Drought resistance drives population temporal stability of annuals in drylands

Understanding the mechanisms determining population temporal stability is key to explaining species diversity and coexistence, and to maintaining multiple ecosystem functions over time. Functional traits should offer mechanistic insights into the drivers of stability, but the generalization of a trait–stability relationship is lacking. Our overarching hypothesis is that traits predicted by bet-hedging theory to reduce variability in population size, i.e., delayed germination and/or bigger seeds and/or traits associated with higher drought resistance (high intrinsic water-use efficiency, high turgor loss point, slow relative growth rate, high leaf dry matter content, low SLA), lead to higher population temporal stability. We linked these traits to the year-to-year variation in winter annuals’ abundance of 178 populations (66 species) over 13 years. We tested the generality of these relationships in a biodiversity hotspot along a gradient of rainfall mean, variability, and unpredictabilit..., , # Data from: Drought resistance drives population temporal stability of annuals in drylands

Dataset DOI: [10.5061/dryad.jm63xsjqx](https://doi.org/10.5061/dryad.jm63xsjqx)

## Description of the data and file structure

This dataset includes species‑level functional trait measurements (relative growth rate, RGR; leaf carbon isotopic ratio, δ¹³C; osmotic potential at turgor loss point, TLP; specific leaf area, SLA; leaf dry matter content, LDMC; germination fraction; and seed size) of winter annual species, calculated as averages across five individuals per species measured in 2022. It also includes interannual variability in species population size, expressed as the coefficient of variation (CV) of individual counts from winter growing seasons between 2001/2002 and 2014/2015 in permanent plots, with CV values averaged across five plots per microhabitat in each climate. Data were collected across four climate types (arid, semi‑arid, Mediterranean, and mesic‑Mediterranean) and two micro...,