Increased tree carbon storage in response to nitrogen deposition in the US
Increased tree carbon storage in response to nitrogen deposition in the US
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DOI：
10.1038/ngeo721
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发表时间：
2010
影响因子：
18.3
通讯作者：
R. Q. Thomas;C. Canham;K. Weathers;C. Goodale
中科院分区：
文献类型：
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作者：
R. Q. Thomas;C. Canham;K. Weathers;C. Goodale
人类活动大大加速了二氧化碳和生物活性氮向大气的排放。由于氮的可用性往往限制森林生产力，长期以来人们一直期望人为氮沉降可以刺激森林中的碳固存。然而，关于沉积引起的森林生长刺激的空间广泛证据一直缺乏，从模型和样地水平研究中得出的定量估计是有争议的，，，，，。在这里，我们使用森林清查数据来研究20世纪80年代和90年代美国东北部和中北部的氮沉积对树木生长、生存和碳储存的影响。我们展示了该地区24种最常见树种的生长和死亡对氮沉降的一系列响应。氮沉降（3 ~ 11 kg ha−1yr−1）促进了11种植物的生长，抑制了3种植物的生长。氮沉降促进了所有具有丛枝菌根真菌关联的树种的生长。在没有干扰使碳储量减少50%以上的情况下，每沉积1公斤氮，地上生物量增加61公斤碳，比工业化前的条件增加了40%。外推到全球，我们估计氮沉降可以使树木碳储量增加0.31 Pg碳年−1。
Human activities have greatly accelerated emissions of both carbon dioxide and biologically reactive nitrogen to the atmosphere,. As nitrogen availability often limits forest productivity, it has long been expected that anthropogenic nitrogen deposition could stimulate carbon sequestration in forests. However, spatially extensive evidence for deposition-induced stimulation of forest growth has been lacking, and quantitative estimates from models and plot-level studies are controversial,,,,,. Here, we use forest inventory data to examine the impact of nitrogen deposition on tree growth, survival and carbon storage across the northeastern and north-central USA during the 1980s and 1990s. We show a range of growth and mortality responses to nitrogen deposition among the region’s 24 most common tree species. Nitrogen deposition (which ranged from 3 to 11 kg ha−1yr−1) enhanced the growth of 11 species and decreased the growth of 3 species. Nitrogen deposition enhanced growth of all tree species with arbuscular mycorrhizal fungi associations. In the absence of disturbances that reduced carbon stocks by more than 50%, above-ground biomass increment increased by 61 kg of carbon per kg of nitrogen deposited, amounting to a 40% enhancement over pre-industrial conditions. Extrapolating to the globe, we estimate that nitrogen deposition could increase tree carbon storage by 0.31 Pg carbon yr−1.