The SLA is calculated in Reich et al. 97 by :
\begin{equation} 
SLA = \exp (5.615 - 0.46 \cdot \ln (a_{leaf}))
\end{equation}
where : \\
\begin{itemize}
 \item  $a_{leaf}$ is a PFT-specific value for leaf longevity in months.
\end{itemize}

