Foliar summer frost resistance measured via electrolyte leakage approach as related to plant distribution, community composition and plant traits

Abstract

Abstract Frost resistance (FR) is a fundamental process determining various aspects of plant life. Measurements of FR remain challenging as existing methods are time‐ and labour‐intensive. Here, we test the applicability of foliar summer FR measured via the ‘electrolyte leakage’ approach (FRPEL), a simple and inexpensive technique so far underused in ecological research to estimate FR. We tested the ability of this trait to predict (a) species occurrence, (b) community composition along an elevation gradient and (c) analysed its relationship with nine other traits (SLA, Cmass, Nmass, Pmass, Camass, Mgmass, Kmass, canopy height and the ability to form rosettes) related to plant performance. We studied 183 vascular species occurring at 37 sites, which we also analysed in terms of species composition along an elevation gradient from 656 to 2,363 m a.s.l. in the Bavarian Alps, Germany. Species' FRPEL values correlated significantly with the species occurrence along the elevation gradient. However, this relationship was weak as it explained only 10% in the variation of the Landolt indicator values, a proxy for species geographic ranges. We found a strong positive relationship between community‐weighted FRPEL values and elevation suggesting a strong environmental filtering of this trait that removes species with low FR from the local species pool at high elevations. The community functional diversity of FRPEL significantly increased with increasing elevation suggesting a higher trait divergence in harsher climates. We found significant negative relationships between FRPEL and SLA, canopy height and the ability to form leaf rosettes, indicating a trade‐off in plants between the investment in conservative strategies, in our case FR, and fast resource acquisition. Our study highlights the potential of using FRPEL more frequently in ecological research as we were able to reconfirm three patterns inferred by more precise yet time‐consuming and labour‐intensive approaches. We demonstrate that FRPEL can be used to predict species occurrence and infer assembly rules along elevation gradients. Furthermore, we found that FRPEL is linked to plant functional traits associated with plant performance and morphological features of the plants. However, the trait's predictive power varied greatly among the study objectives and levels. A free Plain Language Summary can be found within the Supporting Information of this article.