Specific Leaf Area on Fresh Matter Basis: A Soft Trait for Leaf Thickness?

Leaf dry matter content (LDMC) and the specific leaf area (SLA), are leaf traits frequently measured in field studies. Unfortunately, leaf thickness (LT) rarely is measured because that is time consuming and needs special equipment. Specific leaf mass (SLM), or leaf dry matter content/unit of leaf area, has been correlated positively to leaf density (Van Arendonk & Poorter 1994) but very few studies have examined its correlation with leaf thickness (Witkowsky & Lamont 1991). Since leaf volume is basically related to its water content, specific leaf area on a fresh matter basis (SLAW) could be consistently correlated to leaf thickness. Hard traits are linked to plant functions but are difficult to measure. Therefore, it is necessary to find traits easier to measure and correlated to hard traits in order to integrate the latter in field studies on natural vegetation. The aim of this study was to find out to what extent SLAW is a reliable estimator of LT