Moss tundra with a thick peat layer dominated by bryophytes is one of the most important ecosystems in the High Arctic of Svalbard, but little is known about the carbon dynamics of moss tundra. Here, we estimated the net primary production (NPP) and net ecosystem production (NEP) of moss tundra on Brøggerhalvøya (Brøgger Peninsula) of north-western Svalbard (79°N). The net photosynthetic and respiration rates of the two dominant moss species, Calliergon richardsonii and Tomenthypnum nitens, were measured under laboratory conditions. On the basis of the photosynthetic and respiration characteristics and climatic data, we estimated the cumulative NPP of the dominant moss species during the growing season to be 143–207 gC m^-2. Net CO₂ exchange, which was determined by subtracting the respiration of the brown moss layer from NPP, was similar to that estimated using field gas flux measurements. The field measurements indicated that methane emissions contributed little to carbon flow. The NEP estimated in this study was much larger than the long-term carbon accumulation rate reported in a previous study. These data suggest that a significant amount of fixed carbon was lost from the peat layer or that carbon accumulation has recently increased. The NPP and NEP values of the moss tundra are larger than those reported for other vegetation types in this area, suggesting that moss tundra is an active site with high rates of carbon fixation.

苔藓苔原具有厚厚的泥炭层，以苔藓植物为主，是斯瓦尔巴群岛高北极地区最重要的生态系统之一，但人们对苔藓苔原的碳动态知之甚少。在这里，我们估算了斯瓦尔巴特群岛西北部 (79°N) Brøggerhalvøya（Brøgger 半岛）苔原的净初级生产量 (NPP) 和净生态系统生产量 (NEP)。在实验室条件下测量了两种主要苔藓物种Calliergon richardsonii 和 Tomenthypnum nitens的净光合和呼吸速率 。根据光合作用和呼吸特性以及气候数据，我们估计生长季节优势苔藓物种的累积 NPP 为 143–207 gC m ^-2。净二氧化碳₂ 交换是通过从 NPP 中减去棕色苔藓层的呼吸来​​确定的，与使用现场气体通量测量估计的结果相似。现场测量表明，甲烷排放对碳流量的贡献很小。本研究中估计的 NEP 远大于先前研究中报告的长期碳积累率。这些数据表明，大量固定碳从泥炭层中流失，或者最近碳积累有所增加。苔原的 NPP 和 NEP 值大于该地区其他植被类型的报告值，表明苔原是一个具有高固碳率的活跃场所。