DOI: 10.5061/dryad.p2ngf1vxn
title: Precipitation predictability drives evolution of drought strategies in the common poppy, Papaver rhoeas

description: Current climate change leads to an increase in the frequency and intensity
 of droughts and to decreased precipitation predictability. The few studies
 investigating plant evolutionary responses to contrasting predictability
 regimes showed that intrinsic precipitation predictability shapes plant
 phenotypic variation, drives evolution of phenotypic plasticity, and can
 vary in strength and direction of selection. This suggests that the
 selection pressure induced by decreased precipitation predictability may
 lead to plants coping better with severe drought events.  To
 investigate whether past precipitation predictability influences plant
 responses to different drought conditions, we performed a common-garden
 experiment applying control, short-term and long-term drought treatments
 on seedlings of Papaver rhoeas (Papaveraceae) whose progenitors
 experienced less versus more precipitation predictability treatments for
 three consecutive generations. In addition, to assess whether competition
 modulates plant responses, half of the plants were grown together with the
 widespread herbaceous plant Galium album (Rubiaceae). In the presence of
 long drought episodes, plants whose progenitors experienced less
 predictable precipitation survived longer than those whose progenitors
 experienced more predictable precipitation. Furthermore, plants whose
 progenitors experienced less predictable precipitation had lower biomass,
 which is likely to reduce water loss via transpiration, and, across all
 drought treatments, they showed lower root investment. However, no trait
 differences were detected under competition, indicating that interspecific
 competition may limit the expression of evolutionary responses to changes
 induced by precipitation predictability. Altogether our results indicate
 that lower precipitation predictability mainly promotes the evolution of
 drought-escape and drought-avoidance strategies. Overall, our experiment
 highlights that precipitation predictability is an important evolutionary
 driver of plant functional responses, potentially shifting evolutionary
 trajectories of plants under increasing intensity of drought
 events. 
description: Data collected in greenhouse experimental settings.
description: # Precipitation predictability drives evolution of drought strategies in
 the common poppy, Papaver rhoeas Greenhouse evolution experiment
 manipulating Past predictability treatment (i.e., preceding generations
 were exposed to less or more precipitation predictability for three
 generations), drought treatments (long-term, short-term, or control
 drought treatment) and competition (yes or no, with Galium album). ##
 Description of the data and file structure Data variables include:
 FACTORS: * drought\_treat: Drought treatment: long drought, short drought
 or control treatment * precip\_pred: Past precipitation predictability
 treatment for three consecutive generations: More predictable (M), Less
 predictable (L) * competition: Competition: 0 (No), 1 (Yes) REPLICATES: *
 family: Seed family: six seed families were selected from each past
 predictability treatment * replicate: Individual replicates per treatment
 group. (a total of 288 pots were used in the experiment, i.e., two
 predictability treatments × six seed families × three drought treatments ×
 two competition treatments × four replicates) CONTINUOUS VARIABLES: *
 nb\_leaves1: Initial number of leaves * longest\_leaf1: Initial length of
 the longest leaf (in cm) * SPAD\_16th\_01: SPAD measure at day 16 *
 SPAD\_18th\_01: SPAD measure at day 18 * SPAD\_20th\_01: SPAD measure at
 day 20 * SPAD\_26th\_01: SPAD measure at day 26 * wilt\_16th\_01: Wilt (1)
 or no wilt (0) at day 16 * wilt\_17th\_01: Wilt (1) or no wilt (0) at day
 17 * wilt\_18th\_01: Wilt (1) or no wilt (0) at day 18 * wilt\_19th\_01:
 Wilt (1) or no wilt (0) at day 19 * wilt\_20th\_01: Wilt (1) or no wilt
 (0) at day 20 * wilt\_21th\_01: Wilt (1) or no wilt (0) at day 21 *
 wilt\_22th\_01: Wilt (1) or no wilt (0) at day 22 * wilt\_23th\_01: Wilt
 (1) or no wilt (0) at day 23 * wilt\_24th\_01: Wilt (1) or no wilt (0) at
 day 24 * wilt\_25th\_01: Wilt (1) or no wilt (0) at day 25 *
 wilt\_26th\_01: Wilt (1) or no wilt (0) at day 26 * longest\_leaff: Length
 of the longest leaf - final measure (in cm) * nb\_leavesf: Number of
 leaves - final measure * root\_length: Maximum root length (in mm) *
 bground\_biomass: Root biomass (in g) * abground\_biomass: Aboveground
 biomass (in g) ## Code/Software All statistical analyses were conducted
 with R version 4.1.1 (R Development Core Team, 2021).