Short-term simulated nitrogen deposition increases carbon sequestration in a Pleioblastus amarus plantation
Short-term simulated nitrogen deposition increases carbon sequestration in a Pleioblastus amarus plantation
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DOI：
10.1007/s11104-010-0610-0
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发表时间：
2011-03
期刊：
影响因子：
4.9
通讯作者：
L. Tu;T. Hu;Jian Zhang;Renzhi Li;Hong-zhong Dai;Shou-hua Luo
中科院分区：
文献类型：
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作者：
L. Tu;T. Hu;Jian Zhang;Renzhi Li;Hong-zhong Dai;Shou-hua Luo
为了了解氮(N)沉降对竹林碳(C)平衡的关键过程的影响，在中国西南多雨区进行了为期两年的模拟苦竹人工林N沉降的田间试验。本研究设4个氮素水平：对照(不加氮)、低氮(50亿kg/N ha−1年期−1)、中氮(150亿kg/N ha−1年−1)、高氮(300亿kg/N ha−1年−1)。结果表明，土壤呼吸具有明显的季节变化规律，盛夏土壤呼吸速率最大，冬末土壤呼吸速率最小。对照样地土壤年累计呼吸量为585 ± ，43 g−-C/2a−1。模拟氮沉降显著提高了土壤年平均呼吸速率、细根生物量、土壤微生物量C(MBC)和细根和鲜叶凋落物中的N浓度。土壤呼吸与土壤温度呈指数正相关，与土壤微生物量碳呈线性关系。各处理的净第一性生产量变化范围为10.95~15.01mg.C ha−1年−1，高于土壤年呼吸量(5.85~7.62mg.C ha−1年期−1)。模拟氮沉降增加了生态系统净生产量(NEP)，且对照与高N处理NEP差异显著，而对照、低N、中N之间NEP差异不显著。结果表明，氮素控制着该竹林生态系统的初级生产力。模拟氮沉降通过增加植物碳库来增加苦瓜人工林生态系统的固碳量，但通过土壤呼吸释放的二氧化碳也有所增加。
In order to understand the influence of nitrogen (N) deposition on the key processes relevant to the carbon (C) balance in a bamboo plantation, a two-year field experiment involving the simulated deposition of N in aPleioblastus amarusplantation was conducted in the rainy region of SW China. Four levels of N treatments: control (no N added), low-N (50 kg N ha−1year−1), medium-N (150 kg N ha−1year−1), and high-N (300 kg N ha−1year−1) were set in the present study. The results showed that soil respiration followed a clear seasonal pattern, with the maximum rates in mid-summer and the minimum in late winter. The annual cumulative soil respiration was 585 ± 43 g CO2-C m−2year−1in the control plots. Simulated N deposition significantly increased the mean annual soil respiration rate, fine root biomass, soil microbial biomass C (MBC), and N concentration in fine roots and fresh leaf litter. Soil respirations exhibited a positive exponential relationship with soil temperature, and a linear relationship with MBC. The net primary production (NPP) ranged from 10.95 to 15.01 Mg C ha−1year−1and was higher than the annual soil respiration (5.85 to 7.62 Mg C ha−1year−1) in all treatments. Simulated N deposition increased the net ecosystem production (NEP), and there was a significant difference between the control and high N treatment NEP, whereas, the difference of NEP among control, low-N, and medium-N was not significant. Results suggest that N controlled the primary production in this bamboo plantation ecosystem. Simulated N deposition increased the C sequestration of theP.amarusplantation ecosystem through increasing the plant C pool, though CO2emission through soil respiration was also enhanced.