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\hypersetup{pdftitle={The Effect of Grazing and Successional Stages on Seed Bank Density and Similarity Between Seed Bank and Above Ground Vegetation},pdfauthor={Reza Erfanzadeh, Maurice Hoffmann},pdfsubject={Tropentag 2010: Abstract},pdfkeywords={Salt marsh, Seed bank, Sheep grazing, succession, Vegetation },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{The Effect of Grazing and Successional Stages on Seed Bank Density and Similarity Between Seed Bank and Above Ground Vegetation\footnote{\textbf{Contact Address:} Reza Erfanzadeh, Tarbiat Modares University, Rangeland Ecology, Imam Khomeini, 64414356~Noor, Iran, \mbox{e-mail}: \email{erfanzadeh@yahoo.com}}\\[0.8ex]}}
\normalsize{\textsc{Reza Erfanzadeh$^{1}$, Maurice Hoffmann$^{2}$}}
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\begin{itemize*}
\item[]{\small{\textit{$^{1}$Tarbiat Modares University, Rangeland Ecology, Iran}}}
\item[]{\small{\textit{$^{2}$Ghent University, Terrestrial Ecology, }}}
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\index[author]{Erfanzadeh, Reza}
\index[author]{Hoffmann, Maurice}
\begin{center}
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\textbf{Abstract}
\begin{abstract}
\normalsize{
The effect of grazing and successional stages on seed bank density and similarity between seed bank and above ground vegetation was investigated. The study was conducted in a salt marsh that contained both old and newly created and both grazed and ungrazed habitats. Two old salt marshes were selected to study the effect of grazing on seed bank. One of them is intensively grazed and one of them has never or only recently been grazed. Ten plots of 4m$^2$ were situated in the new salt marsh and 80(50 in grazed and 30 in ungrazed) plots in the old salt marshes. Soil samples were collected at two different depths (0--5, 5--\mbox{10\,cm}) in spring 2006. After washing by fresh water, the soil samples were spread in the greenhouse to allow viable seeds to germinate. Germination experiments lasted 6 months and all seedlings were identified and removed after identification. Above"=ground vegetation composition was determined during the growing season in all plots. 



The results didn't detect a clear effect of grazing on seed density and similarity. The results showed that seed density and similarity was higher in the new salt marsh than old salt marsh. Seed density was mostly composed of new colonizers during the successional stages while they disappear or decreased intensively in late successional stage from above ground vegetation. Most perennial species was absent in soil while they were dominant in the vegetation. 



This study implies that restoration is possible from a long"=term persistent seed bank only if the target species would be pioneer colonizers.}

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\noindent \textbf{Keywords:} Salt marsh, Seed bank, Sheep grazing, succession, Vegetation 
\index[key]{Salt!marsh}
\index[key]{Seed!bank}
\index[key]{Sheep grazing}
\index[key]{Succession}
\index[key]{Vegetation }
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