DOI: 10.5061/dryad.15dv41p88
title: Data from: The duration of high spring light for understory plants: contrasting responses to spatial and temporal temperature variation

description: This dataset contains leaf phenology observations of canopy and two
 understory spring herbs (Trillium erectum and Erythronium americanum)
 derived from automated camera imagery collected between 2017 and 2023 from
 10 sites in Mont St. Joseph, Québec, Canada. Additionally, it
 contains mean monthly temperatures estimated for each site-year
 combination using data from in situ climate stations at the base
 of the mountain. The data were used to investigate how spatial and
 inter-annual climate variation affect the duration of the high light
 period for spring understory herbaceous plants. For both
 understory species and the tree canopy, leaf phenology was sensitive to
 spatial and temporal variation in spring temperature; earlier leaf
 expansion occurred at warmer sites and in warmer years. Temporal variation
 in spring temperature had a stronger effect on understory than canopy
 phenology, such that warmer temperatures were associated with an increase
 in the duration of high spring light, especially at high elevation. Across
 the spatial (elevational) temperature gradient, temperature sensitivity of
 one understory species (T. erectum) was weaker than for the canopy. Thus,
 the combination of warmer conditions and different canopy tree species at
 low elevation was associated with a shorter duration of high spring light.
description: # The duration of high spring light for understory plants: contrasting
 responses to spatial and temporal temperature variation Dataset DOI:
 [10.5061/dryad.15dv41p88](10.5061/dryad.15dv41p88) ## Description of the
 data and file structure This dataset contains leaf phenological
 observations for canopy and two understory spring herbs (*Trillium
 erectum* and *Erythronium* *americanum*) derived from automated camera
 imagery collected between 2017 and 2023 from 10 sites in Mont St. Joseph,
 Québec, Canada. Additionally, it contains mean monthly
 temperatures estimated for each site-year combination using data from *in
 situ* climate stations at the base of the mountain. This data supports the
 manuscript titled "The duration of high light for understory spring
 plants: contrasting responses to spatial and temporal temperature
 variation" accepted for publication in the Journal of Ecology. ###
 Files and variables #### File: Canopy_DOY.csv ##### Variables * Year: The
 calendar year during which the observation was recorded. * Site: A coded
 identifier for the location of the observation. For example; A01G - the
 first character indicates the transect ('A' -transect A;
 'B'-transect B); The numeric portion indicates the elevation
 level along the mountain (1 and 3 - low elevation; 5 - mid elevation; 7
 and 8 - high elevation); The last character indicates the camera type: G -
 ground camera for understory, C - canopy camera * Transect: Indicates the
 transect line (either `'A'` or `'B'`) along which
 observations were made. * Plot: A numeric identifier representing the
 elevation level at which the plot is located, progressing from the base to
 the top of the mountain. (1 and 3 - low elevation; 5 - mid elevation; 7
 and 8 - high elevation) * DOY_canopy greenup: the day of year at which
 canopy greenness had reached 75% #### File: Erythronium_DOY.csv #####
 Variables * Site: A coded identifier for the location of the observation.
 For example; A01G - the first character indicates the transect
 ('A' -transect A; 'B'-transect B); The numeric portion
 indicates the elevation level along the mountain (1 and 3 - low elevation;
 5 - mid elevation; 7 and 8 - high elevation); The last character indicates
 the camera type: G - ground camera for understory, C - canopy camera *
 Transect: Indicates the transect line (either `'A'` or
 `'B'`) along which observations were made. * Plot: A numeric
 identifier representing the elevation level at which the plot is located,
 progressing from the base to the top of the mountain. (1 and 3 - low
 elevation; 5 - mid elevation; 7 and 8 - high elevation) * Year: The
 calendar year during which the observation was recorded. * Plant: A
 numeric code indicating individual plants selected for measurement within
 the image.\ For each site–year combination, selected plants are labeled
 `'1'`, `'2'`, `'3'`, etc., depending on how
 many were chosen. These numbers refer only to the individuals measured in
 the image and do not necessarily correspond across years. * DOY: the day
 of year at which leaf area reached 50%. #### File: Trillium_DOY.csv #####
 Variables * Year: The calendar year during which the observation was
 recorded. * Site: A coded identifier for the location of the observation.
 For example; A01G - the first character indicates the transect
 ('A' -transect A; 'B'-transect B); The numeric portion
 indicates the elevation level along the mountain (1 and 3 - low elevation;
 5 - mid elevation; 7 and 8 - high elevation); The last character indicates
 the camera type: G - ground camera for understory, C - canopy camera *
 Transect: Indicates the transect line (either `'A'` or
 `'B'`) along which observations were made. * Plot: A numeric
 identifier representing the elevation level at which the plot is located,
 progressing from the base to the top of the mountain. (1 and 3 - low
 elevation; 5 - mid elevation; 7 and 8 - high elevation) * Plant: A numeric
 code indicating individual plants selected for measurement within the
 image.\ For each site–year combination, selected plants are labeled
 `'1'`, `'2'`, `'3'`, etc., depending on how
 many were chosen. These numbers refer only to the individuals measured in
 the image and do not necessarily correspond across years. * DOY: the day
 of year at which leaf area reached 50%. #### File: climate_data.csv #####
 Variables * CombStationT: The name of the climate station from which
 temperature data were obtained. * CombTAvg: The average daily temperature
 in degrees Celsius (°C) * DOY: Day of Year ## Code/software Associated
 code is publicly available on
 GitHub: [https://github.com/HasankiTG/Phenology_MSJ](https://github.com/HasankiTG/Phenology_MSJ)