高寒草原土壤交换性盐基离子对氮添加的响应: 以紫花针茅草原为例

秦书琪,房凯,王冠钦,彭云峰,张典业,李飞,周国英,杨元合

Responses of exchangeable base cations to continuously increasing nitrogen addition in alpine steppe: A case study of Stipa purpurea steppe

Shu-Qi QIN,Kai FANG,Guan-Qin WANG,Yun-Feng PENG,Dian-Ye ZHANG,Fei LI,Guo-Ying ZHOU,Yuan-He YANG

表1 不同氮水平下土壤与植物基本理化性质(平均值±标准误差)

Table 1 Soil and plant properties under different nitrogen rates (mean ± SE)

	年 Year	N0	N1	N2	N4	N8	N16	N24	N32
pH值 pH value	2014	8.9 ± 0.10^b	9.2 ± 0.06^a	9.2 ± 0.08^a	9.1 ± 0.07^ab	9.1 ± 0.08^ab	9.1 ± 0.07^ab	9.0 ± 0.03^ab	9.1 ± 0.10^ab
	2015	9.0 ± 0.07^bc	9.1 ± 0.06^a	9.0 ± 0.03^ab	9.0 ± 0.05^ab	8.9 ± 0.03^cd	9.0 ± 0.04^ab	8.8 ± 0.04^d	8.8 ± 0.05^d
	2016	8.5 ± 0.11^a	8.5 ± 0.05^a	8.5 ± 0.09^a	8.4 ± 0.07^ab	8.3 ± 0.07^bc	8.6 ± 0.02^a	8.2 ± 0.05^c	8.2 ± 0.05^c
TIN (mg·kg^-1)	2014	34.3 ± 2.6^cd	37.8 ± 3.1^bcd	35.9 ± 3.7^bcd	33.1 ± 0.9^d	52.6 ± 9.1^a	46.8 ± 3.4^ab	43.5 ± 1.8^abcd	45.5 ± 1.4^abc
	2015	9.5 ± 0.3^e	11.4 ± 1.5^e	11.8 ± 1.1^e	11.9 ± 0.7^e	22.4 ± 2.5^d	41.8 ± 2.5^c	56.7 ± 5.0^b	69.6 ± 7.1^a
	2016	32.0 ± 0.9^d	32.3 ± 1.5^cd	31.2 ± 2.0^d	32.9 ± 2.0^cd	37.4 ± 1.9^bc	41.4 ± 2.8^ab	43.2 ± 3.0^a	41.1 ± 2.1^ab
AGB (g·m^-2)	2014	126.9 ± 10.0^d	142.2 ± 17.8^d	152.4 ± 13.9^cd	186.7 ± 13.9^c	256.6 ± 14.3^ab	241.2 ± 21.4^b	271.7 ± 26.1^ab	284.9 ± 27.6^a
	2015	146.0 ± 11.6^c	146.8 ± 8.3^c	175.7 ± 14.7^c	180.4 ± 13.6^c	265.1 ± 23.5^b	287.5 ± 21.0^b	350.4 ± 13.3^a	373.0 ± 18.6^a
	2016	93.7 ± 9.3^e	117.0 ± 17.8^de	127.0 ± 19.3^cde	144.2 ± 9.3^bcd	181.2 ± 18.4^ab	161.9 ± 8.3^abc	190.2 ± 21.1^a	195.7 ± 7.1^a