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\hypersetup{pdftitle={Estimation of Current Aboveground Carbon Stocks and Annual Increment of Different Successional Stages of Secondary Forest Stands in Yucatan, Mexico},pdfauthor={Alexander Röll, Martin Worbes},pdfsubject={Tropentag 2010: Abstract},pdfkeywords={ Yucatan, average annual increment, biomass estimation, carbon stock, dendrochronology, forest management, Mexico, secondary forest},pdfpagemode=None,colorlinks=true}
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\parbox[b]{13.4cm}{\centering \large{\textbf{Tropentag, September 14-16, 2010, Zurich}}\\[1ex] \Large{``World Food System  ---\\A Contribution from Europe''\\[2ex]}}
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\begin{center}
\Large{\textbf{Estimation of Current Aboveground Carbon Stocks and Annual Increment of Different Successional Stages of Secondary Forest Stands in Yucatan, Mexico\footnote{\textbf{Contact Address:} Martin Worbes, Georg-August-Universität Göttingen, Department of Crop Sciences - Tropical Agronomy, Griesebachstraße 6, 37077~Göttingen, Germany, \mbox{e-mail}: \email{mworbes@gwdg.de}}\\[0.8ex]}}
\normalsize{\textsc{Alexander Röll$^{1}$, Martin Worbes$^{2}$}}
\end{center}
\begin{itemize*}
\item[]{\small{\textit{$^{1}$Georg-august-university of Göttingen, Department of Crop Sciences - Tropical Agronomy, }}}
\item[]{\small{\textit{$^{2}$Georg-August-Universität Göttingen, Department of Crop Sciences - Tropical Agronomy, Germany}}}
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\index[author]{Röll, Alexander}
\index[author]{Worbes, Martin}
\begin{center}
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\textbf{Abstract}
\begin{abstract}
\normalsize{
The area of secondary forests has been increasing throughout the tropics over decades and is expected to continue rising, fueled by conversion of agricultural systems that are abandoned after soil fertility decreases. These forests therefore play a major role in the global carbon cycle. 



This project focuses on the estimation of current tree carbon stocks and annual increment of secondary semi"=deciduous forest in Tzucacab, Yucatan, Mexico as a measure for the carbon allocation potential. Destructive sampling allowed for establishing biomass values by weighing trees on sight. By applying specific wood densities, those values could ultimately be transformed into carbon stock values. Additionally, this method provided the opportunity to collect stem discs, making possible the exact determination of tree age - and hence increment rates - through dendrochronological analysis. 



A total of three plots of secondary forest, located in different successional stages, were investigated, focusing on raising data on carbon stock and average annual increment.  All individuals with a DBH $>$ \mbox{1\,cm} were treated as sample trees.



Over succession, growing stock and carbon stock values increased, reaching 170.81 m$^3$ ha$^{-1}$ and 59.17 Mg ha$^{-1}$ after about 60 years of secondary forest regeneration. Diversity also regenerated to considerable levels, with a species richness of 45 and Simpson's Diversity Index and Shannon-Wiener-Index values of 5.71 and 3.24 on an area of \mbox{0.06\,ha}. 



The growing stock value (170.81 m$^3$ ha$^{-1}$) in the oldest successional stage compares to the average of semi"=deciduous forests in tropical America (190.0 m$^3$ ha$^{-1}$), and the same goes for the carbon stock level (59.17 Mg ha$^{-1}$) as compared to 47--55 Mg ha$^{-1}$ for dry forests and 44--59 Mg ha$^{-1}$ for disturbed forests throughout the tropics.



Regarding annual increment rates, the investigated stands feature low overall rates when compared to other forest types or managed stands. This is at least partly due to their status of non---management. 



Given proper management plans considering ecological, economic and social circumstances, silviculture is believed to be a considerable land"=use alternative in the region.



}

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\end{abstract}
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\noindent \textbf{Keywords:}  Yucatan, average annual increment, biomass estimation, carbon stock, dendrochronology, forest management, Mexico, secondary forest
\index[key]{ Yucatan}
\index[key]{Average annual increment}
\index[key]{Biomass!estimation}
\index[key]{Carbon stock}
\index[key]{Dendrochronology}
\index[key]{Forest!management}
\index[key]{Mexico}
\index[key]{Secondary forest}
\end{document}