10.5061/DRYAD.T9T28
van Heerwaarden, Belinda
Monash University
Kellermann, Vanessa
Monash University
Sgrò, Carla M.
Monash University
Data from: Limited scope for plasticity to increase upper thermal limits
Dryad
dataset
2017
hardening
heat
CTmax
2017-05-03T00:00:00Z
2017-05-03T00:00:00Z
en
https://doi.org/10.1111/1365-2435.12687
30557 bytes
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CC0 1.0 Universal (CC0 1.0) Public Domain Dedication
Increases in average temperature and the frequency of extreme temperature
events are likely to pose a major risk to species already close to their
upper physiological thermal limits. The extent to which thermal phenotypic
plasticity can buffer these changes and whether plasticity is constrained
by basal tolerance levels, remains unknown. We examined the effect of
developmental temperature under both constant and fluctuating thermal
regimes (developmental acclimation), as well as short-term heat hardening
on upper thermal limits (CTmax) in a tropical and temperate population of
Drosophila melanogaster. We found evidence for thermal plasticity in
response to both developmental acclimation and hardening treatments; CTmax
increased at warmer developmental temperatures and with a prior heat
hardening treatment. However, hardening and acclimation responses were
small, improving CTmax by a maximum of 1.01° C. These results imply that
overheating risk will only be minimally reduced by plasticity. We observed
significant associations between developmental temperature and both basal
CTmax and hardening capacity (a measure of the extent of the plastic
response). Basal CTmax increased, while hardening capacity decreased, with
increasing developmental acclimation temperature. This indicates that
increases in basal heat resistance at warmer temperatures may come at the
cost of a reduced capacity to harden. While plasticity in CTmax is evident
in both populations of D. melanogaster we studied, plastic increases in
upper thermal limits, particularly at warmer temperatures, may not be
sufficient to keep pace with temperature increases predicted under climate
change.
Constant temperature dataRaw data for CTmax when flies were developed at
six constant temperaturesconstant temperatures.csvFluctating
temperaturesRaw estimates of CTmax when flies were developed at
fluctuating temperatures.fluctating temperatures.csv