Data from: Combined heat and drought events reduce first-year survival of tree seedlings, especially at southern range margins
Data files
Jan 26, 2026 version files 174.13 KB
-
final_biomass_RS.csv
38.92 KB
-
final_height.csv
44.79 KB
-
final_survival.csv
45.55 KB
-
gmin_lma.csv
3.02 KB
-
mean_sm.csv
8.14 KB
-
min_sm.csv
13.03 KB
-
README.md
9.75 KB
-
tlp.csv
3.23 KB
-
water_potential.csv
7.70 KB
Abstract
These are the data associated with a project testing how experimental drought and heat treatments impact survival and growth of first-year tree seedlings common to the northeastern United States. The datasets include seedling-level metrics of survival and growth (height and total biomass), approximate substrate moisture throughout the experimental period, and data on traits including leaf mass per area, minimum epidermal conductance, turgor loss point, and root-to-shoot biomass ratio.
Dataset DOI: 10.5061/dryad.k3j9kd5ph
Description of the data and file structure
Project: Combined heat and drought events reduce first-year survival of tree seedlings, especially at southern range margins
Authors: Emily G. MacDonald, Melissa D. Cullina, Bryan J. Peterson, Jay W. Wason
Date compiled: December 2025
Data compiled by Emily MacDonald
Files and variables
Note: NA= Not applicable, or absent information
File: final_biomass_RS.csv
Description: These data contain the total biomass and root-to-shoot biomass ratio of a subset of seedlings from this experiment, sampled at the end of the growing season.
Variables
- ID: unique seedling identifier
- chamber: treatment chamber (representing on experimental unit and a single application of a heat and drought treatment). There are 27 total chambers, 3 per unique combination of heat and drought.
- species: abbreviation for species names, including the first two letters of genus and the first two letters of species. ABBA = Abies balsamea, ACRU = Acer rubrum, ACSA = Acer saccharum, FRNI = Fraxinus nigra, PIRU = Picea rubens, PIST = Pinus strobus, QURU = Quercus rubra, THOC = Thuja occidentalis
- treatment: combination of heat treatment (first letter) and drought treatment (second letter)
- drought: drought treatment. I = irrigated, R = repeated, E = extended
- heat: heat treatment. A = ambient temperature, M = moderate warming, E = extreme warming
- r.s: the root-to-shoot biomass ratio, where root = below-ground biomass and shoot = all above-ground biomass
- total: the total biomass (in g), including root, stem, and leaf biomass
- total.log: the log of the total column (used in total biomass models)
- r.s.log: the log of the r.s column (used in root-to-shoot models)
File: final_height.csv
Description: These data contain the height of all individuals used in height analyses at the start of treatments and at the end of the growing season.
Variables
- ID: unique seedling identifier
- chamber: treatment chamber (representing on experimental unit and a single application of a heat and drought treatment). There are 27 total chambers, 3 per unique combination of heat and drought.
- species: abbreviation for species names, including the first two letters of genus and the first two letters of species. ABBA = Abies balsamea, ACRU = Acer rubrum, ACSA = Acer saccharum, FRNI = Fraxinus nigra, PIRU = Picea rubens, PIST = Pinus strobus, QURU = Quercus rubra, THOC = Thuja occidentalis
- treatment: combination of heat treatment (first letter) and drought treatment (second letter)
- drought: drought treatment. I = irrigated, R = repeated, E = extended
- heat: heat treatment. A = ambient temperature, M = moderate warming, E = extreme warming
- SOT: height (in cm) at the start of treatments. Measurements were conducted June 26 2024 through July 3 2024.
- EOS: height (in cm) at the end of the growing season. Measurements were conducted September 18 2024 through September 20 2024.
- EOS.log: the log of the EOS column (used in height models)
File: final_survival.csv
Description: These data contain the final survival of all tree seedlings.
Variables
- ID: unique seedling identifier
- date: date of final survival data collection, format yyyy-mm-dd
- chamber: treatment chamber (representing on experimental unit and a single application of a heat and drought treatment). There are 27 total chambers, 3 per unique combination of heat and drought.
- species: abbreviation for species names, including the first two letters of genus and the first two letters of species. ABBA = Abies balsamea, ACRU = Acer rubrum, ACSA = Acer saccharum, FRNI = Fraxinus nigra, PIRU = Picea rubens, PIST = Pinus strobus, QURU = Quercus rubra, THOC = Thuja occidentalis
- treatment: combination of heat treatment (first letter) and drought treatment (second letter)
- drought: drought treatment. I = irrigated, R = repeated, E = extended
- heat: heat treatment. A = ambient temperature, M = moderate warming, E = extreme warming
- survival.binom: binomial survival data. 0 = dead, 1 = alive
- survival: descriptions of survival.binom
File: gmin_lma.csv
Description: These data contain the minimum epidermal conductance (gmin) and leaf-mass-per-area (LMA) for all sampled individuals on August 26 2024.
Variables
- ID: unique seedling identifier
- species: abbreviation for species names, including the first two letters of genus and the first two letters of species. ABBA = Abies balsamea, ACRU = Acer rubrum, ACSA = Acer saccharum, FRNI = Fraxinus nigra, PIRU = Picea rubens, PIST = Pinus strobus, QURU = Quercus rubra, THOC = Thuja occidentalis
- chamber: treatment chamber (representing on experimental unit and a single application of a heat and drought treatment). There are 27 total chambers, 3 per unique combination of heat and drought.
- treatment: combination of heat treatment (first letter) and drought treatment (second letter)
- drought: drought treatment. I = irrigated, R = repeated, E = extended
- heat: heat treatment. A = ambient temperature, M = moderate warming, E = extreme warming
- gmin: minimum epidermal conductance (mmol m -2 s -1)
- LMA.m2: leaf-mass-per-area (g m -2)
File: tlp.csv
Description: These data contain the turgor loss point (TLP) of all individuals sampled on August 24 2024.
Variables
- time: denotes whether the measurement was collected in the morning (AM) or evening (PM)
- ID: unique seedling identifier
- species: abbreviation for species names, including the first two letters of genus and the first two letters of species. ABBA = Abies balsamea, ACRU = Acer rubrum, ACSA = Acer saccharum, FRNI = Fraxinus nigra, PIRU = Picea rubens, PIST = Pinus strobus, QURU = Quercus rubra, THOC = Thuja occidentalis
- chamber: treatment chamber (representing on experimental unit and a single application of a heat and drought treatment). There are 27 total chambers, 3 per unique combination of heat and drought.
- treatment: combination of heat treatment (first letter) and drought treatment (second letter)
- drought: drought treatment. I = irrigated, R = repeated, E = extended
- heat: heat treatment. A = ambient temperature, M = moderate warming, E = extreme warming
- TLP: turgor loss point (MPa)
File: water_potential.csv
Description: These data contain the mid-day leaf water potential of all individuals sampled at multiple timepoints.
Variables
- date: date of data collection, format yyyy-mm-dd
- ID: unique seedling identifier
- species: abbreviation for species names, including the first two letters of genus and the first two letters of species. ABBA = Abies balsamea, ACRU = Acer rubrum, ACSA = Acer saccharum, FRNI = Fraxinus nigra, PIRU = Picea rubens, PIST = Pinus strobus, QURU = Quercus rubra, THOC = Thuja occidentalis
- chamber: treatment chamber (representing on experimental unit and a single application of a heat and drought treatment). There are 27 total chambers, 3 per unique combination of heat and drought.
- treatment: combination of heat treatment (first letter) and drought treatment (second letter)
- drought: drought treatment. I = irrigated, R = repeated, E = extended
- heat: heat treatment. A = ambient temperature, M = moderate warming, E = extreme warming
- WP.c: water potential (MPa)
File: mean_sm.csv
Description: These data contain the average approximate substrate moisture for each treatment combination each day that substrate moisture measurements took place and were used to create a Figure 2 of the manuscript.
Variables
- date: date of data collection, format yyyy-mm-dd
- treatment: combination of heat treatment (first letter) and drought treatment (second letter)
- drought: drought treatment. I = irrigated, R = repeated, E = extended
- heat: heat treatment. A = ambient temperature, M = moderate warming, E = extreme warming
- meanSM: the average approximate substrate moisture of all seedlings for which data was collected for a given treatment. This was first averaged at the chamber level (9 chambers per treatment) and then at the treatment level.
- seSM: one standard error from the mean, calculate when averaging from chamber to treatment
File: min_sm.csv
Description: These data contain the minimum approximate substrate moisture achieved by each containerized seedling throughout the drought treatment period and were used in models of substrate moisture.
Variables
- date: date of data collection, format yyyy-mm-dd
- ID: unique seedling identifier
- species: abbreviation for species names, including the first two letters of genus and the first two letters of species. ABBA = Abies balsamea, ACRU = Acer rubrum, ACSA = Acer saccharum, FRNI = Fraxinus nigra, PIRU = Picea rubens, PIST = Pinus strobus, QURU = Quercus rubra, THOC = Thuja occidentalis
- chamber: treatment chamber (representing on experimental unit and a single application of a heat and drought treatment). There are 27 total chambers, 3 per unique combination of heat and drought.
- treatment: combination of heat treatment (first letter) and drought treatment (second letter)
- drought: drought treatment. I = irrigated, R = repeated, E = extended
- heat: heat treatment. A = ambient temperature, M = moderate warming, E = extreme warming
- sm.per: the approximate substrate moisture as a percent for a given ID on a given date