Shortened Fire Intervals Stimulate Carbon Losses from Heterotrophic Respiration and Reduce Understorey Plant Productivity in Boreal Forests
Shortened Fire Intervals Stimulate Carbon Losses from Heterotrophic Respiration and Reduce Understorey Plant Productivity in Boreal Forests
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火灾间隔的缩短会刺激异养呼吸造成的碳损失，并降低北方森林林下植物的生产力
DOI：
10.1007/s10021-022-00761-w
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发表时间：
2022
期刊：
影响因子：
3.7
通讯作者：
Vogel, Jason G.
中科院分区：
文献类型：
--
作者：
Shabaga, Jason A.;Bracho, Rosvel;Klockow, Paul A.;Lucash, Melissa S.;Vogel, Jason G.
在阿拉斯加内陆的北方地区，火灾频率随着气候变暖而增加，火灾重现期短（< 50年）变得越来越普遍。最近的研究表明，这些“再烧”将减少绝缘表面有机层（SOL）和种子库，抑制黑云杉再生和增加落叶覆盖。这些变化预计将放大土壤变暖，增加矿物土壤有机碳（SOC）的分解率，并损害重建林下植被和SOL。我们研究了再烧如何改变土壤温度，异养土壤呼吸（RH），和下层总初级生产力（GPP），并与这些植被组成和SOL深度的变化。两个不同的燃烧复合体以前覆盖的云杉进行了测量;都包括地区烧毁1x，2x，和3x超过60年和成熟（190岁）云杉林下的永久冻土。从1次到3次烧伤，每年近地表土壤温度增加2.7 °C，与SOL深度减少和每年RH排放增加1.9 Mg C ha− 1相关。然而，近地表土壤变暖占较高的相对湿度流出量的≤ 23%;落叶层顶植被和根系生物量的增加与再燃烧更好地与相对湿度相关，而不是土壤温度。再烧也温暖了深层土壤，减少了林下植物的生物量和GPP，减少了它们抵消RH升高的潜力，并有助于SOL的发展。这表明，再燃烧导致的损失矿物SOC以前存储在永冻层由于土壤变暖和植被组成的变化，说明燃烧频率如何创建加速区域C损失的途径。
Fire frequency is increasing with climate warming in the boreal regions of interior Alaska, with short fire return intervals (< 50 years) becoming more common. Recent studies suggest these “reburns” will reduce the insulating surface organic layer (SOL) and seedbanks, inhibiting black spruce regeneration and increasing deciduous cover. These changes are projected to amplify soil warming, increasing mineral soil organic carbon (SOC) decomposition rates, and impair re-establishment of understorey vegetation and the SOL. We examined how reburns changed soil temperature, heterotrophic soil respiration (RH), and understorey gross primary production (GPP), and related these to shifts in vegetation composition and SOL depths. Two distinct burn complexes previously covered by spruce were measured; both included areas burned 1x, 2x, and 3x over 60 years and mature (≈ 90 year old) spruce forests underlain by permafrost. A 2.7 °C increase in annual near-surface soil temperatures from 1x to 3x burns was correlated with a decrease in SOL depths and a 1.9 Mg C ha−1increase in annual RH efflux. However, near-surface soil warming accounted for ≤ 23% of higher RH efflux; increases in deciduous overstorey vegetation and root biomass with reburning better correlated with RH than soil temperature. Reburning also warmed deeper soils and reduced the biomass and GPP of understory plants, lessening their potential to offset elevated RH and contribute to SOL development. This suggests that reburning led to losses of mineral SOC previously stored in permafrost due to warming soils and changes in vegetation composition, illustrating how burn frequency creates pathways for accelerated regional C loss.
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明尼苏达州两个地点的白杨、云杉和松树干的分解
DOI：
--
发表时间：
1993
期刊：
影响因子：
--
作者：
D. Alban;J. Pastor
通讯作者：
J. Pastor
影响因子：
64.8
作者：
Walker, Xanthe J.;Baltzer, Jennifer L.;Mack, Michelle C.
通讯作者：
Mack, Michelle C.
影响因子：
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作者：
K. Yoshikawa;W. Bolton;V. Romanovsky;M. Fukuda;L. Hinzman
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K. Yoshikawa;W. Bolton;V. Romanovsky;M. Fukuda;L. Hinzman
DOI：
10.1073/pnas.1719903115
发表时间：
2018-04-10
影响因子：
11.1
作者：
McGuire AD;Lawrence DM;Koven C;Clein JS;Burke E;Chen G;Jafarov E;MacDougall AH;Marchenko S;Nicolsky D;Peng S;Rinke A;Ciais P;Gouttevin I;Hayes DJ;Ji D;Krinner G;Moore JC;Romanovsky V;Schädel C;Schaefer K;Schuur EAG;Zhuang Q
通讯作者：
Zhuang Q
影响因子：
3.9
作者：
Bradshaw, Corey J. A.;Warkentin, Ian G.
通讯作者：
Warkentin, Ian G.