Measuring Changes in Phenology of Oklahoma Asteraceae Using Herbarium Specimens

Analyzing shifts in plant flowering times (flowering phenology) in response to changing climate is crucial to understanding the impacts of climate change on plants. Herbaria contain the physical record of reproductive events from past seasons, making them an important source of long-term data for studies of phenology. We measured changes in flowering phenology of four Oklahoma native plants in the Asteraceae (sunflower) family: Grindelia ciliata, Liatris punctata, Ratibida columnifera, and Vernonia baldwinii. These species were selected to represent the morphological and phylogenetic diversity of the Asteraceae in Oklahoma and were represented in the Robert Bebb Herbarium (OKL) with over 100 specimens each. We created novel protocols for scoring the flowering phenology of these species into numeric categories, called phenophases. We looked for correlations between the collection date and both the year of collection and the temperature in that year. There was a significant relationship between collection date and year only in peak flowering specimens of G. ciliata. There was a significant relationship between statewide annual temperature and collection date only in peak flowering specimens of V. baldwinii. There was a significant relationship between the annual temperature of the climate division of the state where the plants were collected and collection date for peak flowering in G. ciliata, R. columnifera, and V. baldwinii, for first flowers in V. baldwinii, and for last flowers in L. punctata. More precise temperature data thus lead to an improvement of the model, but in all cases temperature or year explained relatively little of the total variation in flowering time.The authors thank the MPBIO department at the University of Oklahoma for supporting John Unterschuetz with the George L. and Cleo Cross Endowed Scholarship as an undergraduate student researcher during this investigation.Ye

Measuring changes in phenology of Oklahoma Asteraceae using herbarium specimens

One Read Me file explaining the formatting of the included files: read_me.txt Four data files, one each for the individual species: Grindelia_ciliata_data.txt Liatris_punctata_data.txt Ratibida_columnifera_data.txt Vernonia_baldwinii_data.txt Four R scripts: Asteraceae_phenology_seasons.R: The script with the code for all analyses, with comments explaining the different parts. This script makes the plots for the intial data exploration, but they are not as polished as the plots in the paper itself (except for the boxplots, which are the same). Asteraceae_phenology_year_plots.R: The script that makes the plots for DOY versus year, with the x-axis modified for the different species that are shown in figures 5, 7, 8, and 10. Asteraceae_phenology_seasons_Grindelia_ciliata_plots.R: The script that makes the plots for the significant temperature by DOY comparisons for Peak flowering for Grindelia ciliata, shown in figure 6. Asteraceae_phenology_seasons_Ratibida_columnifera_plots.R: The script that makes the plots for the significant temperature by DOY comparisons for Peak flowering for Ratibida columnifera, shown in figure 9. Four results files, one each for the individual species: Grindelia_ciliata_results.txt Liatris_punctata_results.txt Ratibida_columnifera_results.txt Vernonia_baldwinii_results.txtAnalyzing shifts in plant flowering times (flowering phenology) in response to changing climate is crucial to understanding the impacts of climate change on plants. Herbaria contain the physical record of reproductive events from past seasons, making them an important source of long-term data for studies of phenology. We measured changes in flowering phenology of four Oklahoma native plants in the Asteraceae (sunflower) family: Grindelia ciliata, Liatris punctata, Ratibida columnifera, and Vernonia baldwinii. These species were selected to represent the morphological and phylogenetic diversity of the Asteraceae in Oklahoma and were represented in the Robert Bebb Herbarium (OKL) with over 100 specimens each. We created novel protocols for scoring the flowering phenology of these species into numeric categories, called phenophases. We looked for correlations between the collection date and both the year of collection and the temperature in that year. There was a significant relationship between collection date and year only in peak flowering specimens of G. ciliata. There was a significant relationship between statewide annual temperature and collection date only in peak flowering specimens of V. baldwinii. There was a significant relationship between the annual temperature of the climate division of the state where the plants were collected and collection date for peak flowering in G. ciliata, R. columnifera, and V. baldwinii, for first flowers in V. baldwinii, and for last flowers in L. punctata. More precise temperature data thus lead to an improvement of the model, but in all cases temperature or year explained relatively little of the total variation in flowering time.This is the dataset for "Measuring changes in phenology of Oklahoma Asteraceae using herbarium specimens," forthcoming in Oklahoma Native Plant Record 21. doi: 10.22488/okstate.21.100002MPBIO department at the University of OklahomaYesThe article the dataset is from was reviewed by two anonymous reviewres