Woody phenology and weather data related to Trelease Woods, Urbana, IL, USA 1993-2023
Data files
Dec 20, 2022 version files 1.44 MB
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Augspurger1889-1912MikesellPhenologyDatesComparisons.csv
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Augspurger1949-1964SmithPhenologyDates.csv
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Augspurger1992-2022WeatherTemperature_Precipitation.csv
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Augspurger1993-2022WoodyPhenologyAutumnDates.csv
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Augspurger1993-2022WoodyPhenologySpringDates.csv
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README.md
Jun 07, 2024 version files 1.48 MB
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Augspurger1889-1912MikesellPhenologyDatesComparisons.csv
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Augspurger1949-1964SmithPhenologyDates.csv
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Augspurger1992-2023WeatherTemperature_Precipitation.csv
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Augspurger1993-2023WoodyPhenologyAutumnDates.csv
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Augspurger1993-2023WoodyPhenologySpringDates.csv
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README.md
Abstract
In this study, weekly phenological observations throughout spring and autumn were made annually over 30 years for 22 woody plant taxa of multiple growth forms in Trelease Woods, a mature old-growth deciduous forest remnant near Urbana, Illinois, USA. The growth forms included canopy trees, saplings, sub canopy treelets, shrubs, and vines. Data collection began in the spring of 1993 and continued through the end of autumn 2023. The phenological data set is paired with weather data collected from a nearby weather station in Champaign, Illinois. These two data sets were used to determine if dates of phenological events and durations of phenophases were changing over time, possibly in connection with changing weather related to global climate change. To supplement these phenological data, two older phenological data sets are made available here. First, Charles Smith, Woods Custodian at the University of Illinois, made comparable observations from 1949 to 1964 of seven of the same phenological events on six of the same woody species. Data were collected from Trelease Woods and Brownfield Woods. The latter is an old-growth forest separated by 2 km from Trelease Woods, and the two sites were connected in a larger forest before the mid-19th century. Second, Thomas Mikesell, a farmer from Ohio, USA, made comparable observations from 1883 to 1912 of six of the same phenological events on 11 of the same woody species. Mikesell’s data were collected in a deciduous forest near Wauseon, Ohio, USA. Because of the distance between the Mikesell study site and the site of the current study in Urbana, Illinois, to compare the two data sets, adjustments were made to the event dates in the Mikesell data set based on bioclimatic laws. Comparison of the current data to those collected by Charles Smith and Thomas Mikesell provides evidence as to whether the trends in phenological event dates observed from 1993 to 2021 held consistent when investigated at longer time scales.
README: Woody Phenology and Weather Data related to Trelease Woods, Urbana, IL, USA 1993-2023
Authors
Carol K. Augspurger, Department of Plant Biology, University of Illinois Urbana-Champaign, carolaug@illinois.edu
David N. Zaya, Illinois Natural History Survey, University of Illinois Urbana-Champaign, dzaya1@illinois.edu
References
Augspurger, C. K. and D. N. Zaya. 2020a. Concordance of long-term shifts with climate warming varies among phenological events and herbaceous species. Dryad. Dataset. https://doi.org/10.5061/dryad.mcvdncjxh
Augspurger, C. K. and D. N. Zaya. 2020b. Concordance of long-term shifts with climate warming varies among phenological events and herbaceous species. Ecological Monographs 90: e01421.
Hopkins, A. D. 1920a. The Bioclimatic Law. Journal of the Washington Academy of Sciences 10:34–40.
Hopkins, A. D. 1920b. The Bioclimatic Law. Monthly Weather Review 10:355–355.
Hopkins, A. D. 1938. Bioclimatics: A science of life and climate relations. United States Department of Agriculture, Miscellaneous Publication No. 280. United States Department of Agriculture, Washington, D.C., USA.
Richardson, A. D., K. Hufkens, X. Li, and T. R. Ault. 2019. Testing Hopkins’ Bioclimatic Law with PhenoCam data. Applications in Plant Sciences 7(3): e1228.
Smith, J.W. 1915. Phenological dates and meteorological data recorded by Thomas Mikesell at Wauseon, Fulton County, Ohio. Monthly Weather Review Supplement 2:21-93.
Data Set 1
Phenological Observations of Woody Species: Spring 1993-2023 Trelease Woods
Carol K. Augspurger and David N. Zaya
File Name: Augspurger1993-2023WoodyPhenologySpringDates.csv
Description of the data and file structure:
Each unique event in a specific year (e.g., 1993-BS1) is labeled in the top row of its column of data. The unique number assigned to each individual is on one row of this column: 'Ind. No.'. A value in a cell is the day of the year in one year of one individual exhibiting one event (see Appendix S2: Text S1 and Appendix S1: Table S1 for the name and description of each event). From these data, durations (number of days) of phenophases for each individual were calculated. The phenophase durations calculated were Bud Swell, Bud Burst/Leafing Out, Leaf Expansion, Flowering, and overall Spring Phenology (see Appendix S1: Table S5). NA indicates empty cells.
Descriptive statistics summarizing each event for all individuals for a given species for each year are provided, as well as the total number of individuals. Also included are species nomenclature (following USDA, NRCS 2024) and growth form.
Literature Cited:
USDA, NRCS. 2024. The PLANTS Database (http://plants.usda.gov, 22 January 2024). National Plant Data Team, Greensboro, NC 27401-4901 USA.
Relationship between data files:
'Data Set 2' has the same file structure and information as this data set ('Data Set 1'), except the observations were made annually from July - December to obtain autumn phenological data on the same individuals. Both 'Data Set 1' and 'Data Set 2' are needed to calculate the duration of the growing season. These two data sets were used in combination with 'Data Set 5' to find weather predictors for specific event dates.
Data Set 2
Phenological Observations of Woody Species: Autumn 1993-2023 Trelease Woods
Carol K. Augspurger and David N. Zaya
File Name: Augspurger1993-2023WoodyPhenologyAutumnDates.csv
Description of the data and file structure:
Each unique event in a specific year (e.g.,1993-LC1) is labeled in the top row of its column of data. The unique number assigned to each individual is on one row of this column: 'Ind. No.'. A value in a cell is the day of the year in one year of one individual exhibiting one event (see Appendix S2: Text S1 and Appendix S1: Table S1 for the name and description of each event). From these data, durations (number of days) of phenophases for each individual were calculated. The phenophase durations calculated were Leaf Coloration, Leaf Drop, and overall Autumn Phenology (see Appendix S1: Table S2).
Descriptive statistics summarizing each event for all individuals for a given species for each year are provided, as well as the total number of individuals. Also included are species nomenclature (following USDA, NRCS 2024) and growth form. NA indicates empty cells.
Literature Cited:
USDA, NRCS. 2024. The PLANTS Database (http://plants.usda.gov, 22 January 2024). National Plant Data Team, Greensboro, NC 27401-4901 USA.
Relationship between data files:
'Data Set 1' file has the same structure and information as this data set ('Data Set 2'), except the observations were made annually from February - June to obtain spring phenological data on the same individuals. Both 'Data Set 1' and 'Data Set 2' are needed to calculate the duration of the growing season. These two data sets were used in combination with ‘Data Set 5’ to find weather predictors for specific event dates.
Data Set 3
Smith Phenology in Trelease Woods and Brownfield Woods: 1949-1964
Carol K. Augspurger and David N. Zaya
File Name: 'Augspurger1949-1964SmithPhenologyDates.csv'
Description of the data and file structure:
Field observations of phenology were made for six woody species in Trelease Woods (TW), nearby Brownfield Woods (BW), or a non-specified location (N-S) near Urbana in Champaign Co., Illinois, USA from 1949-1964 by Charles Smith, Woods Custodian at the University of Illinois. The seven events observed are: Begin Budburst (BB1), End Leaf Expansion (LE3), Begin Leaf Coloration (LC1), Begin Leaf Drop (LD1), End Leaf Drop (LD3), Begin Flowering (FL1), and End Flowering (FL2). Each unique event (e.g., LC1) is labeled in the top row of its column of data. A cell number is the day of year of one event in one year. Descriptions of events used by Smith and Augspurger differ slightly and are noted below. Also included are species nomenclature (following USDA, NRCS 2024) and growth form.
Smith did not describe whether the number represents the first (or last) individual of a species or the general perceived ‘average’ of the species. The frequency of observation and the number of individuals on which a given datum is based are unknown. For species that can reach the canopy, it is assumed the data represent canopy-sized individuals and not saplings.
Differences between means of 1946-1964 vs. 1993-2021 were tested for each event in each species by t-tests. NA indicates empty cells.
Comparison of the description of events by the two data collectors.
- EVENT Augspurger's description of the event Smith's description of the event
- BB1 First leaf tips visible beyond bud scales Bursting of leaf buds
- LE3 Leaves fully expanded Leaves fully grown
- LC1 Begin leaf coloration Leaves begin to color
- LD1 Begin leaf drop Leaves begin to fall/wither
- LD3 End leaf drop Leaves all fallen or withered
- FL1 First flowers Beginning of flowers
- FL2 No flowers End of flowering (seven days added to census date to add one week to date the last flower was seen)
Literature Cited
USDA, NRCS. 2024. The PLANTS Database (http://plants.usda.gov, 22 January 2024). National Plant Data Team, Greensboro, NC 27401-4901 USA.
Relationship between data files:
Data from the files for 'Data Set 1' and 'Data Set 2' were used to compare with 'Data Set 3'.
Unpublished data from Charles Smith (1949-1964) were made available from the files of the Natural Areas Manager, University of Illinois, Urbana, IL, USA.
Data Set 4
Mikesell Phenology in Wauseon, Ohio, USA: 1883-1912
Carol K. Augspurger and David N. Zaya
File Name: 'Augspurger1889-1912MikesellPhenologyDatesComparisons.csv'
Description of the data and file structure:
Thomas Mikesell's original phenological data for field observations of 11 woody species for 1883-1912 were extracted from Smith (1915) and compared to data for the same species from the current study (1993-2021). Mikesell’s data are contained in the third to twelfth columns, and data from the current study are contained in the thirteenth to seventeenth columns. Each row represents one year of data (given in the third and thirteenth columns).
Original values for phenological events of Mikesell's years represent the mean date of the year for each species in each year for Begin Leaf Expansion (LE1 Mikesell, fourth column), End Leaf Expansion (LE3 Mikesell, seventh column), and End Leaf Coloration (LC3 Mikesell, tenth column). Also shown are the adjusted dates of Mikesell’s data based on Hopkin’s Bioclimatic Law (Hopkins 1920a, b, 1938) and Richardson et al.’s (2019) revisions of the law, to make the values from Ohio comparable to the current study’s data collected in Illinois. The adjustments based on Hopkins Law were applied only to spring events (LE1 in the fifth column and LE3 in the eighth column), while the Richardson et al. (2019) adjustments were applied to all events (LE1 in sixth column, LE3 in ninth column, LC3 in eleventh column) and growing season duration (twelfth column). Column headings provide the event and number of adjustment days that were subtracted (for LE1 Mikesell and LE3 Mikesell) or added (for LC3 Mikesell). Adjusted Growing Season (Growing Season (da) Mikesell, twelfth column) was calculated as (LC3 - LE1), which are the values in the eleventh and sixth column, respectively.
See Appendix S1: Table 7a for a comparison of elevation and coordinates of locations for Urbana, Illinois, USA vs. Wauseon Ohio, USA. See Appendix S1: Table 7b for adjustments made to Mikesell data based on geographic differences between locations.
Data from the current study are the mean date of the year for each species in each year for Begin Leaf Expansion (LE1, fourteenth column), End Leaf Expansion (LE3, fifteenth column), End Leaf Coloration (LC3, sixteenth column), and Growing season (seventeenth column, calculated as (LC3-LE1).
Mean and sample sizes summarizing each event for all years for each species are provided. Also included are species nomenclature (following USDA, NRCS 2022) and growth form. See Appendix S2: Text S1 and Appendix S1: Table S1 for name and description of each event. NA indicates empty cells.
Literature Cited:
Hopkins, A. D. 1920a. The Bioclimatic Law. Journal of the Washington Academy of Sciences 10:34–40.
Hopkins, A. D. 1920b. The Bioclimatic Law. Monthly Weather Review 10:355–355.
Hopkins, A. D. 1938. Bioclimatics: A science of life and climate relations. United States Department of Agriculture, Miscellaneous Publication No. 280. United States Department of Agriculture, Washington, D.C., USA.
Richardson, A. D., K. Hufkens, X. Li, and T. R. Ault. 2019. Testing Hopkins’ Bioclimatic Law with PhenoCam data. Applications in Plant Sciences 7(3): e1228.
Smith, J.W. 1915. Phenological dates and meteorological data recorded by Thomas Mikesell at Wauseon, Fulton County, Ohio. Monthly Weather Review Supplement 2:21-93.
USDA, NRCS. 2024. The PLANTS Database (http://plants.usda.gov, 22 January 2024). National Plant Data Team, Greensboro, NC 27401-4901 USA.
Relationship between data files:\
Data from 'Data Set 1' and 'Data Set 2' were used to compare with 'Data Set 4'. Relevant data from those two files are included in 'Data Set 4'.
The Mikesell data presented here are available in the following publication:
Smith, J.W. 1915. Phenological dates and meteorological data recorded by Thomas Mikesell at Wauseon, Fulton County, Ohio. Monthly Weather Review Supplement 2:21-93.
Data Set 5
Temperature and precipitation data from Champaign, Illinois, USA, 1992-2023
Carol K. Augspurger and David N. Zaya
File Name: 'Augspurger1992-2023WeatherTemperaturePrecipitation.csv'
Description of the data and file structure:
Daily weather data from Champaign, Illinois, USA are provided here. These weather data were used to predict dates of phenological events in 22 woody taxa in Trelease Woods near Urbana, Illinois. This weather station is approximately 8 km southwest of Trelease Woods. The weather station is part of the National Weather Service Cooperative Observer Program (US-COOP, https://www.weather.gov/coop/). Data were obtained by the authors through the Midwestern Regional Climate Center (http://mrcc.purdue.edu/) using the cli-MATE Online Data Portal. The weather station's name is ‘CHAMPAIGN 3S’, and the NWS Coop Number is 118740.
The original data set included daily precipitation measured in inches, maximum daily temperature measured in degrees Fahrenheit, and minimum daily temperature measured in degrees Fahrenheit. We used these columns to calculate precipitation and temperature in metric units (cm, degrees Celsius).
The file format is comma-separated values (CSV), and column definitions follow.
- year – the year of the daily observation.
- month – the month (as a number) of the daily observation.
- day – the day of the month of the daily observation.
- precip.inch – the amount of daily precipitation, measured in inches.
- max.t.f – the daily maximum temperature, measured in degrees Fahrenheit.
- min.t.f – the daily minimum temperature, measured in degrees Fahrenheit.
- precip.cm – the amount of daily precipitation, measured in centimeters. This was calculated from ‘precip.inch’ by dividing by 2.54.
- max.t.c – the daily maximum temperature, measured in degrees Celsius. This was calculated from ‘max.t.f’ by subtracting 32, and then dividing the result by 1.8.
- min.t.c – the daily minimum temperature, measured in degrees Celsius. This was calculated from ‘min.t.f’ by subtracting 32, and then dividing the result by 1.8.
- DayOfYear – The day of the year for the daily observation. This was determined by setting January 1st as day 1 and taking into consideration leap day.
Relationship between data files: Data from 'Data Set 5', through 2021, were analyzed, along with event dates from 'Data Set 1' and 'Data Set 2' (both through 2021) to determine which weather variables were the most predictive of event dates.
Links to other publicly accessible locations of the data:
The data can be obtained from the Midwest Regional Climate Center using the cli-MATE Online Data Portal.
Other Data Sources
The data on woody plant phenology from the current study were collected from the same study site as the herbaceous plant phenology data described by and published in Augspurger and Zaya (2020a, b).
Thomas Mikesell’s data were obtained from Smith (1915). Bioclimatic laws used for event date adjustments to the Mikesell data were derived from Hopkins (1920a), Hopkins (1920b), Hopkins (1938), and Richardson et al. (2019).
Weather data for Champaign, Illinois, USA were collected from a station that is part of the National Weather Service Cooperative Observer Program (US-COOP, https://www.weather.gov/coop/), and data were obtained through the Midwestern Regional Climate Center (http://mrcc.purdue.edu/).
Methods
Field observations of spring phenology of mature individuals of 22 woody taxa (21 species and 1 genus which may have represented multiple species) were made in Trelease Woods, Champaign Co., Illinois, USA from 1993-2023. Also, observations were made of saplings of three of the canopy tree species. The study site is the north half of a 24.5 ha fragment of temperate mature deciduous forest, dominated by sugar maple near Urbana, Illinois, USA. Elevation varies by less than 5 m across the study area.
The phenological status of each individual was recorded by the same observer (CKA) weekly from February to June of each year. Measurements were recorded and later analyzed, at the individual plant level. Within each of three vegetative phases, Bud Swell (BS), Bud Burst (BB), and Leaf Expansion (LE), three dates were noted (e.g., BS1 (1/3 of units exhibit event), BS2 (2/3 completed event), BS3 (all completed event), each date being one event; see Appendix S1: Table S1 for event summaries); the exception was flowering for which only beginning (FL1) and ending of flowering (FL2) were recorded. Species classified as Late Flowering (see Appendix S1: Table S6) were not observed in all years. Middle events (e.g., BS2) were not used in any analyses but were critical in determining, by simple linear interpolation, estimated dates of non-observed events that passed in the one week between observations.
From these data, durations (number of days) of phenophases for each individual were calculated: Bud Swell, Bud Burst, Leaf Expansion, Flowering, and Overall Spring Phenology (See Appendix S1: Table S5).
Species were analyzed together in seasonal groups (Appendix S1: Table S6). For most events, species were grouped as early or late. Aesculus glabra (canopy trees and saplings) were usually analyzed as a separate group(s) because of their very early phenology.
We used linear mixed-effects models to analyze data from 1993 to 2021 to test for phenological changes through time, and the weather variables that had the most predictive power of phenological events.