Nitrogen deposition and increased precipitation interact to affect fine root production and biomass in a temperate forest: Implications for carbon cycling
Nitrogen deposition and increased precipitation interact to affect fine root production and biomass in a temperate forest: Implications for carbon cycling
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氮沉降和降水增加相互作用，影响温带森林的细根生产和生物量：对碳循环的影响
DOI：
10.1016/j.scitotenv.2020.144497
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发表时间：
2021-01-05
影响因子：
9.8
通讯作者：
Fu, Shenglei
中科院分区：
文献类型：
--
作者：
Li, Xiaowei;Zhang, Chenlu;Fu, Shenglei
细根连接地下和地上系统，并通过为植物提供营养和水分来帮助调节陆地生态系统的碳平衡。通过6年的试验，研究了大气氮沉降和降水增加对温带落叶林细根生产力和现存生物量的影响。从2013年到2018年，我们在森林冠层上方施氮（25 kg N ha（-1）yr（-1））和水（336 mm，环境年降水量的30%），并量化了2017年和2018年的细根产量和生物量。在0-10 cm土层，施氮与水分的交互作用对细根产量和生物量的影响不显著。在0-10 cm土层，施氮显著增加细根产量，增加幅度为18.1%，但对细根生物量无影响。水分处理显著提高了细根产量和生物量，分别提高了13.6%和17.0%。施氮量和灌水量均对细根产量有显著的直接正效应，灌水量通过降低土壤NO3-浓度对细根生物量有间接正效应。在10-30 cm土层，施氮量与灌水量的交互作用在细根产量和生物量方面均达到显著水平，施氮量的正效应被灌水量减弱，反之亦然。这些研究结果表明，细根，因此地下碳储量可能有复杂的响应，增加大气氮沉降和降水量的变化预测的未来。研究结果还表明，从只考虑一个自变量的实验中获得的结果（例如，氮输入或水输入）和只有一个土壤深度应谨慎解释。(C)2020爱思唯尔B. V.保留所有权利。
Fine roots connect belowground and aboveground systems and help regulate the carbon balance of terrestrial ecosystems by providing nutrients and water for plants. To evaluate the effects of atmospheric nitrogen (N) deposition and increased precipitation on fine root production and standing biomass in a temperate deciduous forest in central China, we conducted a 6-year experiment. From 2013 to 2018, we applied N (25 kg N ha(-1) yr(-1)) and water (336 mm, 30% of the ambient annual precipitation) above the forest canopy, and we quantified fine root production and biomass in 2017 and 2018. At 0-10 cm soil depth, the statistical interaction between addition of N and water was not significant in terms of fine root production or biomass. At 0-10 cm soil depth, N addition significantly increased fine root production by 18.1%, but did not affect fine root biomass. Water addition significantly increased fine root production and biomass by 13.6 and 17.0%, respectively. Both N and water addition had significant direct positive effects on fine root production, and water addition had indirect positive effects on fine root biomass through decreasing soil NO3- concentration. At 10-30 cm soil depth, the statistical interaction between N addition andwater addition was significant in terms of both fine root production and biomass, i.e., the positive effect of N addition was reduced bywater addition, and vice versa. These findings indicate that fine roots and therefore belowground carbon storage may have complex responses to increases in atmospheric N deposition and changes in precipitation predicted for the future. The findings also suggest that results obtained from experiments that consider only one independent variable (e.g., N input or water input) and only one soil depth should be interpreted with caution. (C) 2020 Elsevier B.V. All rights reserved.