Peat macropore networks – new insights into episodic and hotspot methane emission

大孔隙 泥炭 土壤科学 土壤孔隙空间特征 多孔性 甲烷 环境科学 微尺度化学 大气(单位) 地质学 化学 生态学 岩土工程 气象学 物理 数学教育 生物 催化作用 有机化学 介孔材料 生物化学 数学
作者
Petri Kiuru,Marjo Palviainen,Tiia Grönholm,Maarit Raivonen,Leonie Kohl,Vincent Gauci,Iñaki Urzainki,Ari Laurén
出处
期刊:Biogeosciences [Copernicus Publications]
卷期号:19 (7): 1959-1977 被引量:6
标识
DOI:10.5194/bg-19-1959-2022
摘要

Abstract. Peatlands are important natural sources of atmospheric methane (CH4) emissions. The production and emission of CH4 are strongly influenced by the diffusion of oxygen into the soil and of CH4 from the soil to the atmosphere, respectively. This diffusion, in turn, is controlled by the structure of macropore networks. The characterization of peat pore structure and connectivity through complex network theory approaches can give conceptual insight into how the relationship between the microscale pore space properties and CH4 emissions on a macroscopic scale is shaped. The evolution of the pore space that is connected to the atmosphere can also be conceptualized through a pore network modeling approach. Pore regions isolated from the atmosphere may further develop into anaerobic pockets, which are local hotspots of CH4 production in unsaturated peat. In this study, we extracted interconnecting macropore networks from three-dimensional X-ray micro-computed tomography (µCT) images of peat samples and evaluated local and global connectivity metrics for the networks. We also simulated the water retention characteristics of the peat samples using a pore network modeling approach and compared the simulation results with measured water retention characteristics. The results showed large differences in peat macropore structure and pore network connectivity between vertical soil layers. The macropore space was more connected and the flow paths through the peat matrix were less tortuous near the soil surface than at deeper depths. In addition, macroporosity, structural anisotropy, and average pore throat diameter decreased with depth. Narrower and more winding air-filled diffusion channels may reduce the rate of gas transport as the distance from the peat layer to the soil–air interface increases. The network analysis also suggests that both local and global network connectivity metrics, such as the network average clustering coefficient and closeness centrality, might serve as proxies for assessing the efficiency of gas diffusion in air-filled pore networks. However, the applicability of the network metrics was restricted to the high-porosity near-surface layer. The spatial extent and continuity of the pore network and the spatial distribution of the pores may be reflected in different network metrics in contrasting ways. The hysteresis of peat water content between wetting and drying was found to affect the evolution of the volume of connected air-filled pore space in unsaturated peat. Thus, the formation of anaerobic pockets may occur in a smaller soil volume and methanogenesis may be slower when the peat is wetting compared to in drying conditions. This hysteretic behavior might explain the hotspots and episodic spikes of CH4 emissions, and therefore, it should be taken into account in biogeochemical models.
最长约 10秒,即可获得该文献文件

科研通智能强力驱动
Strongly Powered by AbleSci AI
更新
PDF的下载单位、IP信息已删除 (2025-6-4)

科研通是完全免费的文献互助平台,具备全网最快的应助速度,最高的求助完成率。 对每一个文献求助,科研通都将尽心尽力,给求助人一个满意的交代。
实时播报
冷静如松完成签到 ,获得积分10
1秒前
3秒前
浮云完成签到 ,获得积分10
4秒前
屈岂愈完成签到,获得积分10
5秒前
19秒前
Pupil完成签到,获得积分10
19秒前
偏偏意气用事完成签到,获得积分10
20秒前
安安完成签到,获得积分10
24秒前
cttc完成签到,获得积分10
25秒前
Chnimike完成签到 ,获得积分10
25秒前
29秒前
红茸茸羊完成签到 ,获得积分10
29秒前
年轻千愁完成签到 ,获得积分10
31秒前
liu完成签到,获得积分10
32秒前
量子星尘发布了新的文献求助10
32秒前
Wanyeweiyu完成签到,获得积分10
34秒前
Fury完成签到 ,获得积分10
39秒前
风中幻梦完成签到,获得积分10
41秒前
bigpluto完成签到,获得积分10
42秒前
44秒前
是谁还没睡完成签到 ,获得积分10
45秒前
盘尼西林发布了新的文献求助10
49秒前
zzz完成签到 ,获得积分10
51秒前
dktrrrr完成签到,获得积分10
53秒前
科研通AI2S应助科研通管家采纳,获得10
53秒前
丘比特应助科研通管家采纳,获得20
53秒前
53秒前
ccc完成签到,获得积分10
58秒前
萧秋灵完成签到,获得积分10
59秒前
缓慢冥幽完成签到,获得积分10
59秒前
旺仔同学完成签到,获得积分10
1分钟前
吉以寒完成签到,获得积分10
1分钟前
科研老兵完成签到,获得积分10
1分钟前
量子星尘发布了新的文献求助10
1分钟前
fys131415完成签到 ,获得积分10
1分钟前
执着的忆雪完成签到 ,获得积分10
1分钟前
1分钟前
闵不悔完成签到,获得积分10
1分钟前
阳光火车完成签到 ,获得积分10
1分钟前
cc完成签到,获得积分10
1分钟前
高分求助中
【提示信息,请勿应助】关于scihub 10000
Les Mantodea de Guyane: Insecta, Polyneoptera [The Mantids of French Guiana] 3000
徐淮辽南地区新元古代叠层石及生物地层 3000
The Mother of All Tableaux: Order, Equivalence, and Geometry in the Large-scale Structure of Optimality Theory 3000
Handbook of Industrial Diamonds.Vol2 1100
Global Eyelash Assessment scale (GEA) 1000
Picture Books with Same-sex Parented Families: Unintentional Censorship 550
热门求助领域 (近24小时)
化学 材料科学 医学 生物 工程类 有机化学 生物化学 物理 内科学 纳米技术 计算机科学 化学工程 复合材料 遗传学 基因 物理化学 催化作用 冶金 细胞生物学 免疫学
热门帖子
关注 科研通微信公众号,转发送积分 4038066
求助须知:如何正确求助?哪些是违规求助? 3575779
关于积分的说明 11373801
捐赠科研通 3305584
什么是DOI,文献DOI怎么找? 1819239
邀请新用户注册赠送积分活动 892655
科研通“疑难数据库(出版商)”最低求助积分说明 815022