Pub Date : 2024-11-30DOI: 10.1016/j.ejsobi.2024.103696
Jinpeng Ma , Lin Chen , Danbo Pang , Yinglong Chen , Mengyao Wu , Yaqi Zhang , Wenqiang He , Xuebin Li
Soil microorganisms are essential in maintaining terrestrial ecosystem function and are central drivers of soil-plant nutrient cycling. However, relatively few studies have explored the impact of precipitation and nitrogen (N) addition on soil microbial community structure beneath litter. In this study, we conducted a field simulation control experiment on litter decomposition under varying precipitation regimes (normal, increased by 30 %, and decreased by 30 %) and N addition levels (0 and 10 g m−2 y−1) in the desert steppe of Yanchi County, China. Our findings revealed that changes in precipitation and N addition promoted litter decomposition and caused the accumulation of soil nutrients. Specifically, N addition significantly increased nitrate nitrogen (51.95 %), ammonium nitrogen (42.92 %), soil organic carbon (6.81 %), and total phosphorus (7.82 %)(P<0.05), decreased precipitation significantly elevated contents of nitrate nitrogen (26.80 %), total nitrogen (24.47 %), soil organic carbon (37.62 %), total phosphorus (22.78 %), and microbial biomass C (33.20 %) (P<0.05). N addition decreased microbial biomarkers content by 1.13 %, but increased microbial diversity indices (Shannon-Wiener index (1.53 %), Brillouin diversity index (0.54 %), Pielou evenness index (1.12 %), Simpson dominance index (0.91 %), Mcintosh diversity index (1.11 %)) (P<0.05). Meanwhile, decreased precipitation significantly enhanced microbial biomarkers content by 5.83 % and diversity indices (Shannon-Wiener index (3.67 %), Brillouin diversity index (2.16 %), Pielou evenness index (1.55 %), Simpson dominance index (1.82 %), Mcintosh diversity index (2.63 %)) (P<0.05). We indicated the decreased precipitation enhanced the effect of N addition on microbial community and diversity, while increased precipitation showed the opposite trend. Redundancy analysis highlighted MBC as a critical factor influencing microbial community structure, accounting for 35.3 % of the variation (P<0.01). This study provides valuable insights into managing and conserving desert steppe ecosystems.
土壤微生物对维持陆地生态系统功能至关重要,是土壤-植物养分循环的核心驱动力。然而,关于降水和氮添加对凋落物下土壤微生物群落结构影响的研究相对较少。在盐池县荒漠草原进行了不同降水(正常、增加30%和减少30%)和N添加水平(0和10 g m−2 y−1)下凋落物分解的野外模拟对照试验。结果表明,降水和施氮量的变化促进了凋落物的分解,引起了土壤养分的积累。其中,氮添加显著提高了硝态氮(51.95%)、铵态氮(42.92%)、土壤有机碳(6.81%)和全磷(7.82%)含量(P<0.05);降水减少显著提高了硝态氮(26.80%)、全氮(24.47%)、土壤有机碳(37.62%)、全磷(22.78%)和微生物生物量C(33.20%)含量(P<0.05)。添加氮使微生物生物标志物含量降低了1.13%,而微生物多样性指数(Shannon-Wiener指数(1.53%)、Brillouin多样性指数(0.54%)、Pielou均匀度指数(1.12%)、Simpson优势度指数(0.91%)、Mcintosh多样性指数(1.11%))升高(P<0.05)。同时,降水减少使微生物生物标志物含量和多样性指数(Shannon-Wiener指数(3.67%)、Brillouin多样性指数(2.16%)、Pielou均匀度指数(1.55%)、Simpson优势度指数(1.82%)、Mcintosh多样性指数(2.63%))显著提高了5.83% (P<0.05)。结果表明,降水减少增强了氮添加对微生物群落和多样性的影响,而降水增加则相反。冗余分析显示MBC是影响微生物群落结构的关键因素,占变异量的35.3% (P<0.01)。该研究为管理和保护荒漠草原生态系统提供了有价值的见解。
{"title":"Responses of soil microbial community structure under litter to changes in precipitation and nitrogen addition in a desert steppe","authors":"Jinpeng Ma , Lin Chen , Danbo Pang , Yinglong Chen , Mengyao Wu , Yaqi Zhang , Wenqiang He , Xuebin Li","doi":"10.1016/j.ejsobi.2024.103696","DOIUrl":"10.1016/j.ejsobi.2024.103696","url":null,"abstract":"<div><div>Soil microorganisms are essential in maintaining terrestrial ecosystem function and are central drivers of soil-plant nutrient cycling. However, relatively few studies have explored the impact of precipitation and nitrogen (N) addition on soil microbial community structure beneath litter. In this study, we conducted a field simulation control experiment on litter decomposition under varying precipitation regimes (normal, increased by 30 %, and decreased by 30 %) and N addition levels (0 and 10 g m<sup>−2</sup> y<sup>−1</sup>) in the desert steppe of Yanchi County, China. Our findings revealed that changes in precipitation and N addition promoted litter decomposition and caused the accumulation of soil nutrients. Specifically, N addition significantly increased nitrate nitrogen (51.95 %), ammonium nitrogen (42.92 %), soil organic carbon (6.81 %), and total phosphorus (7.82 %)(<em>P</em><0.05), decreased precipitation significantly elevated contents of nitrate nitrogen (26.80 %), total nitrogen (24.47 %), soil organic carbon (37.62 %), total phosphorus (22.78 %), and microbial biomass C (33.20 %) (<em>P</em><0.05). N addition decreased microbial biomarkers content by 1.13 %, but increased microbial diversity indices (<em>Shannon-Wiener</em> index (1.53 %)<em>, Brillouin</em> diversity index (0.54 %)<em>, Pielou</em> evenness index (1.12 %)<em>, Simpson</em> dominance index (0.91 %)<em>, Mcintosh</em> diversity index (1.11 %)) (<em>P</em><0.05). Meanwhile, decreased precipitation significantly enhanced microbial biomarkers content by 5.83 % and diversity indices (<em>Shannon-Wiener</em> index (3.67 %)<em>, Brillouin</em> diversity index (2.16 %)<em>, Pielou</em> evenness index (1.55 %)<em>, Simpson</em> dominance index (1.82 %)<em>, Mcintosh</em> diversity index (2.63 %)) (<em>P</em><0.05). We indicated the decreased precipitation enhanced the effect of N addition on microbial community and diversity, while increased precipitation showed the opposite trend. Redundancy analysis highlighted MBC as a critical factor influencing microbial community structure, accounting for 35.3 % of the variation (<em>P</em><0.01). This study provides valuable insights into managing and conserving desert steppe ecosystems.</div></div>","PeriodicalId":12057,"journal":{"name":"European Journal of Soil Biology","volume":"124 ","pages":"Article 103696"},"PeriodicalIF":3.7,"publicationDate":"2024-11-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142756786","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-23DOI: 10.1016/j.ejsobi.2024.103693
Yongliang Mo , Jiwei Li , Xiaotong Peng , Adrian Ho , Zhongjun Jia
Microbial methane oxidation under widespread suboxic environment is crucial for understanding methane emission. However, the role of aerobic methanotrophs in mediating methane oxidation and nitrogen fixation is less understood in oxygen-limiting environments. In this study, we identified diazotrophic methanotrophs under oxygen-limited conditions (initial O2 of 6–8 μM) in two contrasting habitats (paddy soil and marine sediment) using DNA-based stable isotope probing combined with amplicon sequencing. Consistently, we documented significant 13CH4 oxidation and 15N2 fixation after 740 days of suboxic isotope labeling. Sequencing analysis revealed the predominance of Methylobacter–affiliated aerobic methanotrophs in the 13C-labeled DNA fractions. These Methylobacter-like OTUs accounted for 97.86 % in paddy soil and 99.49 % in marine sediment of the total pmoA gene sequences; while relative abundances for the nifH gene sequences were 91.59 % in paddy soil and 99.49 % in marine sediment. Taken together, our analyses revealed that Methylobacter is responsible for methane oxidation and nitrogen fixation under oxygen limitation in both habitats, demonstrating convergent emergence of this aerobic methanotroph under oxygen deficiency.
广泛亚氧环境下的微生物甲烷氧化作用对于了解甲烷排放至关重要。然而,人们对限氧环境中好氧甲烷营养体在介导甲烷氧化和固氮作用方面的作用了解较少。在本研究中,我们利用基于 DNA 的稳定同位素探针结合扩增子测序,在两种截然不同的生境(水稻土壤和海洋沉积物)中鉴定了限氧条件(初始氧气为 6-8 μM)下的重氮甲烷营养体。一致的是,经过 740 天的亚缺氧同位素标记,我们记录了 13CH4 的显著氧化和 15N2 的固定。测序分析表明,在 13C 标记的 DNA 片段中,主要是与 Methylobacter 相关的需氧甲烷营养体。在水稻田土壤和海洋沉积物的 pmoA 基因总序列中,这些类似甲基杆菌的 OTU 分别占 97.86% 和 99.49%;而在水稻田土壤和海洋沉积物中,nifH 基因序列的相对丰度分别为 91.59% 和 99.49%。总之,我们的分析表明,在缺氧条件下,甲基细菌在两种生境中都负责甲烷氧化和固氮作用,这表明在缺氧条件下这种好氧甲烷营养体的出现是趋同的。
{"title":"Coupling methane oxidation and N2 fixation under methanogenic conditions in contrasting environments","authors":"Yongliang Mo , Jiwei Li , Xiaotong Peng , Adrian Ho , Zhongjun Jia","doi":"10.1016/j.ejsobi.2024.103693","DOIUrl":"10.1016/j.ejsobi.2024.103693","url":null,"abstract":"<div><div>Microbial methane oxidation under widespread suboxic environment is crucial for understanding methane emission. However, the role of aerobic methanotrophs in mediating methane oxidation and nitrogen fixation is less understood in oxygen-limiting environments. In this study, we identified diazotrophic methanotrophs under oxygen-limited conditions (initial O<sub>2</sub> of 6–8 μM) in two contrasting habitats (paddy soil and marine sediment) using DNA-based stable isotope probing combined with amplicon sequencing. Consistently, we documented significant <sup>13</sup>CH<sub>4</sub> oxidation and <sup>15</sup>N<sub>2</sub> fixation after 740 days of suboxic isotope labeling. Sequencing analysis revealed the predominance of <em>Methylobacter</em>–affiliated aerobic methanotrophs in the <sup>13</sup>C-labeled DNA fractions. These <em>Methylobacter</em>-like OTUs accounted for 97.86 % in paddy soil and 99.49 % in marine sediment of the total <em>pmoA</em> gene sequences; while relative abundances for the <em>nifH</em> gene sequences were 91.59 % in paddy soil and 99.49 % in marine sediment. Taken together, our analyses revealed that <em>Methylobacter</em> is responsible for methane oxidation and nitrogen fixation under oxygen limitation in both habitats, demonstrating convergent emergence of this aerobic methanotroph under oxygen deficiency.</div></div>","PeriodicalId":12057,"journal":{"name":"European Journal of Soil Biology","volume":"123 ","pages":"Article 103693"},"PeriodicalIF":3.7,"publicationDate":"2024-11-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142705591","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-16DOI: 10.1016/j.ejsobi.2024.103695
Yuxuan Zhang , Mengya Lu , Zhiquan Wang , Kun Zhang , Bin Zhang , Reziwanguli Naimaiti , Shangyuan Wei , Xueli Ding
Straw return accelerates the decomposition of soil organic C (SOC), a phenomenon referred to as the priming effect. However, the interactive influence of nutrient supply levels on priming effect intensity and SOC sequestration in paddy soils still needs to be better understood. In this study, we investigated the dynamics of the priming effect and associated changes in phospholipid fatty acids, enzyme activity, and microbial necromass following the addition of 13C-labelled rice straw (98 % atom) to soils under three nutrient supply levels during a 300-d incubation period. Our results showed that the addition of straw (5 g C kg−1 soil) with no-nutrient (S + Nu0), low nutrient (S + Nulow, 42 mg N kg−1, 10 mg P kg−1), and high nutrient (S + Nuhigh, 126 mg N kg−1, 30 mg P kg−1) supply increased total CO2 production by 42.9 %, 59.0 %, and 97.3 %, respectively, compared to the control soil. After 300 d, the cumulative priming effect was nearly doubled in the S + Nulow and tripled in the S + Nuhigh compared to the S + Nu0. Moreover, the intensity of priming varied with the incubation stage under nutrient treatments. Similar patterns of priming effect were observed across all straw amendments during the early incubation stages; however, the priming effect increased with the nutrient supply levels in the later stages. These patterns are linked to microbial metabolic limitation and resource acquisition strategies, as evidenced by a lower C-to-N stoichiometry of extracellular enzymes and necromass in the S + Nulow S + Nuhigh. A greater proportion of straw-derived C incorporation into SOC (indicated by higher levels 13C-SOC) in nutrient-enriched was found, which largely offset the native SOC losses, resulting in high SOC content by the end of incubation. Our findings highlight the critical role of nutrient supply in regulating the priming effect and the balance of SOC after straw return in paddy soils.
秸秆还田可加速土壤有机碳(SOC)的分解,这种现象被称为引诱效应。然而,养分供应水平对稻田土壤引诱效应强度和 SOC 固碳的交互影响仍有待进一步了解。在本研究中,我们研究了在三种养分供应水平下的土壤中添加 13C 标记的稻草(原子含量为 98%)后,在 300 天的培养期内引诱效应的动态变化以及磷脂脂肪酸、酶活性和微生物坏死物质的相关变化。结果表明,与对照土壤相比,在无养分(S + Nu0)、低养分(S + Nulow,42 mg N kg-1,10 mg P kg-1)和高养分(S + Nuhigh,126 mg N kg-1,30 mg P kg-1)条件下添加稻草(5 g C kg-1 土壤)可使二氧化碳总产量分别增加 42.9%、59.0% 和 97.3%。300 d 后,与 S + Nu0 相比,S + Nulow 的累积引诱效果几乎翻了一番,S + Nuhigh 的累积引诱效果则翻了三番。此外,在营养处理下,引诱作用的强度随培养阶段的不同而变化。在早期培养阶段,所有秸秆改良剂都观察到了类似的引诱效应模式;然而,在后期阶段,引诱效应随着营养供应水平的提高而增加。这些模式与微生物的代谢限制和资源获取策略有关,S + Nulow S + Nuhigh 中细胞外酶和坏死物质的 C-N 比化学计量较低就是证明。在营养丰富的情况下,秸秆衍生的碳有更大比例掺入 SOC(13C-SOC 含量更高),这在很大程度上抵消了原生 SOC 的损失,导致培养结束时 SOC 含量较高。我们的研究结果突显了养分供应在调节稻田土壤秸秆还田后的引诱效应和 SOC 平衡中的关键作用。
{"title":"Nutrient supply enhances positive priming of soil organic C under straw amendment and accelerates the incorporation of straw-derived C into organic C pool in paddy soils","authors":"Yuxuan Zhang , Mengya Lu , Zhiquan Wang , Kun Zhang , Bin Zhang , Reziwanguli Naimaiti , Shangyuan Wei , Xueli Ding","doi":"10.1016/j.ejsobi.2024.103695","DOIUrl":"10.1016/j.ejsobi.2024.103695","url":null,"abstract":"<div><div>Straw return accelerates the decomposition of soil organic C (SOC), a phenomenon referred to as the priming effect. However, the interactive influence of nutrient supply levels on priming effect intensity and SOC sequestration in paddy soils still needs to be better understood. In this study, we investigated the dynamics of the priming effect and associated changes in phospholipid fatty acids, enzyme activity, and microbial necromass following the addition of <sup>13</sup>C-labelled rice straw (98 % atom) to soils under three nutrient supply levels during a 300-d incubation period. Our results showed that the addition of straw (5 g C kg<sup>−1</sup> soil) with no-nutrient (S + Nu<sub>0</sub>), low nutrient (S + Nu<sub>low</sub>, 42 mg N kg<sup>−1</sup>, 10 mg P kg<sup>−1</sup>), and high nutrient (S + Nu<sub>high</sub>, 126 mg N kg<sup>−1</sup>, 30 mg P kg<sup>−1</sup>) supply increased total CO<sub>2</sub> production by 42.9 %, 59.0 %, and 97.3 %, respectively, compared to the control soil. After 300 d, the cumulative priming effect was nearly doubled in the S + Nu<sub>low</sub> and tripled in the S + Nu<sub>high</sub> compared to the S + Nu<sub>0</sub>. Moreover, the intensity of priming varied with the incubation stage under nutrient treatments. Similar patterns of priming effect were observed across all straw amendments during the early incubation stages; however, the priming effect increased with the nutrient supply levels in the later stages. These patterns are linked to microbial metabolic limitation and resource acquisition strategies, as evidenced by a lower C-to-N stoichiometry of extracellular enzymes and necromass in the S + Nu<sub>low</sub> S + Nu<sub>high</sub>. A greater proportion of straw-derived C incorporation into SOC (indicated by higher levels <sup>13</sup>C-SOC) in nutrient-enriched was found, which largely offset the native SOC losses, resulting in high SOC content by the end of incubation. Our findings highlight the critical role of nutrient supply in regulating the priming effect and the balance of SOC after straw return in paddy soils.</div></div>","PeriodicalId":12057,"journal":{"name":"European Journal of Soil Biology","volume":"123 ","pages":"Article 103695"},"PeriodicalIF":3.7,"publicationDate":"2024-11-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142652449","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-16DOI: 10.1016/j.ejsobi.2024.103694
Hao Wang , JinPing Chen , Mingxue Du , Yihao Ruan , Jiameng Guo , Ruixin Shao , Yongchao Wang , Qinghua Yang
Carbohydrate-active enzymes (CAZymes) play a crucial role in plant-derived carbon utilization and decomposition and are influenced by the crop rotation system; however, our knowledge of how different agricultural systems impact CAZyme functionality is still limited. We conducted a metagenomic analysis to evaluate the functional genes of CAZymes in a 12-year in situ farmland with three commonly used crop rotation systems: wheat-maize rotation (WM), wheat-cotton rotation (WC), and wheat-soybean rotation (WS). We aimed to study the impact of long-term use of crop rotation, especially crop rotation involving soybean, on soil organic carbon (SOC) content and to gain an in-depth understanding of the CAZyme genes in context of the disparities in SOC. After 12 years, the SOC content was significantly higher in WS than in WC (5.44 %) and WM (17.6 %). Furthermore, the crop rotation system had a significant effect on the soil microbial communities and CAZyme function genes. Detailly, WS increased the phyla abundance of Proteobacteria, Actinobacteria, and Firmicutes and enriched the glycoside hydrolase (GH) and carbohydrate-binding modules (CBM) genes; WC increased the abundance of Acidobacteria and Bacteroidota and enriched the polysaccharide lyase gene; WM increased the abundance of Nitrospirae, Candidatus_Rokubacteria, Chloroflexi and Gemmatimonadetes and enriched the gene abundance of glycosyltransferases and auxiliary activity genes. Additionally, Acidobacteria, Proteobacteria, and Actinobacteria are key phyla involved in soil carbon cycling and collectively contribute >70 % of the total CAZyme functional genes, which highlights their importance. In addition, our results indicated that total nitrogen content played a major role in influencing genes related to CAZymes, especially those belonging to the GH family. Our study demonstrates that WS conferred the advantage of increasing SOC across the three crop rotation systems. CAZyme analysis revealed that WS's could potentially support the increased abundance of Proteobacteria, Actinobacteria and Firmicutes in the soil community, at the same time potentially leading to increased number of GH and CBM genes in the soil, which may bolster the decomposition and transformation of plant-derived carbon, thus promoting an increase in SOC content. The findings of this study offer new insights into the microbial factors contributing to SOC enhancement in rotation systems.
{"title":"In-depth insights into carbohydrate-active enzyme genes regarding the disparities in soil organic carbon after 12-year rotational cropping system field study","authors":"Hao Wang , JinPing Chen , Mingxue Du , Yihao Ruan , Jiameng Guo , Ruixin Shao , Yongchao Wang , Qinghua Yang","doi":"10.1016/j.ejsobi.2024.103694","DOIUrl":"10.1016/j.ejsobi.2024.103694","url":null,"abstract":"<div><div>Carbohydrate-active enzymes (CAZymes) play a crucial role in plant-derived carbon utilization and decomposition and are influenced by the crop rotation system; however, our knowledge of how different agricultural systems impact CAZyme functionality is still limited. We conducted a metagenomic analysis to evaluate the functional genes of CAZymes in a 12-year in situ farmland with three commonly used crop rotation systems: wheat-maize rotation (WM), wheat-cotton rotation (WC), and wheat-soybean rotation (WS). We aimed to study the impact of long-term use of crop rotation, especially crop rotation involving soybean, on soil organic carbon (SOC) content and to gain an in-depth understanding of the CAZyme genes in context of the disparities in SOC. After 12 years, the SOC content was significantly higher in WS than in WC (5.44 %) and WM (17.6 %). Furthermore, the crop rotation system had a significant effect on the soil microbial communities and CAZyme function genes. Detailly, WS increased the phyla abundance of <em>Proteobacteria</em>, <em>Actinobacteria</em>, and <em>Firmicutes</em> and enriched the glycoside hydrolase (GH) and carbohydrate-binding modules (CBM) genes; WC increased the abundance of <em>Acidobacteria</em> and <em>Bacteroidota</em> and enriched the polysaccharide lyase gene; WM increased the abundance of <em>Nitrospirae</em>, <em>Candidatus_Rokubacteria</em>, <em>Chloroflexi</em> and <em>Gemmatimonadetes</em> and enriched the gene abundance of glycosyltransferases and auxiliary activity genes. Additionally, <em>Acidobacteria</em>, <em>Proteobacteria</em>, and <em>Actinobacteria</em> are key phyla involved in soil carbon cycling and collectively contribute >70 % of the total CAZyme functional genes, which highlights their importance. In addition, our results indicated that total nitrogen content played a major role in influencing genes related to CAZymes, especially those belonging to the GH family. Our study demonstrates that WS conferred the advantage of increasing SOC across the three crop rotation systems. CAZyme analysis revealed that WS's could potentially support the increased abundance of <em>Proteobacteria</em>, <em>Actinobacteria</em> and <em>Firmicutes</em> in the soil community, at the same time potentially leading to increased number of GH and CBM genes in the soil, which may bolster the decomposition and transformation of plant-derived carbon, thus promoting an increase in SOC content. The findings of this study offer new insights into the microbial factors contributing to SOC enhancement in rotation systems.</div></div>","PeriodicalId":12057,"journal":{"name":"European Journal of Soil Biology","volume":"123 ","pages":"Article 103694"},"PeriodicalIF":3.7,"publicationDate":"2024-11-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142652448","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-06DOI: 10.1016/j.ejsobi.2024.103692
Danni Li , Yi Li , Shuihong Yao , Hu Zhou , Shan Huang , Xianlong Peng , Yili Meng
Soil pore distribution influences the permeability of gas, water, and solutes, affecting microbial activities such as nitrogen (N) mineralization. Understanding its impact on N mineralization and the subsequent N transformations is essential for managing compacted paddy soils. This study conducted incubation experiments on two paddy soils from typical Chinese rice regions, Northeastern meadow chernozemic Mollisols, and Southern umbric Ferralsols, under three bulk densities (1.0 g cm−3, 1.2 g cm−3, and 1.4 g cm−3) to investigate the effects of soil porosity on N mineralization and N cycling functional genes. Although the cumulative mineralized N showed no significant difference, with increased macropores (>100 μm) and mesopores (30–100 μm), Ferralsols exhibited a significantly higher net N mineralization rate from day 0 to day 7, while Mollisols extended the mineralization after day 21. Soil dissolved organic carbon (DOC) had a similar temporal trend to the net N mineralization rate, suggesting DOC was the product of mineralization. Soil microbial biomass carbon (MBC) showed an opposite temporal trend to the net N mineralization rate in Mollisols, suggesting microbial biomass as a key N source for mineralization. Soil pores distribution did not affect nitrification under waterlogged conditions, but it affected nirK, nirS and nosZ genes by altering redox potential and substrates availability in the pore micro-environment. Overall, soil pores over 30 μm were the key pore size ranges affecting the intensity and duration of N mineralization, with different effects on DOC, MBC, and N cycling functional genes in Mollisols and Ferralsols. These findings emphasized the role of pore size in regulating N transformation in waterlogged conditions, contributing to the understanding of the N availability in compacted paddy soils from typical geographic rice-growing regions.
{"title":"Dynamics of nitrogen mineralization and nitrogen cycling functional genes in response to soil pore size distribution","authors":"Danni Li , Yi Li , Shuihong Yao , Hu Zhou , Shan Huang , Xianlong Peng , Yili Meng","doi":"10.1016/j.ejsobi.2024.103692","DOIUrl":"10.1016/j.ejsobi.2024.103692","url":null,"abstract":"<div><div>Soil pore distribution influences the permeability of gas, water, and solutes, affecting microbial activities such as nitrogen (N) mineralization. Understanding its impact on N mineralization and the subsequent N transformations is essential for managing compacted paddy soils. This study conducted incubation experiments on two paddy soils from typical Chinese rice regions, Northeastern meadow chernozemic Mollisols, and Southern umbric Ferralsols, under three bulk densities (1.0 g cm<sup>−3</sup>, 1.2 g cm<sup>−3</sup>, and 1.4 g cm<sup>−3</sup>) to investigate the effects of soil porosity on N mineralization and N cycling functional genes. Although the cumulative mineralized N showed no significant difference, with increased macropores (>100 μm) and mesopores (30–100 μm), Ferralsols exhibited a significantly higher net N mineralization rate from day 0 to day 7, while Mollisols extended the mineralization after day 21. Soil dissolved organic carbon (DOC) had a similar temporal trend to the net N mineralization rate, suggesting DOC was the product of mineralization. Soil microbial biomass carbon (MBC) showed an opposite temporal trend to the net N mineralization rate in Mollisols, suggesting microbial biomass as a key N source for mineralization. Soil pores distribution did not affect nitrification under waterlogged conditions, but it affected <em>nirK</em>, <em>nirS</em> and <em>nosZ</em> genes by altering redox potential and substrates availability in the pore micro-environment. Overall, soil pores over 30 μm were the key pore size ranges affecting the intensity and duration of N mineralization, with different effects on DOC, MBC, and N cycling functional genes in Mollisols and Ferralsols. These findings emphasized the role of pore size in regulating N transformation in waterlogged conditions, contributing to the understanding of the N availability in compacted paddy soils from typical geographic rice-growing regions.</div></div>","PeriodicalId":12057,"journal":{"name":"European Journal of Soil Biology","volume":"123 ","pages":"Article 103692"},"PeriodicalIF":3.7,"publicationDate":"2024-11-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142593465","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-05DOI: 10.1016/j.ejsobi.2024.103690
Elena Kost , Dominika Kundel , Rafaela Feola Conz , Paul Mäder , Hans-Martin Krause , Johan Six , Jochen Mayer , Martin Hartmann
The impacts of climate change, such as drought, can affect soil microbial communities. These communities are crucial for soil functioning and crop production. Organic and conventional cropping systems can promote distinct soil microbiomes and soil organic carbon contents, which might generate different capacities to mitigate drought effects on these cropping systems. A field-scale drought simulation was performed in long-term organically and conventionally managed cropping systems differing in fertilization and pesticide application. The soil microbiome was assessed during and after drought in bulk soil, rhizosphere, and roots of wheat. We found that drought reduced soil respiration and altered microbial community structures, affecting fungi in the bulk soil and rhizosphere more strongly than prokaryotes. Microbial communities associated with crops (i.e. rhizosphere and root) were more strongly influenced by drought compared to bulk soil communities. Drought legacy effects were observed in the bulk soil after harvesting and rewetting. The extent of the structural shifts in the soil microbiome in response to severe drought did not differ significantly between the organic and conventional cropping systems but each cropping system maintained a unique microbiome under drought. All cropping systems showed relative increases in potential plant growth-promoting genera under drought but some genera such as Streptomyces, Rhizophagus, Actinomadura, and Aneurinibacillus showed system-specific drought responses. This agricultural field study indicated that fungal communities might be less resistant to drought than prokaryotic communities in cropping systems and these effects get more pronounced in closer association with plants. Organic fertilization and the associated increase in soil organic carbon, or the reduction in pesticide application might not have the proposed ability to buffer severe drought stress on soil microbial taxonomic diversity. Yet, it remains to be elucidated whether the ability to maintain system-specific soil microbiomes also during drought translates into different functional capabilities to cope with the stress.
{"title":"Soil microbial resistance and resilience to drought under organic and conventional farming","authors":"Elena Kost , Dominika Kundel , Rafaela Feola Conz , Paul Mäder , Hans-Martin Krause , Johan Six , Jochen Mayer , Martin Hartmann","doi":"10.1016/j.ejsobi.2024.103690","DOIUrl":"10.1016/j.ejsobi.2024.103690","url":null,"abstract":"<div><div>The impacts of climate change, such as drought, can affect soil microbial communities. These communities are crucial for soil functioning and crop production. Organic and conventional cropping systems can promote distinct soil microbiomes and soil organic carbon contents, which might generate different capacities to mitigate drought effects on these cropping systems. A field-scale drought simulation was performed in long-term organically and conventionally managed cropping systems differing in fertilization and pesticide application. The soil microbiome was assessed during and after drought in bulk soil, rhizosphere, and roots of wheat. We found that drought reduced soil respiration and altered microbial community structures, affecting fungi in the bulk soil and rhizosphere more strongly than prokaryotes. Microbial communities associated with crops (i.e. rhizosphere and root) were more strongly influenced by drought compared to bulk soil communities. Drought legacy effects were observed in the bulk soil after harvesting and rewetting. The extent of the structural shifts in the soil microbiome in response to severe drought did not differ significantly between the organic and conventional cropping systems but each cropping system maintained a unique microbiome under drought. All cropping systems showed relative increases in potential plant growth-promoting genera under drought but some genera such as <em>Streptomyces</em>, <em>Rhizophagus, Actinomadura</em>, and <em>Aneurinibacillus</em> showed system-specific drought responses. This agricultural field study indicated that fungal communities might be less resistant to drought than prokaryotic communities in cropping systems and these effects get more pronounced in closer association with plants. Organic fertilization and the associated increase in soil organic carbon, or the reduction in pesticide application might not have the proposed ability to buffer severe drought stress on soil microbial taxonomic diversity. Yet, it remains to be elucidated whether the ability to maintain system-specific soil microbiomes also during drought translates into different functional capabilities to cope with the stress.</div></div>","PeriodicalId":12057,"journal":{"name":"European Journal of Soil Biology","volume":"123 ","pages":"Article 103690"},"PeriodicalIF":3.7,"publicationDate":"2024-11-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142587210","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-03DOI: 10.1016/j.ejsobi.2024.103691
Min Wang , Chang Liao , Weili Lai , Songyi Huang , Shihong Xiao , Caiqiong Deng , Xianhua Gan , Qing Ma , Mengyun Liu
<div><h3>Context</h3><div>Stand conversion in subtropical regions has altered soil physicochemical properties and microbial communities, leading to changes in microbially mediated processes, such as microbial necromass C (MNC) formation and accumulation. However, previous studies on the effects of stand conversion on MNC are lacking, leading to gaps in our understanding regarding the influence of long-term stand conversion on MNC accumulation in different soil layers and the relative importance of soil properties for regulating MNC.</div></div><div><h3>Aims</h3><div>In this study, we used field surveys and soil analysis to assess the effects of converting a <em>Eucalyptus</em> forest into other planted forest (broadleaf mixed forest [BM] and <em>Acacia mangium</em> × <em>Acacia auriculiformis</em> forest [AM]) on soil properties, enzyme activity, microbial community composition, and MNC after conversion 20 years in Guangdong, South China.</div></div><div><h3>Results</h3><div>We found that the content of soil organic C (SOC) in the surface soil (0–10 cm after litter removal) increased by 64.9 % when <em>Eucalyptus</em> was converted to AM, whereas there was no significant difference in the subsurface soil (10–20 cm). β-1,4-glucosidase (BG) and β-1,4-N-acetaminophen glucosidase (NAG) activity increased significantly, while leucine aminopeptidase (LA) activity decreased significantly in the surface soil. In the subsurface soil, BG activity did not change significantly; nonetheless, acid phosphomonoesterase (AP) activity decreased. The fungal, bacterial, and gram-negative bacterial biomass did not significantly differ among the different forests in the surface soil, but the fungal, bacterial, gram-positive, and gram-negative bacterial biomass decreased significantly in the subsurface soil. The ratio of fungi to bacteria was highest in the BM, whereas the ratio of gram-positive to gram-negative bacteria was highest in the AM. Soil fungal and microbial necromass C and the ratio of fungal to bacterial necromass C increased significantly in the surface soil when <em>Eucalyptus</em> was converted to AM. The contribution of MNC and fungal necromass C to SOC content significantly increased by 22.20 % and 26.23 %, respectively, when <em>Eucalyptus</em> was converted to AM. The main controlling factors of MNC accumulation in the surface soil were pH and total N, whereas soil enzyme activity (BG related to C-acquisition) was the dominant determinant of MNC accumulation in the subsurface soil.</div></div><div><h3>Conclusion</h3><div>Our study provides evidence that converting <em>Eucalyptus</em> to AM may promote MNC accumulation in the surface soil by changing soil pH and TN content to affect soil enzyme activity and microbial community structure, and ultimately changed MNC accumulation. Therefore, developing effective forest management practices, such as reasonable stand conversion may help to enhance forest SOC accumulation by increasing MNC accumulation.</d
背景亚热带地区的林分转换改变了土壤理化性质和微生物群落,导致微生物介导的过程发生变化,如微生物坏死物质 C(MNC)的形成和积累。然而,以前缺乏有关林分转换对 MNC 影响的研究,导致我们对长期林分转换对不同土层中 MNC 积累的影响以及土壤特性对调节 MNC 的相对重要性的认识存在差距。目的 在本研究中,我们利用实地调查和土壤分析评估了在中国南方广东将桉树林改造成其他人工林(阔叶混交林 [BM] 和芒果相思树 × 金合欢林 [AM])20 年后对土壤性质、酶活性、微生物群落组成和 MNC 的影响。结果我们发现,当桉树转化为 AM 后,表层土壤(去除枯落物后 0-10 厘米)的土壤有机碳(SOC)含量增加了 64.9%,而表层下土壤(10-20 厘米)则无显著差异。表层土壤中,β-1,4-葡萄糖苷酶(BG)和β-1,4-N-乙酰氨基酚葡萄糖苷酶(NAG)活性显著增加,而亮氨酸氨肽酶(LA)活性显著降低。在地下土壤中,BG 活性没有明显变化;但酸性磷单酯酶(AP)活性有所下降。在表层土壤中,不同森林的真菌、细菌和革兰氏阴性菌生物量没有显著差异,但在表层下土壤中,真菌、细菌、革兰氏阳性菌和革兰氏阴性菌生物量显著下降。真菌与细菌的比例在 BM 中最高,而革兰氏阳性菌与革兰氏阴性菌的比例在 AM 中最高。当桉树转化为 AM 时,表层土壤中的土壤真菌和微生物坏死物质 C 以及真菌与细菌坏死物质 C 之比显著增加。桉树转化为 AM 后,MNC 和真菌坏死物质 C 对 SOC 含量的贡献率分别大幅增加了 22.20 % 和 26.23 %。表层土壤中 MNC 积累的主要控制因素是 pH 值和全氮,而土壤酶活性(与 C 获取有关的 BG)是表层下土壤中 MNC 积累的主要决定因素。因此,制定有效的森林管理措施,如合理的林分转换,可能有助于通过增加 MNC 积累来提高森林 SOC 积累。
{"title":"Plantation conversion of Eucalyptus promotes soil microbial necromass C accumulation","authors":"Min Wang , Chang Liao , Weili Lai , Songyi Huang , Shihong Xiao , Caiqiong Deng , Xianhua Gan , Qing Ma , Mengyun Liu","doi":"10.1016/j.ejsobi.2024.103691","DOIUrl":"10.1016/j.ejsobi.2024.103691","url":null,"abstract":"<div><h3>Context</h3><div>Stand conversion in subtropical regions has altered soil physicochemical properties and microbial communities, leading to changes in microbially mediated processes, such as microbial necromass C (MNC) formation and accumulation. However, previous studies on the effects of stand conversion on MNC are lacking, leading to gaps in our understanding regarding the influence of long-term stand conversion on MNC accumulation in different soil layers and the relative importance of soil properties for regulating MNC.</div></div><div><h3>Aims</h3><div>In this study, we used field surveys and soil analysis to assess the effects of converting a <em>Eucalyptus</em> forest into other planted forest (broadleaf mixed forest [BM] and <em>Acacia mangium</em> × <em>Acacia auriculiformis</em> forest [AM]) on soil properties, enzyme activity, microbial community composition, and MNC after conversion 20 years in Guangdong, South China.</div></div><div><h3>Results</h3><div>We found that the content of soil organic C (SOC) in the surface soil (0–10 cm after litter removal) increased by 64.9 % when <em>Eucalyptus</em> was converted to AM, whereas there was no significant difference in the subsurface soil (10–20 cm). β-1,4-glucosidase (BG) and β-1,4-N-acetaminophen glucosidase (NAG) activity increased significantly, while leucine aminopeptidase (LA) activity decreased significantly in the surface soil. In the subsurface soil, BG activity did not change significantly; nonetheless, acid phosphomonoesterase (AP) activity decreased. The fungal, bacterial, and gram-negative bacterial biomass did not significantly differ among the different forests in the surface soil, but the fungal, bacterial, gram-positive, and gram-negative bacterial biomass decreased significantly in the subsurface soil. The ratio of fungi to bacteria was highest in the BM, whereas the ratio of gram-positive to gram-negative bacteria was highest in the AM. Soil fungal and microbial necromass C and the ratio of fungal to bacterial necromass C increased significantly in the surface soil when <em>Eucalyptus</em> was converted to AM. The contribution of MNC and fungal necromass C to SOC content significantly increased by 22.20 % and 26.23 %, respectively, when <em>Eucalyptus</em> was converted to AM. The main controlling factors of MNC accumulation in the surface soil were pH and total N, whereas soil enzyme activity (BG related to C-acquisition) was the dominant determinant of MNC accumulation in the subsurface soil.</div></div><div><h3>Conclusion</h3><div>Our study provides evidence that converting <em>Eucalyptus</em> to AM may promote MNC accumulation in the surface soil by changing soil pH and TN content to affect soil enzyme activity and microbial community structure, and ultimately changed MNC accumulation. Therefore, developing effective forest management practices, such as reasonable stand conversion may help to enhance forest SOC accumulation by increasing MNC accumulation.</d","PeriodicalId":12057,"journal":{"name":"European Journal of Soil Biology","volume":"123 ","pages":"Article 103691"},"PeriodicalIF":3.7,"publicationDate":"2024-11-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142572269","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-24DOI: 10.1016/j.ejsobi.2024.103689
Ying Wang , Yimei Huang , Na Li , Qian Huang , Baorong Wang , Shaoshan An
Autotrophic microorganisms can fix carbon dioxide (CO2) into organic carbon (C), potentially offering a natural mechanism to mitigate global climate change. Forest soils, recognized as vast and critical C repositories with significant microbial CO2 fixation rates, remain understudied, particularly regarding the spatial variations of autotrophic bacteria and their relationship to soil functions in arid regions. In this study, we systematically investigated soil multifunctionality, along with the spatial distribution of autotrophic bacterial communities identified by the RubisCO cbbL and cbbM genes, and the driving factors across a longitudinal gradient in the Loess Plateau forest soils. The investigation spanned an ∼850 km west-east transect with precipitation below 600 mm. The alpha diversity of cbbL-containing bacteria, as measured by the Chao1 index, was correlated with climatic variables such as precipitation and elevation instead of local soil characteristics. In contrast, the alpha diversity of cbbM-containing bacteria was associated with soil properties. The community composition of autotrophic bacteria, based on cbbL and cbbM genes, showed greater similarity in soils from the eastern Loess Plateau and was distinct from those in the western region. The cbbL- and cbbM-containing generalist taxa were subject to differential selection and promotion between the eastern and western regions. Temperature, soil pH and spatial variables were key drivers influencing the community composition of cbbL- and cbbM-containing bacteria. The diversity and communities of soil autotrophic bacteria significantly affected soil multifunctionality. The study demonstrates that soil autotrophic bacteria in forest soils are intricately connected to climatic conditions, soil pH and spatial factors, significantly impacting soil multifunctionality. These insights provide evidence that can be instrumental in predicting and potentially enhancing the functional capacity of forest ecosystems in the Loess Plateau.
{"title":"Longitudinal distributions of CO2-fixing bacteria in forest soils and their potential associations with soil multifunctionality","authors":"Ying Wang , Yimei Huang , Na Li , Qian Huang , Baorong Wang , Shaoshan An","doi":"10.1016/j.ejsobi.2024.103689","DOIUrl":"10.1016/j.ejsobi.2024.103689","url":null,"abstract":"<div><div>Autotrophic microorganisms can fix carbon dioxide (CO<sub>2</sub>) into organic carbon (C), potentially offering a natural mechanism to mitigate global climate change. Forest soils, recognized as vast and critical C repositories with significant microbial CO<sub>2</sub> fixation rates, remain understudied, particularly regarding the spatial variations of autotrophic bacteria and their relationship to soil functions in arid regions. In this study, we systematically investigated soil multifunctionality, along with the spatial distribution of autotrophic bacterial communities identified by the RubisCO <em>cbbL</em> and <em>cbbM</em> genes, and the driving factors across a longitudinal gradient in the Loess Plateau forest soils. The investigation spanned an ∼850 km west-east transect with precipitation below 600 mm. The alpha diversity of <em>cbbL</em>-containing bacteria, as measured by the Chao1 index, was correlated with climatic variables such as precipitation and elevation instead of local soil characteristics. In contrast, the alpha diversity of <em>cbbM</em>-containing bacteria was associated with soil properties. The community composition of autotrophic bacteria, based on <em>cbbL</em> and <em>cbbM</em> genes, showed greater similarity in soils from the eastern Loess Plateau and was distinct from those in the western region. The <em>cbbL-</em> and <em>cbbM-</em>containing generalist taxa were subject to differential selection and promotion between the eastern and western regions. Temperature, soil pH and spatial variables were key drivers influencing the community composition of <em>cbbL-</em> and <em>cbbM-</em>containing bacteria. The diversity and communities of soil autotrophic bacteria significantly affected soil multifunctionality. The study demonstrates that soil autotrophic bacteria in forest soils are intricately connected to climatic conditions, soil pH and spatial factors, significantly impacting soil multifunctionality. These insights provide evidence that can be instrumental in predicting and potentially enhancing the functional capacity of forest ecosystems in the Loess Plateau.</div></div>","PeriodicalId":12057,"journal":{"name":"European Journal of Soil Biology","volume":"123 ","pages":"Article 103689"},"PeriodicalIF":3.7,"publicationDate":"2024-10-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142528960","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-22DOI: 10.1016/j.ejsobi.2024.103687
L. Vang Sørensen , S. Rodríguez-Martínez , M. Rollo , J. Klaminder
Ants serve as ecosystem engineers that maintain important ecological processes within forests. Given their ecological importance, it is a clear scientific shortcoming that we lack non-invasive methods to survey their behaviour inside common opaque habitats such as mounds, litter, and soil. In this study, we assess if acoustic signals from red wood ant (Formica rufa) mounds are useful to infer temporal changes in ant activity within forested ecosystems. We found that acoustic indices used previously as a proxy for soil fauna in soil ecological studies (Acoustic Complexity Index, Bioacoustic Index) can indeed separate sounds generated by the ant's daily routines (biophony) from other forest sounds. Yet, we also show that these indices are problematic proxies for soil diversity as they increase not only due to an increased number of species but also due to an increased number of the same species. Acoustic measures that incorporated the strength of acoustic signals, Average Power Density (APD) and Peak Power Density (PPD) also increased with increasing ant abundance and constituted the conceptually best proxy for ant activity. For example, the PPD could i) track diurnal changes in Formica rufa activity with a high temporal resolution (minutes) and ii) detect altered behavioural responses to temperature changes. We conclude that microphones detecting biophony can provide high-resolution information about in situ ant behaviours in forested ecosystems. Thus, passive acoustics monitoring offers a promising avenue as a non-invasive monitoring tool for soil macrofauna studies.
蚂蚁是维持森林重要生态过程的生态系统工程师。鉴于蚂蚁在生态方面的重要性,我们缺乏非侵入式方法来调查蚂蚁在土丘、垃圾和土壤等常见不透明栖息地内的行为,这是一个明显的科学缺陷。在这项研究中,我们评估了来自红木蚁(Formica rufa)蚁丘的声学信号是否有助于推断森林生态系统中蚂蚁活动的时间变化。我们发现,以前在土壤生态研究中用作土壤动物群替代物的声学指数(声学复杂性指数、生物声学指数)确实可以将蚂蚁日常活动产生的声音(生物声音)与其他森林声音区分开来。然而,我们也发现,这些指数是有问题的土壤多样性代用指标,因为它们的增加不仅是由于物种数量的增加,也是由于相同物种数量的增加。声学指标包括声信号强度、平均功率密度(Average Power Density,APD)和峰值功率密度(Peak Power Density,PPD),它们也随着蚂蚁数量的增加而增加,在概念上是蚂蚁活动的最佳代表。例如,PPD 可以 i) 以较高的时间分辨率(分钟)跟踪 Formica rufa 活动的昼夜变化;ii) 检测对温度变化的行为反应变化。我们的结论是,探测生物声音的麦克风可以提供有关森林生态系统中蚂蚁现场行为的高分辨率信息。因此,被动声学监测作为一种非侵入式监测工具,为土壤大型底栖动物研究提供了一条前景广阔的途径。
{"title":"Continuous measurement of red wood ant (Formica rufa) outdoor behaviour using passive acoustic monitoring","authors":"L. Vang Sørensen , S. Rodríguez-Martínez , M. Rollo , J. Klaminder","doi":"10.1016/j.ejsobi.2024.103687","DOIUrl":"10.1016/j.ejsobi.2024.103687","url":null,"abstract":"<div><div>Ants serve as ecosystem engineers that maintain important ecological processes within forests. Given their ecological importance, it is a clear scientific shortcoming that we lack non-invasive methods to survey their behaviour inside common opaque habitats such as mounds, litter, and soil. In this study, we assess if acoustic signals from red wood ant (<em>Formica rufa</em>) mounds are useful to infer temporal changes in ant activity within forested ecosystems. We found that acoustic indices used previously as a proxy for soil fauna in soil ecological studies (Acoustic Complexity Index, Bioacoustic Index) can indeed separate sounds generated by the ant's daily routines (biophony) from other forest sounds. Yet, we also show that these indices are problematic proxies for soil diversity as they increase not only due to an increased number of species but also due to an increased number of the same species. Acoustic measures that incorporated the strength of acoustic signals, Average Power Density (APD) and Peak Power Density (PPD) also increased with increasing ant abundance and constituted the conceptually best proxy for ant activity. For example, the PPD could i) track diurnal changes in <em>Formica rufa</em> activity with a high temporal resolution (minutes) and ii) detect altered behavioural responses to temperature changes. We conclude that microphones detecting biophony can provide high-resolution information about <em>in situ</em> ant behaviours in forested ecosystems. Thus, passive acoustics monitoring offers a promising avenue as a non-invasive monitoring tool for soil macrofauna studies.</div></div>","PeriodicalId":12057,"journal":{"name":"European Journal of Soil Biology","volume":"123 ","pages":"Article 103687"},"PeriodicalIF":3.7,"publicationDate":"2024-10-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142528959","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Soil health is an emerging concern in agriculture and is dependent on the microbial communities in the rhizosphere (rhizobiome). Phosphite-based products are used as bio-stimulants and/or fungicides. However, there is a lack of studies evaluating the impact of these products in nurseries, especially at the level of the rhizobiome. This work aims to assess the impact of phosphite (Phi) application on the rhizobiome of Pinus radiata seedlings. Two application modes (foliar and irrigation) were compared in an experimental setup with control treatments. Gas exchange parameters were evaluated to assess plant physiological performance. Bacterial rhizobiome analysis was performed using next generation sequencing targeting the 16S rRNA gene. Results showed that Phi application did not significantly affect plant photosynthetic performance. However, Phi irrigation led to a significant decrease in rhizobiome richness and diversity compared to control. Beta diversity analysis confirmed distinct microbial communities in the irrigated group. At the genus level, several acidophilic taxa, including Burkholderia and Aciditerrimonas, were significantly enriched in phosphite-irrigated samples, while others like Mucilaginibacter were reduced. The study reveals that Phi application, especially through irrigation, alters the structure of the rhizobiome in pine seedlings, leading to a decrease in richness and bacterial diversity. These findings highlight the importance of understanding the effects of commercial products, such as phosphite. This understanding is crucial to ensure sustainable plant growth and maintain soil health.
{"title":"Pinus radiata seedlings rhizobiome shifts in response to foliar and root phosphite application","authors":"Frederico Leitão , Glória Pinto , Isabel Henriques","doi":"10.1016/j.ejsobi.2024.103688","DOIUrl":"10.1016/j.ejsobi.2024.103688","url":null,"abstract":"<div><div>Soil health is an emerging concern in agriculture and is dependent on the microbial communities in the rhizosphere (rhizobiome). Phosphite-based products are used as bio-stimulants and/or fungicides. However, there is a lack of studies evaluating the impact of these products in nurseries, especially at the level of the rhizobiome. This work aims to assess the impact of phosphite (Phi) application on the rhizobiome of <em>Pinus radiata</em> seedlings. Two application modes (foliar and irrigation) were compared in an experimental setup with control treatments. Gas exchange parameters were evaluated to assess plant physiological performance. Bacterial rhizobiome analysis was performed using next generation sequencing targeting the 16S rRNA gene. Results showed that Phi application did not significantly affect plant photosynthetic performance. However, Phi irrigation led to a significant decrease in rhizobiome richness and diversity compared to control. Beta diversity analysis confirmed distinct microbial communities in the irrigated group. At the genus level, several acidophilic taxa, including <em>Burkholderia</em> and <em>Aciditerrimonas</em>, were significantly enriched in phosphite-irrigated samples, while others like <em>Mucilaginibacter</em> were reduced. The study reveals that Phi application, especially through irrigation, alters the structure of the rhizobiome in pine seedlings, leading to a decrease in richness and bacterial diversity. These findings highlight the importance of understanding the effects of commercial products, such as phosphite. This understanding is crucial to ensure sustainable plant growth and maintain soil health.</div></div>","PeriodicalId":12057,"journal":{"name":"European Journal of Soil Biology","volume":"123 ","pages":"Article 103688"},"PeriodicalIF":3.7,"publicationDate":"2024-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142441986","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}