau environment, over-fertilizing or non-order-fertilizing may destroy the co-occurrence pattern of the fungal communities and Loess Plateau ecosystem.IMPORTANCE Determining the response of soil fungi in sensitive ecosystems to external environmental disturbances is an important, yet little-known, topic in microbial ecology. In this study, we evaluated the impact of traditional fertilization management practices on the composition, co-occurrence pattern, and functional groups of fungal communities in loessial soil. Our results show that in the fragile Loess Plateau environment, fertilizer management changed the composition of the fungal community and disrupted the co-occurrence pattern between fungi. The application of straw alleviates the destroying of the co-occurrence pattern. The current research emphasizes the necessity of rational fertilization of farmland in loessial soil.

Fungal Perspective of Pine and Oak Colonization in Mediterranean Degraded Ecosystems

Forest restoration has become one of the most important challenges for restoration ecology in the recent years. In this regard, soil fungi are fundamental drivers of forest ecosystem processes, with significant implications for plant growth and survival. However, the post-disturbance recovery of belowground communities has been rarely assessed, especially in highly degraded systems such as mines. Our aim was to compare forests and mined systems for biomass and structure of fungal communities in soil during early stages of tree establishment after disturbance. We performed ergosterol analysis and PacBio and Illumina sequencing of internal transcribed spacer 2 amplicons across soil layers in P. sylvestris, Q. robur and Q. ilex (holm oak) forests and naturally revegetated mined sites. In pine forests, total fungal biomass was significantly higher in litter and humus compared to mineral layers, with dominance of the mycorrhizal genera Tomentella, Inocybe and Tricholoma. Conversely, in oak forests the most abundant mycorrhizal genera were Tomentella, Cortinarius and Sebacina, but the biomass of saprotrophic fungi was greater in the litter layer compared to mycorrhizal fungi, with the genus Preussia being the most abundant. In the revegetated mined sites, ectomycorrhizal fungi dominated in the humus and mineral layers, with the mycorrhizal genus Oidiodendron being dominant. In contrast, in holm oak forests saprotrophic fungi dominated both soil humus and mineral layers, with the genera of Alternaria, Bovista and Mycena dominating the soil humus forest layer, while the genus Cadophora dominated the mineral layer. The habitat-specific differences in soil fungal community composition and putative functions suggest that an understanding of soil–plant–microbial interactions for different tree species and use of specific soil/litter inoculum upon planting/seeding might help to increase the effectiveness of tree restoration strategies in Mediterranean degraded sites.

Integrated microbiology and metabolomics analysis reveal responses of soil microorganisms and metabolic functions to phosphorus fertilizer on semiarid farm

Localized fertilization of phosphorus has potential benefits in achieving higher crop productivity and nutrient use efficiency, but the underlying biological mechanisms of interactions between soil microorganisms and related metabolic cycle remain largely to be recognized. Here, we combined microbiology with non-target metabolomics to explore how P fertilizer levels and fertilization patterns affect wheat soil microbial communities and metabolic functions based on high-throughput sequencing and UPLC-MS/MS platforms. The results showed P fertilizer decreased the diversity of bacterial 16S rRNA genes and fungal ITS genes, and it did significantly change both soil bacterial and fungal overall community structures and compositions. The P levels and patterns also interfered with complexity of soil bacterial and fungal symbiosis networks. Moreover, metabolomics analysis showed that P fertilizer significantly changed soil metabolite spectrum, and the differential metabolites were significantly enriched to 7 main metabolic pathways, such as arginine and proline metabolism, biosynthesis of plant hormones, amino acids, plant secondary metabolites, and alkaloids derived from ornithine. Additionally, microbes also were closely related to the accumulation of metabolites through correlation analysis. Our results indicated that localized appropriate phosphorus fertilizer plays an important role in regulating soil microbial metabolism, and their interactions in soil providing valuable information for understanding how the changed phosphorus management practices affect the complex biological processes and the adaption capacity of plants to environments.

Seasonal Variations in Alpha-Diversity and Composition of Soil Fungal Communities in Subalpine Coniferous and Broadleaved Forests

Seasonal Variations in Alpha-Diversity and Composition of Soil Fungal Communities in Subalpine Coniferous and Broadleaved Forests

喀斯特森林常见树种倒木分解对土壤真菌群落组成及分布规律的影响

PDF HTML阅读 XML下载 导出引用 引用提醒 喀斯特森林常见树种倒木分解对土壤真菌群落组成及分布规律的影响 DOI: 10.5846/stxb202101280295 作者: 作者单位: 作者简介: 通讯作者: 中图分类号: 基金项目: 国家自然科学基金项目（32060266，31700385）；贵州省科技计划项目（黔科合基础[2020]1Y124）；贵州省一流学科建设项目（GNYL[2017]007） Effects of fallen woods decomposition of common tree species on soil fungal community composition and distribution in karst forest Author: Affiliation: Fund Project: 摘要 | 图/表 | 访问统计 | 参考文献 | 相似文献 | 引证文献 | 资源附件 | 文章评论 摘要:倒木是森林生态系统的重要组分，其分解调控着土壤的养分循环，同时也影响着土壤微生物群落结构。但目前鲜见关于倒木分解对土壤微生物群落影响方面的报道。选取贵州茂兰喀斯特常绿落叶阔叶混交林中处于轻、中和重度腐烂等级的狭叶润楠（Machilus rehderi）、枫香（Liquidambar formosana）、青冈栎（Cyclobalanopsis glauca）和圆果化香（Platycarya longipes）4种常见树种倒木为研究对象，以距倒木外围的3个不同水平距离（10cm、30cm和50cm）的土壤样品为实验材料，分析倒木树种、腐烂等级和距离对土壤真菌种类及多样性的影响。结果表明：1）喀斯特森林4种树种倒木所影响土壤真菌群落在门级分类上主要为子囊菌门、担子菌门和毛霉门，优势属有Mortierella spp.、Phlebia spp.、Pluteus spp.和Chaetomium spp.等；2）倒木的树种对土壤真菌群落相对丰度的影响有差异，圆果化香倒木下的土壤真菌丰富度Chao1指数显著高于青冈栎；3）随腐烂程度加深，4种树种倒木下的土壤真菌群落多样性呈显著增加趋势；4）土壤真菌群落丰度随着距倒木距离的增大（10-50cm）变化明显，如狭叶润楠影响的Pluteus spp.、Mortierella spp.和Ganoderma spp.，枫香的Chaetomium spp.，圆果化香的Mortierella spp.和青冈栎的Phlebia spp.和Oliveonia spp.等。本研究量化了喀斯特森林倒木所影响的土壤真菌群落组成及分布规律，在一定程度上为倒木分解与土壤微生物群落之间的作用机制的深入探索提供了科学依据。 Abstract:Fallen wood is an important component of the forest ecosystem, which plays an important role in ecological conservation, biodiversity maintenance, and forest renewal. Its decomposition regulates the nutrient cycle of the soil and often changed to changes in microbial community structure of the soil. Therefore, quantify the influence of the fallen wood on soil fungus community and distribution is very significance. However, there are few reports about the effects of decomposition of fallen wood on soil microbial community, especially in Maolan kast evergreen broad-leaved deciduous mixed forest, a rare remaining subtropical karst forest with strong original in China and even the world. In this paper, the fallen woods of four common tree species (Machilus rehderi, Liquidambar formosana, Cyclobalanopsis glauca, and Platycarya longipes) that are in mildly, moderately and severely deciduous decay levels in Maolan's evergreen and deciduous broad-leaved mixed forest in Guizhou are selected as the research object. Three different horizontal distances (10 cm, 30 cm, and 50 cm) from the outer edge of the fallen wood were used to analyze the effects of tree species, decay grade and distance on the types and abundance of soil fungi community. The results show that:1) the soil fungi affected by the fallen woods of the four tree species in the karst forest are mainly Ascomycota, Basidiomycota and Mucor in the phylum classification, and the dominant genera are Mortierella spp., Phlebia spp., Pluteus spp. and Chaetomium spp., etc; 2) Different tree species of fallen woods have different effects on the relative abundance of soil fungi communities. The soil fungi richness Chao1 index under the fallen wood of the Platycarya longipes is significantly higher than that of Cyclobalanopsis glauca; 3) With the deepening of decay, the soil fungal community diversity under the fallen wood of the four tree species showed a significant increasing trend; 4) The abundance of soil fungal communities changes significantly with the increase of the distance from the fallen wood (10- 50 cm), such as Pluteus spp., Mortierella spp. and Ganoderma spp. are affected by Machilus rehderi, Chaetomium spp. of Liquidambar formosana, Mortierella spp. of Platycarya longipes, Phlebia spp. and Oliveonia spp. of Cyclobalanopsis glauca, etc. This study quantified the soil fungal communities composition and distribution patterns affected by fallen woods in karst forests, and provided a scientific basis for further exploration of the mechanism of interaction between soil microbial communities and fallen wood decomposition to some extent. 参考文献 相似文献 引证文献

Composition of Soil Bacterial and Fungal Communities and Their Functions Along a Soil Depth Gradient in a Natural Picea Crassifolia Forest

Composition of Soil Bacterial and Fungal Communities and Their Functions Along a Soil Depth Gradient in a Natural Picea Crassifolia Forest

柏木人工林林窗位置对香椿细根分解及土壤真菌群落多样性的影响

PDF HTML阅读 XML下载 导出引用 引用提醒 柏木人工林林窗位置对香椿细根分解及土壤真菌群落多样性的影响 DOI: 10.5846/stxb202101210225 作者: 作者单位: 作者简介: 通讯作者: 中图分类号: 基金项目: 国家重点研发计划项目（2017YFD0600302-05）；国家自然科学基金项目（32071747）；绵阳师范学院生态安全与保护四川省重点实验室开放基金项目（ESP-2104）；绵阳师范学院高层次人才科研启动项目（QD2020A17） Effects of gap locations on the decomposition of fine root of Toona sinensis and soil fungal community diversity in cypress plantation forest Author: Affiliation: Fund Project: The Key Program of the Chinese Academy of Sciences 摘要 | 图/表 | 访问统计 | 参考文献 | 相似文献 | 引证文献 | 资源附件 | 文章评论 摘要:为了解林窗位置对香椿细根分解及土壤真菌群落多样性的影响，以川中丘陵区30a生柏木人工林为研究对象，采用Illumina Miseq高通量测序技术研究200 m2人工林窗中心位置（GC）、边缘位置（GB）、郁闭林（CC）对香椿细根2a自然分解后土壤真菌群落结构及多样性的影响。结果表明，林窗内不同位置之间微环境差异显著（P<0.05），土壤理化性质对林窗位置变化的响应较细根养分元素更积极，GB位置细根分解速率显著高于GC和CC。土壤真菌门水平在3个林窗位置间无显著差异，其中子囊菌门、担子菌门是优势类群；腐生营养型真菌在3个林窗位置上具有显著差异，散囊菌目、粪壳菌目、肉座菌目、刺盾炱目、伞菌目是3个位置上相对丰度值>1%的优势类群，刺盾炱目、伞菌目相对丰度在GB和CC之间有显著差异（P<0.05）；青霉属和曲霉属是真菌在属水平上的优势类群，其相对丰度在3个位置间有极显著差异（P<0.01）。林窗位置未对真菌群落α多样性产生显著影响，但群落β多样性对位置变化的响应显著。GB位置群落β多样性显著高于GC和CC （P<0.05），共有种数量最多，GC位置特有种数量最多。冗余分析发现较多环境因子对真菌群落的影响显著（P<0.01），Mantel test （和partial Mantel test）分析结果表明土壤pH值、土壤含水量、土壤温度、土壤速效磷、土壤全氮是真菌群落多样性的重要影响因子。综上所述，林窗内位置对土壤真菌类群构成和群落β多样性具有差异性影响，在柏木人工林内实施林窗式干扰有助于调节细根分解等地下生态进程。 Abstract:The effect of gap location heterogeneity on decomposition of plant fine roots and soil fungal community diversity was investigated in a forest with Cupressus funebris plantation for 30 years, in the hilly region in central Sichuan Province. In an area with gap size 200 m2, the structure and diversity of soil fungal community associated with 2a natural decomposition of fine root of Toona sinensis were investigated separately on three different locations:gap center (GC), gap boarder (GB) and closed canopy (CC), by using Illumina MiSeq high-throughput sequencing technology. The results showed that there were significant differences in microenvironment across different gap locations (P<0.05). The response of soil physical and chemical properties to the gap position was more sensitive than that of fine root nutrient elements, and the decomposition rate of fine roots at GB position was significantly higher than that of GC and CC. There was no significant difference in soil fungal community at phylum level. Ascomycetes and Basidiomycetes were dominant groups across different gap locations. Base on FUNGuild results, the trophic modes of saprotrophs showed significant differences across different gap locations, the classes of Eurotiales, Hypocreales, Sordariales, Chaetothyriales and Agaricales were dominant with the relative abundances>1% across the three locations. The relative abundances of Agaricales and Chaetothyriales were significantly different between GB and CC (P<0.05). The genera of Penicillium, Aspergillus, Chaetomium and Staphylotrichum were the dominant taxa, and there were significant differences in their relative abundances across the three locations (P<0.01). The α diversities of the fungal communities were not significantly affected by the gap locations, but their β diversities were more responsive to different gap locations. The β diversity at GB was significantly higher than those at GC and CC (P<0.05), with the largest number of shared species at GB and the largest number of endemic species at GC site. Redundancy analysis revealed significant effects of the environmental factors on the fungal community (P<0.01). Partial Mantel test showed that the factors such as pH, water content (SWC), temperature (ST), available P (SNP) and total N (STN) in soil were important factors influencing fungal community diversity. In conclusion, forest gap locations significantly affected the composition and diversity of soil fungal community. The findings were helpful to regulate the underground ecological processes such as fine root decomposition in cypress plantation forests. 参考文献 相似文献 引证文献

湘西石漠化区3种造林模式土壤真菌群落结构差异

PDF HTML阅读 XML下载 导出引用 引用提醒 湘西石漠化区3种造林模式土壤真菌群落结构差异 DOI: 10.5846/stxb202008072061 作者: 作者单位: 作者简介: 通讯作者: 中图分类号: 基金项目: 中央级科研院所基本科研业务费重点项目（CAFYBB2019SZ003）；中南林业科技大学研究生科技创新基金（CX20192026） Differences of soil fungal community structure under three afforestation modes in rocky desertification region of Western Hunan Province Author: Affiliation: Fund Project: “Degradation mechanism and restoration technology of typical forests in South China 摘要 | 图/表 | 访问统计 | 参考文献 | 相似文献 | 引证文献 | 资源附件 | 文章评论 摘要:湘西石漠化地区是我国生态系统脆弱而又敏感的区域，土壤微生物在维持石漠化区森林生态系统结构和功能稳定中发挥重要作用。选取石漠化地区立地条件相同的32年生的马尾松纯林、光皮桦纯林及马尾松-光皮桦混交林为研究对象，以立地条件相似的未造林荒地演变成的灌草群落作为对照，比较分析石漠化地区不同造林模式对土壤真菌群落结构和多样性的影响及其主要驱动因素。采用Illumina HiSeq第二代高通量测序技术，分析了3种森林土壤真菌群落组成及多样性。结果表明，不同造林模式下土壤真菌优势类群不同，光皮桦、马尾松-光皮桦混交林以及石漠化灌草地土壤真菌优势门均为子囊菌门（Ascomycota），且在石漠化灌草地相对丰度最大，为64.0%；马尾松则以担子菌门（Basidiomycota）为优势类群，其相对丰度占57.9%。混交林土壤真菌物种总数和Shannon指数显著高于马尾松和光皮桦林地，整体上真菌群落多样性表现为：未造林灌草地 > 混交林 > 马尾松林 > 光皮桦林。与未造林灌草地相比，马尾松-光皮桦混交林和光皮桦纯林显著提升了土壤有机碳（SOC）和全氮（TN）含量。Mantel test检验结果显示，真菌群落结构与全磷（TP）、有机碳（SOC）、铵态氮（NH4+-N）、硝态氮（NO3--N）、全氮（TN）、pH和含水量（SWC）具有显著相关性（P<0.05），其中土壤SOC、TN、pH值对真菌群落结构影响最大。冗余分析（RDA）结果发现，子囊菌（Ascomycota）与pH、TP、SOC、TN、AP、NO3--N含量均呈正相关；担子菌门（Basidiomycota）和被孢霉门（Mortierellomycota）主要与NH4+-N成正相关，与pH、TP、SOC、TN、AP、NO3--N呈负相，而罗氏菌门（Rozellomycota）与SWC呈正相关（P<0.05）。综上，相比针叶纯林，石漠化地区针阔混交林能通过增加土壤SOC、TN而显著提高真菌群落多样性，促进土壤肥力状况的提升。此研究结果可以为石漠化区人工植被恢复以及土壤肥力管理提供依据。 Abstract:Rocky desertification area in Western Hunan province is a fragile and sensitive area of ecosystem in China. Soil microorganisms play an important role in maintaining the stability of forest ecosystem structure and function in rocky desertification area. Thirty two year-old pure Pinus massoniana forest, pure Betula luminifera forest and mixed Pinus massoniana and Betula luminifera forest in rocky desertification area with the same site conditions were selected as the research objects. The non-forested shrub grassland with the similar site conditions was taken as the control to compare and analyze the influence of different afforestation modes on soil fungal community structure and diversity and their main driving factors. The composition and diversity of soil fungal communities in three forests were analyzed by Illumina HiSeq second-generation high-throughput sequencing technology. The results showed that the dominant groups of soil fungi were different under different afforestation modes. The dominant phylum of soil fungi in Betula luminifera, mixed forest and non-forested shrub grassland were Ascomycota, and the relative abundance was the largest in non-forested shrub grassland, which was 64.0%. Basidiomycota was the dominant group in Pinus massoniana, its relative abundance accounted for 57.9%. The total number of soil fungal species and Shannon index of mixed forest were significantly higher than those of Pinus massoniana and Betula luminifera forest. On the whole, the diversity of fungal community was as follows:non-forested shrub grassland > mixed forest > Pinus massoniana forest > Betula luminifera forest. The contents of soil organic carbon (SOC) and total nitrogen (TN) in the mixed forest and Betula luminifera pure forest were significantly higher than those in non-forested shrub grassland. Mantel test showed that fungal community structure was significantly correlated with total phosphorus (TP), SOC, ammonium nitrogen (NH4+-N), nitrate nitrogen (NO3--N), TN, pH and water content (SWC) (P<0.05). Soil SOC, TN and pH had the greatest impact on fungal community structure. Redundancy analysis (RDA) showed Ascomycetes were positively correlated with pH, TP, SOC, TN, AP and NO3--N content; Basidiomycetes and Mortierella were mainly positively correlated with NH4+-N, and negatively correlated with pH, TP, SOC, TN, AP and NO3--N. There was a positive correlation between Rozellomycota and SWC. In conclusion, compared with pure coniferous forest, coniferous and broad-leaved mixed forest in rocky desertification area can significantly improve the diversity of fungal community by increasing soil SOC and TN, and promote the improvement of soil fertility. The results can provide basis for artificial vegetation restoration and soil fertility management in rocky desertification area. 参考文献 相似文献 引证文献

Differences in Green Cover Management Affect Soil Nutrients, Aggregates, and Fungal Community Composition in a Vineyard in North China

Differences in Green Cover Management Affect Soil Nutrients, Aggregates, and Fungal Community Composition in a Vineyard in North China

Short-Term Effects of Cover Grass on Soil Microbial Communities in an Apple Orchard on the Loess Plateau

Grass cover may improve soil environmental conditions in apple orchards. However, the mechanisms for how the soil microbial community changes after cover grass treatments are not well understood. In this study, we analyzed soil properties, microbial community diversity and composition in an apple orchard after being covered with native wild grasses for 3 years on the Loess Plateau, China. The ratios of cover grass were 0% (no cover, NC), 20% (low-intensity cover, LIC), 40% (moderate-intensity cover, MIC1), 60% (moderate-intensity cover, MIC2) and 80% (high-intensity cover, HIC). Meanwhile, the relationships between soil nutrients, cover grass properties, and microbial communities was analyzed by redundancy analysis and Pearson correlations. The results showed that cover grass altered the bacterial community composition, and significant changes at the phylum level were mainly caused by Proteobacteria, Bacteroidetes and Chloroflexi. Compared with NC, the abundance of Proteobacteria was lower in LIC, and the abundance of Bacteroidetes was lower in LIC, MIC1 and MIC2, while that of Chloroflexi was higher in LIC. LIC and MIC1 were the only cover grass intensities that altered the soil fungal community composition; there were no significant differences at the phylum level. The changes in the soil microbial community at the given phyla may be related to the change in soil available nitrogen content caused by cover grass. Here, we demonstrate that cover grass changed the soil microbial community, and the changes may be attributed to the given phyla in the bacterial community; soil copiotrophic groups (e.g., Proteobacteria and Bacteroidetes) were found to be at lower abundance in the low-intensity cover grass.

The influence of aboveground and belowground species composition on spatial turnover in nutrient pools in alpine grasslands

AbstractAimAn important research question in ecology is how climate and the biodiversity of aboveground plants and belowground microbiomes affect ecosystem functions such as nutrient pools. However, little is studied on the concurrent role of above‐ and belowground species composition in shaping the spatial distribution patterns of ecosystem functions across environmental gradients. Here, we investigated the relationships between the taxonomic composition of plants, soil bacteria and soil fungi and spatial turnover in nutrient pools, and assessed how species composition–nutrient pool relationships were mediated by contemporary climatic conditions.LocationQinghai‐Tibetan Plateau.Time periodCurrent.Major taxa studiedPlants, soil bacteria and soil fungi.MethodsWe surveyed plant assemblages, sampled the taxonomic composition of soil bacteria and soil fungi, and measured plant‐ and soil‐mediated nutrient pools at 60 alpine grasslands on the Qinghai‐Tibetan Plateau. Using Mantel tests, structural equation models and general linear models, we investigated the relative importance of the taxonomic composition of plant, soil bacterial, and soil fungal communities on the spatial turnover of alpine grassland nutrient pools.ResultsWe found that the taxonomic composition of plant, soil bacterial, and soil fungal communities was associated with local climate. However, the effects of local climate on the spatial turnover of plant‐ and soil‐mediated nutrient pools were mainly indirect and mediated through plant and soil bacterial species composition, but not through soil fungal species composition. We further found that the replacement component of soil bacterial β‐diversity and the richness difference of plant β‐diversity were the direct predictors of nutrient pools in the alpine grasslands.Main conclusionsThese results highlight that belowground bacterial composition together with aboveground plant species composition are related to spatial turnover in nutrient pools, perhaps even driving it. Conserving above‐ and belowground biodiversity may therefore safeguard against the impacts of local climate on the functions of climate‐sensitive alpine grasslands.

Quantifying the immediate response of the soil microbial community to different grazing intensities on irrigated pastures

Grazing is known to affect soil microbial communities, nutrient cycling, and forage quantity and quality over time. However, a paucity of information exists for the immediate changes in the soil physicochemical and microbial environment in response to different grazing strategies. Soil microbes drive nutrient cycling and are involved in plant-soil-microbe relationships, making them potentially vulnerable to plant-driven changes in the soil environment caused by grazing. To test the hypothesis that variable grazing intensities modulate immediate effects on the soil microbial community, we conducted a grazing trial of three management approaches; high-intensity, short-duration grazing (HDG), low-intensity, medium-duration grazing (LDG), and no grazing (NG). Soil and vegetation samples were collected before grazing and 24h, 1 week, and 4 weeks after HDG grazing ended. Soil labile carbon (C) and nitrogen (N) pools, vegetation biomass, and soil microbial diversity and functional traits were determined, including extracellular enzymatic assays and high-throughput sequencing of the bacterial 16S rRNA and fungal ITS2 regions. We found that labile soil C and inorganic N increased following LDG grazing while C-cycling extracellular enzymatic activities increased in response to HDG grazing but both total extracellular enzymatic activity profiles and soil abiotic profiles were mostly affected by temporal fluxes. The soil fungal community composition was strongly affected by the interaction of sampling time and grazing treatment, while the soil bacterial community composition was largely affected by sampling time with a lesser impact from grazing treatment. We identified several key fungal taxa that may influence immediate responses to grazing and modulate plant-soil-microbe interactions. There was strong evidence of temporal influences on soil biogeochemical variables and the soil microbiome, even within our narrow sampling scheme. Our results indicate that the soil ecosystem is dynamic and responsive to different grazing strategies within very short time scales, showing the need for further research to understand plant-soil-microbe interactions and how these feedback mechanisms can inform sustainable land management.

Fungal community and functional responses to soil warming are greater than for soil nitrogen enrichment

Soil fungi are key regulators of forest carbon cycling and their responses to global change have effects that ripple throughout ecosystems. Global changes are expected to push many fungi beyond their environmental niches, but there are relatively few studies involving multiple, simultaneous global change factors. Here, we studied soil fungal diversity, community composition, co-occurrence patterns, and decomposition gene responses to 10 years of soil warming and nitrogen addition, alone and in combination. We specifically examined whether there were fungal community characteristics that could explain changes in soil carbon storage and organic matter chemistry in chronically warmed and fertilized soil. We found that fungal communities in warmed soils are less diverse and shift in composition. Warming also favored hyperdominance by a few mycorrhizal fungal species and lowered manganese peroxidase but increased hydrolytic enzyme encoding gene potentials. Nitrogen addition did not significantly affect fungal community composition but, like warming, did reduce fungal diversity and favored overdominance by a unique set of mycorrhizal taxa. Warming alone and in combination with nitrogen addition also reduced negative but increased positive fungal co-occurrence probabilities, promoting species coexistence. Negative fungal co-occurrence was positively correlated to soil carbon content, while the proportion of fungal hydrolytic enzyme encoding genes was negatively correlated with soil carbon content. This may reflect fungal life history trade-offs between competition (e.g., reduced negative co-occurrence) and resource acquisition (e.g., higher abundance of hydrolytic enzyme encoding genes) with implications for carbon storage.

Green manure incorporation accelerates enzyme activity, plant growth, and changes in the fungal community of soil.

Green manure can sustain agricultural production, preserve biodiversity, and mitigate soil degradation caused by long-term application of chemical fertilizers. Moreover, the application of green manure can improve soil health through increased soil biological activities. Nevertheless, little attention has been paid to the effects of leguminous and non-leguminous plants on phosphorus- and carbon-related enzyme activities and fungal community composition in soil. In this study, a pot experiment was carried out to elucidate the effects of two green manures on plant growth promoting potential, phosphorus- and carbon-related enzyme activities, and soil fungal community composition. Two green manure treatments (Brassica juncea and hairy vetch), poultry compost and control (no amendment) were applied and soil samples were collected after incorporation of green manure and after plant harvest. The results revealed that plant growth with hairy vetch was significantly higher than that with B. juncea and poultry compost, and soil enzyme activities were markedly higher with hairy vetch than with B. juncea. Both green manure amendments altered the soil fungal community composition. It is possible that the incorporation of green manure into soil and their mineralization and decomposition were controlled by the carbon: nitrogen ratio of the manures and that these manures were easily degradable by soil fungi. In particular, the incorporation of leguminous (hairy vetch) green manure with a low carbon: nitrogen ratio resulted in better plant growth through fast mineralization. Our findings suggest that green manure incorporation is an effective practice and provides substantial benefits to the soil-plant system.

Sensitivity of soil fungal and bacterial community compositions to nitrogen and phosphorus additions in a temperate meadow

Sensitivity of soil fungal and bacterial community compositions to nitrogen and phosphorus additions in a temperate meadow

Soil bacterial and fungal communities are linked with plant functional types and soil properties under different grazing intensities

AbstractAs a grassland management strategy in the typical steppe, livestock grazing can affect soil microbes and ecosystem functions via vegetation removal, trampling and manure deposition. However, the effects of grazing and its main consequences (e.g. the shifts in plant functional types and alterations in soil properties) on soil bacterial and fungal community composition remain unresolved. Taking advantage of a 5‐year grazing exclosure experiment that tested different grazing intensities [control: no grazing (G0); light: 0.75 sheep ha−1 (G1); moderate: 1.50 sheep ha−1 (G2); heavy: 2.25 sheep ha−1 (G3); and overgrazing: 3.00 sheep ha−1 (G4)], we examined grazing‐related changes in plant communities, soil chemistry and soil microbial communities. Grazing intensity affected the diversity and composition of soil bacterial and fungal communities via changes in plant species and soil nutrient contents. Increased grazing intensity reduced soil organic carbon (OC), suppressed the dominant bacterial phyla Proteobacteria and Bacteriodetes, and increased the abundance of oligotrophic bacteria in subordinate phyla (e.g. Verrucomicroba and Chloroflexi). Increased grazing intensity also promoted the dominant fungal phylum Ascomycetes because of the poor‐nutrient soil environment. The decreased soil carbon‐to‐nitrogen (C/N) ratio in the G2 treatment was associated with an effect on the fungal community composition. Structural equation modelling demonstrated that responses of the bacterial community to grazing intensity were related to changes in soil OC and soil pH, whereas the combination of C4 plant community biomass and soil pH drove changes in the fungal community. Our study provides novel evidence that grazing affects plant functional group and soil chemistry through the soil pH and C/N ratio, which in turn affects bacterial and fungal communities.Highlights Heavy and overgrazing suppressed bacterial phylum Proteobacteria and increased fungal phylum Ascomycete. Soil OC was the predominant driver of changes in bacterial richness and community composition. C4 plant community biomass modulated fungal richness and community composition.

Contrasting Patterns and Drivers of Soil Fungal Communities between Two Ecosystems Divided by the Treeline.

The treeline is a sensitive region of the terrestrial ecosystem responding to climate change. However, studies on the composition and formation mechanisms of soil fungal communities across the treeline are still lacking. In this study, we investigated the patterns of soil fungal community composition and interactions among functional guilds above and below the treeline using Illumina high-throughput sequencing and ecological network analysis. The results showed that there were significant differences in the soil environment and soil fungal community composition between the two ecosystems above and below the treeline. At the local scale of this study, geographic distance and environmental factors affected the composition of the soil fungal community. Soil temperature was an important environmental predictor of soil fungal community composition. Species in soil fungal communities in the subalpine meadow were more closely related to each other compared to those in the montane forest. Furthermore, the soil fungal community in montane forest was more stable. Our findings contribute to a better understanding of how mountain ecological functions respond to global climate change.