\documentclass[a4paper]{article}
\usepackage{pgfplots}

\pgfplotstableread{
0 10
1 10
2 8
3 15
4 13
5 20
}\datatable


\begin{document}
% strange example: 'stack plots' is only active in ONE \addplot!?
% does that make any sense!?
\begin{tikzpicture}
\begin{semilogyaxis}[title={Log basis default}]
\addplot table {\datatable};
\addplot [draw=red, stack plots=y] table {\datatable};
\end{semilogyaxis}
\end{tikzpicture}
\begin{tikzpicture}
\begin{semilogyaxis}[log basis y=2, title={Log basis 2}]
\addplot table {\datatable};
\addplot [draw=red, stack plots=y] table {\datatable};
\end{semilogyaxis}
\end{tikzpicture}

\end{document}

