Frost damage measured by electrolyte leakage in subarctic bryophytes increases with climate warming

1. Observed climate change in northern high latitudes is strongest in winter, but still relatively little is known about the effects of winter climate change on tundra ecosystems. Ongoing changes in winter climate and snow cover will change the intensity, duration, and frequency of frost events. Bryophytes form a major component of northern ecosystems but their responses to winter climate changes are largely unknown. 2. Here, we studied how changes in overall winter climate and snow regime affect frost damage in three common bryophyte taxa that differ in desiccation tolerance in a subarctic tundra ecosystem. We used a snow manipulation experiment where bryophyte cores were transplanted from just above the treeline to similar elevation (i.e., current cold climate) and lower elevation (i.e., near-future warmer climate scenario) in Abisko, Sweden. Here we measured frost damage in shoots of Ptilidium ciliare, Hylocomium splendens and Sphagnum fuscum with the relative electrolyte leakage (RE..., We used a snow manipulation experiment where bryophyte cores were transplanted from just above the treeline to similar elevation (i.e., current cold climate) and lower elevation (i.e., near-future warmer climate scenario) in Abisko, Sweden. For full details on the experimental design, see the corresponding publication in Journal of Ecology (Van Zuijlen et al. 2023).
Sampling and frost damage assessment
To capture periods when bryophytes may be more vulnerable to freezing, we sampled multiple times after snowmelt (i.e., when all plots had melted out at least partially), and across two consecutive years to increase the generality of our findings. In 2015 sampling took place on May 10 and 27 at the low site and on May 11 and 29 at the high site. In 2016, we sampled on May 2, 11 and 16 and June 1 at the low site and on May 3, 10 and 17 and June 2 at the high site. At each sampling occasion, we collected bryophyte shoots from each species in each plot. Five living (i.e., healthy looking) ind..., , # Data from: Frost damage measured by electrolyte leakage in subarctic bryophytes increases with climate warming

[https://doi.org/10.5061/dryad.79cnp5j2q](https://doi.org/10.5061/dryad.79cnp5j2q)

The dataset include relative electrolyte leakage (REL) values for three subarctic bryophyte taxa, microclimate variables calculated from hourly measurements taken inside the bryophyte cores, and maximum shoot growth per bryophyte core from a snow manipulation field experiment in Abisko, Sweden. In addition, REL values of unmanipulated bryophyte shoots are included.

## File list

* vanzuijlen\_et\_al\_2023\_rel.txt
* vanzuijlen\_et\_al\_2023\_clim\_exp.txt
* vanzuijlen\_et\_al\_2023\_clim\_rel.txt
* vanzuijlen\_et\_al\_2023\_shootgrowth.txt
* vanzuijlen\_et\_al\_2023\_unm\_rel.txt

## File and variable descriptions

vanzuijlen\_et\_al\_2023\_rel.txt - This file contains the REL values for the bryophyte cores within the snow manipulation field experiment. There are two elevational sites (\"site...