A standardized protocol for the determination of specific leaf area and leaf dry matter content

TLDR

The study examined how sample preparation, rehydration procedure, and sampling time influence specific leaf area and leaf dry matter content in three wild species and proposes a standardized protocol for measuring these traits. Researchers measured SLA and LDMC in mature leaves of three wild species by varying sample preparation, rehydration procedure, and sampling time to assess their effects on trait determination. Complete rehydration within 6 h yielded SLA and LDMC values that were unaffected by pre‑rehydration preparation or temperature, though water‑saturated leaves had lower LDMC and higher SLA—especially in species with high SLA—and sampling time between 09:00–16:30 had no effect, indicating that SLA and LDMC measured on water‑saturated leaves are suitable for species comparisons and support the proposed standardized protocol.

Abstract

Summary The impact of sample preparation, rehydration procedure and time of collection on the determination of specific leaf area (SLA, the ratio of leaf area to leaf dry mass) and leaf dry matter content (LDMC, the ratio of leaf dry mass to fresh mass) of mature leaves was studied in three wild species growing in the field, chosen for their contrasting SLA and LDMC. Complete rehydration was achieved 6 h after samples were placed into water, but neither of the procedures tested – preparation of samples before rehydration or temperature applied during rehydration – had a significant effect on the final values of SLA or LDMC. As expected, water‐saturated leaves had a lower LDMC than non‐rehydrated leaves; more surprisingly, their SLA was also higher. The impact of rehydration on SLA was especially important when the SLA of the species was high. There was no significant effect of time of sampling on either trait in any species over the time period covered (09·00–16·30 h). These results suggest that SLA and LDMC obtained on water‐saturated leaves (SLA SAT and LDMC SAT ) can be used for species comparisons. We propose a standardized protocol for the measurement of these traits. This would allow for better consistency in data collection, a prerequisite for the constitution of large databases of functional traits.