School of Geographical and Earth Sciences, University of Glasgow, Glasgow, G128QQ, UK.
Centre for Ecology and Hydrology, Bush Estate, Penicuik, Midlothian, EH26 0QB, UK.
J Environ Manage. 2019 Mar 1;233:321-328. doi: 10.1016/j.jenvman.2018.12.036. Epub 2018 Dec 22.
Large amounts of carbon are stored in northern peatlands. There is concern that greater wildfire severity following projected increases in summer drought will lead to higher post-fire carbon losses. We measured soil carbon dynamics in a Calluna heathland and a raised peat bog after experimentally manipulating fire severity. A gradient of fire severity was achieved by simulating drought in 2 × 2 m plots. Ecosystem respiration (ER), net ecosystem exchange (NEE), methane (CH) flux and concentration of dissolved organic carbon ([DOC], measured at the raised bog only) were measured for up to two years after burning. The response of these carbon fluxes to increased fire severity in drought plots was similar to plots burnt under ambient conditions associated with traditional managed burning. Averaged across all burnt plots, burning altered mean NEE from a net carbon sink at the heathland (-0.33 μmol CO m s in unburnt plots) to a carbon source (0.50 μmol m s in burnt plots) and at the raised bog (-0.38 and 0.16 μmol m s, respectively). Burning also increased CH flux at the raised bog (from 1.16 to 25.3 nmol m s in the summer, when it accounted for 79% of the CO-equivalent emission). Burning had no significant effect on soil water [DOC].
大量的碳被储存在北方泥炭地中。人们担心，随着夏季干旱预计会加剧，野火的严重程度将会增加，这将导致火灾后碳的损失更高。我们在实验性地操纵火灾严重程度后，对一种石楠荒地和一种凸起的泥炭沼泽地的土壤碳动态进行了测量。通过在 2×2 平方米的地块中模拟干旱，实现了火灾严重程度的梯度。在燃烧后最多两年的时间里，我们测量了生态系统呼吸（ER）、净生态系统交换（NEE）、甲烷（CH）通量和溶解有机碳浓度（仅在凸起的沼泽地测量）。这些碳通量对干旱地块中火灾严重程度增加的反应与与传统管理燃烧相关的环境条件下燃烧的地块相似。在所有燃烧的地块中，燃烧将荒地的平均 NEE 从净碳汇（未燃烧地块中的-0.33μmol CO m s）改变为碳源（燃烧地块中的 0.50μmol m s），在凸起的沼泽地从-0.38 和 0.16μmol m s 分别改变。燃烧还增加了凸起沼泽地的 CH 通量（夏季从 1.16 增加到 25.3nmol m s，占 CO 当量排放的 79%）。燃烧对土壤水分[DOC]没有显著影响。
