Abstract
Abstract. Biogenic volatile organic compounds (BVOCs) profoundly affect atmospheric chemistry and ecosystem functioning. BVOCs emission and their responses to global change are still unclear in grasslands, which cover one quarter of the Earth's land surface and are currently undergoing the largest changes. Over two growing seasons, we conducted a field experiment in a semi-arid grassland (Inner Mongolia, China) to examine the emission and the responses of BVOCs emissions to warming and nitrogen deposition. The natural emission rate (NER) of monoterpene (dominant BVOCs here) is 107 ± 16 μg m−2 h−1 in drought 2007, and 266 ± 53 μg m−2 h−1 in wet 2008, respectively. Warming decreased the standard emission factor (SEF) by 24% in 2007, while it increased by 43% in 2008. The exacerbated soil moisture loss caused by warming in dry season might be responsible for the decrease of SEF in 2007. A possible threshold of soil moisture (8.2% (v/v)), which controls the direction of warming effects on monoterpene emission, existed in the semiarid grassland. Nitrogen deposition decreased the coverage of Artemisia frigida and hence reduced the NER by 24% across the two growing seasons. These results suggest that the grasslands dominated by the extended Artemisia frigida are an important source for BVOCs, while the responses of their emissions to global changes are more uncertain since they depend on multifactorial in-situ conditions.
Highlights
Biogenic volatile organic compounds (BVOCs), as the largest source of non-methane VOCs (Guenther et al, 1995), have essential roles in regional and global atmospheric chemistry with important implications in climatic change (Laothawornkitkul et al, 2009; Penuelas and Llusia, 2003; Penuelas and Staudt, 2010)
The objective of this study was to obtain the first estimate of BVOCs emission, and to assess the effects of climatic warming and nitrogen deposition on their emission from arid and semiarid grassland
Compared with long-term (1953–2007) mean growing-season precipitation (348 mm), the growing-season precipitation in 2007 (194 mm) was the lowest in the past 55 yr, which resulted in that the daily mean SM was lower than 9 % (v/v) during the growing season (Fig. 1)
Summary
Biogenic volatile organic compounds (BVOCs), as the largest source of non-methane VOCs (Guenther et al, 1995), have essential roles in regional and global atmospheric chemistry with important implications in climatic change (Laothawornkitkul et al, 2009; Penuelas and Llusia, 2003; Penuelas and Staudt, 2010). Grasslands covering one quarter of the Earth’s land surface still receive disproportionately little attention with regard to BVOCs emissions (Guenther et al, 2006; Lerdau and Slobodkin, 2002; Penuelas and Llusia, 2003). Grasslands are sensitive to climatic and anthropogenic disturbances, and are currently undergoing the largest changes (Lerdau and Slobodkin, 2002), which may affect BVOCs emission pattern. Global warming and increase of CO2 concentrations have substantially enhanced the abundance of shrub and subshrub
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
