Soil Biology & Biochemistry最新文献_第7页

Simulated erosion of A horizon influences the dissolved organic matter chemodiversity and carbon sequestration of B horizon in Mollisols 模拟 A 层侵蚀对软质土 B 层溶解有机物化学多样性和固碳的影响

IF 9.8 1区农林科学 Q1 SOIL SCIENCE

Soil Biology & Biochemistry

Pub Date : 2024-11-17 DOI: 10.1016/j.soilbio.2024.109648

Meng Zhou , Yang Xiao , Yansheng Li , Jian Liu , Yueyu Sui , Xingyi Zhang , Xiaobing Liu

Erosion of the A horizon of Mollisols is expected to change the dissolved organic matter (DOM) chemodiversity in the underlying B horizon. Three simulated erosion treatments, which had an A horizon of 30, 20, and 10 cm depth, were established for 9 years under a corn-soybean rotation on Mollisols. Compared to the A horizon that was 30 cm deep, the 20 cm treatment had 24–63% more dissolved lignin-like compounds, a significant increase, in the 0–10, 10–20, and 20–30 cm layers of the B horizon. When the A horizon was 10 cm deep, 41% more lignin-like compounds accumulated in the 10–20 cm layer of the B horizon and 22% more lignin-like compounds were detected in the 20–30 cm layer of the B horizon. Relative to the A horizon of 30 cm depth, the 20 and 10 cm treatments reduced the lipid- and protein-like compounds by 69–87% in 10–20 and 20–30 cm layers of the B horizon layers. Labile compounds increased in the 0–10 cm layer of the B horizon but decreased in the 10–20 and 20–30 cm layers of the B horizon. The DOM degradation degree, expressed in terms of the degradation index and Gibbs free energy, were related to the lignin accumulation, indicating that lignin, a recalcitrant compound, was degraded. Notably, variations in DOM chemodiversity in eroded Mollisols were primarily controlled by soil physicochemical properties and not microbial traits. Therefore, eroded Mollisols have less carbon sequestration potential in the B horizon. To prevent soil deterioration in corn-soybean rotations, we recommend to incorporate a combination of organic and mineral fertiliser to a 20–30 cm soil depth in erosion-susceptible Mollisols.

预计莫利土 A 层的侵蚀会改变下层 B 层的溶解有机物 (DOM) 化学多样性。在玉米-大豆轮作的莫利土层上建立了三种模拟侵蚀处理，其 A 层深度分别为 30、20 和 10 厘米，为期 9 年。与深度为 30 厘米的 A 地层相比，深度为 20 厘米的处理在 B 地层的 0-10、10-20 和 20-30 厘米层中溶解的木质素类化合物增加了 24-63%，增幅显著。当 A 地层深度为 10 厘米时，B 地层 10-20 厘米层中积累的木质素类化合物增加了 41%，B 地层 20-30 厘米层中检测到的木质素类化合物增加了 22%。与 30 厘米深的 A 地层相比，20 厘米和 10 厘米处理使 B 地层 10-20 厘米层和 20-30 厘米层的类脂和类蛋白化合物减少了 69-87%。在 B 地层 0-10 厘米层中，易溶化合物有所增加，但在 B 地层 10-20 厘米层和 20-30 厘米层中，易溶化合物有所减少。用降解指数和吉布斯自由能表示的 DOM 降解程度与木质素积累有关，表明木质素这种难降解化合物被降解了。值得注意的是，侵蚀莫利土中 DOM 化学多样性的变化主要受土壤理化性质的控制，而不是受微生物特性的控制。因此，受侵蚀的莫利土在 B 层的固碳潜力较小。为了防止玉米-大豆轮作中的土壤退化，我们建议在易受侵蚀的莫利土壤中将有机肥和矿物肥结合施入 20-30 厘米深的土壤中。

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引用次数: 0

Cropping systems and ecological groups of soil animals jointly affect the transfer of root-derived carbon and mineral nitrogen into the soil food web 种植系统和土壤动物生态群共同影响根系衍生的碳和矿质氮向土壤食物网的转移

IF 9.8 1区农林科学 Q1 SOIL SCIENCE

Soil Biology & Biochemistry

Pub Date : 2024-11-12 DOI: 10.1016/j.soilbio.2024.109646

Linlin Zhong , Zhipeng Li , Lingling Shi , Thomas Larsen , Stefan Scheu , Melanie M. Pollierer

Root-derived carbon (C) is a crucial resource fuelling soil food webs. However, the quantity of these resources varies with plant communities and may also influence the flux of mineral nitrogen (N) into belowground food webs. Yet, little is known about how different plant communities, especially in agricultural systems, influence the incorporation of plant C and mineral N into the soil macrofauna. Here, we combined pulse ¹³C-labelling of plants with ¹⁵N-labelling of soil in a crop monoculture (oilseed rape), a mixed grass community (grass and legume mixture) and a young tree plantation (willow) to trace the fluxes of root-derived C and mineral N into earthworms and centipedes as major soil decomposers and predators, respectively, over 28 days. Bulk stable isotope analysis and compound-specific stable isotope analysis of amino acids were used to quantify the uptake of ¹³C and ¹⁵N by soil macrofauna and to investigate the pathways by which these resources are channelled into soil macrofauna. Aligning with their use of plant-derived resources, epigeic and anecic earthworms incorporated more root-derived C than endogeic earthworms, with endogeic earthworms mainly relying on bacteria or bacterial necromass associated with soil organic matter. Generally, macrofauna incorporated both root-derived C and mineral N across cropping systems, but incorporation was more pronounced in rape and grass than in willow. Importantly, root-derived resources facilitated the incorporation of mineral N into soil animal food webs. Centipedes, as one of the most important predators in soil, mainly incorporated root-derived C and mineral N via preying on collembolans, whereas in willow epigeic earthworms likely also contributed to their diet. Overall, the fluxes of root-derived C and mineral N into the soil food web depended on plant communities and soil animal ecological groups, with higher fluxes in herbaceous crops than in tree plantations.

根源碳（C）是为土壤食物网提供燃料的重要资源。然而，这些资源的数量随植物群落的不同而变化，也可能影响矿质氮（N）进入地下食物网的通量。然而，人们对不同植物群落（尤其是农业系统中的植物群落）如何影响土壤大型动物对植物碳和矿质氮的吸收知之甚少。在这里，我们将植物的脉冲 13C 标记与土壤的 15N 标记相结合，在作物单一栽培（油菜）、混合禾本科群落（禾本科与豆科植物的混合物）和幼树种植园（柳树）中追踪 28 天内根源 C 和矿质 N 分别进入作为主要土壤分解者和捕食者的蚯蚓和蜈蚣的通量。大量稳定同位素分析和氨基酸的特定化合物稳定同位素分析被用来量化土壤大型动物对 13C 和 15N 的吸收，并研究这些资源进入土壤大型动物体内的途径。表皮蚯蚓和无尾蚯蚓比内生蚯蚓吸收更多的根源性 C，这与它们使用植物资源的情况一致，内生蚯蚓主要依靠与土壤有机质相关的细菌或细菌新陈代谢产物。一般来说，大型动物在不同的种植系统中都能吸收根源碳和矿质氮，但在油菜和禾本科植物中的吸收比在柳树中更明显。重要的是，根源资源促进了土壤动物食物网中矿质氮的吸收。作为土壤中最重要的捕食者之一，蜈蚣主要通过捕食禾本科植物来吸收根源碳和矿质氮，而柳树中的表皮蚯蚓很可能也是它们的食物来源。总体而言，根源碳和矿质氮进入土壤食物网的通量取决于植物群落和土壤动物生态群，草本作物的通量高于树木种植园。

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引用次数: 0

How to produce an effective manuscript: Further perspectives from the Editors-in-Chief of Soil Biology and Biochemistry 如何撰写有效稿件：《土壤生物学与生物化学》主编的进一步观点

IF 9.8 1区农林科学 Q1 SOIL SCIENCE

Soil Biology & Biochemistry

Pub Date : 2024-11-05 DOI: 10.1016/j.soilbio.2024.109645

Karl Ritz (co-Editor-in-Chief), Joshua Schimel (co-Editor-in-Chief), Joann Whalen (co-Editor-in-Chief)

引用次数: 0

Plant community composition and traits modulate the impacts of drought intensity on soil microbial community composition and function 植物群落组成和性状调节干旱强度对土壤微生物群落组成和功能的影响

IF 9.8 1区农林科学 Q1 SOIL SCIENCE

Soil Biology & Biochemistry

Pub Date : 2024-11-02 DOI: 10.1016/j.soilbio.2024.109644

Natalie J. Oram , Fiona Brennan , Nadine Praeg , Richard D. Bardgett , Paul Illmer , Johannes Ingrisch , Michael Bahn

Terrestrial ecosystems are increasingly threatened by extreme drought events. Soil microbial communities are central to terrestrial ecosystem function via their role in regulating biogeochemical cycling. Consequently, the impact of increasingly intense drought events on soil microbial communities will have knock-on effects for how ecosystems cope with climate change. In an outdoor grassland mesocosm experiment, we determined how increasing drought intensity affects bacterial and fungal community composition, and functioning, during and after drought. We also tested whether plant community resource acquisition strategy (fast-versus slow-strategy plant communities), plant community composition, and plant functional traits mediate soil microbial responses to increasing drought intensity. We found that increasing drought intensity markedly shifted bacterial and fungal community composition, and these effects persisted until the end of the experiment (two months after re-wetting). Bacterial and fungal communities that experienced severe droughts did not return to baseline composition, while those that experienced a mild drought did. Microbial community functioning (potential extracellular enzyme activity) was reduced at peak drought and shortly after re-wetting. While drought intensity effects on bacterial or fungal communities were insensitive to plant community resource acquisition strategy, functional group abundance (aboveground biomass of grass or forb plant species) composition (grass:forb ratio) and leaf traits (leaf dry matter content and leaf nitrogen concentration) explained significant variation in bacterial and fungal community composition during and after drought. Notably, plant community leaf dry matter content and soil nitrogen were the key factors mediating the effect of increasing drought intensity on microbial indicator taxa (ASVs). We conclude that increasing drought intensity affects grassland soil microbial communities during and after drought, and this impact is influenced by plant community composition and functional traits.

陆地生态系统正日益受到极端干旱事件的威胁。土壤微生物群落在调节生物地球化学循环方面发挥着重要作用，是陆地生态系统功能的核心。因此，日益严重的干旱事件对土壤微生物群落的影响将对生态系统如何应对气候变化产生连锁反应。在室外草地中观实验中，我们确定了干旱强度的增加如何影响干旱期间和干旱后细菌和真菌群落的组成和功能。我们还测试了植物群落资源获取策略（快速策略植物群落与慢速策略植物群落）、植物群落组成和植物功能特征是否介导了土壤微生物对干旱强度增加的反应。我们发现，干旱强度的增加明显改变了细菌和真菌群落的组成，这些影响一直持续到实验结束（复湿后两个月）。经历过严重干旱的细菌和真菌群落没有恢复到基线组成，而经历过轻度干旱的群落则恢复到了基线组成。在干旱高峰期和复湿后不久，微生物群落的功能（潜在的胞外酶活性）都有所降低。虽然干旱强度对细菌或真菌群落的影响对植物群落资源获取策略不敏感，但功能群丰度（禾本科或草本植物物种的地上生物量）组成（禾本科与草本植物的比例）和叶片特征（叶片干物质含量和叶片氮浓度）解释了干旱期间和干旱后细菌和真菌群落组成的显著变化。值得注意的是，植物群落叶片干物质含量和土壤氮是介导干旱强度增加对微生物指示类群（ASVs）影响的关键因素。我们的结论是，干旱强度的增加会在干旱期间和之后影响草地土壤微生物群落，而这种影响受到植物群落组成和功能特征的影响。

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引用次数: 0

Reduction of forest soil biota impacts tree performance but not greenhouse gas fluxes 森林土壤生物群的减少会影响树木的性能，但不会影响温室气体通量

IF 9.8 1区农林科学 Q1 SOIL SCIENCE

Soil Biology & Biochemistry

Pub Date : 2024-11-02 DOI: 10.1016/j.soilbio.2024.109643

Konstantinos Georgopoulos , T Martijn Bezemer , Jesper Riis Christiansen , Klaus Steenberg Larsen , Gina Moerman , Roos Vermeulen , Sten Anslan , Leho Tedersoo , Sofia IF. Gomes

Soil communities are essential to ecosystem functioning, yet the impact of reducing soil biota on root-associated communities, tree performance, and greenhouse gas (GHG) fluxes remains unclear. This study examines how different size fractions of soil biota from young and mature forests influence Alnus glutinosa performance, root-associated community composition, and GHG fluxes. We conducted a mesocosm experiment using soil community fractions (wet sieving through 250, 20, 11, and 3 μm) from young and mature forest developmental stages as inocula. The results indicate that the root-associated community composition was shaped by forest developmental stage but not by the size of the community fractions. Inoculation with the largest size fraction from mature forests negatively affected tree growth, likely due to increased competition between the plants and soil biota. In addition, GHG fluxes were not significantly impacted by either size fraction or forest developmental stage despite the different community composition supplied. Overall, our research indicates that A. glutinosa strongly selects the composition of the root-associated community, despite differences in the initial inoculum, and this composition varies depending on the stage of ecosystem development, impacting the performance of the trees but not GHG fluxes.

土壤生物群落对生态系统的功能至关重要，但土壤生物群落的减少对根系相关群落、树木性能和温室气体通量的影响仍不清楚。本研究探讨了幼林和成熟森林中不同大小的土壤生物群如何影响桤木（Alnus glutinosa）的表现、根相关群落组成和温室气体通量。我们使用幼林和成熟林发育阶段的土壤群落分馏物（湿筛分过 250、20、11 和 3 μm）作为接种物，进行了中观宇宙实验。结果表明，根相关群落的组成受森林发育阶段的影响，但与群落组分的大小无关。接种成熟森林中尺寸最大的部分会对树木生长产生负面影响，这可能是由于植物与土壤生物群之间的竞争加剧所致。此外，尽管提供的群落组成不同，但温室气体通量并没有受到群落大小或森林发育阶段的显著影响。总之，我们的研究表明，尽管初始接种物不同，但谷氨酰氨对根相关群落的组成有强烈的选择性，而且这种组成随生态系统发展阶段的不同而变化，会影响树木的表现，但不会影响温室气体通量。

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引用次数: 0

Natural seasonal freeze-thaw processes influenced soil quality in alpine grasslands: Insights from soil functions 自然季节性冻融过程对高山草地土壤质量的影响土壤功能的启示

IF 9.8 1区农林科学 Q1 SOIL SCIENCE

Soil Biology & Biochemistry

Pub Date : 2024-10-29 DOI: 10.1016/j.soilbio.2024.109642

Yuanhong Deng , Xiaoyan Li , Zhigang Wang , Fangzhong Shi , Shaojie Zhao , Guangrong Hu

Effects of freeze-thaw cycles on nutrient cycling and microbial activity have been well documented in laboratory simulations; however, field evidence remains insufficient, and studies regarding their effects on soil quality index (SQI)—as evaluated by soil functions that are influenced by multiple soil properties—are scarce. Therefore, we conducted spatiotemporal paired soil profile surveys along a freeze-thaw intensity gradient covering six grassland types. Results are as follows: 1) After a seasonal freeze-thaw event, soil properties across the 0–80 cm profile changed by 0.96%–31.02% (physical), −34.29%–44.04% (chemical), and −70.46%–272.97% (biological), with change rates varying across soil layers. 2) A function-based framework was employed to assess SQI_0–30 under freeze-thaw conditions, and the reliability of the function indices and SQI_0–30 was validated. 3) Compared to pre-freezing levels, post-thawing water retention and regulation index changed negligibly (+5.31%), carbon sequestration index remained stable (+2.52%), and the primary productivity index declined noticeably (−9.43%). Conversely, the nutrient supply and cycling index increased notably (+23.89%) due to elevated total potassium, catalase activity, and urease activity. The biodiversity provision index improved substantially (+95.63%) owing to increased dissolved organic carbon. Collectively, the SQI_0–30 increased evidently by 11.78%. 4) These alterations were associated with different freeze-thaw indicators, and the daily freeze-thaw temperature difference at 0–10 cm during the “freezing→frozen→thawing” period explained 55% of the SQI_0–30 change, surpassing impacts of meteorological factors (precipitation, air temperature, and snow depth). Our study suggests that natural seasonal freeze-thaw events can raise alpine grassland soil quality, with varied functional responses. The identified soil indicators and functions sensitive to freeze-thaw cycles facilitate the research on seasonal dynamics of alpine grassland soil and its multi-objective management, and the quantitative relationships with freeze-thaw indicators provide new insights for regional soil mapping in frozen areas under climate change.

冻融循环对养分循环和微生物活动的影响已在实验室模拟中得到充分证明；然而，实地证据仍然不足，有关冻融循环对土壤质量指数（SQI）影响的研究也很少，而土壤质量指数是通过受多种土壤特性影响的土壤功能来评估的。因此，我们沿冻融强度梯度对六种草地类型的土壤剖面进行了时空配对调查。结果如下1）在季节性冻融事件后，0-80 厘米剖面的土壤属性变化了 0.96%-31.02%（物理）、-34.29%-44.04%（化学）和-70.46%-272.97%（生物），不同土层的变化率各不相同。2) 采用基于功能的框架评估冻融条件下的 SQI0-30，并验证了功能指数和 SQI0-30 的可靠性。3) 与冻融前相比，冻融后的水分保持和调节指数变化微小（+5.31%），固碳指数保持稳定（+2.52%），初级生产力指数明显下降（-9.43%）。相反，由于总钾、过氧化氢酶活性和脲酶活性的提高，养分供应和循环指数显著上升（+23.89%）。由于溶解有机碳的增加，生物多样性供应指数大幅提高（+95.63%）。总之，SQI0-30 明显提高了 11.78%。4) 这些变化与冻融过程有关，在 "冻结→冰冻→解冻 "期间，0-10 厘米处的日冻融温差解释了 55% 的 SQI0-30 变化，超过了气象因素（降水、气温和积雪深度）的影响。我们的研究表明，自然季节性冻融事件可提高高寒草地的土壤质量，并产生不同的功能反应。所确定的对冻融周期敏感的土壤指标和功能有助于研究高寒草原土壤的季节动态及其多目标管理，而与冻融指标的定量关系则为气候变化下冰冻地区的区域土壤制图提供了新的见解。

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引用次数: 0

The rhizosphere contributes disproportionately to free-living nitrogen fixation in subalpine forest soils 根圈对亚高山森林土壤中的自由固氮作用贡献过大

IF 9.8 1区农林科学 Q1 SOIL SCIENCE

Soil Biology & Biochemistry

Pub Date : 2024-10-28 DOI: 10.1016/j.soilbio.2024.109641

Min Li , Jipeng Wang , Na Li , Qitong Wang , Peipei Zhang , Qiuhong Feng , Huajun Yin

Root activity creates a unique microbial hotspot in the rhizosphere, profoundly regulating free-living nitrogen fixation (FLNF). However, empirical assessments of rhizosphere FLNF and its ecological consequences for nitrogen (N) budgets remain lacking, particularly for different root functional modules. Here, we separately collected rhizosphere soils attached to two root functional modules, absorptive roots and transport roots, and investigated the rates (¹⁵N₂ incorporation) and regulators of rhizosphere FLNF in a N-limited subalpine coniferous forest. The measured rates were further extrapolated to annual fluxes based on the volume of the rhizosphere and the relationship between FLNF rate and temperature. We found that absorptive roots drove significantly higher rhizosphere FLNF rates than did transport roots (12.2 vs. 7.5 ng N g⁻¹ d⁻¹), with both rhizosphere compartments exhibiting rates well exceeding those in the bulk soil (0.9 ng N g⁻¹ d⁻¹). The FLNF rates were positively correlated with soil organic carbon content but showed no significant relationship with the abundance or composition of the diazotrophic community. Moreover, when extrapolated to the ecosystem level the FLNF fluxes were 2-fold greater in the rhizosphere of absorptive roots than in that of transport roots (0.13 vs. 0.04 kg N ha⁻¹ yr⁻¹). Taken together, despite representing only 6.0% of the soil volume, the two rhizosphere compartments contributed as much as 47.2% to the total soil FLNF fluxes. Overall, we provide empirical evidence that despite its limited volume, the rhizosphere contributes disproportionately to the FLNF in subalpine forest soils. Our findings also underscore the critical role of root functional differentiation in regulating rhizosphere FLNF, which is essential for integrating this process into the ecosystem-level N cycle.

根系活动在根圈中形成了一个独特的微生物热点，对自由生活固氮（FLNF）产生了深远的影响。然而，对根圈自由固氮作用及其对氮（N）预算的生态影响的实证评估仍然缺乏，尤其是对不同根系功能模块的评估。在这里，我们分别采集了附着在两种根功能模块（吸收根和运输根）上的根瘤土壤，并研究了氮限制亚高山针叶林中根瘤FLNF的速率（15N2吸收）和调节因子。根据根圈体积以及FLNF速率与温度之间的关系，将测得的速率进一步推断为年通量。我们发现，吸收根驱动的根圈 FLNF 速率（12.2 纳克 N g-1 d-1 与 7.5 纳克 N g-1 d-1）明显高于运输根，两个根圈分区的速率都远远超过了块状土壤中的速率（0.9 纳克 N g-1 d-1）。FLNF速率与土壤有机碳含量呈正相关，但与重氮营养群落的丰度或组成无明显关系。此外，当推断到生态系统水平时，吸收根根圈中的 FLNF 通量是运输根根圈中的 2 倍（0.13 vs. 0.04 kg N ha-1 yr-1）。总之，尽管这两个根圈只占土壤体积的 6.0%，但对土壤 FLNF 通量的贡献却高达 47.2%。总之，我们提供的经验证据表明，尽管根圈的体积有限，但它对亚高山森林土壤中的 FLNF 的贡献却不成比例。我们的研究结果还强调了根系功能分化在调节根圈 FLNF 中的关键作用，这对于将这一过程纳入生态系统级氮循环至关重要。

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引用次数: 0

Nitrogen induced soil carbon gains are resistant to loss after the cessation of excess nitrogen inputs 氮引起的土壤碳增量在停止过量氮输入后不易流失

IF 9.8 1区农林科学 Q1 SOIL SCIENCE

Soil Biology & Biochemistry

Pub Date : 2024-10-22 DOI: 10.1016/j.soilbio.2024.109640

Emel Kangi , Joanna R. Ridgeway , Hannah D. DeHetre , Edward R. Brzostek

Nitrogen (N) deposition has increased soil carbon (C) storage across eastern US temperate forests by reducing microbial decomposition. However, the fate of these N-induced soil C gains are uncertain given strong declines in N-deposition rates and rising soil temperatures. As N deposition has reduced soil pH and plant C investments into the rhizosphere, we compared the extent to which removing limitations to microbial decomposition by increasing soil pH, adding artificial root exudates, or elevating soil temperature would increase microbial decomposition in soils that have and have not received excess N inputs. We hypothesized that alleviating these microbial decomposition limitations would prime soil C losses from soils that have received excess N inputs. To test this hypothesis, we conducted a soil microcosm experiment where we compared microbial respiration, microbial biomass, and soil enzyme activity in soils from an unfertilized watershed and a previously N-fertilized watershed 4 years after the end of a 30-year N deposition experiment at the Fernow Experimental Forest in West Virginia. In both watersheds, we found that removing pH, plant carbon, or temperature limitations to decomposition stimulated microbial respiration. However, microbial decomposition and soil C losses were consistently lower in the previously N-fertilized watershed across all treatments. This response, coupled with a lack of differences in microbial biomass between watersheds and treatments, suggests that long-term N fertilization has fundamentally altered soil microbial communities and has led to a sustained impairment of the ability of the microbial community to decompose soil organic matter. Collectively, our results indicate that the legacy effect of N deposition on microbial communities may influence the persistence of soil C stocks in the face of global change.

氮（N）沉积通过减少微生物分解增加了美国东部温带森林的土壤碳（C）储存。然而，由于氮沉降率的大幅下降和土壤温度的升高，这些由氮引起的土壤碳增加的命运并不确定。由于氮沉积降低了土壤 pH 值，减少了植物对根圈的碳投资，因此我们比较了通过提高土壤 pH 值、添加人工根系渗出物或提高土壤温度来消除对微生物分解的限制，将在多大程度上增加氮输入过量和未输入过量的土壤中的微生物分解。我们假设，减轻这些微生物分解的限制将减少土壤中过量氮的流失。为了验证这一假设，我们在西弗吉尼亚州费尔诺实验森林进行了一项为期 30 年的氮沉积实验，实验结束 4 年后，我们对未施肥流域和之前施过氮肥流域的土壤中的微生物呼吸、微生物生物量和土壤酶活性进行了比较。我们发现，在这两个流域中，消除 pH 值、植物碳或温度对分解的限制都会刺激微生物呼吸。然而，在以前施过氮肥的流域，所有处理中的微生物分解和土壤碳损失都一直较低。这种反应，再加上不同流域和处理之间微生物生物量没有差异，表明长期施氮肥从根本上改变了土壤微生物群落，导致微生物群落分解土壤有机物的能力持续下降。总之，我们的研究结果表明，氮沉积对微生物群落的遗留效应可能会影响土壤碳储量在全球变化中的持久性。

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引用次数: 0

Warming increases CH4 emissions from rice paddies through shifts in methanogenic and methanotrophic communities 气候变暖通过甲烷发生群落和甲烷营养群落的变化增加稻田的甲烷排放量

IF 9.8 1区农林科学 Q1 SOIL SCIENCE

Soil Biology & Biochemistry

Pub Date : 2024-10-20 DOI: 10.1016/j.soilbio.2024.109639

Danmei Mo , Yunlong Liu , Min Li , Huixin Li , Jun Zhang , Haoyu Qian , Yanfeng Ding , Yu Jiang

Warming often stimulates methane (CH₄) emissions from rice paddies, one of the largest anthropogenic sources of CH₄ emissions. However, the responses of methanogenic and methanotrophic communities to warming, particularly within active communities, remain unclear. Therefore, based on a field warming experiment in a rice-wheat system, we investigated the effects of warming on methanogenic and methanotrophic communities, using the DNA stable-isotope probing technology. Our results indicated that warming increased CH₄ emissions by 27–49% over two rice growing seasons compared to ambient conditions. Warming significantly increased the abundance of methanogens by 53%, whereas did not affect activities of methanogens and active methanogenic community. Conversely, warming did not influence the abundance of methanotrophs, but reduced activities of methanotrophs by 44%. Notably, warming led to a significant rise in the relative abundance of the active type II methanotrophic community, which exhibits lower CH₄ oxidation efficiency. These findings suggest that the observed increase in CH₄ emissions under warming conditions is primarily driven by the enhanced abundance of methanogens and the increased presence of less efficient active type II methanotrophs. This study underscores the critical role of active microbial communities in understanding and managing CH₄ emissions from rice paddies in a warming world.

气候变暖通常会刺激稻田的甲烷（CH4）排放，而稻田是最大的人为甲烷排放源之一。然而，甲烷发生群落和甲烷营养群落对气候变暖的反应，尤其是在活跃群落中的反应，仍不清楚。因此，我们在水稻-小麦系统田间增温实验的基础上，利用DNA稳定同位素探测技术研究了增温对甲烷发生群落和甲烷营养群落的影响。结果表明，与环境条件相比，在两个水稻生长季中，气候变暖使甲烷排放量增加了 27-49%。气候变暖使甲烷菌的丰度明显增加了 58%，但并不影响甲烷菌的活性和活跃的甲烷菌群落。相反，气候变暖并不影响甲烷营养体的数量，但却使甲烷营养体的活动减少了 44%。值得注意的是，气候变暖导致活跃的 II 型甲烷营养群落的相对丰度显著上升，而 II 型甲烷营养群落的 CH4 氧化效率较低。这些发现表明，在气候变暖条件下观察到的CH4排放量增加主要是由甲烷菌的丰度增加和效率较低的活性II型甲烷营养体的增加所驱动的。这项研究强调了在气候变暖的世界中，活性微生物群落在了解和管理稻田甲烷排放中的关键作用。

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引用次数: 0

Divergent responses of soil glomalin and microbial necromass to precipitation reduction: New perspectives from soil aggregates and multi-trophic networks 土壤胶霉素和微生物坏死物对降水减少的不同反应：来自土壤聚集体和多营养网络的新视角

IF 9.8 1区农林科学 Q1 SOIL SCIENCE

Soil Biology & Biochemistry

Pub Date : 2024-10-20 DOI: 10.1016/j.soilbio.2024.109638

Xing Wang , Fang Chen , Jia Zeng , Zhengchen Wang , Yongzhong Feng , Xiaojiao Wang , Chengjie Ren , Gaihe Yang , Zekun Zhong , Xinhui Han

Global warming and increased drought are predicted to alter soil aggregation, biota composition, and carbon (C) balance. Microbial-derived C, such as microbial necromass C (MNC) and glomalin-related soil proteins (GRSP), are critical for soil organic carbon (SOC) stability. However, little is known about how climate change affects microbial-derived C within soil aggregates and its contribution to SOC. Here, we investigated the effects of 4-year warming (ca. 0.68 °C) and precipitation reduction (ca. −50% and −25%) on soil GRSP and MNC concentrations in semi-arid secondary grasslands and combined these results with a meta-analysis for GRSP. Results showed that warming increased MNC and its contribution to SOC, while precipitation reduction decreased MNC concentrations. Surprisingly, precipitation reduction increased GRSP concentrations and their contribution to SOC. Field experiments and meta-analysis also revealed that SOC and total nitrogen were negatively correlated with the C contribution of GRSP. Given the chemical recalcitrance of GRSP, this result may imply that the decrease in C and N content under precipitation reduction stimulates the formation of GRSP to enhance its subsequent protection of the SOC pool. Mechanistically, soil biota composition and its interactions dominated the variation in MNC between aggregates and climate change scenarios. The highest MNC concentrations in microaggregates may be attributed to higher fungal diversity, more stable multi-trophic networks, and weaker negative interactions across trophic levels. In addition, precipitation reduction significantly increased the abundance of modules in the multi-trophic network associated with SOC and MNC degradation, which were positively correlated with GRSP accumulation. These results suggest that climate change may regulate SOC dynamics by altering micro-food web structure in soil aggregates. Our study has direct implications for predicting the dynamics and stability of SOC fractions under future climate scenarios.

据预测，全球变暖和干旱加剧将改变土壤团聚、生物群组成和碳（C）平衡。微生物衍生的碳，如微生物坏死碳（MNC）和胶蛋白相关土壤蛋白质（GRSP），对土壤有机碳（SOC）的稳定性至关重要。然而，人们对气候变化如何影响土壤团聚体中的微生物衍生碳及其对 SOC 的贡献知之甚少。在这里，我们研究了 4 年气候变暖（约 0.68 °C）和降水减少（约 -50% 和 -25%）对半干旱次生草地土壤 GRSP 和 MNC 浓度的影响，并将这些结果与 GRSP 的荟萃分析相结合。结果表明，气候变暖增加了 MNC 及其对 SOC 的贡献，而降水减少则降低了 MNC 浓度。令人惊讶的是，降水量的减少增加了GRSP浓度及其对SOC的贡献。现场实验和荟萃分析还显示，SOC 和总氮与 GRSP 的碳贡献呈负相关。鉴于 GRSP 的化学脆性，这一结果可能意味着在降水减少的情况下，C 和 N 含量的减少会刺激 GRSP 的形成，从而加强其对 SOC 池的保护。从机理上讲，土壤生物群组成及其相互作用主导了不同聚集体和气候变化情景下 MNC 的变化。微团聚体中 MNC 浓度最高的原因可能是真菌多样性较高、多营养网络更稳定以及各营养级之间的负作用较弱。此外，降水量的减少显著增加了多营养网络中与 SOC 和 MNC 降解相关的模块的丰度，而这些模块与 GRSP 的积累呈正相关。这些结果表明，气候变化可能会通过改变土壤团聚体中的微食物网结构来调节SOC动态。我们的研究对预测未来气候情景下SOC组分的动态和稳定性有直接的意义。

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