[Effects of warming and nitrogen addition on community production and biomass allocation in an alpine meadow.] / å¢æ¸©æ½æ°®å¯¹é«å¯èç¸ç产ååçç©éåé
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Ying Yong Sheng Tai Xue Bao
; 29(1): 59-67, 2018 Jan.
Article
em Zh
| MEDLINE
| ID: mdl-29692013
ABSTRACT
A long-term experiment, involving exogenous N addition and simulated warming, was conducted in an alpine meadow in Damxung, northern Tibet, to study how warming and N addition influence community production and biomass allocation. The results showed that warming resulted in a warm but dry microsite, that was, air temperature increased by 1.6 â and soil surface temperature increased by 1.4 â, and soil water content decreased by 4.7%. Under no N addition treatments, warming significantly decreased plant aboveground biomass by 61.5%, 108.8% and 77.1% in 2012, 2013 and 2014, respectively. Under high N treatments (40 and 80 kg N·hm-2·a-1), warming had no significant effect on aboveground biomass. These findings indicated that the effect of warming might be dependent on N addition level, and N addition could compensate for soil N loss caused by warming. Warming led to an increase in root/shoot by 98.6%, 60.7% and 97.8% in 2012, 2013 and 2014 under no N addition treatments, respectively. Under the ambient condition, the change percentages of aboveground and belowground biomass of plant communities first increased and then decreased along an N gradient, with the saturation thresholds of above- and below-ground biomass for N addition 56.0 and 55.5 kg N·hm-2·a-1, respectively. Under the warming condition, above- and belowground biomass increased linearly with increasing N addition. These findings suggested that warming modulated the response patterns of alpine meadows to exogenous N input, which was mainly caused by decreased soil inorganic N under warming. The estimation of N thresholds highlights that alpine meadows are more sensitive to future N deposition than other types of grasslands.
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Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Pradaria
/
Nitrogênio
País/Região como assunto:
Asia
Idioma:
Zh
Revista:
Ying Yong Sheng Tai Xue Bao
Assunto da revista:
SAUDE AMBIENTAL
Ano de publicação:
2018
Tipo de documento:
Article
País de afiliação:
China