Weak local adaptation to drought in seedlings of a widespread conifer
Data files
Jan 16, 2024 version files 737.14 KB
Abstract
Tree seedlings from populations native to drier regions are often assumed to be more drought tolerant than those from wetter provenances. However, intraspecific variation in drought tolerance has not been well characterized despite being critical for developing climate change mitigation and adaptation strategies, and for predicting the effects of drought on forests.
We used a large-scale common-garden drought-to-death experiment to assess range-wide variation in drought tolerance measured by decline of photosynthetic efficiency, growth, and plastic responses to extreme summer drought in seedlings of 73 natural populations of the two main varieties of Douglas-fir (Pseudotsuga menziesii var. menziesii and var. glauca).
Local adaptation to drought was weak in var. glauca and nearly absent in menziesii. Var. glauca showed higher tolerance to drought but slower growth than var. menziesii. Clinal variation in drought tolerance and growth species-wide was mainly associated with temperature rather than precipitation. A higher degree of plasticity for growth was observed in var. menziesii in response to extreme drought.
Genetic variation for drought tolerance in seedlings within varieties is maintained primarily within populations. Selective breeding within populations may facilitate adaptation to drought more than assisted gene flow.
README: Weak local adaptation to drought in seedlings of a widespread conifer
https://doi.org/10.5061/dryad.w3r2280wr
This dataset contains the raw phenotypic data of individual plants from the drought experiment conducted for the study. The data includes height growth, visual damage, and Fv/Fm measurements collected at five different time points. For the manuscript by Candido-Ribeiro and Aitken (2024), only the 73 provenances from "natural" origin and varieties glauca and menziesii were used. Provenances from "orchard" origin and the species Pseudotsuga macrocarpa (in the variety column as "macrocarpa") were excluded from the analysis.
Description of the dataset (columns):
- box = the boxes used in the experiment with 90 active plants ("subplot" column). In total, there were 16 boxes (8 for "Dry" treatment and the other 8 for "Wet treatment").
- block = Each block contains 2 boxes (1 for "Dry" treatment and 1 for "Wet" treatment). There were 8 blocks in total.
- provenance = provenance (population) number. the provenance number matches the number in Table S1 and Fig. 1 of the manuscript.
- treatment = two treatments used in the experiment (details of the experiment can be found in the manuscript).
- wide-plot = the two boxes within a block.
- subplot = sequential position of each plant within a box (from 1 to 90).
- seed_id = unique identification of each plant in the experiment. Each seed_id consists of the provenance number and a unique number within that provenance separated by "_".
- y_treatment = y position of the plant in a tratment.
- x_treatment = x position of the plant in a tratment.
- y_experiment = y position of the plant in the whole experiment.
- x_experiment = x position of the plant in the whole experiment.
- variety = two Pseudotsuga menziesii varieties ("glauca" and "menziesii") plus one provenance (99) of Pseudotsuga macrocarpa ("macrocarpa") (excluded from the analysis).
- origin = either "natural" when seeds were collected from natural stands or "orchard" when seeds were generated and collected from breeding programs (with cycles of selection). "Orchard" seedlots were excluded from the analysis.
- group = general region where seedlots came from. For more details, see Table S1.
- date = date when phenotypes were measured.
- measurement = 1-5 measurement time points.
- exp_day = day of experiment since establishment.
- VWC = volumetric water content (%) in each box.
- h = height (cm).
- h_max = maximum height reached at the time (regardless of survival state).
- cumul_grow = cumulative height increment
- h_increment = height at measurement t minus height at measurement t-1.
- visual damage = 0 (0%); 1 (1% to 25%); 2 (26% to 50%); 3 (51% to 75%); and 4 (76% to 100% canopy damage).
- fv_fm = Fv/Fm (dark adapted chlorophyll fluorescence).