Effects of fire on soil respiration and its components in a Dahurian larch (Larix gmelinii) forest in northeast China: Implications for forest ecosystem carbon cycling
Effects of fire on soil respiration and its components in a Dahurian larch (Larix gmelinii) forest in northeast China: Implications for forest ecosystem carbon cycling
复制标题
DOI：
10.1016/j.geoderma.2021.115273
复制
发表时间：
2021-06-10
期刊：
影响因子：
6.1
通讯作者：
Sun, Long
中科院分区：
文献类型：
--
作者：
Hu, Tongxin;Zhao, Binqing;Sun, Long
火在调节森林生态系统土壤碳收支中起着至关重要的作用。然而，很少有研究集中在火对土壤呼吸（R-s）及其异养（R-h）和自养（R-a）组分的影响。本文研究了中国东北落叶松（Larix gmelinii）林火干扰后R-s、R-h和R-a对火的响应以及影响R-s的驱动因子。火干扰显着增加R-h约24%，显着降低R-a约66%，在燃烧的地块相比，未燃烧的地块。R-h与R-s的比值从未燃烧样地的0.57显著增加到燃烧样地的0.79。火烧迹地在生长季和春季冻融循环期间的R-sC排放量分别增加了约10%和28%。此外，使用结构方程模型，我们表明，T-5（土壤温度在5厘米深）是主要的非生物因子影响R-S在未燃烧和燃烧的地块。细根生物量（FR）是主要的生物驱动器的R-s在对照地块，而微生物生物量碳（MBC）是主要的生物驱动器的R-s在燃烧的地块。我们的研究结果表明，R-S组件的响应火干扰的显着差异。在寒温带森林生态系统中，森林火灾会造成土壤碳的大量流失，因此，在森林火灾干扰后，应积极进行森林更新管理。
Fire plays a critical part in regulating soil carbon (C) budgets in forest ecosystems. However, few studies have focused on the effects of fire on soil respiration (R-s) and its heterotrophic (R-h) and autotrophic (R-a) components. In this study, we examined the response of R-s, R-h, and R-a to fire and the driving factors that affect R-s after a fire disturbance in a Dahurian larch (Larix gmelinii) forest in northeastern China. Fire disturbance significantly increased R-h by approximately 24% and significantly reduced R-a by approximately 66% in burned plots compared to unburned plots. The ratio of R-h to R-s significantly increased from 0.57 in the unburned plots to 0.79 in the burned plots. Fire disturbance also led to cumulative R-s C efflux increasing by approximately 10% and 28% during the growing season and the period of spring freeze-thaw cycles (FTC) in the burned plots. Furthermore, using structural equation modelling, we showed that T-5 (soil temperature at 5 cm depth) was the main abiotic factor affecting R-s in both unburned and burned plots. Fine root biomass (FR) was the dominant biotic driver of R-s in the control plots, whereas microbial biomass carbon (MBC) was the dominant biotic driver of R-s in burned plots. Our findings demonstrated a significant discrepancy in the response of R-s components to fire disturbance. Forest fires can cause considerable losses of soil C in a cold temperate forest ecosystem, which suggests that proactive management of forest regeneration should be carried out after forest fire disturbances.