DOI: 10.5061/dryad.g1jwstr44
title: Data from: Heatwaves decrease fitness and alter maternal provisioning in natural populations of Mimulus guttatus

description: Premise of study: The increasing frequency and severity of heatwaves and
 droughts occurring across the globe is well known. However, there are few
 longitudinal studies tracking demographic change and fitness within
 natural populations, and fewer still that span multiple extreme events.
 Determining how organisms tolerate, respond, and potentially adapt to
 extreme events is key for assessing long-term population viability.
 Methods: We examine how mortality, fecundity, seed provisioning, and
 offspring germination differ across 12 populations of annual common
 monkeyflower (Mimulus guttatus) over a five-year span. Key Results: Two
 heatwaves occurred within the study: a 2019 heatwave occurring within the
 first 10 days of the growing season, and a 2021 heat dome event occurring
 nearly a month into the growing season. Mortality was high and fecundity
 decreased in a population-specific manner due to both heatwaves. However,
 the 2021 heat dome caused declines of 34.5% in seed size and 22.1% in the
 ability to germinate, while the 2019 heatwave did not. Structural equation
 models indicate that similar climatic factors including early season
 maximum temperatures and late season precipitation are associated both
 with declines in fecundity and slower germination. Conclusions: These
 results suggest that the consequences of heatwaves will depend on the
 relative severity and timing of the heatwave in the growing season, and
 further suggest that this timing may have amplified longer-term impacts as
 offspring have lower provisioning. Specifically, with growing seasons
 shifting earlier into the spring, later or slower germination could
 exacerbate population extirpation risk.
description: # Data from: Heatwaves decrease fitness and alter maternal provisioning in
 natural populations of *Mimulus guttatus* --- This README file contains
 information for three separate data files included in this repository: *
 fileA - A survivorship dataset * fileB - A seed germination and seed mass
 dataset * filec - A fecundity dataset # fileA: Survivorship dataset for
 'Heatwaves decrease fitness and alter maternal provisioning in
 natural populations of *Mimulus guttatus*' --- This is a comma
 delimited file (.csv) which contains survivorship information from 12
 populations of common monkeyflowers (*Mimulus guttatus*) in the central
 Oregon Cascades during heatwave periods in 2019 and 2021. Full methods are
 available in the associated manuscript (Kooyers et al. 2025). Briefly,
 this data is derived from surveys of alive individuals within two 0.25m2
 quadrats per population during the 2019 and 2021 growing seasons. This
 dataset was collected by Laura McDonald and Anna Schranagl in 2019 and by
 Benjamin LeBlanc and Simon Innes in 2021. ## Description of the Data and
 file structure Each row of this spreadsheet represents data from a single
 quadrat during a single growing season except for the first row header.
 Missing data are coded as '999' Questions? Please contact Nic
 Kooyers ([nkooyers@gmail.com](mailto:nkooyers@gmail.com)). Format (Column
 -- Variable -- Description) * Column A -- HeatwavePeriod -- The Julian
 dates of the heatwave period in question. For instance, 2019 refers to the
 dates of the early season heatwave period in 2019. * Column B -- Year --
 The year which survivorship is being assessed (2019 or 2021) during the
 particular Julian dates where each heatwave occurred. * Column C -- Pop --
 The population where survivorship is being assessed. * Column D -- Plot --
 The particular quadrat within each population were survivorship is being
 assessed. * Column E -- UniqID -- A unique ID consisting of the
 information from Columns B, C, and D. * Column F -- DayDiff -- The number
 of days between the first and last surveys on either side of the the
 Julian dates in question. * Column H -- PropAliveDiff -- The difference in
 the proportion of individuals alive between first and last surveys. A
 negative number indicates a decline in individuals between the first and
 last surveys. * Column I -- PropFlowedDiff -- The difference in the
 proportion of individuals flowering between first and last surveys. A
 negative number indicates less individuals are flowering between the first
 and last surveys. * Column J -- VWCdiff -- The difference in average
 volumetric water content across the quadrat between the first and last
 survey. * Column K -- Aliverate -- The per day rate of change in
 survivorship. Calculated by dividing Column H by Column F. * Column L --
 Floweredrate -- The per day rate of change in flowering individuals.
 Calculated by dividing Column I by Column F. * Column M -- VWCrate -- The
 per day rate of change in volumetric water content within a quadrat.
 Calculated by dividing Column J by Column F. # fileB: Seed Mass and Seed
 Germination dataset for 'Heatwaves decrease fitness and alter
 maternal provisioning in natural populations of *Mimulus guttatus*'
 --- This is a comma delimited file (.csv) which contains seed mass and
 seed germination information for plants collected yearly from 2018-2022
 for 12 populations of common monkeyflowers (*Mimulus guttatus*) in the
 central Oregon Cascades. Full methods are available in the associated
 manuscript (Kooyers et al. 2025\). Briefly, plants were collected by
 running two transects across each population at uniform distances along
 the transect (distances differed between years). Each plant collected was
 considered a single maternal line. For a subset of our original
 collections, we weighted ~30 seeds to get an average mass per seed. We
 attempted to germinate a number of seeds per line in growth shelving. We
 report germination success as the proportion of seeds germinating for a
 given maternal line by day five or whether seeds were able to germinate
 for a particular maternal line. Seed germination experiments were
 preformed by Andrea Turcu, Courtney Patterson, and Donna Hinrichs. ##
 Description of the Data and file structure Each row of this spreadsheet
 represents fitness data from a single maternal line. Missing data is coded
 as '999'. Questions? Please contact Nic Kooyers
 ([nkooyers@gmail.com](mailto:nkooyers@gmail.com)). Format (Column --
 Variable -- Description) * Column A -- UniqID -- A unique ID for each
 maternal line. * Column B -- Pop -- The population where the plant was
 collected. * Column C -- Year -- The year the plant was collected. *
 Column D -- Line -- An identifier of the maternal line within a particular
 year and population. * Column E -- Aveseedmass -- Average seed mass (in
 mg) for a single seed. Calculated as an average of ~30 seeds per line. *
 Column F -- PbyD5 -- The proportion of seeds germinated by day 5 of the
 germination trial. * Column G-- HadGerm -- Whether any seeds germinated
 from a given maternal line. Maternal lines with a value of 1 had
 germination, while maternal lines with value of 0 had no germination. *
 Column H -- NSeeds -- The number of seeds counted for a given plant
 (maternal line) from all fruits collected in the field. # fileC:
 Longitudinal fecundity dataset for 'Heatwaves decrease fitness and
 alter maternal provisioning in natural populations of *Mimulus
 guttatus*' --- This is a comma delimited file (.csv) which contains
 fitness data collected yearly from 2018-2022 for 12 populations of common
 monkeyflowers (*Mimulus guttatus*) in the central Oregon Cascades. Full
 methods are available in the associated manuscript (Kooyers et al. 2025).
 Briefly, this data was collected by running two transects across each
 population and assessing fitness for plants closest to the tape at uniform
 distances along the transect (distances differed between years). For each
 plant, we assessed plant height, number of flowers, and number of seeds.
 This data was collected by Nic Kooyers in 2018, Andrea Turcu and Nic
 Kooyers in 2019 and 2020, Simon Innes and Benjamin LeBlanc in 2021, and
 Simon Innes, Donna Hinrichs and Stacy Holt in 2022. ## Description of the
 Data and file structure Each row of this spreadsheet represents fitness
 data from a single individual. Missing data is coded as '999'.
 Questions? Please contact Nic Kooyers
 ([nkooyers@gmail.com](mailto:nkooyers@gmail.com)). Format (Column --
 Variable -- Description) * Column A -- Year -- The year the plant was
 collected. * Column B -- Pop -- The population where the plant was
 collected. * Column C -- Transect -- The transect within population where
 the plant was collected (1 or 2). * Column D -- Distance -- The distance
 (in cm) along the transect where the plant was collected. * Column E --
 Nflowers -- The number of flowers on a given plant. Assessed by number of
 calyxes present. * Column F -- NSeeds -- The number of seeds counted for a
 given plant from all collected fruits.