Nitrogen-induced new net primary production and carbon sequestration in global forests
Nitrogen-induced new net primary production and carbon sequestration in global forests
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DOI：
10.1016/j.envpol.2018.08.041
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发表时间：
2018-11-01
影响因子：
8.9
通讯作者：
de Vries, Wim
中科院分区：
文献类型：
--
作者：
Du, Enzai;de Vries, Wim
氮沉降和生物固氮是陆地生态系统的主要外部氮输入。然而，很少有研究同时量化这两种外部氮输入对全球NPP和随之产生的碳固存的贡献。在文献分析的基础上，我们通过化学计量尺度方法估算了全球北方、温带和热带森林生物群落中由于BNF和N沉积的外部N输入以及随之产生的C汇而产生的新净初级生产量（NPP）。在全球已建立的森林中，氮诱导的新NPP估计为3.48 Pg - C /年（-1），对碳汇的贡献为1.83 Pg - C /年（-1）。更具体地说，地上和地下的新NPP估计分别为2.36和1.12 Pg C /年（-1），而木材和土壤中外部n诱导的C汇估计分别为1.51和0.32 Pg C /年（-1）。全球森林n诱导的新NPP （3.07 Pg C yr(-1)）主要由BNF贡献，碳汇为1.58 Pg C yr（-1）。与BNF相比，N沉降对全球森林新NPP （0.41 Pg C yr(-1)）和C汇（0.25 Pg C yr(-1)）的贡献较小。在生物群系尺度上，氮素诱导的新NPP速率和碳汇速率表现出从北方森林向热带森林增加的趋势，这主要是受BNF增加的驱动。相反，氮沉降导致温带森林的碳汇（0.11 Pg C /年（-1））大于北方森林（0.06 Pg C /年（-1））和热带森林（0.08 Pg C /年（-1））。我们对氮诱导的新NPP导致的总碳汇的估计与全球已建立森林的总碳汇的独立评估大致相符，这表明BNF和大气沉降的外部N输入是全球森林碳汇的关键驱动因素。(C) 2018 Elsevier Ltd.版权所有。
Nitrogen (N) deposition and biological N fixation (BNF) are main external N inputs into terrestrial ecosystems. However, few studies have simultaneously quantified the contribution of these two external N inputs to global NPP and consequent C sequestration. Based on literature analysis, we estimated new net primary production (NPP) due to external N inputs from BNF and N deposition and the consequent C sinks in global boreal, temperate and tropical forest biomes via a stoichiometric scaling approach. Nitrogen-induced new NPP is estimated to be 3.48 Pg C yr(-1) in global established forests and contributes to a C sink of 1.83 Pg C yr(-1) . More specifically, the aboveground and belowground new NPP are estimated to be 2.36 and 1.12 Pg C yr(-1), while the external N-induced C sinks in wood and soil are estimated to be 1.51 and 0.32 Pg C yr(-1), respectively. BNF contributes to a major proportion of N-induced new NPP (3.07 Pg C yr(-1)) in global forest, and accounts for a C sink of 1.58 Pg C yr(-1). Compared with BNF, N deposition only makes a minor contribution to new NPP (0.41 Pg C yr(-1)) and C sinks (0.25 Pg C yr(-1)) in global forests. At the biome scale, rates of N-induced new NPP and C sink show an increase from boreal forest towards tropical forest, as mainly driven by an increase of BNF. In contrast, N deposition leads to a larger C sink in temperate forest (0.11 Pg C yr(-1)) than boreal (0.06 Pg C yr(-1)) and tropical forest (0.08 Pg C yr(-1)). Our estimate of total C sink due to N-induced new NPP approximately matches an independent assessment of total C sink in global established forests, suggesting that external N inputs by BNF and atmospheric deposition are key drivers of C sinks in global forests. (C) 2018 Elsevier Ltd. All rights reserved.