DOI: 10.5061/dryad.cfxpnvxjm
title: Warming-driven shifts in floral traits generate flower-pollinator size mismatch and decrease reproductive output

description: Plant-pollinator interactions are essential for maintaining pollination
 services, but may be sensitive to disruption from climate change. Higher
 temperatures can reduce flower size, nectar availability, and other floral
 traits, and shorten pollinator tongue and increase body size. This could,
 in turn, reduce flower-pollinator size matching, leading to difficulties
 accessing nectar and effectively transferring pollen between flowers.
 However, the effects of climate change on plant-pollinator trait matching
 are rarely experimentally tested. We conducted a two-year simulated
 warming experiment and a follow-up trait manipulation experiment in the
 field. Our aim was to link the effects of simulated warming on flower size
 and morphology, pollination efficiency, and, ultimately, reproductive
 success of the bumblebee-pollinated Impatiens oxyanthera (Balsaminaceae).
 Warming significantly decreased the lengths of corolla tubes and nectar
 spurs in I. oxyanthera but did not affect the size of bumblebee visitors,
 leading to a size mismatch between the flowers and their pollinators. This
 mismatch resulted in a shorter visit duration of bumblebees on a single
 flower, reducing pollen deposition on the stigmas and female reproductive
 success. Experimental reductions in nectar spur length, mirroring the
 decreases observed under warming, impaired pollen depositio,n and reduced
 seed production, independent of bumblebee size. These findings suggest an
 additional mechanism through which climate change may result in size
 mismatch between interacting partners, consequently disrupting pollination
 services beyond climate-driven distribution range and phenological shifts.
description: # Warming-driven shifts in floral traits generate flower-pollinator size
 mismatch and decrease reproductive output Open Source Data We have
 submitted our raw data (**Appendix S2 (R code and raw data).xls**,
 including 20 sheets), R script (**R code.R**). * R_code.txt: This code
 summarizes all the Bayesian statistical models used in the study, showing
 which figure or table each analysis corresponds to, what biological
 variable was tested, which year(s) of data were used, and the exact brms
 model fitted in R. Each model examines how a response variable (such as
 floral traits, pollination measures, temperature, seed production, or
 pollinator body size) is affected by experimental treatment, year, or
 both, while accounting for the hierarchical design of the experiment using
 random effects (e.g., plants nested within plots). Different probability
 distributions were chosen depending on the type of data: Gamma for
 positive continuous traits, Gaussian for normally distributed data,
 Poisson or negative binomial for count data, Beta for proportions,
 Student-t for robust modeling of continuous data with outliers, and
 zero-inflated Poisson when many zeros occurred. All models were fitted
 using Bayesian Markov chain Monte Carlo methods with multiple chains and
 tuning parameters to ensure stable and reliable estimation. ##
 Descriptions **File name: Appendix_S2_(R_code_and_raw_data).xls**
 **Appendix S2 (R code and raw data).xls, sheet = “2 flower shape”** *
 year: year of data measurement * Y2017* = 2017 * Y2018* = 2018 *
 treatment: warming treatment *ambient * = ambient condition *warmed * =
 warmed condition * group: experimental groups of the overall study *
 plotID: identity of experimental plot * plantID: identity of experimental
 plant individual * corolla_tube_length: corolla tube length (mm) *
 corolla_tube_width: corolla tube width (mm) * corolla_tube_height: corolla
 tube height (mm) * nectar_spur_length: nectar spur length (mm) **Appendix
 S2 (R code and raw data).xls, sheet = “3-12 flower-pollinator match”** *
 treatment: warming treatment *ambient * = ambient condition *warmed * =
 warmed condition * plotID: identity of experimental plot * plantID:
 identity of experimental plant individual * bumblebee_body_length(mm):
 body length of bumblebee (mm) * bumblebee_body_width(mm): body width of
 bumblebee (mm) * bumblebee_body_height(mm): body height of bumblebee (mm)
 * bumblebee_tongue_length(mm): tongue length of bumblebee (mm) *
 total_bumblebee_length(mm): total length of bumblebee (mm), which is equal
 to body length plus tongue length of bumblebee * LD: length difference
 between corolla tube and pollinator body (mm) * WD: width difference
 between corolla tube and pollinator body (mm) * HD: height difference
 between corolla tube and pollinator body (mm) * STLD: length difference
 between nectar spur and tongue (mm) * TLD: total length difference between
 flower and pollinator(mm) * RLD: relative length difference between
 corolla tube and pollinator body 　　　 * RLD = (corolla tube length -
 pollinator body length)/corolla tube length * RWD: relative width
 difference between corolla tube and pollinator body 　　　 * RWD = (corolla
 tube width - pollinator body width)/corolla tube width * RHD: relative
 height difference between corolla tube and pollinator body 　　　 * RHD =
 (corolla tube height - pollinator body height )/corolla tube height *
 RSTLD: relative length difference between nectar spur and pollinator
 tongue * RSTLD = (nectar spur length - pollinator tongue length )/nectar
 spur length * RTLD: relative total length difference between flower and
 pollinator * RTLD = (total flower length - total pollinator length )/total
 flower length **Appendix S2 (R code and raw data).xls, sheet = “13 visit
 frequency”** * treatment: warming treatment ambient = ambient condition
 warmed = warmed condition * robber: focal flowers are sometimes?visited by
 nectar robbers. NR indicates non-robbing nectar group, in which the nectar
 spurs of focal flowers were bagged by nylon mesh nets to avoid the
 visitation by nectar robbers. R indicates robbing nectar group, in which
 the nectar spurs of focal flowers were exposed to nectar robbers. * group:
 experimental groups of the overall study * observation_date: the date that
 pollinator visiting behavior is observed * initial_date: January 1, 2017,
 was used as the initial date of the study * dateID: observation date ID
 　　　*dateID = observation_date - initial_date * Time_period: time of day
 when pollinator behavior is observed. * timeID: identity of time period,
 8:30-9:00, 9:30-10:00, 10:30-11:00, 14:30-15:00, 15:30-16:00,16:30-17:00
 are labeled as time periods 1 to 6, respectively. * flowerID: identity of
 focal flower * visit30min: the number of times of the focal flower which
 is visited by pollinators every 30 minutes (no. flower-1. 30 min-1).
 **Appendix S2 (R code and raw data).xls, sheet = “14 visit duration
 time”** * treatment: warming treatment ambient = ambient condition warmed
 = warmed condition * robber: focal flowers are sometimes?visited by nectar
 robbers. NR indicates non-robbing nectar group, in which the nectar spurs
 of focal flowers were bagged by nylon mesh nets to avoid the visitation by
 nectar robbers. R indicates robbing nectar group, in which the nectar
 spurs of focal flowers were exposed to nectar robbers. * group:
 experimental groups of the overall study * observation_date: the date that
 pollinator visiting behavior is observed * initial_date: January 1, 2017,
 was used as the initial date of the study * dateID: observation date ID
 　　　*dateID = observation_date - initial_date * time_period: time of day
 when pollinator behavior is observed. * timeID: identity of time period,
 9:00-9:20, 10:00-10:20, 11:00-11:20, 15:00-15:20,16:00-16:20,17:00-17:20
 are labeled as timeID 1 to 6, respectively. * flowerID: identity of focal
 flower * visit_duration_time: the visit duration time of pollinator per
 visit (s) 　　　 **Appendix S2 (R code and raw data).xls, sheet = “15 pollen
 deposition”** * year: year of data measurement 　　　* Y2017* = 2017 　　　*
 Y2018* = 2018 * treatment: warming treatment 　　　*ambient * = ambient
 condition 　　　*warmed * = warmed condition * group: experimental groups of
 the overall study * plotID: identity of experimental plot * plantID:
 identity of experimental plant individual * pollen_deposition: the number
 of pollen grains deposited on the stigma **Appendix S2 (R code and raw
 data).xls, sheet = “16 pollen deposition under spur”** * year: year of
 data measurement 　　　* Y2018* = 2018, the treatment of nectar spur length
 was conducted only in 2018 * treatment: warming treatment 　　　*ambient * =
 ambient condition 　　　*warmed * = warmed condition * spur: the treatment of
 nectar spur length 　　　CK = natural spur treatment as the control 　　　SS =
 spur-shortened treatment * group: experimental groups of the overall study
 * plotID: identity of experimental plot * plantID: identity of
 experimental plant individual * observation_date: the date that pollen
 deposition is observed * initial date: January 1, 2018, was used as the
 initial date of the experiment of spur length treatment * dateID:
 observation date ID 　　　dateID = observation_date - initial date *
 pollen_deposition: the number of pollen grains deposited on the stigma
 **Appendix S2 (R code and raw data).xls, sheet = “17 seed number and
 seedset”** * year: year of data measurement 　　　* Y2017* = 2017 　　　* Y2018*
 = 2018 * treatment: warming treatment 　　　*ambient * = ambient condition
 　　　*warmed * = warmed condition * group: experimental groups of the
 overall study * plotID: identity of experimental plot * plantID: identity
 of experimental plant individual * seed_number: average seed number per
 fruit * ovule_number: average ovule number per flower * seedset: average
 seed set per fruit seedset = seed number per fruit/ovule number per flower
 * sn: average seed number per fruit is rounded to the nearest integer
 **Appendix S2 (R code and raw data).xls, sheet = “18 seed number and
 seedset”** * treatment: warming treatment 　　　*ambient * = ambient
 condition 　　　*warmed * = warmed condition * spur: the treatment of nectar
 spur length 　　　CK = natural spur treatment as the control 　　　SS =
 spur-shortened treatment * group: experimental groups of the overall study
 * plotID: identity of experimental plot * plantID: identity of
 experimental plant individual * collected date: the date of fruit
 collected * seed_number: seed number per fruit * seedset: seed set per
 fruit **Appendix S2 (R code and raw data).xls, sheet = “19 air
 temperature”** * year: year of data measurement 　　　* Y2017* = 2017 　　　*
 Y2018* = 2018 * treatment: warming treatment 　　　*ambient * = ambient
 condition 　　　*warmed * = warmed condition * plotID: identity of
 experimental plot * air_temperature_during_day: average air temperature
 during the day (7:00-19:00) per experimental plot (℃) *
 air_temperature_during_night: average air temperature during the night
 (19:00-7:00) per experimental plot (℃) * air_temperature: average air
 temperature of the whole day per experimental plot (℃) **Appendix S2 (R
 code and raw data).xls, sheet = “20 soil temperature”** * year: year of
 data measurement 　　　* Y2017* = 2017 　　　* Y2018* = 2018 * treatment:
 warming treatment 　　　*ambient * = ambient condition 　　　*warmed * = warmed
 condition * plotID: identity of experimental plot * soil_temperature:
 average soil temperature of the whole day per experimental plot (℃) *
 soil_temperature_during_night: average soil temperature during the night
 (19:00-7:00) per experimental plot (℃) * soil temperature_during_day:
 average soil temperature during the day (7:00-19:00) per experimental plot
 (℃) **Appendix S2 (R code and raw data).xls, sheet = “21-2017 paired air
 temperature”** * treatment: warming treatment 　　　*ambient * = ambient
 condition 　　　*warmed * = warmed condition * DateTime: the date and time of
 air temperature readings from thermohygrograph * Date: the date of air
 temperature readings from thermohygrograph * initial_date: January 1,
 2017, was used as the initial date in 2017 * dateID: observation date ID
 　　　*dateID = Date - initial_date * time_period : the day or night 　　　day=
 07:00-19:00 　　　night=19:00-07:00 * air_temperature: average air
 temperature per warming treatment (℃) **Appendix S2 (R code and raw
 data).xls, sheet = “22-2018 paired air temperature” paired air temperature
 in 2018.xls_Data** * treatment: warming treatment 　　　*ambient * = ambient
 condition 　　　*warmed * = warmed condition * time_period : the day or night
 　　　day= 07:00-19:00 　　　night=19:00-07:00 * Date/Time: the date and time of
 air temperature readings from thermohygrograph * initial_date: January 1,
 2018, was used as the initial date in 2018 * dateID: observation date ID
 　　　*dateID = Date/Time - initial_date * air_temperature: average air
 temperature per warming treatment (℃) **Appendix S2 (R code and raw
 data).xls, sheet = “23 flower number”** * year: year of data measurement
 　　　* Y2017* = 2017 　　　* Y2018* = 2018 * treatment: warming treatment
 　　　ambient = ambient condition 　　　warmed = warmed condition * group:
 experimental groups of the overall study * plotID: identity of
 experimental plot * plantID: identity of experimental plant individual *
 Flower_No: flower number per plant **Appendix S2 (R code and raw
 data).xls, sheet = “24 nectrar_volume”** * treatment: warming treatment
 　　　ambient = ambient condition 　　　warmed = warmed condition * plotID:
 identity of experimental plot * plantID: identity of experimental plant
 individual * nectrar_volume: nectar volume per flower (μL) **Appendix S2
 (R code and raw data).xls, sheet = “25 nectar sugar concentration”** *
 treatment: warming treatment 　　　ambient = ambient condition 　　　warmed =
 warmed condition * plotID: identity of experimental plot * plantID:
 identity of experimental plant individual * nectarcon: nectar sugar
 concentration per sample (%) **Appendix S2 (R code and raw data).xls,
 sheet = “26 pollen number per flower”** * year: year of data measurement
 　　　* Y2017* = 2017 　　　* Y2018* = 2018 * treatment: warming treatment
 　　　ambient = ambient condition 　　　warmed = warmed condition * group:
 experimental groups of the overall study * plotID: identity of
 experimental plot * plantID: identity of experimental plant individual *
 pollen_number: pollen number per mature flower bud **Appendix S2 (R code
 and raw data).xls, sheet = “27 ovule_number per flower”** * year: year of
 data measurement 　　　* Y2017* = 2017 　　　* Y2018* = 2018 * treatment:
 warming treatment 　　　ambient = ambient condition 　　　warmed = warmed
 condition * group: experimental groups of the overall study * plotID:
 identity of experimental plot * plantID: identity of experimental plant
 individual * ovule_number: ovule number per flower **Appendix S2 (R code
 and raw data).xls, sheet = “Fig.5 flower traits and pollen”** * Year: year
 of data measurement 　　　* Y2017* = 2017 　　　* Y2018* = 2018 * Treatment:
 warming treatment 　　　ambient = ambient condition 　　　warmed = warmed
 condition * Corolla tube length(mm): corolla tube length(mm) * Nectar spur
 length(mm): nectar spur length(mm) * pollen deposition (No.): the number
 of pollen deposited on the stigma(No.) **Appendix S2 (R code and raw
 data).xls, sheet = “Fig.5 flower traits and seed”** * Year: year of data
 measurement * Y2017* = 2017 * Y2018* = 2018 * Treatment: warming treatment
 　　　ambient = ambient condition 　　　warmed = warmed condition * Corolla tube
 length(mm): corolla tube length(mm) * Nectar spur length(mm): nectar spur
 length(mm) * Seed number per fruit: seed number per fruit * Seed set per
 fruit: seed set per fruit