\documentclass[english,german]{scrartcl}
\usepackage[latin1]{inputenc}
\usepackage{geometry}
\geometry{verbose,a4paper,tmargin=1.75cm,bmargin=2cm,lmargin=2cm,rmargin=2cm,headheight=0.8cm,headsep=0.5cm,footskip=0.5cm}
\usepackage{babel}
\usepackage{url}
\urlstyle{same}
\newcommand\email{\begingroup \urlstyle{same}\Url}\usepackage{graphicx}
\usepackage{units}
\usepackage{tabularx}
\usepackage{wasysym} % enable use of \permil instead of \textperthousand
\usepackage{marvosym}
\usepackage{arabtex}
\usepackage{hyphenat}
\usepackage{booktabs}
\usepackage{mdwlist}
\renewcommand{\thefootnote}{\relax}
\usepackage{index}
\newindex{key}{kdx}{knd}{Keywords}
\newindex{author}{idx}{ind}{Authors}
\usepackage{fancyhdr}
\pagestyle{fancy}
\renewcommand{\headrulewidth}{0pt}
\fancyfoot{}
\usepackage{ifpdf}
\ifpdf
%\usepackage[activate]{pdfcprot}
%\usepackage[owner=Tapioka, print=true, copy=true, edit=false, annotate=false,set]{pdfcrypt}
%encryption: not supported any more (since pdftex 1.10)
\usepackage[pdftex]{thumbpdf}
\usepackage[pdftex]{hyperref}
\hypersetup{pdftitle={Waterbirds Biodiversity: A Comparative Analysis Between Rice Fields and Natural Wetlands},pdfauthor={Maria Fabiana Navarro Rau},pdfsubject={Tropentag 2010: Abstract},pdfkeywords={Aquatic birds, biodiversity index, Oryza sativa, Province of Corrientes},pdfpagemode=None,colorlinks=true}
\else
\usepackage{ae}
\usepackage{textcomp}
\fi
\begin{document}
\ifpdf
\parbox[b]{2.5cm}{\resizebox*{2.5cm}{!}{\includegraphics{dtt2010.jpg}}}
\else
\parbox[b]{2.5cm}{\resizebox*{2.5cm}{!}{\includegraphics{dtt2010.eps}}}
\fi
\hfill
\parbox[b]{13.4cm}{\centering \large{\textbf{Tropentag, September 14-16, 2010, Zurich}}\\[1ex] \Large{``World Food System  ---\\A Contribution from Europe''\\[2ex]}}
\hspace{0.1cm}
\begin{center}
\Large{\textbf{Waterbirds Biodiversity: A Comparative Analysis Between Rice Fields and Natural Wetlands\footnote{\textbf{Contact Address:} Maria Fabiana Navarro Rau, National Institute of Agricultural Research, Corrientes Experimental Station, Ruta 12 km 1008, 3400~Corrientes, Argentina, \mbox{e-mail}: \email{mnavarro@corrientes.inta.gov.ar}}\\[0.8ex]}}
\normalsize{\textsc{Maria Fabiana Navarro Rau}}
\end{center}
\begin{itemize*}
\item[]{\small{\textit{National Institute of Agricultural Research, Corrientes Experimental Station, Argentina}}}
\end{itemize*}
\index[author]{Navarro Rau, Maria Fabiana}
\begin{center}
\vspace{1.1cm}
\textbf{Abstract}
\begin{abstract}
\normalsize{
Rice (\textit{Oryza sativa}) is currently a major agricultural crop in the Province of Corrientes (Argentina), covering around 100 thousand hectares. Despite their cultivation has implied the conversion of natural wetlands, the behaviour as temporary artificial wetland, alternating between periods of flooding in the summer and dry periods in the winter and with a spatial and temporal heterogeneity, allows the establishment of large populations of birds with different trophic and structural requirements. For some waterbird species, rice fields provide feeding habitat in both, breeding and non"=breeding seasons. It provides also refuge areas and, to a lesser degree, nesting sites. Due to these facts, rice fields have been recognised for their high potential for the waterbirds. Until now, no researches regarding this topic were carried out in this province.



The aim of this work was to evaluate biodiversity differences between a natural wetland and an artificial wetland (rice field). Surveys were carried out between January 2008 and January 2009. The sampled rice fields were not randomly selected. Our choices were based on accessibility and logistics, trying to distribute the surveys as widely as possible within the study area. In each survey, all waterbird observed in the point area were counted over a 10 minutes period. Information on the species, number and behaviour was recorded for each bird or group of birds. Different well known biodiversity indexes were calculated. A total of 85 species were recorded, of which 52 species were related to some crop stage, and 33 of them belong to the waterbird group. The specific richness (R), structural biodiversity (H) and dominance (S) were similar or even higher in the rice fields when compared to the natural wetlands. The Neartic migrants were also higher in the rice fields. Additionally, species richness and abundance showed significant differences ($p < 0.001$) between stages of the rice crop cycle. As a conclusion, facing the worldwide loss of natural wetlands, rice fields are an important feeding site and a valuable alternative habitat for waterbirds. The latter, will be possible only with an appropriate water and agrochemical management.



}

\vspace{0.5cm}
\end{abstract}
\end{center}
\noindent \textbf{Keywords:} Aquatic birds, biodiversity index, \textit{Oryza sativa}, Province of Corrientes
\index[key]{Aquatic birds}
\index[key]{Biodiversity index}
\index[key]{Oryza sativa@\textit{Oryza sativa}}
\index[key]{Province of Corrientes}
\end{document}