Effects of Nitrogen Addition on Ecosystem CO2 Exchange in a Meadow Steppe, Inner Mongolia

doi:10.11983/CBB17041

Abstract

Abstract: Increasing nitrogen deposition influences carbon sequestration in grassland ecosystems, but we have no consistent results on how it impacts the exchange of CO₂ at the ecosystem level. As well, the impact of different types of N fertilizers and rates of N increase are not clear yet. This study aimed to evaluate the effect of N addition on ecosystem CO₂ exchange and was performed in a meadow steppe in Erguna, Inner Mongolia. A field experiment compared two types of N fertilizers (urea and slow-release urea) with five N addition rates (0, 5.0, 10.0, 20.0 and 50.0 g N·m^-2·a^-1). At the start and middle stage of the growing season, N addition had weak and inhibitive effects on ecosystem CO₂ exchange when precipitation was low, and significantly increased ecosystem CO₂ exchange in the late growing season when precipitation was high. Both net ecosystem CO₂ exchange and gross ecosystem photosynthesis increased significantly with N addition rate but showed a tendency of saturation when the N addition rate reached 10 g N·m^-2·a^-1. The two types of N fertilizers resulted in slightly different responses of ecosystem CO₂ exchange: slow-release urea had a stronger positive effect at 5 g N·m^-2·a^-1 with no significant difference at other addition rates. Our study suggests that increasing N deposition has significant effects on carbon assimilation in this semi-arid grassland, but the direction and magnitude of effects are strongly affected by seasonal pattern and amount of precipitation. The effects of different types of N fertilizers (i.e., urea and slow-release urea) on ecosystem CO₂ exchange may differ.

Key words: nitrogen addition, net ecosystem CO₂ exchange, ecosystem respiration, gross ecosystem photosynthesis, meadow steppe

Muqier Hasi, Xueyao Zhang, Guoxiang Niu, Yinliu Wang, Jianhui Huang. Effects of Nitrogen Addition on Ecosystem CO₂Exchange in a Meadow Steppe, Inner Mongolia[J]. Chinese Bulletin of Botany, 2018, 53(1): 27-41.

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URL: https://www.chinbullbotany.com/EN/10.11983/CBB17041

https://www.chinbullbotany.com/EN/Y2018/V53/I1/27

Figures/Tables 13

Figure 1 Daily precipitation (bars) and daily mean air temperature (line) of the research plots in 2016

Table 1 Means of growing season soil temperature, soil moisture, net ecosystem CO2 exchange, ecosystem respiration and gross ecosystem photosynthesis under different nitrogen addition rates

	N addition rates (g N·m^-2·a^-1)	θν	Ts	NEE	ER	GEP
Urea	0	11.48^a±0.74	17.94^a±0.66	-2.98^a±0.38	3.85^ab±0.12	6.81^ab±0.48
	5	12.79^a±0.97	17.69^a±0.76	-3.13^a±0.49	3.35^a±0.22	6.48^a±0.31
	10	12.29^a±0.61	17.66^a±0.32	-3.77^a±0.32	4.10^ab±0.42	7.88^b±0.29
	20	13.79^a±0.47	17.71^a±0.49	-3.82^a±0.27	4.23^ab±0.23	8.05^b±0.19
	50	13.41^a±0.71	17.22^a±0.22	-2.88^a±0.44	4.59^b±0.33	7.48^ab±0.61
Slow-release urea	0	11.48^a±0.74	17.94^a±0.66	-2.98^b±0.38	3.85^a±0.12	6.81^a±0.48
	5	12.01^a±0.74	18.07^a±0.35	-3.77^ab±0.32	3.81^a±0.25	7.58^a±0.19
	10	12.51^a±0.55	17.72^a±0.35	-4.80^a±0.39	4.29^a±0.32	9.10^b±0.39
	20	14.49^a±1.28	17.06^a±0.27	-3.15^b±0.46	4.19^a±0.37	7.34^a±0.23
	50	14.26^a±0.82	17.44^a±0.42	-2.93^b±0.54	4.55^a±0.27	7.47^a±0.40

Table 2 Results (P-values) of repeated-measures ANOVA on the effects of sampling time, N addition (urea and slow-release urea), and their interactions on soil temperature, soil moisture, net ecosystem CO2 exchange, ecosystem respiration and gross ecosystem photosynthesis during the growing season

		θν	Ts	NEE	ER	GEP
Urea	Time	<0.001	<0.001	<0.001	<0.001	<0.001
	N	0.22	0.91	0.29	0.08	0.07
	Time×N	0.66	0.56	0.01	0.01	0.03
Slow-release urea	Time	<0.001	<0.001	<0.001	<0.001	<0.001
	SN	0.38	0.49	0.04	0.34	0.01
	Time×SN	0.63	0.74	0.003	0.15	0.002

Figure 2 Seasonal dynamics of soil NH4+-N and NO3--N at 0-10 cm depth(A), (B) Addition with urea; (C), (D) Addition with slow-release urea. In-set figures showed mean soil inorganic N contents with addition of N (means±SE, n=4). Different lowercase letters among columns indicate significant differences among treatments (P<0.05).

Figure 3 Seasonal means of pH at 0-10 cm soil (means±SE, n=4)(A) Addition with urea; (B) Addition with slow-release urea. Different lowercase letters among columns indicate significant differences among treatments (P<0.05).

Table 3 Aboveground net primary productivity, grasses aboveground biomass, forb aboveground biomass and total belowground biomass under different nitrogen addition rates (means±SE, n=4)

	N addition rates (g N·m^-2·a^-1)	ANPP	GB	FB	BGB
Urea	0	142.52^a±16.85	96.86^a±19.68	42.37^a±13.05	1718.44^a±172.36
	5	157.74^a±5.51	129.37^a±11.10	24.33^a±8.48	1575.31^a±64.48
	10	216.29^a±23.24	190.59^a±19.71	24.07^a±5.09	1941.26^ab±226.12
	20	167.54^a±21.06	125.55^a±38.81	37.01^a±16.07	2320.85^b±99.68
	50	191.38^a±40.72	182.04^a±42.34	10.26^a±3.16	1915.27^ab±74.55
Slow-release urea	0	142.52^a±16.85	96.86^a±19.68	42.37^a±13.05	1718.44^a±172.36
	5	166.24^ab±11.86	129.16^ab±10.48	28.49^a±3.39	1632.48^a±67.81
	10	238.34^bc±35.71	188.39^bc±45.45	50.16^a±25.57	2127.48^b±111.51
	20	261.06^c±26.01	220.86^c±19.61	40.48^a±7.82	1942.56^ab±123.40
	50	254.41^c±24.63	227.08^c±16.94	31.36^a±16.22	1750.71^ab±105.22

Figure 4 Seasonal variations in net ecosystem CO2 exchange, ecosystem respiration and gross ecosystem photosynthesis under different nitrogen addition rates (means±SE)(A)-(C) Addition with urea; (D)-(F) Addition with slow-release urea. NEE, ER and GEP see Table 1.

Figure 5 Seasonal patterns of net ecosystem CO2 exchange, ecosystem respiration and gross ecosystem photosynthesis at different nitrogen addition rates with urea in each month (means±SE, n=4)NEE, ER and GEP see Table 1. Different lowercase letters among columns indicate significant differences among treatments (P<0.05).

Figure 6 Seasonal patterns of net ecosystem CO2 exchange, ecosystem respiration and gross ecosystem photosynthesis at different nitrogen addition rates with slow-release urea in each month (means±SE, n=4) NEE, ER and GEP see Table 1. Different lowercase letters among columns indicate significant differences among treatments (P<0.05).

Figure 7 Relationships of net ecosystem CO2 exchange, ecosystem respiration or gross ecosystem photosynthesis with 0-10 cm soil temperature(A)-(C) Addition with urea; (D)-(F) Addition with slow-release urea. NEE, ER and GEP see Table 1.

Figure 8 Relationships of net ecosystem CO2 exchange, ecosystem respiration or gross ecosystem photosynthesis with 0-10 cm soil moisture(A)-(C) Addition with urea; (D)-(F) Addition with slow-release urea. NEE, ER and GEP see Table 1.

Figure 9 Relationships of net ecosystem CO2 exchange, ecosystem respiration or gross ecosystem photosynthesis with belowground biomass(A)-(C) Addition with urea; (D)-(F) Addition with slow-release urea. NEE, ER and GEP see Table 1.

Table 4 Sensitivity of ecosystem respiration (ER) and gross ecosystem photosynthesis (GEP) to soil moisture under different nitrogen addition rates (means±SE, n=4)

	N addition rates (g N·m^-2·a^-1)	ER	GEP
Urea	0	0.72^a±0.09	1.86^a±0.64
	5	0.95^a±0.16	3.23^ab±0.62
	10	0.59^a±0.15	3.72^ab±0.71
	20	0.76^a±0.19	3.67^ab±1.35
	50	0.74^a±0.09	4.54^b±0.34
Slow-release urea	0	0.72^a±0.09	1.86^a±0.64
	5	0.89^a±0.14	4.21^b±0.16
	10	1.43^b±0.27	5.86^c±0.61
	20	0.69^a±0.12	3.46^b±0.62
	50	0.92^a±0.12	4.99^bc±0.36

References 41

[1]	陈德明, 王亭杰, 雨山江, 金涌 (2002). 缓释和控释尿素的研究与开发综述. 化工进展 21, 455-461.
[2]	陈佐忠, 汪诗平 (2000).中国典型草原生态系统. 北京: 科学出版社.
[3]	顾峰雪, 于贵瑞, 温学发, 陶波, 李克让, 刘允芬 (2008). 干旱对亚热带人工针叶林碳交换的影响. 植物生态学报 32, 1041-1051.
[4]	吴平霄, 廖宗文, 毛小云 (2000). 改性尿素的肥效及淋溶特性研究初探. 土壤与环境 9, 75-76.
[5]	游成铭, 胡中民, 郭群, 干友民, 李凌浩, 白文明, 李胜功 (2016). 氮添加对内蒙古温带典型草原生态系统碳交换的影响. 生态学报 36, 2142-2150.
[6]	张丽华, 宋长春, 王德宣 (2006). 氮输入对沼泽湿地碳平衡的影响. 环境科学 27, 1257-1263.
[7]	Aber J, McDowell W, Nadelhoffer K, Magill A, Berntson G, Kamakea M, McNulty S, Currie W, Rustad L, Fernandez I (1998). Nitrogen saturation in temperate forest ecosy- stems: hypotheses revisited.Bioscience 48, 921-934.
[8]	Aires LMI, Pio CA, Pereira JS (2008). Carbon dioxide exchange above a Mediterranean C3/C4 grassland during two climatologically contrasting years.Global Change Biol 14, 539-555.
[9]	Arens SJT, Sullivan PF, Welker JM (2008). Nonlinear responses to nitrogen and strong interactions with nitrogen and phosphorus additions drastically alter the structure and function of a high arctic ecosystem. J Geophys Res 113, G03S09.
[10]	Bai YF, Wu JG, Clark CM, Naeem S, Pan QM, Huang JH, Zhang LX, Han XG (2010). Tradeoffs and thresholds in the effects of nitrogen addition on biodiversity and eco- system functioning: evidence from inner Mongolia grass- lands.Global Change Biol 16, 358-372.
[11]	Bai YF, Wu JG, Xing Q, Pan QM, Huang JH, Yang DL, Han XG (2008). Primary production and rain use efficiency across a precipitation gradient on the Mongolia plateau.Ecology 89, 2140-2153.
[12]	Bubier JL, Moore TR, Bledzki LA (2007). Effects of nutrient addition on vegetation and carbon cycling in an ombrotro- phic bog.Global Change Biol 13, 1168-1186.
[13]	Chen SP, Lin GH, Huang JH, Jenerette GD (2009). Dependence of carbon sequestration on the differential responses of ecosystem photosynthesis and respiration to rain pulses in a semiarid steppe.Global Change Biol 15, 2450-2461.
[14]	Elser JJ, Bracken MES, Cleland EE, Gruner DS, Harpole WS, Hillebrand H, Ngai JT, Seabloom EW, Shurin JB, Smith JE (2007). Global analysis of nitrogen and phospho- rus limitation of primary producers in freshwater, marine and terrestrial ecosystems.Ecol Lett 10, 1135-1142.
[15]	Gruber N, Galloway JN (2008). An earth-system perspec- tive of the global nitrogen cycle.Nature 451, 293-296.
[16]	Harpole WS, Potts DL, Suding KN (2007). Ecosystem responses to water and nitrogen amendment in a Cali- fornia grassland.Global Change Biol 13, 2341-2348.
[17]	Hooper DU, Johnson L (1999). Nitrogen limitation in dryland ecosystems: responses to geographical and temporal va- riation in precipitation.Biogeochemistry 46, 247-293.
[18]	Huxman TE, Smith MD, Fay PA, Knapp AK, Shaw MR, Loik ME, Smith SD, Tissue DT, Zak JC, Weltzin JF, Pockman WT, Sala OE, Haddad BM, Harte J, Koch GW, Schwinning S, Small EE, Williams DG (2004). Conver- gence across biomes to a common rain-use efficiency.Nature 429, 651-654.
[19]	Hyvönen R, Agren GI, Linder S, Persson T, Cotrufo MF, Ekblad A, Freeman M, Grelle A, Janssens IA, Jarvis PG, Kellomäki S, Lindroth A, Loustau D, Lundmark T, Norby RJ, Oren R, Pilegaard K, Ryan MG, Sigurdsson BD, Strömgren M, van Oijen M, Wallin G (2007). The likely impact of elevated [CO2], nitrogen deposition, in- creased temperature and management on carbon seq- uestration in temperate and boreal forest ecosystems: a literature review.New Phytol 173, 463-480.
[20]	Jasoni RL, Smith SD, Arnone JA (2005). Net ecosystem CO2 exchange in Mojave desert shrublands during the eighth year of exposure to elevated CO2.Global Change Biol 11, 749-756.
[21]	Kwon H, Pendall E, Ewers BE, Cleary M, Naithani K (2008). Spring drought regulates summer net ecosystem CO2 exchange in a sagebrush-steppe ecosystem.Agric Forest Meteor 148, 381-391.
[22]	LeBauer DS, Treseder KK (2008). Nitrogen limitation of net primary productivity in terrestrial ecosystems is globally distributed.Ecology 89, 371-379.
[23]	Lü FM, Lü XT, Liu W, Han X, Zhang GM, Kong DL, Han XG (2011). Carbon and nitrogen storage in plant and soil as related to nitrogen and water amendment in a temperate steppe of northern China.Biol Fertility Soils 47, 187-196.
[24]	Niu SL, Wu MY, Han YI, Xia JY, Li LH, Wan SQ (2008). Water-mediated responses of ecosystem carbon fluxes to climatic change in a temperate steppe.New Phytol 177, 209-219.
[25]	Niu SL, Wu MY, Han YI, Xia JY, Zhang ZHE, Yang HJ, Wan SQ (2010). Nitrogen effects on net ecosystem carbon exchange in a temperate steppe.Global Change Biol 16, 144-155.
[26]	Niu SL, Yang HJ, Zhang Z, Wu MY, Lu Q, Li LH, Han XG, Wan SQ (2009). Non-additive effects of water and nitrogen addition on ecosystem carbon exchange in a temperate steppe.Ecosystems 12, 915-926.
[27]	Patrick L, Cable J, Potts D, lgnace D, Barron-Gafford G, Griffith A, Alpert H, Van Gestel N, Robertson T, Huxman TE, Zak J, Loik ME, Tissue D (2007). Effects of an increase in summer precipitation on leaf, soil, and ecosystem fluxes of CO2 and H2O in a sotol grassland in Big Bend National Park, Texas.Oecologia 151, 704-718.
[28]	Pepper DA, Del Grosso SJ, McMurtrie RE, Parton WJ (2005). Simulated carbon sink response of shortgrass steppe, tallgrass prairie and forest ecosystems to rising [CO2], temperature and nitrogen input. Global Biogeochem Cycl 19, GB1004.
[29]	Saarnio S, Järviö S, Saarinen T, Vasander H, Silvola J (2003). Minor changes in vegetation and carbon gas balance in a boreal mire under a raised CO2 or NH4NO3 supply.Ecosystems 6, 46-60.
[30]	Seagle SW, McNaughton SJ (1993). Simulated effects of precipitation and nitrogen on serengeti grassland produc- tivity.Biogeochemistry 22, 157-178.
[31]	Shaver GR, Johnson LC, Cades DH, Murray G, Laundre JA, Rastetter EB, Nadelhoffer KJ, Giblin AE (1998). Biomass and CO2 flux in wet sedge tundras: responses to nutrients, temperature, and light.Ecol Monogr 68, 75-97.
[32]	Tian DS, Niu SL, Pan QM, Ren TT, Chen SP, Bai YF, Han XG (2016). Nonlinear responses of ecosystem carbon fluxes and water-use efficiency to nitrogen addition in Inner Mongolia grassland.Funct Ecol 30, 490-499.
[33]	Tilman D, Fargione J, Wolff B, D`Antonio C, Dobson A, Howarth R, Schindler D, Schlesinger WH, Simeberloff D, Swackhamer D (2001). Forecasting agriculturally driven global environmental change.Science 292, 281-284.
[34]	Vitousek PM, Aber JD, Howarth RW, Likens GE, Matson PA, Schindler DW, Schlesinger WH, Tilman D (1997). Human alteration of the global nitrogen cycle: sources and consequences.Ecol Appl 7, 737-750.
[35]	Vose JM, Elliott KJ, Johnson DW, Tingey DT, Johnson MG (1997). Soil respiration response to three years of elevated CO2 and N fertilization in ponderosa pine ( Pinus ponderosa Dong. ex Laws.). Plant Soil 190, 19-28.
[36]	Wang LX, D'odorico P, O'halloran LR, Caylor K, Macko S (2010). Combined effects of soil moisture and nitrogen availability variations on grass productivity in African sa- vannas.Plant Soil 328, 95-108.
[37]	Xia JY, Niu SL, Wan SQ (2009). Response of ecosystem carbon exchange to warming and nitrogen addition during two hydrologically contrasting growing seasons in a tem- perate steppe.Global Change Biol 15, 1544-1556.
[38]	Xia JY, Wan SQ (2008). Global response patterns of terr- estrial plant species to nitrogen addition.New Phytol 179, 428-439.
[39]	Yan LM, Chen SP, Huang JH, Lin GH (2010). Differential responses of auto- and heterotrophic soil respiration to water and nitrogen addition in a semiarid temperate step- pe.Global Change Biol 16, 2345-2357.
[40]	Yan LM, Chen SP, Huang JH, Lin GH (2011). Increasing water and nitrogen availability enhanced net ecosystem CO2 assimilation of a temperate semiarid steppe.Plant Soil 349, 227-240.
[41]	Zhang XL, Tan YL, Li A, Ren TT, Chen SP, Wang LX, Huang JH (2015). Water and nitrogen availability co- control ecosystem CO2 exchange in a semiarid temperate steppe.Sci Rep 5, 15549.

Effects of Nitrogen Addition on Ecosystem CO₂Exchange in a Meadow Steppe, Inner Mongolia

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