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\hypersetup{pdftitle={The Response of Soil Respiration and Carbon Cycling to Nitrogen Additions and Warming in Songnen Grassland },pdfauthor={Li Jiang, Niu Xuedun, Lou Yujie},pdfsubject={Tropentag 2016: Abstract},pdfkeywords={Soil respiration,soil organic mater ,Q10,grassland, warming},pdfpagemode=None,colorlinks=true}
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\parbox[b]{13.4cm}{\centering \large{\textbf{Tropentag, September 18-21, 2016, Vienna, Austria}}\\[1ex] \Large{``Solidarity in a competing world ---\\fair use of resources''\\[2ex]}}
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\Large{\textbf{The Response of Soil Respiration and Carbon Cycling to Nitrogen Additions and Warming in Songnen Grassland \footnote{\textbf{Contact Address:} Li Jiang, Jilin Agricultural University, College of Horticulture, 2888 Xincheng Street, 130118~Changchun, China, \mbox{e-mail}: \email{chinajiangli579@163.com}}\\[0.8ex]}}
\normalsize{\textsc{Li Jiang$^{1}$, Niu Xuedun$^{2}$, Lou Yujie$^{3}$}}
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\begin{itemize*}
\item[]{\small{\textit{$^{1}$Jilin Agricultural University, College of Horticulture, China}}}
\item[]{\small{\textit{$^{2}$Jilin Agricultural University, Key Laboratory for Molecular Enzymology and Engineering of Ministry of Education, China}}}
\item[]{\small{\textit{$^{3}$Jilin Agricultural University, College of Animal Science and Technology, China}}}
\end{itemize*}
\index[author]{Jiang, Li}
\index[author]{Xuedun, Niu}
\index[author]{Yujie, Lou}
\begin{center}
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\textbf{Abstract}
\begin{abstract}
\normalsize{
The response of soil respiration and soil organic matter to global change is  the main factor that affect the terrestrial ecosystem carbon budget, and is also the main contents of the current global change research. The sensitivity of soil respiration (Q10) to a large extent determines the feedback relationship between global climate change and carbon cycle. This study investigated the 4-year response to warming (+ 1.7\&\#8451;) and nitrogen addition (10gN m$^{-2}$yr$^{-1}$) in Songnen grassland in Northeast China. Using the li-6400--09 soil respiration system measurement of different treatments of soil respiration and temperature, and determination of soil carbon content, soil total nitrogen content  and soil carbon- nitrogen ratio. 4 years results show that warming significantly increased the soil respiration rate by \mbox{19.31\,\%}, N addition increased  the soil respiration  by \mbox{12.29\,\%}, warming plus N addition treatment  significantly increased  the soil respiration by 16.25\%; the temperature sensitivity of Songnen grassland significantly  increased in 2006, 2007 and 2008 in warming treatment, but  no significantly change in 2009. Soil respiration in grassland ecosystems are sensitive to warming and N addition. In the studied water"=limited grassland, both warming and N addition influence soil respiration by affecting water availability, which is the primary driver in many arid and semiarid ecosystems. N addition not only enhanced the soil respiration, but also ameliorated the negative C balance caused by experimental warming on soil respiration. Although our data suggest that the mechanisms driving the observed respiratory responses to warming and N addition may be different, the large CO$_{2}$ losses stimulated by warming and N addition suggest that knowledge of such patterns and their effects on soil organic mater understanding the role of grassland in a rapidly changing global C cycle.}

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\noindent \textbf{Keywords:} Soil respiration,soil organic mater ,Q10,grassland, warming
\index[key]{Soil!respiration,soil organic mater ,Q10,grassland}
\index[key]{Warming}
\end{document}
