氮添加对黄土高原草原生态系统净碳交换的影响

doi:10.7522/j.issn.1000-694X.2018.00055

摘要/Abstract

摘要： 以黄土高原典型草原为对象，采用静态箱-红外分析仪联用法进行野外原位试验，研究氮添加对生态系统CO₂通量的影响。设置6个氮添加水平，分别为N0（0）、N1（1.15 g·m^-2·a^-1）、N2（2.3 g·m^-2·a^-1）、N3（4.6 g·m^-2·a^-1）、N4（9.2 g·m^-2·a^-1）和N5（13.8 g·m^-2·a^-1），氮素类型为尿素（（NH₂）₂CO）。结果表明：氮添加处理没有改变生态系统碳交换的季节动态趋势，但是增加了生态系统净碳交换能力（NEE）、生态系统呼吸（ER）和总生态系统生产力（GEP）的峰值。N2、N3、N4、N5处理的NEE生长季绝对累积量分别比对照增加62%、45%、72%和48%；ER累积量分别增加66%、69%、78%、70%；GEP累积量分别增加65%、66%、77%、68%。氮添加处理增强了黄土高原典型草原植物生长季的碳汇功能。0~10 cm层土壤温度和湿度是影响黄土高原典型草原生态系统净碳交换的重要因素。

关键词: 氮添加, 草原, 生态系统净碳交换, 黄土高原

Abstract: The static chamber and infrared analyzer were used to investigate the effect of increased nitrogen (N) deposition on ecosystem carbon (C) exchange, and a field experiment that simulated N deposition was conducted in a steppe located in the Loess Plateau. There were six N treatments included in the experiment: 0, 1.15, 2.3, 4.6, 9.2 and 13.8 gN·m^-2·a^-1 with (NH₂)₂CO. The results indicated that the N treatments did not change the seasonal patterns of ecosystem C exchange, but increased the peak values of net ecosystem exchange (NEE), ecosystem respiration (ER), and general ecosystem production (GEP). The seasonal accumulation of NEE under 2.3, 4.6, 9.2 and 13.8 gN·m^-2·a^-1 N treatments increased by 62%, 45% ,72% and 48%, respectively, while the seasonal accumulation of ER increased by 66%, 69%, 78% and 70%, and GEP by 65%, 66%, 77% and 68%, compared with the control treatment. Therefore, the N treatments could significantly reduce C sequestration in the typical steppe of the Loess Plateau. Soil temperature and soil moisture in the 0-10 cm soil layer were the most important factors affecting ecosystem C exchange.

Key words: nitrogen addition, steppe, NEE, Loess Plateau

中图分类号:

S812.4

文海燕, 吴淑娟, 傅华. 氮添加对黄土高原草原生态系统净碳交换的影响[J]. 中国沙漠, 2019, 39(3): 34-40.

Wen Haiyan, Wu Shujuan, Fu Hua. Influence of Nitrogen Addition on Net Ecosystem Carbon Exchange of Steppe in the Loess Plateau[J]. Journal of Desert Research, 2019, 39(3): 34-40.

参考文献

[1] Galloway J N,Townsend A R,Erisman J W,et al.Transformation of the nitrogen cycle:recent trends,questions,and potential solutions[J].Science,2008,320(5878):889-892.
[2] Hooper D U,Johnson L.Nitrogen limitation in dryland ecosystems:responses to geographical and temporal variation in precipitation[J].Biogeochemistry,1999,46:247-293.
[3] Heimann M,Reichstein M.Terrestrial ecosystem carbon dynamics and climate feedbacks[J].Nature,2008,451:289-292.
[4] 夏建阳.中国温带典型草原碳循环对气候变暖与氮素添加的响应[M].北京:中国科学院,2010:3-4.
[5] Kuzyakov Y,Larionova A A.Root and rhizomicrobial respiration:a review of approaches to estimate respiration by autotrophic and heterotrophic organisms in soil[J].Journal of Plant Nutrition and Soil Science,2005,168(4):503-520.
[6] Li J,Guo R,Zhu T C,et al.Water-and plant-mediated responses of ecosystem carbon fluxes to wanning and nitrogen addition on the Songnen grassland in northeast China[J].Plos One,2012,7(9):1-11.
[7] Kivimäkia S K,Shepparda L J,Leitha I D,et al.Long-term enhanced nitrogen deposition increases ecosystem respiration and carbon loss from a Sphagnum bog in the Scottish Borders[J].Environmental and Experimental Botany,2013,(90):53-61.
[8] Zhang L H,Song C C,Nkrumah P N.Responses of ecosystem carbon dioxide exchange to nitrogen addition in a freshwater marshland in Sanjiang Plain,Northeast China[J].Environmental Pollution,2013,180:55-62.
[9] Tian D S,Niu S L,Pan Q G,et al.Nonlinear responses of ecosystem carbon fluxes and water-use efficiency to nitrogen addition in Inner Mongolia grassland[J].Functional Ecology,2016,30:490-499.
[10] Moinet G Y K,Cieraad E,Rogers G N D.Addition of nitrogen fertiliser increases net ecosystem carbon dioxide uptake and the loss of soil organic carbon in grassland growing in mesocosms[J].Geoderma,2016,266:75-83.
[11] Xia J Y,Niu S L,Wan S Q.Response of ecosystem carbon exchange to warming and nitrogen addition during two hydrologically contrasting growing seasons in a temperate steppe[J].Global Change Biology,2009,15:1544-1556.
[12] Niu S L,Wu M Y,Han Y,et al.Nitrogen effects on net ecosystem carbon exchange in a temperate steppe[J].Global Change Biology,2010,16:144-155.
[13] 游成铭,胡中民,郭群,等.氮添加对内蒙古温带典型草原生态系统碳交换的影响[J].生态学报,2016,36(8):2142-2150.
[14] 张峰,周广胜,王玉辉.基于CASA模型的内蒙古典型草原植被净初级生产力动态模拟[J].植物生态学报,2008,32(4):786-797.
[15] 文海燕,傅华,郭丁.黄土高原典型草原优势植物凋落物分解及养分释放对氮添加的响应[J].生态学报,2017,37(6):2014-2022.
[16] Lü C Q,Tian H.Spatial and temporal patterns of nitrogen deposition in China:synthesis of observational data[J].Journal of Geophysical Research,2007,112:D22S05.
[17] 文海燕,傅华,牛得草,等.大气氮沉降对黄土高原土壤氮特征的影响[J].草业科学,2013,30(5):694-698.
[18] 朱慧森,李刚,董宽虎,等.放牧对赖草草地土壤呼吸日、季动态的影响[J].植物学报,2015,50(5):605-613.
[19] 沈晓坤,刘明惠,张燕堃,等.黄土高原围封与自然放牧草地碳交换特征[J].西北植物学报,2014,34(9):1869-1877.
[20] Heijmans M M P D,Berendse F,Arp W J,et al.Effects of elevated carbon dioxide and increased nitrogen deposition on bog vegetation in the Netherlands[J].Journal of Ecology,2001,89:268-279.
[21] 武倩,韩国栋,王忠武,等.模拟增温和氮素添加对荒漠草原生态系统碳交换的影响[J].生态学杂志,2016,35(6):1427-1434.
[22] 张丽华,宋长春,王德宣.氮输入对沼泽湿地碳平衡的影响[J].环境科学,2006,27(7):1257-1263.
[23] 马俐,周志强,王正文.刈割和氮添加对松嫩平原羊草草原碳固持的影响[J].生态学杂志,2016,35(1):87-94.
[24] 安卓,牛得草,文海燕,等.氮素添加对黄土高原典型草原长芒草氮磷重吸收率及C:N:P化学计量特征的影响[J].植物生态学报,2011,35(8):801-807.
[25] Yan L,Chen S,Huang J,et al.Increasing water and nitrogen availability enhanced net ecosystem CO₂ assimilation of a temperate semiarid steppe[J].Plant and Soil,2011,349:227-240.
[26] Bai Y,Wu J,Clark C M,et al.Tradeoffs and thresholds in the effects of nitrogen addition on biodiversity and ecosystem functioning:evidence from Inner Mongolia Grasslands[J].Global Change Biology,2010,16:358-372.
[27] Fornara D A,Tilman D.Soil carbon sequestration in prairie grasslands increased by chronic nitrogen addition[J].Ecology,2012,93:2030-2036.
[28] Lu X T,Dijkstra F A,Kong D L,et al.Plant nitrogen uptake drives responses of productivity to nitrogen and water addition in a grassland[J].Scientific Reports,2014,4:4817.doi:10.1038/srep04817.