Catena最新文献 - Book学术

Moderate grassland use counteracts the combined negative impact of nitrogen deposition and plant diversity decline on carbon exchange 适度利用草地可抵消氮沉积和植物多样性减少对碳交换的综合负面影响

IF 5.4 1区农林科学 Q1 GEOSCIENCES, MULTIDISCIPLINARY

Catena

Pub Date : 2024-11-17 DOI: 10.1016/j.catena.2024.108558

Guangyin Li , Yue Wang , Yann Hautier , Xuxin Song , Yipeng Zhou , Minna Zhang , Ling Wang

Atmospheric nitrogen deposition has inconsistent effects on grassland carbon (C) fluxes. Whether its effects are influenced by other global change drivers such as plant diversity decline, and whether grassland management (livestock grazing/mowing) can regulate these effects remain unclear. We performed a 6-year field manipulative experiment to examine the interactive effects of nitrogen addition, plant diversity decline, and moderate grassland use by livestock grazing and mowing on ecosystem C fluxes. Throughout three consecutive years (2018–2020), we measured net ecosystem CO₂ exchange (NEE) as the balance of gross ecosystem production (GEP) and ecosystem respiration (ER), on a monthly basis during the growing season (from May to September). We found that declines in plant diversity led to a reduction in NEE, whereas moderate grassland use resulted in an increase. The impact of nitrogen addition on NEE was contingent on specific context of grassland plant diversity and grazing/mowing utilization. Specifically, nitrogen addition had no effect on NEE in communities with high plant diversity while reduced NEE in communities with low diversity. However, in low plant diversity communities with grazing/mowing utilization, nitrogen addition increased NEE. Structural equation models further revealed that the combined effects of global changes (nitrogen addition and diversity decline) and grassland use (livestock grazing and mowing) on carbon exchange was regulated primarily by aboveground biomass. Our results indicate that moderate grassland use can reverse the negative effects of nitrogen addition on NEE in the low-diversity community. Our results highlight the potential of moderate grassland use as an effective management strategy for the enhancement of grassland C sequestration under ongoing global changes such as nitrogen deposition and biodiversity loss.

大气氮沉降对草地碳通量的影响并不一致。其影响是否受植物多样性下降等其他全球变化驱动因素的影响，以及草原管理（放牧/割草）是否能调节这些影响，目前仍不清楚。我们进行了一项为期 6 年的野外操纵实验，以研究氮添加、植物多样性下降以及放牧和刈割等适度草地利用方式对生态系统碳通量的交互影响。在连续三年（2018-2020 年）中，我们在生长季节（5 月至 9 月）按月测量了生态系统二氧化碳净交换量（NEE），即生态系统总产量（GEP）和生态系统呼吸量（ER）的平衡。我们发现，植物多样性的减少会导致 NEE 的减少，而适度使用草地则会导致 NEE 的增加。氮添加量对净能效的影响取决于草原植物多样性和放牧/割草利用率的具体情况。具体而言，在植物多样性高的群落中，氮添加量对净能效没有影响，而在多样性低的群落中，氮添加量则会降低净能效。然而，在有放牧/割草利用的低植物多样性群落中，氮的添加增加了净能效。结构方程模型进一步表明，全球变化（氮添加和多样性下降）和草地利用（牲畜放牧和刈割）对碳交换的综合影响主要受地上生物量的调节。我们的结果表明，在低多样性群落中，适度使用草地可以扭转氮添加对净碳排放量的负面影响。我们的研究结果突出表明，在氮沉降和生物多样性丧失等全球持续变化的情况下，适度利用草地是提高草地固碳能力的有效管理策略。

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引用次数: 0

Different types of Anthropocene signals recorded in Huguangyan Maar Lake over the past 450 years 湖光岩玛珥湖在过去 450 年中记录到的不同类型的人类世信号

IF 5.4 1区农林科学 Q1 GEOSCIENCES, MULTIDISCIPLINARY

Catena

Pub Date : 2024-11-17 DOI: 10.1016/j.catena.2024.108562

Shiwei Jiang , Xin Zhou , Li Ma , Shukun Cui , Xuanqiao Liu , Xiaoyan Liu , Anze Chen , Yong Luo , Liqiang Xu , Fangming Zeng , Deming Kong , Chao Huang , Guangcheng Zhang

Over the past few centuries, human activities have increasingly impacted global climate and ecological environments. The “Anthropocene” has been proposed to highlight the significant influence of human activities on the environment. However, prior research has focused on analyzing a single type of human activity in lake sediments. In this study, we examined the historical changes in water eutrophication, terrestrial vegetation, and heavy metal pollution in the sediments of Huguangyan Maar Lake over the past 450 years. By comparing different human activity records within the same regional and chronological framework, we found that the timing of significant impacts on lake sediments varied by activity type. Eutrophication, induced by population growth and agricultural fertilization, began around 1950 CE. Changes in vegetation owing to agricultural and forestry practices occurred around 1780, 1880, and 1980 CE. Significant enrichment of heavy metals from industrial production began around 1950 CE. We suggest that, in reconstructing the history of human activities or defining the onset of the “Anthropocene,” it is crucial to consider both the types of human activities and their spatial extent.

过去几个世纪以来，人类活动对全球气候和生态环境的影响与日俱增。为了强调人类活动对环境的重大影响，人们提出了 "人类世"。然而，之前的研究主要集中于分析湖泊沉积物中单一类型的人类活动。在本研究中，我们考察了过去 450 年间湖光岩玛珥湖沉积物中水体富营养化、陆地植被和重金属污染的历史变化。通过比较同一区域和年代框架内的不同人类活动记录，我们发现不同活动类型对湖泊沉积物产生重大影响的时间各不相同。人口增长和农业施肥引起的富营养化始于公元 1950 年左右。农业和林业活动导致的植被变化发生在公元 1780 年、1880 年和 1980 年前后。工业生产造成的重金属严重富集始于公元 1950 年前后。我们建议，在重建人类活动历史或定义 "人类世 "的开始时，必须考虑人类活动的类型及其空间范围。

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引用次数: 0

The contributions of dark microbial CO2 fixation to soil organic carbon along a tropical secondary forest chronosequence on Hainan Island, China 中国海南岛热带次生林时序中暗色微生物固定二氧化碳对土壤有机碳的贡献

IF 5.4 1区农林科学 Q1 GEOSCIENCES, MULTIDISCIPLINARY

Catena

Pub Date : 2024-11-16 DOI: 10.1016/j.catena.2024.108556

Yanfei Sun , Meiqiu Yang , Yi Ding , Danting Deng , Zongrui Lai , Wenxing Long

Nonphototrophic CO₂ fixation by microorganisms can reduce soil pore CO₂ to organic matter in the dark. Tropical forest restoration changes soil microbial community structure and organic carbon (SOC) storage. However, whether the capacity for dark CO₂ fixation is altered and contributes to SOC accumulation during tropical forest restoration remains unclear. Here, in the topsoil and deep soil of a tropical forest restoration chronosequence, we investigated chemoautotrophic and heterotrophic microbes and pathways involved in dark CO₂ fixation using a metagenome and quantified CO₂ fixation rates with a ¹³C–CO₂ labelling experiment. Tropical forest restoration altered the autotrophic CO₂ fixation pathway abundance in the Ah horizon, which showed an increasing trend. Heterotrophic carboxylase gene abundance was influenced by soil layer and was more abundant in the B horizon. The main microbes involved in CO₂ fixation belong to Acidobacteria, Proteobacteria, and Actinobacteria. ¹³C–CO₂ labelling showed that the CO₂ fixation rates across the restoration chronosequence ranged from 0.035 to 0.155 μg C/g soil d⁻¹, and the middle- and late-stage secondary forests exhibited higher rates compared to other stages. The microbial assimilation of CO₂ into mineral-associated organic carbon was also observed and the rate exhibited a similar trend to that into SOC, indicating that dark CO₂ fixation contributes to stable carbon formation. Tropical forest restoration influenced the CO₂ fixation rate indirectly by changing microbial CO₂ fixation gene abundance. Specifically, autotrophic pathways (Calvin, reductive citrate, and Wood−Ljungdahl cycles) and heterotrophic carboxylase genes (phosphoenolpyruvate and pyruvate carboxylases) were vital for CO₂ fixation in the Ah and B horizons, respectively. Our results suggest that SOC formed by microbial CO₂ assimilation contributes to the long-term soil carbon sequestration, especially in secondary forests, which have recovered to middle- and late-stages. The study highlights the importance of dark microbial CO₂ fixation in soil carbon sequestration and provides a new understanding of tropical forest soil carbon processes.

微生物的非光养性二氧化碳固定作用可在黑暗中将土壤孔隙中的二氧化碳转化为有机物。热带森林恢复改变了土壤微生物群落结构和有机碳（SOC）储存。然而，在热带森林恢复过程中，暗固定二氧化碳的能力是否会改变并导致 SOC 的积累，目前仍不清楚。在这里，我们利用元基因组研究了热带森林恢复时序的表土和深层土壤中的化能自养和异养微生物以及参与暗二氧化碳固定的途径，并通过 13C-CO2 标记实验量化了二氧化碳固定率。热带森林恢复改变了Ah地层中自养型二氧化碳固定途径的丰度，其丰度呈上升趋势。异养羧化酶基因丰度受土壤层的影响，在 B 层中更为丰富。参与二氧化碳固定的主要微生物属于酸细菌、蛋白质细菌和放线菌。13C-CO2 标记显示，整个恢复时序的二氧化碳固定率在 0.035 至 0.155 μg C/g 土壤 d-1 之间，中、晚期次生林的固定率高于其他阶段。此外，还观察到微生物将二氧化碳同化为与矿物相关的有机碳，其速率与同化为 SOC 的速率呈相似趋势，表明暗二氧化碳固定有助于稳定碳的形成。热带森林恢复通过改变微生物二氧化碳固定基因的丰度间接影响了二氧化碳固定率。具体而言，自养途径（卡尔文循环、还原柠檬酸循环和伍德-荣格达尔循环）和异养羧化酶基因（磷酸烯醇丙酮酸酶和丙酮酸羧化酶）分别对 Ah 和 B 层的二氧化碳固定至关重要。我们的研究结果表明，微生物二氧化碳同化形成的 SOC 有助于土壤的长期固碳，尤其是在已恢复到中晚期的次生林中。该研究强调了暗色微生物二氧化碳固定在土壤固碳中的重要性，并为热带森林土壤碳过程提供了新的认识。

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引用次数: 0

An adaptive strategy for current afforestation in the forest-steppe ecotone, north China, inferred from the Holocene geo-ecology dynamics 从全新世地理生态动态推断出的华北森林草原生态区当前植树造林的适应性战略

IF 5.4 1区农林科学 Q1 GEOSCIENCES, MULTIDISCIPLINARY

Catena

Pub Date : 2024-11-16 DOI: 10.1016/j.catena.2024.108533

Zhiqiang Yin , Hongjuan Jia , Hai Shao , Yue He , Xiaoguang Qin , Jumei Pang , Yang Fu

The current afforestation in the forest-steppe ecotone of northern China to reduce continental desertification is hindered by a problem of what vegetational assemblage would adapt to local environment. Here we attempted to address the issue by investigating the long-term geo-ecological background in the Saihanba Forest Farm region, using pollen, biomarker, and radiocarbon dating analysis. Results show that natural arboreal species over the past 10,000 years were mainly composed of Quercus, Betula, Ulmus, Pinus and Juglans. Shrub species consisted of Prunus sibirica, and Ericaceae, while herbs included Artemisia, Chenopodiaceae, and Poaceae. The regional vegetation was profoundly altered by anthropogenic factors since ∼300 a B.P., as evidenced by an abrupt increase in coniferous trees. The Holocene climate in this region generally fluctuated from a cold-dry to a warm-humid condition and finally returned to cold and dry, suggesting a similar climatic status between the Holocene optimum (∼6 ka) and the modern warming periods. Therefore, we propose an adaptive vegetational assemblage for current afforestation, enhancing the sustainability of the Three-North Shelterbelt Project.

目前在中国北方森林草原生态区开展的旨在减少大陆荒漠化的植树造林活动受到了植被组合如何适应当地环境问题的阻碍。在此，我们尝试利用花粉、生物标记和放射性碳年代测定分析，调查塞罕坝林场地区的长期地理生态背景，以解决这一问题。结果表明，在过去的一万年中，天然树栖物种主要由柞树、桦树、榆树、松树和鹅掌楸组成。灌木树种包括西伯利亚李属（Prunus sibirica）和鸢尾科（Ericaceae），草本植物包括蒿科（Artemisia）、藜科（Chenopodiaceae）和蒲葵科（Poaceae）。自公元前 300 年以来，该地区的植被受到人为因素的严重影响，针叶树突然增多就是证明。该地区全新世的气候从寒冷干燥到温暖湿润，最后又恢复到寒冷干燥的状态，表明全新世最适宜期（∼6 ka）与现代变暖期的气候状况相似。因此，我们为当前的植树造林提出了一种适应性植被组合，以提高三北防护林工程的可持续性。

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引用次数: 0

Effects of increasing rainfall on organic carbon release and transport processes in permafrost on the central Tibetan Plateau 降雨增加对青藏高原中部永久冻土有机碳释放和迁移过程的影响

IF 5.4 1区农林科学 Q1 GEOSCIENCES, MULTIDISCIPLINARY

Catena

Pub Date : 2024-11-16 DOI: 10.1016/j.catena.2024.108553

Haotian Wei , Enlong Liu , Chuan He , Bingtang Song , Dan Wang , Jian Kang , Ling Chen , Qiong Li

Rainfall can alter the hydrothermal state of permafrost, subsequently affecting organic carbon decomposition and CO₂ transport. However, the mechanisms by which rainfall influences organic carbon decomposition and carbon dioxide transport processes in permafrost remain unclear. In this study, a coupled permafrost water-heat-vapor-carbon model, based on the surface energy-water balance theory, is employed to explore the effects of increased precipitation on permafrost moisture, temperature, organic carbon decomposition, and carbon dioxide transport through numerical simulations. The results are as follows: (1) with increased rainfall, surface latent heat flux rises while surface sensible heat flux declines, leading to a reduction in surface heat flux. The annual mean surface heat fluxes for the three precipitation conditions of no change in precipitation (ΔP = 0 mm), 50 mm increase in precipitation (ΔP = 50 mm) and 100 mm increase in precipitation (ΔP = 100 mm) are −0.1 W/m², −0.2 W/m² and −0.4 W/m² respectively; and (2) as rainfall increases, soil moisture content increases significantly, but the impact of rainfall on soil moisture content diminishes with increasing soil depth; and (3) increased rainfall results in a decrease in soil carbon fluxes, soil organic matter decomposition rates, and CO₂ concentrations. Compared to the case of constant precipitation, the surface carbon fluxes decreased by 0.04

μ mol \cdot m^{-2} s^{-1}

and 0.08

μ mol \cdot m^{-2} s^{-1}

under ΔP = 50 mm and ΔP = 100 mm, respectively. Additionally, the decomposition rate of soil organic matter at 10 cm depth decreased by 3.2 E-8

mol \cdot m^{-2} s^{-1}

and 6.3 E-8

mol \cdot m^{-2} s^{-1}

, respectively, while the soil carbon concentration decreased by 3

μ m o l / m o l

and 5

μ m o l / m o l

, respectively.

降雨可改变永久冻土的水热状态，进而影响有机碳分解和二氧化碳迁移。然而，降雨影响永久冻土中有机碳分解和二氧化碳迁移过程的机制仍不清楚。本研究采用基于地表能量-水分平衡理论的冻土水-热-气-碳耦合模型，通过数值模拟探讨了降水增加对冻土水分、温度、有机碳分解和二氧化碳输运的影响。结果如下(1）随着降雨量的增加，地表潜热通量上升，而地表显热通量下降，导致地表热通量减少。在降水量不变（ΔP = 0 毫米）、降水量增加 50 毫米（ΔP = 50 毫米）和降水量增加 100 毫米（ΔP = 100 毫米）的三种降水条件下，地表年平均热通量分别为-0.1 W/m2、-0.2 W/m2 和-0.4 W/m2 ；（2）随着降水量的增加，土壤含水量显著增加，但降水量对土壤含水量的影响随土壤深度的增加而减弱；（3）降水量的增加导致土壤碳通量、土壤有机质分解率和二氧化碳浓度的降低。与降水量不变的情况相比，在 ΔP = 50 mm 和 ΔP = 100 mm 条件下，地表碳通量分别减少了 0.04 μmol-m-2s-1 和 0.08 μmol-m-2s-1。此外，10 厘米深的土壤有机质分解率分别降低了 3.2 E-8 mol-m-2s-1 和 6.3 E-8 mol-m-2s-1，土壤碳浓度分别降低了 3 μmol/mol 和 5 μmol/mol。

{"title":"Effects of increasing rainfall on organic carbon release and transport processes in permafrost on the central Tibetan Plateau","authors":"Haotian Wei , Enlong Liu , Chuan He , Bingtang Song , Dan Wang , Jian Kang , Ling Chen , Qiong Li","doi":"10.1016/j.catena.2024.108553","DOIUrl":"10.1016/j.catena.2024.108553","url":null,"abstract":"<div><div>Rainfall can alter the hydrothermal state of permafrost, subsequently affecting organic carbon decomposition and CO<sub>2</sub> transport. However, the mechanisms by which rainfall influences organic carbon decomposition and carbon dioxide transport processes in permafrost remain unclear. In this study, a coupled permafrost water-heat-vapor-carbon model, based on the surface energy-water balance theory, is employed to explore the effects of increased precipitation on permafrost moisture, temperature, organic carbon decomposition, and carbon dioxide transport through numerical simulations. The results are as follows: (1) with increased rainfall, surface latent heat flux rises while surface sensible heat flux declines, leading to a reduction in surface heat flux. The annual mean surface heat fluxes for the three precipitation conditions of no change in precipitation (ΔP = 0 mm), 50 mm increase in precipitation (ΔP = 50 mm) and 100 mm increase in precipitation (ΔP = 100 mm) are −0.1 W/m<sup>2</sup>, −0.2 W/m<sup>2</sup> and −0.4 W/m<sup>2</sup> respectively; and (2) as rainfall increases, soil moisture content increases significantly, but the impact of rainfall on soil moisture content diminishes with increasing soil depth; and (3) increased rainfall results in a decrease in soil carbon fluxes, soil organic matter decomposition rates, and CO<sub>2</sub> concentrations. Compared to the case of constant precipitation, the surface carbon fluxes decreased by 0.04 <span><math><mrow><mi>μ</mi><mtext>mol</mtext><mo>·</mo><msup><mrow><mtext>m</mtext></mrow><mtext>-2</mtext></msup><msup><mrow><mtext>s</mtext></mrow><mtext>-1</mtext></msup></mrow></math></span> and 0.08 <span><math><mrow><mi>μ</mi><mtext>mol</mtext><mo>·</mo><msup><mrow><mtext>m</mtext></mrow><mtext>-2</mtext></msup><msup><mrow><mtext>s</mtext></mrow><mtext>-1</mtext></msup></mrow></math></span> under ΔP = 50 mm and ΔP = 100 mm, respectively. Additionally, the decomposition rate of soil organic matter at 10 cm depth decreased by 3.2 E-8 <span><math><mrow><mtext>mol</mtext><mo>·</mo><msup><mrow><mtext>m</mtext></mrow><mtext>-2</mtext></msup><msup><mrow><mtext>s</mtext></mrow><mtext>-1</mtext></msup></mrow></math></span> and 6.3 E-8 <span><math><mrow><mtext>mol</mtext><mo>·</mo><msup><mrow><mtext>m</mtext></mrow><mtext>-2</mtext></msup><msup><mrow><mtext>s</mtext></mrow><mtext>-1</mtext></msup></mrow></math></span>, respectively, while the soil carbon concentration decreased by 3 <span><math><mrow><mi>μ</mi><mi>m</mi><mi>o</mi><mi>l</mi><mo>/</mo><mi>m</mi><mi>o</mi><mi>l</mi></mrow></math></span> and 5 <span><math><mrow><mi>μ</mi><mi>m</mi><mi>o</mi><mi>l</mi><mo>/</mo><mi>m</mi><mi>o</mi><mi>l</mi></mrow></math></span>, respectively.</div></div>","PeriodicalId":9801,"journal":{"name":"Catena","volume":"247 ","pages":"Article 108553"},"PeriodicalIF":5.4,"publicationDate":"2024-11-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142663115","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Unravelling the spatial structure of regular dryland vegetation patterns 揭示常规旱地植被模式的空间结构

IF 5.4 1区农林科学 Q1 GEOSCIENCES, MULTIDISCIPLINARY

Catena

Pub Date : 2024-11-16 DOI: 10.1016/j.catena.2024.108442

Karl Kästner , Roeland C. van de Vijsel , Daniel Caviedes-Voullième , Nanu T. Frechen , Christoph Hinz

Many resource-limited ecosystems exhibit spatial patterns where patches of biomass alternate with bare ground. Patterns can enhance ecosystem functioning and resilience, depending on their spatial structure. Particularly conspicuous are regular patterns, where patches are of similar size and spaced in similar intervals. The spatial structure of regular patterns is often described to be periodic. This has been corroborated by statistical testing of natural patterns and generation of periodic patterns with deterministic reaction–diffusion models. Yet, natural regular patterns appear conspicuously erratic compared to periodic patterns. So far, this has been attributed to perturbations by noise, varying patch size and spacing. First, we illustrate by means of an example that the spatial structure of regular vegetation patterns cannot be reproduced by perturbing periodic patterns. We then compile a large dataset of regular dryland patterns and find that their spatial structure systematically differs from periodic patterns. We further reveal that previous studies testing for periodicity overlook two aspects which dramatically inflate the number of false positives and result in the misclassification of patterns as periodic. We amend the test procedure by accounting for both aspects, finding that regular natural patterns have no significant periodic components. Lastly, we demonstrate that stochastic processes can generate regular patterns with similar visual appearance, spatial structure and frequency spectra as natural regular patterns. We conclude that new methods are required for quantifying the regularity of spatial patterns beyond a binary classification and to further investigate the difference between natural and model generated patterns.

许多资源有限的生态系统呈现出生物量斑块与裸露地面交替出现的空间模式。这种模式可以增强生态系统的功能和恢复力，具体取决于其空间结构。特别明显的是规则模式，即斑块大小相似、间隔相似。规则模式的空间结构通常被描述为周期性的。对自然规律的统计检验以及用确定性反应-扩散模型生成周期性规律都证实了这一点。然而，与周期性图案相比，自然规则图案显得明显不稳定。迄今为止，人们一直将其归咎于噪声、不同斑块大小和间距的扰动。首先，我们通过一个例子说明，周期性模式的扰动无法再现规则植被模式的空间结构。然后，我们汇编了大量有规律的旱地模式数据集，发现它们的空间结构与周期性模式存在系统性差异。我们进一步揭示，以往测试周期性的研究忽略了两个方面，这两个方面极大地增加了假阳性的数量，导致将模式错误地归类为周期性模式。我们修正了测试程序，考虑了这两方面的因素，发现有规律的自然模式没有明显的周期性成分。最后，我们证明了随机过程可以生成与自然规则图案具有相似视觉外观、空间结构和频谱的规则图案。我们的结论是，除了二元分类之外，还需要新的方法来量化空间图案的规律性，并进一步研究自然图案和模型生成图案之间的差异。

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引用次数: 0

Evolution of the Eemian lake-mire ecosystem at the Wola Starogrodzka site (Central Poland) Wola Starogrodzka 遗址（波兰中部）伊埃米湖沼生态系统的演变

IF 5.4 1区农林科学 Q1 GEOSCIENCES, MULTIDISCIPLINARY

Catena

Pub Date : 2024-11-15 DOI: 10.1016/j.catena.2024.108526

Danuta Drzymulska , Magdalena Fiłoc , Mirosława Kupryjanowicz , Joanna Mirosław-Grabowska , Karol Standzikowski , Magdalena Suchora , Marcin Żarski

The assessment of detailed palaeoecological data obtained from the analysis of pollen, plant macrofossils, Cladocera, geochemistry, and stable isotopes of sediments has provided valuable information on the evolution of lakes. The target was the Eemian lake-mire ecosystem located in Central Poland, within palaeolakeland on the Garwolin Plain. Pollen analysis of biogenic sediments from the PWS2-19 profile collected at the Wola Starogrodzka site revealed that the studied lake existed from the beginning (E1 R PAZ) to the final phase (E7 R PAZ) of the Eemian Interglacial. In total, five stages of lake-mire ecosystem development were recognized. Stages I-III spanned a shallow open-water ecosystem with rising trophic state indicated by vegetation and Cladocera communities. However, it remained in opposition to the low content of organic matter in sediments accumulated at the time. Both dense forest cover and possible flow through the water body could be key for the low organic matter content. High mineralization may also have been an important factor. The first signs of lake overgrowth were noted during stage IV, and then the lake was transformed into mire (stage V), which was recorded in all proxies. Mire development was probably associated with two sedimentation hiatuses: in the middle part of E5 R PAZ and at the beginning of E6 R PAZ. Such hiatuses, as the results of lower groundwater level, were also known at these phases from other profiles, and not only from Poland.

通过对花粉、植物大化石、畸形动物、地球化学和沉积物稳定同位素的分析，获得了详细的古生态学数据，这些数据的评估为湖泊的演变提供了宝贵的信息。此次研究的目标是位于波兰中部加沃林平原古湖区内的埃米纪湖沼生态系统。对在 Wola Starogrodzka 遗址采集的 PWS2-19 剖面生物沉积物进行的花粉分析表明，所研究的湖泊存在于埃米纪间冰期的初期（E1 R PAZ）至末期（E7 R PAZ）。湖沼生态系统的发展总共经历了五个阶段。第一至第三阶段为浅水开放生态系统，植被和桡足类群落显示其营养状态不断上升。然而，这仍然与当时积累的沉积物中有机物含量低的情况相反。茂密的森林植被和可能流经水体的水流可能是有机物含量低的关键。高矿化度也可能是一个重要因素。湖泊过度生长的最初迹象出现在第四阶段，随后湖泊变成了沼泽（第五阶段），所有代用指标都记录了这一过程。泥沼的形成可能与两个沉积间断期有关：E5 R PAZ 中期和 E6 R PAZ 初期。这种间断是地下水位降低的结果，在其他剖面上也可见到，而不仅仅是在波兰。

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引用次数: 0

Sem-derived microstructure of cyanobacterial and moss biocrusts and their connections to mechanical stability of two contrasting dryland soils 蓝藻和苔藓生物簇的半衍生微结构及其与两种截然不同的旱地土壤力学稳定性的联系

IF 5.4 1区农林科学 Q1 GEOSCIENCES, MULTIDISCIPLINARY

Catena

Pub Date : 2024-11-15 DOI: 10.1016/j.catena.2024.108537

Xingxing Yu , Bo Xiao , Yousong Cao , Giora J. Kidron

As an important biological component of the soil surface in drylands, biocrusts play an indispensable role in maintaining soil ecosystem multifunctionality. However, the microstructure of these biocrusts remains unclear. For this end, both cyanobacterial and moss crusts inhabiting sandy and loessial soils were collected on the Chinese Loess Plateau, and their profiles were thoroughly studied using scanning electron microscope (SEM). A full SEM image of each biocrust sample were quantitatively analyzed and their mechanical stability was measured. The SEM images showed that moss crusts had a more complex soil structure compared to cyano crusts. Furthermore, the filament density, ratio indices of soil particles to filaments (N_P/L_F and L_F/A_P), and the pore area ratio (PAR) of the moss crusts were higher than that of the cyano crusts on both soils. The penetration resistance (PR) and shear force of the moss crusts were higher than those of the cyano crusts on both soils, but the same type of biocrusts was less stable on the sandy soil than that on loessial soil. In addition, our results showed that the microstructure of biocrusts showed an obvious correlation with their PR, with an apparent threshold value for the effect of soil particles to filaments ratio indices of biocrusts on their mechanical stability. On the sandy soil, the PR of the biocrusts reached the maximum when N_P/L_F was 10.0–13.0 mm⁻¹, and L_F/A_P was 12.0–14.0 mm m⁻² (cyano crusts) and 21.0–29.0 mm m⁻² (moss crusts). While on the loessial soil, the PR of the biocrusts reached its maximum when N_P/L_F and L_F/A_P were 37.0–40.0 mm⁻¹ and 11.0–12.5 mm m⁻², respectively. Our study elucidated the microstructural characteristics of the biocrust profiles on the different soils and their thresholds affecting mechanical stability, which may help in the site-specific application of biocrusts in soil remediation and ecological restoration.

作为干旱地区土壤表面的重要生物组成部分，生物簇在维持土壤生态系统多功能性方面发挥着不可或缺的作用。然而，这些生物结壳的微观结构仍不清楚。为此，研究人员在中国黄土高原采集了栖息于沙土和黄土中的蓝藻和苔藓结壳，并利用扫描电子显微镜（SEM）对其剖面进行了深入研究。对每个生物簇样本的完整扫描电子显微镜图像进行了定量分析，并测量了它们的机械稳定性。扫描电子显微镜图像显示，苔藓结壳与藻类结壳相比，具有更复杂的土壤结构。此外，苔藓结壳的丝状物密度、土壤颗粒与丝状物的比率指数（NP/LF 和 LF/AP）以及孔隙面积比（PAR）均高于两种土壤上的藻类结壳。苔藓结壳的穿透阻力（PR）和剪切力在两种土壤上都高于藻类结壳，但同一类型的生物结壳在沙质土壤上的稳定性低于在黄土上的稳定性。此外，我们的研究结果表明，生物结壳的微观结构与其PR有明显的相关性，生物结壳的土壤颗粒与菌丝比指数对其力学稳定性的影响有一个明显的临界值。在砂质土壤上，当 NP/LF 为 10.0-13.0 mm-1 ，LF/AP 为 12.0-14.0 mm m-2 （藻类结壳）和 21.0-29.0 mm m-2 （苔藓结壳）时，生物结壳的 PR 达到最大值。而在黄土上，当 NP/LF 和 LF/AP 分别为 37.0-40.0 mm-1 和 11.0-12.5 mm m-2 时，生物结壳的 PR 达到最大值。我们的研究阐明了不同土壤上生物簇剖面的微观结构特征及其影响机械稳定性的阈值，这可能有助于生物簇在土壤修复和生态恢复中的具体应用。

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引用次数: 0

Redox conditions and Indicator of Reduction in Soils (IRIS) films in soils of a hypersaline wetland 高盐度湿地土壤中的氧化还原条件和土壤还原指示剂（IRIS）薄膜

IF 5.4 1区农林科学 Q1 GEOSCIENCES, MULTIDISCIPLINARY

Catena

Pub Date : 2024-11-15 DOI: 10.1016/j.catena.2024.108552

Carmen Castañeda , Rafael Rodríguez-Ochoa , José Ramón Olarieta , Eva Medina , Borja Latorre , Brian Scott , Martin C. Rabenhorst , Juan Herrero

Information about the reducing conditions in hypersaline wetland soils is scarce though redox traits are of ecological and agronomical interest. We studied the soils and water in Salineta playa-lake (NE Spain) plus the soil redox conditions using IRIS (Indicators of Reduction in Soils) films during 17 months. Soils had a pH varying from 6.8 to 7.8, a mean gypsum content of 38 %, a mean organic carbon content of 0.6 %, and soil salinity ranged from 219 to 66 dS m⁻¹ in the saturated paste extract. Soil horizons showed distinct morphological features consistent with a redox potential (Eh) ranging from +434 to −108 mV. Minimum Eh occurred in the upper soil horizon indicating intensified reducing conditions with a transition to aerobic conditions with depth. Sulfidic and Anoxic conditions prevailed during the annual cycle despite temporary drying. The IRIS films revealed an irregular removal of manganese and iron oxide coatings through time and through the film depth as triggered by pulses of the water level. The monthly removal rate was 10.6 % for manganese and 5 % for iron films. Iron removal showed a delayed and irregular response due to the alkaline conditions. The persistent accumulation of sulfides in the soil resulted in a distinctive black soil layer which can be a key feature for future monitoring of the impacts of the agricultural flows from surrounding irrigated lands. Further research on pedogenesis of arid wetlands will help the soil resource inventories and the understanding of the various life adaptations to these conditions.

尽管氧化还原特性具有生态学和农学意义，但有关高盐湿地土壤还原条件的信息却很少。我们对西班牙东北部萨利内塔（Salineta playa-lake）的土壤和水进行了为期 17 个月的研究，并使用 IRIS（土壤氧化还原指标）薄膜对土壤氧化还原条件进行了分析。土壤的 pH 值从 6.8 到 7.8 不等，石膏平均含量为 38%，有机碳平均含量为 0.6%，饱和糊状提取物中的土壤盐度从 219 到 66 dS m-1 不等。土壤层的形态特征明显，氧化还原电位（Eh）在 +434 至 -108 mV 之间。上部土壤层的 Eh 值最小，表明还原条件增强，并随着深度的增加向好氧条件过渡。尽管有暂时的干燥，但硫酸和缺氧条件在年周期内普遍存在。IRIS 薄膜显示，随着时间的推移和薄膜深度的增加，锰和氧化铁的脱落是不规则的，这是由水位脉冲引起的。锰膜和铁膜的月去除率分别为 10.6%和 5%。由于碱性条件的影响，铁的去除出现了延迟和不规则的反应。硫化物在土壤中的持续积累形成了独特的黑色土层，这可能是未来监测周边灌溉地农业用水影响的一个关键特征。进一步研究干旱湿地的成土过程将有助于土壤资源的清查和了解生命对这些条件的各种适应性。

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引用次数: 0

Impacts of land use change on soil carbon storage and phosphorus fractions in tropics 土地利用变化对热带地区土壤碳储存和磷组分的影响

IF 5.4 1区农林科学 Q1 GEOSCIENCES, MULTIDISCIPLINARY

Catena

Pub Date : 2024-11-15 DOI: 10.1016/j.catena.2024.108550

Mohsin Mahmood , Waqas Ahmed , Anam Ayyoub , Ahmed Salah Elrys , Adnan Mustafa , Weidong Li , Zhuwen Xu

Human-induced land use transformations in tropical regions have notably impacted soil nutrient dynamics, particularly of carbon (C) and phosphorus (P). This study investigates soil C stocks and P fractions across six distinct land use types (fallow, residential, woodland, garden plots, cultivated lands, and grasslands) and their influence on soil P distribution at varying soil depths in Hainan Island, China. Higher concentrations of total carbon (TC) and soil organic carbon (SOC) were found in woodland (1.29 %, 1.21 %), garden plot (1.18 %, 1.1 %), and grassland (1.12 %, 1.02 %) soils at the topsoil (0–20 cm), with a noticeable decrease in deep soil layers (20–180 cm) compared to fallow, residential, and cultivated lands. In deeper soil layers (20–100 cm and 100–180 cm), woodland and grassland soils exhibited higher SOC and TC densities (10.09, 15.77 kg m⁻²; 15.29, 17.03 kg m⁻², respectively). Using Hedley’s modified Tiessen and Moir scheme, P fractionation analysis indicated P limitation in different land use systems. Grassland soils had higher organic P fractions (NaOH-Po, NaHCO₃-Po, HClc-Po) at 0–20 cm depth, remaining consistent at deeper layers. In cultivated and grassland soils, the inorganic P fraction (HCl_D-Pi) was the most significant contributor to total P across all depths. There was a steady trend in residual P across the land use depths. Correlations between labile (NaHCO₃-Pi, NaHCO₃-Po), moderately (NaOH-Po, NaOH-Pi, HCl_D-Pi) available P fractions and carbon stocks across all depths further revealed the crucial role of SOC in the regulation of P availability. It can thus be concluded that land use differentially influences SOC and P storage potential in Hainan Island, with divergence in soil layers. These findings highlight the significance of region-specific land management practices for maintaining soil health to mitigate climate change.

热带地区由人类引起的土地利用变化对土壤养分动态，尤其是碳（C）和磷（P）产生了显著影响。本研究调查了中国海南岛六种不同土地利用类型（休耕地、居民点、林地、园地、耕地和草地）的土壤碳储量和磷组分及其对不同土壤深度土壤磷分布的影响。与休耕地、居民点和耕地相比，林地（1.29 %，1.21 %）、园地（1.18 %，1.1 %）和草地（1.12 %，1.02 %）土壤表层（0-20 cm）的总碳（TC）和土壤有机碳（SOC）含量较高，深土层（20-180 cm）的总碳（TC）和土壤有机碳（SOC）含量明显降低。在较深的土层（20-100 厘米和 100-180 厘米）中，林地和草地土壤的 SOC 和 TC 密度较高（分别为 10.09、15.77 千克/平方米；15.29、17.03 千克/平方米）。利用 Hedley 改良的 Tiessen 和 Moir 方案，P 分馏分析表明了不同土地利用系统中的 P 限制。草地土壤在 0-20 厘米深处的有机钾分馏（NaOH-Po、NaHCO3-Po、HClc-Po）较高，在更深的土层则保持一致。在耕地和草地土壤中，无机钾部分（HClD-Pi）在所有深度的总钾量中占比最大。不同土地利用深度的残余 P 呈稳定趋势。易溶（NaHCO3-Pi、NaHCO3-Po）、中度（NaOH-Po、NaOH-Pi、HClD-Pi）可利用钾组分与各深度碳储量之间的相关性进一步揭示了 SOC 在调节钾可利用性中的关键作用。因此，可以得出结论：土地利用对海南岛的 SOC 和钾储存潜力有不同的影响，且在土层中存在差异。这些发现凸显了因地制宜的土地管理措施对于保持土壤健康以减缓气候变化的重要意义。

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引用次数: 0