Soil nutrients modulate response of aboveground biomass to warming in alpine grassland on the Qingzang Plateau

doi:10.17521/cjpe.2022.0097

Abstract

Abstract:

Aims In the past 40 years, Qingzang Plateau has experienced rapid warming, and its air temperature is projected to continue to rise in the next few decades. Since climate warming may alter soil moisture and nutrient availability, understanding how these changes affect the responses of alpine grasslands to increasing air temperature is therefore crucial to accurately anticipate the shift in vegetation productivity of alpine grassland ecosystems under future warming.

Methods The aboveground biomass of plant communities and four functional groups (legumes, grasses, sedges, and forbs) in alpine grasslands were measured at the field experiments of warming, fertilization (nitrogen, phosphorus) and their interactions across three altitudes (3 200, 3 700 and 4 050 m).

Important findings 1) We found significantly positive correlation of the warming response ratios with altitude. 2) Warming resulted in the increase of aboveground biomass at middle and high elevation; moreover, under the condition of N, P addition, warming significantly increased aboveground biomass at three altitudes. 3) The responses of relative biomass of four functional groups to warming at different altitudes were inconsistent. Even within the same functional group, they showed significant different responses to warming due to the distinct nutrient conditions across the altitudes. Taken together, our results suggest that the responses of alpine grasslands to warming were altitudes-dependent, which was also modulated by soil nutrient availability.

Key words: aboveground biomass, alpine grassland, functional group, warming, nitrogen addition, phosphorus addition, altitude, Qingzang Plateau

ZHAO Yan-Chao, CHEN Li-Tong. Soil nutrients modulate response of aboveground biomass to warming in alpine grassland on the Qingzang Plateau[J]. Chin J Plant Ecol, 2023, 47(8): 1071-1081.

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Figures/Tables 7

References 55

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处理 Treatment	df	F	p
N	1	33.18	<0.001
P	1	2.56	0.114
N × P	1	1.97	0.167
W	1	51.60	<0.001
W × N	1	1.51	0.223
W × P	1	2.35	0.130
W × N × P	1	1.28	0.261
Altitude	2	213.74	<0.001
Altitude × W	2	11.73	<0.001
Altitude × N	2	0.28	0.756
Altitude × P	2	1.55	0.219
Altitude × N × P	2	0.24	0.787
Altitude × W × N	2	0.17	0.841
Altitude × W × P	2	2.55	0.085
Altitude × W × N × P	2	0.57	0.566

处理 Treatment	df	F	p
N	1	33.18	<0.001
P	1	2.56	0.114
N × P	1	1.97	0.167
W	1	51.60	<0.001
W × N	1	1.51	0.223
W × P	1	2.35	0.130
W × N × P	1	1.28	0.261
Altitude	2	213.74	<0.001
Altitude × W	2	11.73	<0.001
Altitude × N	2	0.28	0.756
Altitude × P	2	1.55	0.219
Altitude × N × P	2	0.24	0.787
Altitude × W × N	2	0.17	0.841
Altitude × W × P	2	2.55	0.085
Altitude × W × N × P	2	0.57	0.566

处理 Treatment	df	3 200 m		3 700 m		4 050 m
处理 Treatment	df	F	p	F	p	F	p
N	1	24.21	<0.001	15.61	<0.001	6.84	<0.05
P	1	6.32	<0.05	0.03	0.860	0.80	0.381
N × P	1	1.79	0.193	1.89	0.182	0.26	0.612
W	1	0.75	0.395	81.63	<0.001	13.57	<0.01
W × N	1	1.95	0.176	3.58	0.070	0.27	0.605
W × P	1	2.30	0.142	8.10	<0.01	0.28	0.600
W × N × P	1	0.08	0.776	0.90	0.353	1.75	0.198

处理 Treatment	df	3 200 m		3 700 m		4 050 m
处理 Treatment	df	F	p	F	p	F	p
N	1	24.21	<0.001	15.61	<0.001	6.84	<0.05
P	1	6.32	<0.05	0.03	0.860	0.80	0.381
N × P	1	1.79	0.193	1.89	0.182	0.26	0.612
W	1	0.75	0.395	81.63	<0.001	13.57	<0.01
W × N	1	1.95	0.176	3.58	0.070	0.27	0.605
W × P	1	2.30	0.142	8.10	<0.01	0.28	0.600
W × N × P	1	0.08	0.776	0.90	0.353	1.75	0.198

功能群 Functional group	处理 Treatment	df	3 200 m		3 700 m		4 050 m
功能群 Functional group	处理 Treatment	df	F	p	F	p	F	p
豆科 Legume	N	1	22.10	<0.001	2.00	0.172	3.79	0.065
	P	1	<0.01	0.971	<0.01	0.977	1.01	0.327
	N × P	1	1.21	0.282	1.23	0.279	2.11	0.160
	W	1	0.73	0.400	0.25	0.620	0.13	0.726
	W × N	1	0.39	0.539	2.48	0.130	0.001	0.974
	W × P	1	1.53	0.229	0.01	0.927	0.59	0.450
	W × N × P	1	0.96	0.336	3.35	0.081	<0.01	0.986
禾草 Grass	N	1	9.83	<0.01	3.46	0.077	2.44	0.133
	P	1	1.27	0.272	1.07	0.312	7.17	<0.05
	N × P	1	14.03	<0.01	0.01	0.937	3.12	0.092
	W	1	0.62	0.441	10.86	<0.01	8.85	<0.01
	W × N	1	1.86	0.187	5.14	<0.05	2.45	0.133
	W × P	1	0.11	0.744	0.20	0.656	0.07	0.793
	W × N × P	1	1.22	0.282	1.01	0.325	0.49	0.493
莎草 Sedge	N	1	0.59	0.449	0.09	0.769	0.28	0.603
	P	1	17.14	<0.001	0.27	0.607	20.59	<0.001
	N × P	1	0.81	0.377	0.34	0.566	1.06	0.314
	W	1	0.04	0.837	4.95	<0.05	12.81	<0.01
	W × N	1	2.00	0.171	0.05	0.833	0.78	0.387
	W × P	1	1.24	0.276	0.78	0.387	<0.01	0.988
	W × N × P	1	0.11	0.739	0.85	0.367	1.52	0.231
杂类草 Forb	N	1	0.46	0.505	0.01	0.917	<0.01	0.983
	P	1	0.22	0.645	5.63	<0.05	4.52	<0.05
	N × P	1	0.43	0.521	0.03	0.874	<0.01	0.977
	W	1	0.67	0.422	0.59	0.450	0.20	0.660
	W × N	1	1.74	0.202	0.07	0.798	0.02	0.899
	W × P	1	0.34	0.567	0.54	0.469	0.12	0.734
	W × N × P	1	0.80	0.381	0.70	0.411	0.32	0.576