首页 > 最新文献

Agricultural and Forest Meteorology最新文献

英文 中文
Refining water and carbon fluxes modeling in terrestrial ecosystems via plant hydraulics integration 通过植物水力学集成完善陆地生态系统的水和碳通量建模
IF 5.6 1区 农林科学 Q1 AGRONOMY Pub Date : 2024-10-31 DOI: 10.1016/j.agrformet.2024.110256
Shanshan Sun , Lingcheng Li , Zong-Liang Yang , Guiling Wang , Nate G. McDowell , Ashley M. Matheny , Jian Wu , Shiqin Xu , Hui Zheng , Miao Yu , Dagang Wang
Plant hydraulics substantially affects terrestrial water and carbon cycles by modulating water transport and carbon assimilation. Despite improved drought simulations in certain ecosystems through their integration into land surface models (LSMs), the broader application of plant hydraulics in diverse ecosystems and hydroclimates is still underexplored. In this study, we implemented the recently developed Noah-Multiparameterization Land Surface Model (Noah-MP LSM) equipped with a plant hydraulics scheme (Noah-MP-PHS) across 40 FLUXNET sites globally. Employing the Shuffled Complex Evolution-University of Arizona (SCE-UA) auto-calibration algorithm, we optimized key plant hydraulics parameters for these sites spanning eight vegetation types in both arid and humid climates. Noah-MP-PHS significantly improves the simulation of evapotranspiration (ET) and gross primary production (GPP) by better representing atmospheric and soil water stress compared to traditional soil hydraulic schemes (SHSs, such as Noah and CLM). The augmented Noah-MP-PHS models reduce surface flux overestimation and underestimation, exhibiting an average increase of 0.14 and 0.15 in Kling-Gupta Efficiency (KGE) compared to Noah and CLM, respectively. The explicit consideration of plant capacitance in PHS reveals substantial deep-layer and nocturnal root water uptake especially under dry conditions. We employed eXplainable Machine learning (XML) to quantify the model's relative sensitivity to newly introduced leaf-, stem- and root-related parameters in PHS. The sensitivity analysis reveals a rise in root parameter importance and a decline in leaf and stem parameters as conditions shift from humid to arid. These findings indicate that as aridity states vary, the most influential parameters affecting surface fluxes variation may change in parameter calibration for PHS applications. Our findings underscore the importance of incorporating plant hydraulics into LSMs to enhance simulations of terrestrial water and carbon dynamics. These findings are crucial for understanding ecosystem responses to global climate changes and guide the broader application of PHS at larger scales.
植物水力学通过调节水输送和碳同化,对陆地水循环和碳循环产生重大影响。尽管通过将植物水力学集成到地表模型(LSM)中,某些生态系统的干旱模拟得到了改善,但植物水力学在不同生态系统和水文气候中的更广泛应用仍未得到充分探索。在这项研究中,我们在全球 40 个 FLUXNET 站点实施了最近开发的配备植物水力学方案(Noah-MP-PHS)的 Noah-Multiparameterization Land Surface Model(Noah-MP LSM)。利用亚利桑那大学(SCE-UA)的洗牌复杂进化(Shuffled Complex Evolution)自动校准算法,我们优化了这些站点的关键植物水力学参数,涵盖了干旱和湿润气候下的八种植被类型。与传统的土壤水力方案(SHS,如 Noah 和 CLM)相比,Noah-MP-PHS 更好地体现了大气和土壤水分压力,从而大大提高了蒸散量(ET)和总初级生产力(GPP)的模拟效果。增强型 Noah-MP-PHS 模型减少了地表通量的高估和低估,与 Noah 和 CLM 相比,Kling-Gupta 效率 (KGE) 平均分别提高了 0.14 和 0.15。PHS 中对植物电容的明确考虑揭示了大量的深层和夜间根系吸水,尤其是在干旱条件下。我们采用可扩展机器学习(XML)来量化模型对 PHS 中新引入的叶、茎和根相关参数的相对敏感性。灵敏度分析表明,随着条件从潮湿转向干旱,根参数的重要性上升,而叶和茎参数的重要性下降。这些发现表明,随着干旱状态的变化,影响地表通量变化的最有影响力的参数可能会在 PHS 应用的参数校准中发生变化。我们的研究结果强调了将植物水力学纳入 LSM 以增强陆地水和碳动力学模拟的重要性。这些发现对于了解生态系统对全球气候变化的反应至关重要,并可指导 PHS 在更大尺度上的广泛应用。
{"title":"Refining water and carbon fluxes modeling in terrestrial ecosystems via plant hydraulics integration","authors":"Shanshan Sun ,&nbsp;Lingcheng Li ,&nbsp;Zong-Liang Yang ,&nbsp;Guiling Wang ,&nbsp;Nate G. McDowell ,&nbsp;Ashley M. Matheny ,&nbsp;Jian Wu ,&nbsp;Shiqin Xu ,&nbsp;Hui Zheng ,&nbsp;Miao Yu ,&nbsp;Dagang Wang","doi":"10.1016/j.agrformet.2024.110256","DOIUrl":"10.1016/j.agrformet.2024.110256","url":null,"abstract":"<div><div>Plant hydraulics substantially affects terrestrial water and carbon cycles by modulating water transport and carbon assimilation. Despite improved drought simulations in certain ecosystems through their integration into land surface models (LSMs), the broader application of plant hydraulics in diverse ecosystems and hydroclimates is still underexplored. In this study, we implemented the recently developed Noah-Multiparameterization Land Surface Model (Noah-MP LSM) equipped with a plant hydraulics scheme (Noah-MP-PHS) across 40 FLUXNET sites globally. Employing the Shuffled Complex Evolution-University of Arizona (SCE-UA) auto-calibration algorithm, we optimized key plant hydraulics parameters for these sites spanning eight vegetation types in both arid and humid climates. Noah-MP-PHS significantly improves the simulation of evapotranspiration (ET) and gross primary production (GPP) by better representing atmospheric and soil water stress compared to traditional soil hydraulic schemes (SHSs, such as Noah and CLM). The augmented Noah-MP-PHS models reduce surface flux overestimation and underestimation, exhibiting an average increase of 0.14 and 0.15 in Kling-Gupta Efficiency (KGE) compared to Noah and CLM, respectively. The explicit consideration of plant capacitance in PHS reveals substantial deep-layer and nocturnal root water uptake especially under dry conditions. We employed eXplainable Machine learning (XML) to quantify the model's relative sensitivity to newly introduced leaf-, stem- and root-related parameters in PHS. The sensitivity analysis reveals a rise in root parameter importance and a decline in leaf and stem parameters as conditions shift from humid to arid. These findings indicate that as aridity states vary, the most influential parameters affecting surface fluxes variation may change in parameter calibration for PHS applications. Our findings underscore the importance of incorporating plant hydraulics into LSMs to enhance simulations of terrestrial water and carbon dynamics. These findings are crucial for understanding ecosystem responses to global climate changes and guide the broader application of PHS at larger scales.</div></div>","PeriodicalId":50839,"journal":{"name":"Agricultural and Forest Meteorology","volume":"359 ","pages":"Article 110256"},"PeriodicalIF":5.6,"publicationDate":"2024-10-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142556206","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
Patterns of methane flux on different temporal scales and its environmental controls over a subtropical “floating blanket” wetland in southwest China 中国西南亚热带 "浮毯 "湿地不同时间尺度的甲烷通量模式及其环境控制
IF 5.6 1区 农林科学 Q1 AGRONOMY Pub Date : 2024-10-30 DOI: 10.1016/j.agrformet.2024.110280
Yamei Shao , Huizhi Liu , Qun Du , Yang Liu , Jihua Sun
Wetlands are the primary natural source of methane (CH4) emissions to the atmosphere, however, the quantification of wetland CH4 flux and net carbon budgets remains uncertain due to limited measurements and large variability across different types of wetlands. Based on continuous measurements using the eddy covariance (EC) technique over a “floating blanket” wetland in southwest China for a period of over three years (2018–2021), we examined the temporal variations of CH4 flux and its environmental controls on different temporal scales. The results showed that this wetland acted as a sink for carbon dioxide (CO2) while simultaneously serving as a source for CH4. The annual CO2 uptake and CH4 emission was 155.9–221.2 g C-CO2 m−2 yr−1 and 44.6–56.9 g C-CH4 m−2 yr−1 during 2019–2021, respectively. The annual total carbon budget varied from -176.6 g C m−2 yr−1 to -99.0 g C m−2 yr−1. From half-hourly to monthly timescales, CH4 flux was mainly controlled by water temperature with a positive correlation. There was a negative correlation between CH4 flux and CO2 flux, and the importance of CO2 flux to CH4 flux increased as the timescale extended. CH4 flux exhibited a significant positive correlation with the ecosystem gross primary production (GPP) and respiration (Re) on daily and monthly timescales. In addition, the fraction of vegetation cover had a positive impact on CH4 emissions. There was a significant variation in the fraction of vegetation cover with wind direction. The southwestern wind sector had the highest fraction of vegetation cover compared to other sectors, leading to the formation of the CH4 emission hotspot. The cumulative CH4 emissions in the southwestern wind sector were also higher than those in other sectors, accounting for around 58.13% of the annual total CH4 emissions, while the cumulative CH4 emissions in other wind sectors accounted for 5.21%–21.50%.
湿地是向大气排放甲烷(CH4)的主要天然来源,然而,由于测量有限以及不同类型湿地之间的巨大差异,湿地CH4通量和净碳预算的量化仍不确定。基于使用涡度协方差(EC)技术对中国西南某 "浮毯 "湿地三年多(2018-2021年)的连续测量,我们研究了不同时间尺度上CH4通量的时间变化及其环境控制。结果表明,该湿地在作为二氧化碳(CO2)汇的同时,也是CH4的源。在2019-2021年期间,年二氧化碳吸收量和CH4排放量分别为155.9-221.2 g C-CO2 m-2 yr-1和44.6-56.9 g C-CH4 m-2 yr-1。年度总碳预算在-176.6 g C m-2 yr-1到-99.0 g C m-2 yr-1之间变化。从半小时到月度时间尺度来看,CH4通量主要受水温控制,两者呈正相关。CH4 通量与 CO2 通量之间呈负相关,随着时间尺度的延长,CO2 通量对 CH4 通量的重要性增加。在日和月时间尺度上,CH4 通量与生态系统总初级生产力(GPP)和呼吸作用(Re)呈显著正相关。此外,植被覆盖率对甲烷排放量也有积极影响。植被覆盖率随风向变化很大。与其他地区相比,西南风区的植被覆盖率最高,从而形成了 CH4 排放热点。西南风区的累积甲烷排放量也高于其他风区,约占全年甲烷总排放量的 58.13%,而其他风区的累积甲烷排放量仅占 5.21%-21.50%。
{"title":"Patterns of methane flux on different temporal scales and its environmental controls over a subtropical “floating blanket” wetland in southwest China","authors":"Yamei Shao ,&nbsp;Huizhi Liu ,&nbsp;Qun Du ,&nbsp;Yang Liu ,&nbsp;Jihua Sun","doi":"10.1016/j.agrformet.2024.110280","DOIUrl":"10.1016/j.agrformet.2024.110280","url":null,"abstract":"<div><div>Wetlands are the primary natural source of methane (CH<sub>4</sub>) emissions to the atmosphere, however, the quantification of wetland CH<sub>4</sub> flux and net carbon budgets remains uncertain due to limited measurements and large variability across different types of wetlands. Based on continuous measurements using the eddy covariance (EC) technique over a “floating blanket” wetland in southwest China for a period of over three years (2018–2021), we examined the temporal variations of CH<sub>4</sub> flux and its environmental controls on different temporal scales. The results showed that this wetland acted as a sink for carbon dioxide (CO<sub>2</sub>) while simultaneously serving as a source for CH<sub>4</sub>. The annual CO<sub>2</sub> uptake and CH<sub>4</sub> emission was 155.9–221.2 g C-CO<sub>2</sub> m<sup>−2</sup> yr<sup>−1</sup> and 44.6–56.9 g C-CH<sub>4</sub> m<sup>−2</sup> yr<sup>−1</sup> during 2019–2021, respectively. The annual total carbon budget varied from -176.6 g C m<sup>−2</sup> yr<sup>−1</sup> to -99.0 g C m<sup>−2</sup> yr<sup>−1</sup>. From half-hourly to monthly timescales, CH<sub>4</sub> flux was mainly controlled by water temperature with a positive correlation. There was a negative correlation between CH<sub>4</sub> flux and CO<sub>2</sub> flux, and the importance of CO<sub>2</sub> flux to CH<sub>4</sub> flux increased as the timescale extended. CH<sub>4</sub> flux exhibited a significant positive correlation with the ecosystem gross primary production (GPP) and respiration (Re) on daily and monthly timescales. In addition, the fraction of vegetation cover had a positive impact on CH<sub>4</sub> emissions. There was a significant variation in the fraction of vegetation cover with wind direction. The southwestern wind sector had the highest fraction of vegetation cover compared to other sectors, leading to the formation of the CH<sub>4</sub> emission hotspot. The cumulative CH<sub>4</sub> emissions in the southwestern wind sector were also higher than those in other sectors, accounting for around 58.13% of the annual total CH<sub>4</sub> emissions, while the cumulative CH<sub>4</sub> emissions in other wind sectors accounted for 5.21%–21.50%.</div></div>","PeriodicalId":50839,"journal":{"name":"Agricultural and Forest Meteorology","volume":"359 ","pages":"Article 110280"},"PeriodicalIF":5.6,"publicationDate":"2024-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142542188","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
Concurrent measurements of bark and xylem water contents in Malus pumila Mill. stems using improved flexible sensors 使用改进的柔性传感器同时测量 Malus pumila Mill.
IF 5.6 1区 农林科学 Q1 AGRONOMY Pub Date : 2024-10-30 DOI: 10.1016/j.agrformet.2024.110290
Xianglin Cheng , Xiaofei Yan , Zhongyi Wang , Junhui Li , Ricardo F. de Oliveira , Taisheng Du , Qiang Cheng
The pattern of radial water transport in tree stems, specifically the interaction between bark and xylem, remains elusive because few measurement techniques are not capable of independently sensing bark water content (BWC) and xylem water content (XWC). To investigate the water variations in stem, two improved flexible sensors operating at 100 MHz and equipped with small interdigital-electrode (IE) probes were developed to measure BWC and XWC independently. The performances of the flexible sensors were tested under laboratory conditions. Software simulations and laboratory measurements were performed to evaluate the volume of sensitivity (VOS) and to assess the impact of variations in stem diameter (SD) on the sensors. Concurrent measurements of BWC and XWC were performed on three trees in Malus pumila Mill. (Red Fuji). The measurements revealed that the difference in predawn water content between the bark and xylem gradually increased as the water deficit intensified. The maximum daily variation of BWC from predawn to afternoon (MDV_BWC) was greater than that of the maximum daily variation of XWC from predawn to afternoon (MDV_XWC). In addition, the dehydration-rehydration loops exhibited a time lag between BWC and XWC under water deficit conditions, with earlier dehydration and rehydration of the bark than of the xylem. Concurrent measurements of BWC and XWC provide a new perspective for examining the pattern of stem radial water transport. However, the time lag between BWC and XWC might need to be validated in other tree species.
由于很少有测量技术能够独立检测树皮含水量(BWC)和木质部含水量(XWC),因此树茎中的径向水分传输模式,特别是树皮和木质部之间的相互作用,仍然难以捉摸。为了研究茎干中的水分变化,我们开发了两种工作频率为 100 MHz 的改进型柔性传感器,并配备了小型数字间电极 (IE) 探头,可独立测量 BWC 和 XWC。在实验室条件下对柔性传感器的性能进行了测试。通过软件模拟和实验室测量来评估灵敏度(VOS),并评估阀杆直径(SD)变化对传感器的影响。同时对三棵 Malus pumila Mill.(红富士)的三棵树上同时进行了 BWC 和 XWC 测量。测量结果表明,随着水分亏缺的加剧,树皮和木质部之间黎明前含水量的差异逐渐增大。BWC从黎明前到下午的最大日变化(MDV_BWC)大于XWC从黎明前到下午的最大日变化(MDV_XWC)。此外,在缺水条件下,脱水-补水环路在 BWC 和 XWC 之间表现出时滞,树皮的脱水和补水早于木质部的脱水和补水。同时测量BWC和XWC为研究茎径向水分运输模式提供了新的视角。不过,BWC和XWC之间的时滞可能还需要在其他树种上进行验证。
{"title":"Concurrent measurements of bark and xylem water contents in Malus pumila Mill. stems using improved flexible sensors","authors":"Xianglin Cheng ,&nbsp;Xiaofei Yan ,&nbsp;Zhongyi Wang ,&nbsp;Junhui Li ,&nbsp;Ricardo F. de Oliveira ,&nbsp;Taisheng Du ,&nbsp;Qiang Cheng","doi":"10.1016/j.agrformet.2024.110290","DOIUrl":"10.1016/j.agrformet.2024.110290","url":null,"abstract":"<div><div>The pattern of radial water transport in tree stems, specifically the interaction between bark and xylem, remains elusive because few measurement techniques are not capable of independently sensing bark water content (BWC) and xylem water content (XWC). To investigate the water variations in stem, two improved flexible sensors operating at 100 MHz and equipped with small interdigital-electrode (IE) probes were developed to measure BWC and XWC independently. The performances of the flexible sensors were tested under laboratory conditions. Software simulations and laboratory measurements were performed to evaluate the volume of sensitivity (VOS) and to assess the impact of variations in stem diameter (SD) on the sensors. Concurrent measurements of BWC and XWC were performed on three trees in <em>Malus pumila</em> Mill. (Red Fuji). The measurements revealed that the difference in predawn water content between the bark and xylem gradually increased as the water deficit intensified. The maximum daily variation of BWC from predawn to afternoon (MDV_BWC) was greater than that of the maximum daily variation of XWC from predawn to afternoon (MDV_XWC). In addition, the dehydration-rehydration loops exhibited a time lag between BWC and XWC under water deficit conditions, with earlier dehydration and rehydration of the bark than of the xylem. Concurrent measurements of BWC and XWC provide a new perspective for examining the pattern of stem radial water transport. However, the time lag between BWC and XWC might need to be validated in other tree species.</div></div>","PeriodicalId":50839,"journal":{"name":"Agricultural and Forest Meteorology","volume":"359 ","pages":"Article 110290"},"PeriodicalIF":5.6,"publicationDate":"2024-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142541650","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
LiDAR insights on stand structure and topography in mountain forest wind extreme events: The Vaia case study 激光雷达对山林风极端事件中林分结构和地形的洞察:维亚案例研究
IF 5.6 1区 农林科学 Q1 AGRONOMY Pub Date : 2024-10-30 DOI: 10.1016/j.agrformet.2024.110267
Michele Torresani , Leonardo Montagnani , Duccio Rocchini , Vítězslav Moudrý , Andrea Andreoli , Camilla Wellstein , Kenta Koyanagi , Luca Da Ros , Giovanni Bacaro , Michela Perrone , Chiara Salvatori , Irene Menegaldo , Enrico Guatelli , Roberto Tognetti
With climate change intensifying, forests globally are becoming more susceptible to extreme weather events, such as windstorms, which account for a significant share of Europe’s economic losses. The Vaia windstorm of late autumn 2018, striking Italy’s North-East alpine ecosystem, highlighted this vulnerability, toppling over 8.5 million cubic meters of timber and sparking debates on forest management’s role in mitigating such disasters. This study aims to evaluate the impact of structural and topographical characteristics on the damage caused by Vaia, using Airborne Light Detection And Ranging (LiDAR) data collected before the storm, in four heavily affected forest areas in the Italian Alps (Carezza in the Province of Bolzano-Bozen, Predazzo, Manghen, and Primiero in the Province of Trento). We analyzed structural metrics like forest height heterogeneity (HH), forest mean height, and density, alongside topographical features such as aspect, slope, and altitude, to discern their influence on the storm’s severity. Our results revealed that the most significant difference between affected and unaffected areas is forest mean height that was found higher in areas hit by the storm. Forest density played a lesser but important role, with denser areas experiencing more severe damage, though this was only significant in certain areas. Contrary to common assumptions, our analysis revealed that forest height heterogeneity (HH) did not have a significant effect on damage levels. The findings, consistent with previous research, revealed a significant association between specific aspects, particularly the South-East orientation, which aligned with the predominant wind direction during the Vaia storm, and an increased likelihood of damage. Both structural and topographical factors interact in complex ways to influence the outcome of such extreme events. The study emphasizes the dominant impact of the Vaia windstorm, noting that while managing forest height and density may help, the diverse topography complicates these efforts. Our study explicitly tested the effectiveness of using Airborne LiDAR data to explore forest structural and topographical factors that influenced Vaia storm damage. The achieved results demonstrate that LiDAR serves as a useful tool to field data, offering valuable insights for broader applications in this domain.
随着气候变化的加剧,全球森林越来越容易受到风灾等极端天气事件的影响,而风灾占欧洲经济损失的很大一部分。2018 年深秋袭击意大利东北部高山生态系统的维亚风灾凸显了这种脆弱性,超过 850 万立方米的木材被吹倒,引发了关于森林管理在减轻此类灾害中的作用的讨论。本研究旨在利用暴风雨前收集的机载光探测和测距(LiDAR)数据,评估结构和地形特征对 "维亚 "所造成破坏的影响,研究对象是意大利阿尔卑斯山的四个重灾林区(博尔扎诺-博岑省的 Carezza、特伦托省的 Predazzo、Manghen 和 Primiero)。我们分析了森林高度异质性(HH)、森林平均高度和密度等结构指标,以及地形特征(如地势、坡度和海拔),以确定它们对风暴严重程度的影响。我们的研究结果表明,受影响地区与未受影响地区之间最显著的差异是森林平均高度,受风暴袭击地区的森林平均高度更高。森林密度的作用较小,但也很重要,密度较高的地区遭受的破坏更严重,但这只在某些地区显著。与通常的假设相反,我们的分析表明,森林高度异质性(HH)对损害程度没有显著影响。研究结果与之前的研究一致,揭示了特定方位(尤其是东南方位,与维亚风暴期间的主要风向一致)与受损可能性增加之间的重要关联。结构因素和地形因素以复杂的方式相互作用,影响着此类极端事件的结果。该研究强调了维亚风暴的主要影响,指出虽然森林高度和密度的管理可能会有所帮助,但多样的地形使这些工作变得复杂。我们的研究明确测试了使用机载激光雷达数据探索影响维亚风暴破坏的森林结构和地形因素的有效性。研究结果表明,激光雷达是一种有用的野外数据工具,可为该领域的更广泛应用提供有价值的见解。
{"title":"LiDAR insights on stand structure and topography in mountain forest wind extreme events: The Vaia case study","authors":"Michele Torresani ,&nbsp;Leonardo Montagnani ,&nbsp;Duccio Rocchini ,&nbsp;Vítězslav Moudrý ,&nbsp;Andrea Andreoli ,&nbsp;Camilla Wellstein ,&nbsp;Kenta Koyanagi ,&nbsp;Luca Da Ros ,&nbsp;Giovanni Bacaro ,&nbsp;Michela Perrone ,&nbsp;Chiara Salvatori ,&nbsp;Irene Menegaldo ,&nbsp;Enrico Guatelli ,&nbsp;Roberto Tognetti","doi":"10.1016/j.agrformet.2024.110267","DOIUrl":"10.1016/j.agrformet.2024.110267","url":null,"abstract":"<div><div>With climate change intensifying, forests globally are becoming more susceptible to extreme weather events, such as windstorms, which account for a significant share of Europe’s economic losses. The Vaia windstorm of late autumn 2018, striking Italy’s North-East alpine ecosystem, highlighted this vulnerability, toppling over 8.5 million cubic meters of timber and sparking debates on forest management’s role in mitigating such disasters. This study aims to evaluate the impact of structural and topographical characteristics on the damage caused by Vaia, using Airborne Light Detection And Ranging (LiDAR) data collected before the storm, in four heavily affected forest areas in the Italian Alps (Carezza in the Province of Bolzano-Bozen, Predazzo, Manghen, and Primiero in the Province of Trento). We analyzed structural metrics like forest height heterogeneity (HH), forest mean height, and density, alongside topographical features such as aspect, slope, and altitude, to discern their influence on the storm’s severity. Our results revealed that the most significant difference between affected and unaffected areas is forest mean height that was found higher in areas hit by the storm. Forest density played a lesser but important role, with denser areas experiencing more severe damage, though this was only significant in certain areas. Contrary to common assumptions, our analysis revealed that forest height heterogeneity (HH) did not have a significant effect on damage levels. The findings, consistent with previous research, revealed a significant association between specific aspects, particularly the South-East orientation, which aligned with the predominant wind direction during the Vaia storm, and an increased likelihood of damage. Both structural and topographical factors interact in complex ways to influence the outcome of such extreme events. The study emphasizes the dominant impact of the Vaia windstorm, noting that while managing forest height and density may help, the diverse topography complicates these efforts. Our study explicitly tested the effectiveness of using Airborne LiDAR data to explore forest structural and topographical factors that influenced Vaia storm damage. The achieved results demonstrate that LiDAR serves as a useful tool to field data, offering valuable insights for broader applications in this domain.</div></div>","PeriodicalId":50839,"journal":{"name":"Agricultural and Forest Meteorology","volume":"359 ","pages":"Article 110267"},"PeriodicalIF":5.6,"publicationDate":"2024-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142541651","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Upgrading and validating a soil water balance model to predict stem water potential in vineyards 升级和验证土壤水分平衡模型,预测葡萄园茎干水势
IF 5.6 1区 农林科学 Q1 AGRONOMY Pub Date : 2024-10-30 DOI: 10.1016/j.agrformet.2024.110281
José M. Mirás-Avalos , José M. Escalona , Eva Pilar Pérez-Álvarez , Pascual Romero , Pablo Botia , Josefa Navarro , Nazareth Torres , Luis Gonzaga Santesteban , David Uriarte , Diego S. Intrigliolo , I. Buesa
Efficient water management is pivotal for viticulture sustainability. Decision support tools can advise on how to optimize irrigation or on the feasibility of growing grapes in rainfed conditions, but reliable algorithms for assessing vine water status are required. In this context, the aim of the current study was to upgrade a soil water balance model specific for vineyards by incorporating meteorological, soil and vine vigor in equations that transform the fraction of transpirable soil water into midday stem water potential (Ψstem). The model's sensitivity to variations in the magnitude of input parameters was analyzed. Furthermore, the model was tested in a broad scope of Spanish vineyards with different grapevine cultivars (both red and white), rootstocks, plant age, soil and climatic conditions, and water regimes, totaling 129 scenarios. The model was only slightly sensitive to variations in the magnitude of most inputs, except for the fraction of transpirable water at which leaf stomatal conductance begin to decline. Moreover, the model satisfactorily reproduced the evolution of Ψstem over the growing season, although it slightly overestimated the measured Ψstem values, as the slopes of the fitted regression lines were lesser than 1 on most occasions, 76 out of 129. Nonetheless, the coefficients of determination for these relationships were greater than 0.9, except for 21 datasets. Mean errors averaged 0.024 ± 0.015 MPa, while root mean square errors averaged 0.27 ± 0.01 MPa. The index of agreement was greater than 0.75 in 51 datasets, with only three datasets showing an index of agreement lower than 0.5. Nevertheless, the deviations between observed and simulated Ψstem values did not alter the classification of the water stress undergone by grapevines. This upgraded model could constitute the core of a decision support system for water management in vineyards, applicable to both rainfed and irrigated conditions.
高效的水资源管理对葡萄栽培的可持续性至关重要。决策支持工具可以就如何优化灌溉或在雨水灌溉条件下种植葡萄的可行性提供建议,但还需要可靠的算法来评估葡萄树的水分状况。在这种情况下,当前研究的目的是升级葡萄园专用的土壤水分平衡模型,将气象、土壤和葡萄树活力纳入将土壤可渗透水分转化为正午茎干水势(Ψstem)的方程中。分析了该模型对输入参数大小变化的敏感性。此外,该模型还在西班牙的多个葡萄园中进行了测试,这些葡萄园的葡萄品种(包括红葡萄和白葡萄)、砧木、株龄、土壤和气候条件以及水制度各不相同,总共有 129 种情况。除了叶片气孔导度开始下降时的可透水分量外,该模型对大多数输入量的变化仅略微敏感。此外,该模型令人满意地再现了Ψ茎在生长季中的变化,尽管它略微高估了测量的Ψ茎值,因为在大多数情况下,拟合回归线的斜率都小于 1,129 条回归线中有 76 条小于 1。不过,除 21 个数据集外,这些关系的决定系数都大于 0.9。平均误差平均为 0.024 ± 0.015 兆帕,均方根误差平均为 0.27 ± 0.01 兆帕。51 个数据集的一致指数大于 0.75,只有 3 个数据集的一致指数低于 0.5。尽管如此,观测值与Ψstem 模拟值之间的偏差并没有改变对葡萄树所承受的水分胁迫的分类。这一升级模型可作为葡萄园水分管理决策支持系统的核心,适用于雨水灌溉和灌溉条件。
{"title":"Upgrading and validating a soil water balance model to predict stem water potential in vineyards","authors":"José M. Mirás-Avalos ,&nbsp;José M. Escalona ,&nbsp;Eva Pilar Pérez-Álvarez ,&nbsp;Pascual Romero ,&nbsp;Pablo Botia ,&nbsp;Josefa Navarro ,&nbsp;Nazareth Torres ,&nbsp;Luis Gonzaga Santesteban ,&nbsp;David Uriarte ,&nbsp;Diego S. Intrigliolo ,&nbsp;I. Buesa","doi":"10.1016/j.agrformet.2024.110281","DOIUrl":"10.1016/j.agrformet.2024.110281","url":null,"abstract":"<div><div>Efficient water management is pivotal for viticulture sustainability. Decision support tools can advise on how to optimize irrigation or on the feasibility of growing grapes in rainfed conditions, but reliable algorithms for assessing vine water status are required. In this context, the aim of the current study was to upgrade a soil water balance model specific for vineyards by incorporating meteorological, soil and vine vigor in equations that transform the fraction of transpirable soil water into midday stem water potential (Ψ<sub>stem</sub>). The model's sensitivity to variations in the magnitude of input parameters was analyzed. Furthermore, the model was tested in a broad scope of Spanish vineyards with different grapevine cultivars (both red and white), rootstocks, plant age, soil and climatic conditions, and water regimes, totaling 129 scenarios. The model was only slightly sensitive to variations in the magnitude of most inputs, except for the fraction of transpirable water at which leaf stomatal conductance begin to decline. Moreover, the model satisfactorily reproduced the evolution of Ψ<sub>stem</sub> over the growing season, although it slightly overestimated the measured Ψ<sub>stem</sub> values, as the slopes of the fitted regression lines were lesser than 1 on most occasions, 76 out of 129. Nonetheless, the coefficients of determination for these relationships were greater than 0.9, except for 21 datasets. Mean errors averaged 0.024 ± 0.015 MPa, while root mean square errors averaged 0.27 ± 0.01 MPa. The index of agreement was greater than 0.75 in 51 datasets, with only three datasets showing an index of agreement lower than 0.5. Nevertheless, the deviations between observed and simulated Ψ<sub>stem</sub> values did not alter the classification of the water stress undergone by grapevines. This upgraded model could constitute the core of a decision support system for water management in vineyards, applicable to both rainfed and irrigated conditions.</div></div>","PeriodicalId":50839,"journal":{"name":"Agricultural and Forest Meteorology","volume":"359 ","pages":"Article 110281"},"PeriodicalIF":5.6,"publicationDate":"2024-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142542104","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
Analysis of scale-dependent spatial correlations of actual evapotranspiration measured by lysimeters 分析莱西米测量的实际蒸散量与尺度的空间相关性
IF 5.6 1区 农林科学 Q1 AGRONOMY Pub Date : 2024-10-30 DOI: 10.1016/j.agrformet.2024.110288
Xiao Lu , Jannis Groh , Alexander Graf , Thomas Pütz , Katrin Schneider , Bingcheng Si , Harry Vereecken , Harrie-Jan Hendricks Franssen
Accurate determination of actual evapotranspiration (ETa) is important in various research fields like hydrology, meteorology, ecology and agriculture. In situ ETa can be determined using weighing lysimeters and eddy covariance. However, despite being regarded as the most precise in situ method for measuring ETa, the information content of lysimeter measurements remains poorly understood. Here we examined the spatial correlations between ETa measured at different locations by lysimeter (ET-LYS) and at different locations by eddy covariance (ET-EC). This was done for the period 2015 - 2020 and the analysis was made for different spatial (range: 0 to 500 km) and temporal scales (range: 1 day to 1 year) using 23 lysimeters and 4 eddy covariance towers. We found that: (a) Same lysimeters at the plot scale show very high correlations of ET-LYS; (b) The Pearson correlation of daily standardized anomalies of ET-LYS between sites exhibit moderate to high correlations and were similar to that of ET-EC, indicating that lysimeter is generally as representative as EC regarding ETa, and can provide certain information at the landscape and larger regional scale. During winter, the spatial correlations for ET-LYS were smaller; (c) Wavelet analysis indicated that temporal correlations in ETa were strongest for distances in time around 12 months (yearly cycle) and less than three months. Spatial correlations were smaller under drought conditions (in the year 2018). Furthermore, combination of multiple ET-LYS from different sites improved the predictability of ET-LYS for another site, suggesting that ET-LYS can be predicted well using ET-LYS from different neighboring sites. Overall, lysimeter measurements can provide information at much larger scales compared to their small measurement area.
准确测定实际蒸散量(ETa)对水文学、气象学、生态学和农业等多个研究领域都非常重要。原位蒸散发可以通过称重式蒸发仪和涡协方差法测定。然而,尽管赖氏仪被认为是测量蒸散发的最精确的现场方法,但人们对赖氏仪测量的信息含量仍然知之甚少。在此,我们研究了在不同地点用赖氏仪测量的蒸散发(ET-LYS)与在不同地点用涡度协方差测量的蒸散发(ET-EC)之间的空间相关性。这项研究是在 2015-2020 年期间进行的,利用 23 个赖氏仪和 4 个涡度协方差塔对不同的空间尺度(范围:0 至 500 公里)和时间尺度(范围:1 天至 1 年)进行了分析。我们发现(a) 在地块尺度上,相同溶样仪的 ET-LYS 相关性非常高;(b) 各站点间 ET-LYS 日标准化异常值的皮尔逊相关性为中等至高等相关性,与 ET-EC 的相关性相似,这表明溶样仪在 ETa 方面与 EC 具有同样的代表性,可以在地貌和更大的区域尺度上提供一定的信息。在冬季,ET-LYS 的空间相关性较小;(c)小波分析表明,ETa 的时间相关性在 12 个月(年周期)和 3 个月以内的时间距离最强。在干旱条件下(2018 年),空间相关性较小。此外,将不同站点的多个 ET-LYS 结合在一起可提高另一站点 ET-LYS 的可预测性,这表明利用不同邻近站点的 ET-LYS 可以很好地预测 ET-LYS。总体而言,相对于较小的测量区域,溶液计测量可提供更大范围的信息。
{"title":"Analysis of scale-dependent spatial correlations of actual evapotranspiration measured by lysimeters","authors":"Xiao Lu ,&nbsp;Jannis Groh ,&nbsp;Alexander Graf ,&nbsp;Thomas Pütz ,&nbsp;Katrin Schneider ,&nbsp;Bingcheng Si ,&nbsp;Harry Vereecken ,&nbsp;Harrie-Jan Hendricks Franssen","doi":"10.1016/j.agrformet.2024.110288","DOIUrl":"10.1016/j.agrformet.2024.110288","url":null,"abstract":"<div><div>Accurate determination of actual evapotranspiration (ETa) is important in various research fields like hydrology, meteorology, ecology and agriculture. <em>In situ</em> ETa can be determined using weighing lysimeters and eddy covariance. However, despite being regarded as the most precise <em>in situ</em> method for measuring ETa, the information content of lysimeter measurements remains poorly understood. Here we examined the spatial correlations between ETa measured at different locations by lysimeter (ET-LYS) and at different locations by eddy covariance (ET-EC). This was done for the period 2015 - 2020 and the analysis was made for different spatial (range: 0 to 500 km) and temporal scales (range: 1 day to 1 year) using 23 lysimeters and 4 eddy covariance towers. We found that: (a) Same lysimeters at the plot scale show very high correlations of ET-LYS; (b) The Pearson correlation of daily standardized anomalies of ET-LYS between sites exhibit moderate to high correlations and were similar to that of ET-EC, indicating that lysimeter is generally as representative as EC regarding ETa, and can provide certain information at the landscape and larger regional scale. During winter, the spatial correlations for ET-LYS were smaller; (c) Wavelet analysis indicated that temporal correlations in ETa were strongest for distances in time around 12 months (yearly cycle) and less than three months. Spatial correlations were smaller under drought conditions (in the year 2018). Furthermore, combination of multiple ET-LYS from different sites improved the predictability of ET-LYS for another site, suggesting that ET-LYS can be predicted well using ET-LYS from different neighboring sites. Overall, lysimeter measurements can provide information at much larger scales compared to their small measurement area.</div></div>","PeriodicalId":50839,"journal":{"name":"Agricultural and Forest Meteorology","volume":"359 ","pages":"Article 110288"},"PeriodicalIF":5.6,"publicationDate":"2024-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142542105","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Partitioning and driver analysis of eddy covariance derived N2O emissions from a grazed and fertilized pasture 对从放牧和施肥牧场得出的涡度协方差 N2O 排放量进行分区和驱动力分析
IF 5.6 1区 农林科学 Q1 AGRONOMY Pub Date : 2024-10-30 DOI: 10.1016/j.agrformet.2024.110278
Lena Barczyk , Johan Six , Christof Ammann
Managed pastures are strong sources for the greenhouse gas nitrous oxide (N2O) through various nitrogen (N) inputs. So far, chamber measurements have been used to quantify N2O emissions and emissions factors of specific emissions sources like grazing cattle excreta. This study presents a three-year dataset of N2O emissions from a grazed and fertilized pasture measured by eddy covariance (EC) in eastern Switzerland. N2O fluxes were gap-filled and disaggregated into the emission sources (flux partitioning) by using random forest. The excreta N deposition in the pasture was estimated based on a cattle nitrogen budget approach using observed milk yield, body weight and feed intake of the cattle herd. Furthermore, a driver analysis was performed to quantify the relationship between N2O emissions and predictor variables. The observed annual N2O emissions amounted to 5.3 ± 0.8, 3.1 ± 0.5 and 4.4 ± 0.7 kg N2O-N ha-1 yr-1 and were disaggregated into background, fertilizer and excreta related N2O emissions with contributions of 27–46 %, 15–40 % and 30–51 %, respectively. Combining the excreta N2O fluxes with the excreta N inputs resulted in an average emission factor (EF) for cattle excreta of 1.1 ± 0.5 %, that tends to be higher than the IPCC default value of 0.6 % for wet climates. While maximum N2O emissions usually were observed after fertilizer application and under optimum soil moisture conditions as expected, distinct N2O emission peaks also occurred during a longer drought period in summer and could be parametrised as a function of precipitation and previous grazing activity. Moreover, peak N2O emissions occurred during the cold season at low temperatures and should be considered in future studies. Overall, we suggest that EC measurements under pasture conditions with subsequent flux partitioning by random forest are suitable for quantifying pasture N2O emissions of different sources.
通过各种氮(N)的输入,人工管理的牧场是温室气体一氧化二氮(N2O)的主要来源。迄今为止,人们一直使用室内测量来量化 N2O 排放量和特定排放源(如放牧牛的排泄物)的排放因子。本研究利用涡度协方差(EC)测量了瑞士东部放牧和施肥牧场三年的 N2O 排放数据集。利用随机森林对 N2O 通量进行了缺口填充和排放源分解(通量分区)。牧场中的排泄物氮沉积是根据牛群氮预算方法,利用观测到的牛群产奶量、体重和饲料摄入量估算得出的。此外,还进行了驱动因素分析,以量化一氧化二氮排放量与预测变量之间的关系。观测到的年 N2O 排放量分别为 5.3 ± 0.8、3.1 ± 0.5 和 4.4 ± 0.7 千克 N2O-N ha-1 yr-1,并细分为背景、肥料和排泄物相关的 N2O 排放量,所占比例分别为 27-46%、15-40% 和 30-51%。将排泄物一氧化二氮通量与排泄物氮输入量相结合,得出牛排泄物的平均排放因子 (EF) 为 1.1 ± 0.5 %,往往高于气候潮湿地区的 IPCC 默认值 0.6 %。虽然一氧化二氮的最大排放量通常出现在施肥后和最佳土壤湿度条件下,但在夏季较长的干旱期间也会出现明显的一氧化二氮排放峰值,并可作为降水和先前放牧活动的函数进行参数化。此外,N2O 排放峰值出现在寒冷季节的低温条件下,这也应在今后的研究中加以考虑。总之,我们认为,在牧场条件下进行EC测量,然后用随机森林进行通量分配,适用于量化不同来源的牧场N2O排放量。
{"title":"Partitioning and driver analysis of eddy covariance derived N2O emissions from a grazed and fertilized pasture","authors":"Lena Barczyk ,&nbsp;Johan Six ,&nbsp;Christof Ammann","doi":"10.1016/j.agrformet.2024.110278","DOIUrl":"10.1016/j.agrformet.2024.110278","url":null,"abstract":"<div><div>Managed pastures are strong sources for the greenhouse gas nitrous oxide (N<sub>2</sub>O) through various nitrogen (N) inputs. So far, chamber measurements have been used to quantify N<sub>2</sub>O emissions and emissions factors of specific emissions sources like grazing cattle excreta. This study presents a three-year dataset of N<sub>2</sub>O emissions from a grazed and fertilized pasture measured by eddy covariance (EC) in eastern Switzerland. N<sub>2</sub>O fluxes were gap-filled and disaggregated into the emission sources (flux partitioning) by using random forest. The excreta N deposition in the pasture was estimated based on a cattle nitrogen budget approach using observed milk yield, body weight and feed intake of the cattle herd. Furthermore, a driver analysis was performed to quantify the relationship between N<sub>2</sub>O emissions and predictor variables. The observed annual N<sub>2</sub>O emissions amounted to 5.3 ± 0.8, 3.1 ± 0.5 and 4.4 ± 0.7 kg N<sub>2</sub>O-N ha<sup>-1</sup> yr<sup>-1</sup> and were disaggregated into background, fertilizer and excreta related N<sub>2</sub>O emissions with contributions of 27–46 %, 15–40 % and 30–51 %, respectively. Combining the excreta N<sub>2</sub>O fluxes with the excreta N inputs resulted in an average emission factor (EF) for cattle excreta of 1.1 ± 0.5 %, that tends to be higher than the IPCC default value of 0.6 % for wet climates. While maximum N<sub>2</sub>O emissions usually were observed after fertilizer application and under optimum soil moisture conditions as expected, distinct N<sub>2</sub>O emission peaks also occurred during a longer drought period in summer and could be parametrised as a function of precipitation and previous grazing activity. Moreover, peak N<sub>2</sub>O emissions occurred during the cold season at low temperatures and should be considered in future studies. Overall, we suggest that EC measurements under pasture conditions with subsequent flux partitioning by random forest are suitable for quantifying pasture N<sub>2</sub>O emissions of different sources.</div></div>","PeriodicalId":50839,"journal":{"name":"Agricultural and Forest Meteorology","volume":"359 ","pages":"Article 110278"},"PeriodicalIF":5.6,"publicationDate":"2024-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142541649","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Optimizing the closure period for improved accuracy of chamber-based greenhouse gas flux estimates 优化封闭期,提高基于室的温室气体通量估算的准确性
IF 5.6 1区 农林科学 Q1 AGRONOMY Pub Date : 2024-10-30 DOI: 10.1016/j.agrformet.2024.110289
C-F. Johannesson , J. Nordén , H. Lange , H. Silvennoinen , K.S. Larsen
Non-steady-state chambers are often used for greenhouse gas flux measurements, and while there are recommendations on how long to keep the chamber closed, it is less investigated to what extent the length of the chamber closure period affects the estimated flux rates and which closure periods may provide the most accurate linear and non-linear flux estimates. Previous studies have shown that the closure of non-steady-state chambers induces a non-linear concentration development inside the chamber, even across short chamber closure periods, and that both linear and non-linear flux estimates are impacted by the chamber closure period itself. Based on 3,159 individual soil CO2 and CH4 flux measurements, we analyzed how linear regression and Hutchinson and Mosier (1981) modeled flux estimates are affected by the length of the chamber closure period by increasing it in increments of 30 sec, with a minimum and maximum chamber closure period of 60 and 300 sec, respectively. Across all detected flux measurements, the effect of chamber closure period length varied between 1.4–8.0 % for linear regression estimates and between 0.4–17.8 % for Hutchinson–Mosier estimates, and the largest effect sizes were observed in high flux regions. While both linear regression and Hutchinson–Mosier based estimates decreased as the chamber closure period increased, we observed a clear convergence of flux estimates as shorter and longer chamber closure periods were used for linear regression and Hutchinson–Mosier based estimation, respectively. This suggests using closure periods as short as possible for linear regression flux estimation or ensuring long-enough closure periods to observe a stabilization of Hutchinson–Mosier flux estimates over time. This analysis was based on soil flux measurements, but because the perturbation of the concentration gradient is related to the non-steady-state chamber technique rather than the measured ecosystem component, our results have implications for all flux measurements conducted with non-steady-state chambers.
非稳态室经常被用于温室气体通量测量,虽然有关于关闭多长时间的建议,但对关闭时间的长短在多大程度上影响通量估算率,以及哪些关闭时间可提供最准确的线性和非线性通量估算,研究较少。之前的研究表明,即使关闭时间较短,非稳态箱的关闭也会导致箱内浓度的非线性发展,而且线性和非线性通量估计值都会受到箱关闭时间本身的影响。基于 3,159 个单独的土壤二氧化碳和甲烷通量测量值,我们分析了线性回归和 Hutchinson 与 Mosier(1981 年)模型通量估算值如何受到试验室关闭时间长度的影响,试验室关闭时间以 30 秒为单位递增,最小和最大试验室关闭时间分别为 60 秒和 300 秒。在所有检测到的通量测量中,腔室关闭时间长度对线性回归估算值的影响在 1.4-8.0% 之间,对 Hutchinson-Mosier 估算值的影响在 0.4-17.8% 之间,在高通量区域观测到的影响最大。虽然线性回归和基于 Hutchinson-Mosier 的估算值都随着腔室关闭期的增加而减少,但我们观察到,当线性回归和基于 Hutchinson-Mosier 的估算值分别使用较短和较长的腔室关闭期时,通量估算值明显趋同。这表明在进行线性回归通量估算时,应尽量缩短封闭期,或确保足够长的封闭期,以便观察到 Hutchinson-Mosier 通量估算值随时间推移而趋于稳定。本分析以土壤通量测量为基础,但由于浓度梯度的扰动与非稳态室技术而非测量的生态系统成分有关,因此我们的结果对所有使用非稳态室进行的通量测量都有影响。
{"title":"Optimizing the closure period for improved accuracy of chamber-based greenhouse gas flux estimates","authors":"C-F. Johannesson ,&nbsp;J. Nordén ,&nbsp;H. Lange ,&nbsp;H. Silvennoinen ,&nbsp;K.S. Larsen","doi":"10.1016/j.agrformet.2024.110289","DOIUrl":"10.1016/j.agrformet.2024.110289","url":null,"abstract":"<div><div>Non-steady-state chambers are often used for greenhouse gas flux measurements, and while there are recommendations on how long to keep the chamber closed, it is less investigated to what extent the length of the chamber closure period affects the estimated flux rates and which closure periods may provide the most accurate linear and non-linear flux estimates. Previous studies have shown that the closure of non-steady-state chambers induces a non-linear concentration development inside the chamber, even across short chamber closure periods, and that both linear and non-linear flux estimates are impacted by the chamber closure period itself. Based on 3,159 individual soil CO<sub>2</sub> and CH<sub>4</sub> flux measurements, we analyzed how linear regression and <span><span>Hutchinson and Mosier (1981)</span></span> modeled flux estimates are affected by the length of the chamber closure period by increasing it in increments of 30 sec, with a minimum and maximum chamber closure period of 60 and 300 sec, respectively. Across all detected flux measurements, the effect of chamber closure period length varied between 1.4–8.0 % for linear regression estimates and between 0.4–17.8 % for Hutchinson–Mosier estimates, and the largest effect sizes were observed in high flux regions. While both linear regression and Hutchinson–Mosier based estimates decreased as the chamber closure period increased, we observed a clear convergence of flux estimates as shorter and longer chamber closure periods were used for linear regression and Hutchinson–Mosier based estimation, respectively. This suggests using closure periods as short as possible for linear regression flux estimation or ensuring long-enough closure periods to observe a stabilization of Hutchinson–Mosier flux estimates over time. This analysis was based on soil flux measurements, but because the perturbation of the concentration gradient is related to the non-steady-state chamber technique rather than the measured ecosystem component, our results have implications for all flux measurements conducted with non-steady-state chambers.</div></div>","PeriodicalId":50839,"journal":{"name":"Agricultural and Forest Meteorology","volume":"359 ","pages":"Article 110289"},"PeriodicalIF":5.6,"publicationDate":"2024-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142541652","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Influence of vegetation phenological carryover effects on plant autumn phenology under climate change 气候变化下植被物候延续效应对植物秋季物候的影响
IF 5.6 1区 农林科学 Q1 AGRONOMY Pub Date : 2024-10-28 DOI: 10.1016/j.agrformet.2024.110284
Huanhuan YUAN , Jiabao YAN , Ying LIU , Jie PENG , Xiaoyue WANG
Vegetation phenological carryover effects refer to the influence of previous phenological events on the current or subsequent ones. These effects can modulate the responses of autumn phenology to climate change, but the magnitude and duration of this effect remain poorly understood. Therefore, we employed multiple remote sensing datasets from 1982 to 2018 in the Northern Hemisphere (> 30°N) and partial correlation to investigate the influence of the carryover effect and environmental factors on the end of the growing season (EOS) over time. The importance of the variables in the projection score was used to quantify their relative importance. Our results showed that the previous year's EOS had a robust positive impact on the EOS for 40.02 % of the study area during 1982–2015, which was mainly located in the northern 50°N region. In contrast, the start of the growing season (SOS) was the main contributor to the EOS during 2001–2018, mainly at 40°N-50°N and in northern Russia. The carryover effect persisted into the subsequent year, but its strength and positive impacts varied dramatically in the next year. Concurrently, the mean correlation coefficient between climate factors and EOS rose from 0.20 to 0.22. Notably, the correlation coefficient for frost day frequency increased significantly (P < 0.05) from 0.15 to 0.36, with its influence area expanding from 10.29 % to 11.85 % of the study area. Compared with climate factors, the phenological carryover effect was the dominant driver of the EOS for each vegetation type, accounting for 72.8 % and 44.23 % of the total pixels during 1982–2015 and 2001–2018, respectively. Our study reveals a cascade of ecological consequences that extend beyond the initial occurrence and emphasizes the interconnectedness of growth stages in the plant life cycle, providing valuable insights into the adaptability and vulnerability of plant communities.
植被物候延续效应是指以前的物候事件对当前或以后物候事件的影响。这些影响可以调节秋季物候对气候变化的反应,但人们对这种影响的程度和持续时间仍然知之甚少。因此,我们采用了北半球(> 30°N)从1982年到2018年的多个遥感数据集和部分相关性,来研究随时间推移的携带效应和环境因素对生长季末期(EOS)的影响。变量在预测得分中的重要性被用来量化它们的相对重要性。结果表明,1982-2015 年间,上一年的 EOS 对 40.02% 的研究区域的 EOS 有显著的积极影响,这些区域主要位于北纬 50°以北地区。相比之下,在 2001-2018 年期间,生长季节的开始(SOS)是 EOS 的主要影响因素,主要集中在 40°N-50°N 和俄罗斯北部地区。结转效应持续到下一年,但其强度和积极影响在下一年有很大不同。同时,气候因子与 EOS 之间的平均相关系数从 0.20 上升到 0.22。值得注意的是,霜冻日频率的相关系数从 0.15 显著增加到 0.36(P <0.05),其影响范围从占研究区域的 10.29% 扩大到 11.85%。与气候因素相比,物候转移效应是各植被类型 EOS 的主要驱动因素,在 1982-2015 年和 2001-2018 年期间分别占总像素的 72.8 % 和 44.23 %。我们的研究揭示了一连串超出最初发生范围的生态后果,并强调了植物生命周期中各生长阶段之间的相互联系,为了解植物群落的适应性和脆弱性提供了宝贵的见解。
{"title":"Influence of vegetation phenological carryover effects on plant autumn phenology under climate change","authors":"Huanhuan YUAN ,&nbsp;Jiabao YAN ,&nbsp;Ying LIU ,&nbsp;Jie PENG ,&nbsp;Xiaoyue WANG","doi":"10.1016/j.agrformet.2024.110284","DOIUrl":"10.1016/j.agrformet.2024.110284","url":null,"abstract":"<div><div>Vegetation phenological carryover effects refer to the influence of previous phenological events on the current or subsequent ones. These effects can modulate the responses of autumn phenology to climate change, but the magnitude and duration of this effect remain poorly understood. Therefore, we employed multiple remote sensing datasets from 1982 to 2018 in the Northern Hemisphere (&gt; 30°N) and partial correlation to investigate the influence of the carryover effect and environmental factors on the end of the growing season (EOS) over time. The importance of the variables in the projection score was used to quantify their relative importance. Our results showed that the previous year's EOS had a robust positive impact on the EOS for 40.02 % of the study area during 1982–2015, which was mainly located in the northern 50°N region. In contrast, the start of the growing season (SOS) was the main contributor to the EOS during 2001–2018, mainly at 40°N-50°N and in northern Russia. The carryover effect persisted into the subsequent year, but its strength and positive impacts varied dramatically in the next year. Concurrently, the mean correlation coefficient between climate factors and EOS rose from 0.20 to 0.22. Notably, the correlation coefficient for frost day frequency increased significantly (<em>P</em> &lt; 0.05) from 0.15 to 0.36, with its influence area expanding from 10.29 % to 11.85 % of the study area. Compared with climate factors, the phenological carryover effect was the dominant driver of the EOS for each vegetation type, accounting for 72.8 % and 44.23 % of the total pixels during 1982–2015 and 2001–2018, respectively. Our study reveals a cascade of ecological consequences that extend beyond the initial occurrence and emphasizes the interconnectedness of growth stages in the plant life cycle, providing valuable insights into the adaptability and vulnerability of plant communities.</div></div>","PeriodicalId":50839,"journal":{"name":"Agricultural and Forest Meteorology","volume":"359 ","pages":"Article 110284"},"PeriodicalIF":5.6,"publicationDate":"2024-10-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142519576","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
Evaluating the phase evolution of CMIP GCMs for agricultural climate-change impact assessments in China 为中国农业气候变化影响评估评估 CMIP GCMs 的阶段演化
IF 5.6 1区 农林科学 Q1 AGRONOMY Pub Date : 2024-10-26 DOI: 10.1016/j.agrformet.2024.110282
Linlin Yao , Qian Tan , Guanhui Cheng , Shuping Wang , Bingming Chen
The performance of general circulation models (GCMs) in the Coupled Model Intercomparison Project (CMIP) critically determines the reliability of climate-change impact assessments and has continuously progressed (e.g., from CMIP3, CMIP5 to CMIP6). It remains unclear whether this progression enhances the reliability in evaluating the effects of climate change on agricultural systems at a daily resolution, particularly concerning crop production. To address this question, the study selected AquaCrop as a crop model for large-scale agricultural impact assessment due to its compatibility, robustness, and simplicity. Subsequently, the study coupled AquaCrop with multiple GCMs from different CMIP phases: 9 from CMIP3, 14 from CMIP5, and 15 from CMIP6, and attributed GCM-driven crop yield simulations to GCM biases over China. According to the modeling results, the progression enhanced the simulation performance for daily precipitation and temperature. The impacts of CMIPs on assessment results exhibited variability across temporal scales and crop types, further modulated by water management practices. Overall, crop simulations across three CMIP phases revealed a reduction in cold and water stresses, a shortened growing period (particularly evident in CMIP6), and an underestimation of yields. The evolution of CMIP phases increased spatial-temporal correlations for maize (0.61 to 0.81), wheat (0.68 to 0.77), and rice (0.63 to 0.77), without significantly reducing yield biases. Yield biases in early growth period were primarily influenced by daily temperature fluctuations, while biases in latter growth period were correlated with precipitation and maximum temperature. Irrigation mitigated the crop model's sensitivity to precise daily precipitation data compared to rainfed systems. This comprehensive analysis suggests, when evaluating climate change impacts on agriculture—at least for Chinese crops—CMIP6 better captured regional and temporal yield distributions than earlier phases, despite potentially underestimating yields and growth periods in certain regions.
耦合模式相互比较项目(CMIP)中的大气环流模式(GCM)的性能对气候变化影响评估的可靠性起着至关重要的决定作用,并且一直在不断进步(例如,从 CMIP3、CMIP5 到 CMIP6)。目前仍不清楚这一进展是否提高了以日分辨率评估气候变化对农业系统影响的可靠性,特别是在作物生产方面。为了解决这个问题,研究选择了 AquaCrop 作为大规模农业影响评估的作物模型,因为 AquaCrop 具有兼容性、稳健性和简易性。随后,研究将 AquaCrop 与 CMIP 不同阶段的多个 GCMs 相耦合:9 个来自 CMIP3,14 个来自 CMIP5,15 个来自 CMIP6,并将 GCM 驱动的作物产量模拟归因于中国上空的 GCM 偏差。根据建模结果,CMIPs 的进展提高了日降水量和温度的模拟性能。CMIPs 对评估结果的影响在不同时间尺度和作物类型上表现出差异性,并受到水资源管理实践的进一步影响。总体而言,CMIP 三个阶段的作物模拟结果表明,冷胁迫和水胁迫减少,生长期缩短(在 CMIP6 中尤为明显),产量被低估。CMIP 阶段的演变增加了玉米(从 0.61 到 0.81)、小麦(从 0.68 到 0.77)和水稻(从 0.63 到 0.77)的时空相关性,但并未显著减少产量偏差。生长前期的产量偏差主要受日气温波动的影响,而生长后期的偏差则与降水和最高气温相关。与雨水灌溉系统相比,灌溉减轻了作物模型对精确的日降水量数据的敏感性。这项综合分析表明,在评估气候变化对农业的影响时--至少对中国作物而言--MMIP6 比早期阶段更好地捕捉了区域和时间产量分布,尽管可能低估了某些地区的产量和生长期。
{"title":"Evaluating the phase evolution of CMIP GCMs for agricultural climate-change impact assessments in China","authors":"Linlin Yao ,&nbsp;Qian Tan ,&nbsp;Guanhui Cheng ,&nbsp;Shuping Wang ,&nbsp;Bingming Chen","doi":"10.1016/j.agrformet.2024.110282","DOIUrl":"10.1016/j.agrformet.2024.110282","url":null,"abstract":"<div><div>The performance of general circulation models (GCMs) in the Coupled Model Intercomparison Project (CMIP) critically determines the reliability of climate-change impact assessments and has continuously progressed (e.g., from CMIP3, CMIP5 to CMIP6). It remains unclear whether this progression enhances the reliability in evaluating the effects of climate change on agricultural systems at a daily resolution, particularly concerning crop production. To address this question, the study selected AquaCrop as a crop model for large-scale agricultural impact assessment due to its compatibility, robustness, and simplicity. Subsequently, the study coupled AquaCrop with multiple GCMs from different CMIP phases: 9 from CMIP3, 14 from CMIP5, and 15 from CMIP6, and attributed GCM-driven crop yield simulations to GCM biases over China. According to the modeling results, the progression enhanced the simulation performance for daily precipitation and temperature. The impacts of CMIPs on assessment results exhibited variability across temporal scales and crop types, further modulated by water management practices. Overall, crop simulations across three CMIP phases revealed a reduction in cold and water stresses, a shortened growing period (particularly evident in CMIP6), and an underestimation of yields. The evolution of CMIP phases increased spatial-temporal correlations for maize (0.61 to 0.81), wheat (0.68 to 0.77), and rice (0.63 to 0.77), without significantly reducing yield biases. Yield biases in early growth period were primarily influenced by daily temperature fluctuations, while biases in latter growth period were correlated with precipitation and maximum temperature. Irrigation mitigated the crop model's sensitivity to precise daily precipitation data compared to rainfed systems. This comprehensive analysis suggests, when evaluating climate change impacts on agriculture—at least for Chinese crops—CMIP6 better captured regional and temporal yield distributions than earlier phases, despite potentially underestimating yields and growth periods in certain regions.</div></div>","PeriodicalId":50839,"journal":{"name":"Agricultural and Forest Meteorology","volume":"359 ","pages":"Article 110282"},"PeriodicalIF":5.6,"publicationDate":"2024-10-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142519537","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
期刊
Agricultural and Forest Meteorology
全部 Acc. Chem. Res. ACS Applied Bio Materials ACS Appl. Electron. Mater. ACS Appl. Energy Mater. ACS Appl. Mater. Interfaces ACS Appl. Nano Mater. ACS Appl. Polym. Mater. ACS BIOMATER-SCI ENG ACS Catal. ACS Cent. Sci. ACS Chem. Biol. ACS Chemical Health & Safety ACS Chem. Neurosci. ACS Comb. Sci. ACS Earth Space Chem. ACS Energy Lett. ACS Infect. Dis. ACS Macro Lett. ACS Mater. Lett. ACS Med. Chem. Lett. ACS Nano ACS Omega ACS Photonics ACS Sens. ACS Sustainable Chem. Eng. ACS Synth. Biol. Anal. Chem. BIOCHEMISTRY-US Bioconjugate Chem. BIOMACROMOLECULES Chem. Res. Toxicol. Chem. Rev. Chem. Mater. CRYST GROWTH DES ENERG FUEL Environ. Sci. Technol. Environ. Sci. Technol. Lett. Eur. J. Inorg. Chem. IND ENG CHEM RES Inorg. Chem. J. Agric. Food. Chem. J. Chem. Eng. Data J. Chem. Educ. J. Chem. Inf. Model. J. Chem. Theory Comput. J. Med. Chem. J. Nat. Prod. J PROTEOME RES J. Am. Chem. Soc. LANGMUIR MACROMOLECULES Mol. Pharmaceutics Nano Lett. Org. Lett. ORG PROCESS RES DEV ORGANOMETALLICS J. Org. Chem. J. Phys. Chem. J. Phys. Chem. A J. Phys. Chem. B J. Phys. Chem. C J. Phys. Chem. Lett. Analyst Anal. Methods Biomater. Sci. Catal. Sci. Technol. Chem. Commun. Chem. Soc. Rev. CHEM EDUC RES PRACT CRYSTENGCOMM Dalton Trans. Energy Environ. Sci. ENVIRON SCI-NANO ENVIRON SCI-PROC IMP ENVIRON SCI-WAT RES Faraday Discuss. Food Funct. Green Chem. Inorg. Chem. Front. Integr. Biol. J. Anal. At. Spectrom. J. Mater. Chem. A J. Mater. Chem. B J. Mater. Chem. C Lab Chip Mater. Chem. Front. Mater. Horiz. MEDCHEMCOMM Metallomics Mol. Biosyst. Mol. Syst. Des. Eng. Nanoscale Nanoscale Horiz. Nat. Prod. Rep. New J. Chem. Org. Biomol. Chem. Org. Chem. Front. PHOTOCH PHOTOBIO SCI PCCP Polym. Chem.
×
引用
GB/T 7714-2015
复制
MLA
复制
APA
复制
导出至
BibTeX EndNote RefMan NoteFirst NoteExpress
×
0
微信
客服QQ
Book学术公众号 扫码关注我们
反馈
×
意见反馈
请填写您的意见或建议
请填写您的手机或邮箱
×
提示
您的信息不完整,为了账户安全,请先补充。
现在去补充
×
提示
您因"违规操作"
具体请查看互助需知
我知道了
×
提示
现在去查看 取消
×
提示
确定
Book学术官方微信
Book学术文献互助
Book学术文献互助群
群 号:481959085
Book学术
文献互助 智能选刊 最新文献 互助须知 联系我们:info@booksci.cn
Book学术提供免费学术资源搜索服务,方便国内外学者检索中英文文献。致力于提供最便捷和优质的服务体验。
Copyright © 2023 Book学术 All rights reserved.
ghs 京公网安备 11010802042870号 京ICP备2023020795号-1