Rooting depth and specific leaf area modify the impact of experimental drought duration on temperate grassland species

Due to climate change, temperate grasslands are being exposed to increasingly severe droughts. Concurrently, land-use intensification is altering grasslands’ functional composition by promoting fast-growing, resource-acquisitive species with high specific leaf area (SLA).
How SLA affects the ability of grassland species to resist and recover from increasingly severe droughts and if deep roots improve their drought performance remains unclear. To investigate this, we established a common garden field experiment including temperate grassland species with SLAs of 17.9–39.3 mm2g-1 and maximal rooting depths of 16–252 cm. After 1.5 years, we simulated droughts for 0, 79, 134, 177 and 220 days.
Drought effects on plant performance increased with drought length, reducing the survival of green tissue and annual biomass by up to ~50% across all 32 species considered. As plant-available water remained in deep soil layers by the end of all treatments, deep roots mitigated the negative effect of in..., We selected 48 plant species from four functionally different seminatural or agricultural Swiss grasslands. In our common garden field experiment, these study species were allocated to four subplot types according to their prevalence in the reference grasslands. This should avoid that species chosen from the more productive reference grasslands would overgrow species from the less productive grasslands. In March 2021, which was 1.5 years after establishement, we covered the whole experimental site with a greenhouse plastic and simulated droughts for 0, 79, 134, 177 and 220 days by omitting the regular watering of the respective plots. 
We measured specific leaf area (SLA) on 12–14 relatively young but fully expanded leaves without obvious signs of herbivory, pathogens, or senescence of 6–12 adult individuals per species growing in control plots in May 2021. For species with both rosette and stem leaves, we measured stem leaves if available and we included all petioles and stipules into ..., , # Data from: Rooting depth and specific leaf area modify the impact of experimental drought duration on temperate grassland species

## File: Species\_traits\_data

**Description:** Trait data of study species used in analyses. We
measured specific leaf area (SLA) on 12--14 relatively young but fully
expanded leaves without obvious signs of herbivory, pathogens, or
senescence of 6--12 adult individuals per species growing in control
plots in May 2021. For species with both rosette and stem leaves, we
measured stem leaves if available and we included all petioles and
stipules into the measurements. We checked and completed our SLA
measurements in June 2022. Further plant traits were compiled from
literature and databases (see references below).

### Variables

* species: scientific species' name
* species.abbr: abbreviation of scientific species' name
* MRD: maximal rooting depth (cm) compiled from the TRY database
(Kattge et al., 2011), Kutschera and Lichtenegger (1982,1992) and
ref...