Tundra landscape heterogeneity, not interannual variability, controls the decadal regional carbon balance in the Western Russian Arctic
Tundra landscape heterogeneity, not interannual variability, controls the decadal regional carbon balance in the Western Russian Arctic
复制标题
苔原景观异质性，而不是年际变化，控制着俄罗斯西部北极地区的十年间区域碳平衡
DOI：
--
复制
发表时间：
2018
影响因子：
11.6
通讯作者：
N. Shurpali
中科院分区：
文献类型：
--
作者：
C. Treat;M. Marushchak;C. Voigt;Yu Zhang;Z. Tan;Q. Zhuang;T. Virtanen;Aleksi Räsänen;C. Biasi;G. Hugelius;D. Kaverin;P. Miller;M. Stendel;V. Romanovsky;F. Rivkin;P. Martikainen;N. Shurpali
在整个北极，冻原生态系统的净生态系统碳（C）平衡是高度不确定的，由于大量的时间变化的C通量和景观异质性。我们使用基于过程的地球化学模型对2006-2015年期间俄罗斯东北部约100 km 2亚北极苔原地区主要土地覆盖类型的二氧化碳（CO2）和甲烷（CH 4）通量进行了建模。模拟的年CO2净通量范围从杨柳沼泽的−300 g C m−2年−1 [净吸收]到干燥地衣苔原的3 g C m−2年−1 [净来源]。模拟的甲烷年排放量在泥炭高原和杨柳围栏分别为-0.2至22.3克C/m-2年-1。与土地覆盖类型之间的变化（150%）相比，十年的年际变化相对较小（20%-25%）。使用高分辨率土地覆盖分类，该地区是大多数土地覆盖类型的大气CO2净汇，但由于永久冻土无沼泽的高排放，该地区是大气CH 4的净来源。使用较低分辨率的土地覆盖分类导致相对于高分辨率分类，区域CH 4通量低估了20%-65%，由于湿地面积低估了60%，区域CO2吸收量高估了10%。高地与湿地的相对比例是确定净区域碳平衡在这个和其他北极苔原网站的关键，因为湿地是北极苔原生态系统的碳循环的热点。
Across the Arctic, the net ecosystem carbon (C) balance of tundra ecosystems is highly uncertain due to substantial temporal variability of C fluxes and to landscape heterogeneity. We modeled both carbon dioxide (CO2) and methane (CH4) fluxes for the dominant land cover types in a ~100‐km2 sub‐Arctic tundra region in northeast European Russia for the period of 2006–2015 using process‐based biogeochemical models. Modeled net annual CO2 fluxes ranged from −300 g C m−2 year−1 [net uptake] in a willow fen to 3 g C m−2 year−1 [net source] in dry lichen tundra. Modeled annual CH4 emissions ranged from −0.2 to 22.3 g C m−2 year−1 at a peat plateau site and a willow fen site, respectively. Interannual variability over the decade was relatively small (20%–25%) in comparison with variability among the land cover types (150%). Using high‐resolution land cover classification, the region was a net sink of atmospheric CO2 across most land cover types but a net source of CH4 to the atmosphere due to high emissions from permafrost‐free fens. Using a lower resolution for land cover classification resulted in a 20%–65% underestimation of regional CH4 flux relative to high‐resolution classification and smaller (10%) overestimation of regional CO2 uptake due to the underestimation of wetland area by 60%. The relative fraction of uplands versus wetlands was key to determining the net regional C balance at this and other Arctic tundra sites because wetlands were hot spots for C cycling in Arctic tundra ecosystems.