Acclimation of thermal tolerance in juvenile plants from three biomes is supressed when extremes co-occur
Cite this dataset
Harris, Rosalie et al. (2024). Acclimation of thermal tolerance in juvenile plants from three biomes is supressed when extremes co-occur [Dataset]. Dryad. https://doi.org/10.5061/dryad.cz8w9gjbg
Abstract
Given the rising frequency of thermal extremes (heatwaves and cold snaps) due to climate change, comprehending how a plant’s origin affects its thermal tolerance breadth becomes vital. We studied juvenile plants from three biomes: temperate coastal rainforest, desert, and alpine. In controlled settings, plants underwent hot days and cold nights in a factorial design to examine thermal tolerance acclimation. We assessed thermal thresholds (Tcrit-hot and Tcrit-cold) and thermal tolerance breadth (TTB). We hypothesised that: 1) desert species would show the highest heat tolerance, alpine the greatest cold tolerance, with temperate species intermediate; 2) all species would increase heat tolerance post hot days and cold tolerance after cold nights; 3) combined exposure would broaden TTB more than individual conditions, especially in desert and alpine species. We found that biome responses were minor compared to the responses to the extreme temperature treatments. All plants increased thermal tolerance in response to hot 40°C days (Tcrit-hot increased by ~3.5°C) but there was minimal change in Tcrit-cold in response to the cold -2°C nights. In contrast, when exposed to both hot days and cold nights, on average plants exhibited an antagonistic response in TTB, where cold tolerance decreased and heat tolerance was reduced, and so we did not see the bi-directional expansion we hypothesised. There was, however, considerable variation among species in these responses. As climate change intensifies, plant communities, especially in transitional seasons, will regularly face such temperature swings. Our results shed light on potential plant responses under these extremes, emphasizing the need for deeper species-specific thermal acclimation insights, ultimately guiding conservation efforts.
README: Acclimation of thermal tolerance in juvenile plants from three biomes is supressed when extremes co-occur
https://doi.org/10.5061/dryad.cz8w9gjbg
| # Thermal tolerance data | |
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| This Excel file contains the data from the paper 'Acclimation of thermal tolerance in juvenile plants from three biomes is supressed when extremes co-occur' |
Test Whether the metric was tcrit hot, tcrit cold or thermal tolerance bredth (TTB)
ID Not a true ID, but gives you the date, block, plate a or b and what test it was
Block Replicate group of species from 1-5. Smaller plants were in block 2 and 4
sp Species name combined with what treatment it went in
Plant_ID ID that tells you block number, species and treatment
Species Species name
Measurement_Day If plants were measured on day 3 or day 5
Biome Which biome: temperate, desert or alpine
Treatment The treatment type: warming, cooling, combnation or control
Warming Either yes or no: e.g. control would be no but heatwave would be yes
Cooling Either yes or no: e.g, control would be no and heatwave woud be no
PAMID The area of interest recordd on the PAM to get F0 values (not unique and not useful in analysis at this point)
Tcrit Derived from tcrit extraction script in R
Tmax Derived from tcrit extraction script in R
NT Calculated from thermocouple temperature output when an exothermic reaction occurs (release of heat during ice formation) and tells you the time/temp when ice formed
TTB Tcrit hot minus tcrit cold gives you the thermal tolerance breadth (TTB)
Growth_Form Type of growth form the plants are
Delta_Tcrit Tcrit of a treatment minus the control treatment
Type The treatment combination type: warming, cooling, combnation or control
NA = failed tcrit or missing data due to error
Methods
Title: Methods for Assessing Thermal Tolerance in Plants from Different Australian Biomes
Summary: This study compared the responses of plants from temperate rainforest, alpine, and desert biomes in Australia to hot days and cold nights using temperature-dependent increases in chlorophyll a fluorescence. For each biome, eight species were selected based on seed availability and family representation. Seeds were obtained from conservation seed banks, sown, and grown under common conditions in glasshouses. Some species were purchased from nurseries.
A fully factorial experimental design was used with three biomes, eight species per biome, five replicates, and four temperature treatments (control, hot days, cold nights, and a combination of hot days and cold nights). Experiments were conducted in growth chambers, and plants were exposed to the temperature regimes for five days. Leaf temperatures were monitored using thermocouples.
Thermal tolerance assays were performed on days three and five of the experiment using Maxi Pulse Amplitude Modulating (PAM) systems. Leaf discs were placed on Peltier plates and subjected to cooling (-25°C) and heating (65°C) ramps. The critical temperatures during heating (Tcrit-hot) and cooling (Tcrit-cold) were defined as the breakpoint between the slow and fast-rise phases of basal fluorescence.
Funding
Australian Research Council, Award: LP180100942