« Previous AbstractApplication of passive sampling on assessment of concentration distribution and health risk of volatile organic compounds at a high-tech science park    Next AbstractLess is more: Independent loss-of-function OCIMENE SYNTHASE alleles parallel pollination syndrome diversification in monkeyflowers (Mimulus) »

PLoS One

Title:		Effects of warming and clipping on ecosystem carbon fluxes across two hydrologically contrasting years in an alpine meadow of the Qinghai-Tibet Plateau
Author(s):		Peng F; You Q; Xu M; Guo J; Wang T; Xue X;
Address:		"Key Laboratory of Desert and Desertification, Chinese Academy of Sciences, Cold and Arid Regions Environmental and Engineering Research Institute, Chinese Academy of Sciences, Lanzhou, China"
Journal Title:		PLoS One
Year:		2014
Volume:		20141007
Issue:		10
Page Number:		e109319 -
DOI:		10.1371/journal.pone.0109319
ISSN/ISBN:		1932-6203 (Electronic) 1932-6203 (Linking)
Abstract:		"Responses of ecosystem carbon (C) fluxes to human disturbance and climatic warming will affect terrestrial ecosystem C storage and feedback to climate change. We conducted a manipulative experiment to investigate the effects of warming and clipping on soil respiration (Rs), ecosystem respiration (ER), net ecosystem exchange (NEE) and gross ecosystem production (GEP) in an alpine meadow in a permafrost region during two hydrologically contrasting years (2012, with 29.9% higher precipitation than the long-term mean, and 2013, with 18.9% lower precipitation than the long-tem mean). Our results showed that GEP was higher than ER, leading to a net C sink (measured by NEE) over the two growing seasons. Warming significantly stimulated ecosystem C fluxes in 2012 but did not significantly affect these fluxes in 2013. On average, the warming-induced increase in GEP (1.49 micro mol m(-2) s(-1)) was higher than in ER (0.80 micro mol m(-2) s(-1)), resulting in an increase in NEE (0.70 micro mol m(-2) s(-1)). Clipping and its interaction with warming had no significant effects on C fluxes, whereas clipping significantly reduced aboveground biomass (AGB) by 51.5 g m(-2) in 2013. These results suggest the response of C fluxes to warming and clipping depends on hydrological variations. In the wet year, the warming treatment caused a reduction in water, but increases in soil temperature and AGB contributed to the positive response of ecosystem C fluxes to warming. In the dry year, the reduction in soil moisture, caused by warming, and the reduction in AGB, caused by clipping, were compensated by higher soil temperatures in warmed plots. Our findings highlight the importance of changes in soil moisture in mediating the responses of ecosystem C fluxes to climate warming in an alpine meadow ecosystem"
Keywords:		"Animals Biomass *Carbon Cycle Carbon Dioxide/*chemistry Climate Change *Grassland Herbivory/physiology Humans Hydrology *Models, Statistical Plants/chemistry/metabolism Seasons Soil/*chemistry Temperature Tibet Water/chemistry;"
Notes:		"MedlinePeng, Fei You, Quangang Xu, Manhou Guo, Jian Wang, Tao Xue, Xian eng Research Support, Non-U.S. Gov't 2014/10/08 PLoS One. 2014 Oct 7; 9(10):e109319. doi: 10.1371/journal.pone.0109319. eCollection 2014"