TY - JOUR
T1 - Phenotypic plasticity is not a cline
T2 - Thermal physiology of an intertidal barnacle over 20° of latitude
AU - Broitman, Bernardo R.
AU - Lagos, Nelson A.
AU - Opitz, Tania
AU - Figueroa, Daniela
AU - Maldonado, Karin
AU - Ricote, Natalia
AU - Lardies, Marco A.
N1 - Funding Information:
We thank Nelson Valdivia (UACh‐IDEAL) and Patricio Manriquez (CEAZA) who generously shared percent cover data for some of the high and low latitude populations respectively. We thank Constanza Weinberger for her valuable advice with statistical analysis. We also thank Wilco Verberk and an anonymous review for very constructive comments on the manuscript. This work was funded by FONDECYT Grant No. 1190444, 1140938 and 1181300 to M.A.L., N.A.L. and B.R.B. respectively. ANID – Millennium Nucleus UPWELL– NCN19_153 provided additional support, N.A.L. and M.A.L. also thank the support from PIA ANID ACT 172037. Further support by the ANID – Millennium Science Initiative Program – Code ICN2019_015 to B.R.B., M.A.L. and N.A.L. is greatly appreciated.
Funding Information:
We thank Nelson Valdivia (UACh-IDEAL) and Patricio Manriquez (CEAZA) who generously shared percent cover data for some of the high and low latitude populations respectively. We thank Constanza Weinberger for her valuable advice with statistical analysis. We also thank Wilco Verberk and an anonymous review for very constructive comments on the manuscript. This work was funded by FONDECYT Grant No. 1190444, 1140938 and 1181300 to M.A.L., N.A.L. and B.R.B. respectively. ANID ? Millennium Nucleus UPWELL? NCN19_153 provided additional support, N.A.L. and M.A.L. also thank the support from PIA ANID ACT 172037. Further support by the ANID ? Millennium Science Initiative Program ? Code?ICN2019_015 to B.R.B., M.A.L. and N.A.L. is greatly appreciated.
Publisher Copyright:
© 2021 British Ecological Society
PY - 2021/8
Y1 - 2021/8
N2 - Our understanding of the plastic and evolutionary potential of ectothermic organisms and their populational impacts in the face of rapid global change remains limited. Studies attempting on the relationship between the magnitude of thermal variability across latitude and the degree of phenotypic plasticity exhibited by marine ectotherms are inconclusive. We state that the latter arises from the narrow range of thermal variability captured by the limited span of the latitudinal gradients studied to date. Using a mechanistic ecophysiological approach and a satellite-based assessment of the relevant environmental variables (i.e. temperature and food availability), we studied individuals of the intertidal barnacle Jehlius cirratus from seven local populations widely spread along the Humboldt current system that spanning two biogeographic regions. At the same time, we synthesized published information on the local abundance of our study species across a total of 76 sites representing 20° of latitude, and spanning from 18 to 42°S. We examined the effects of latitude and environmental variability on metabolic rate plasticity, thermal tolerance (thermal breadth and thermal safety margins) and their impacts on the abundance of this widespread marine invertebrate. We demonstrate that the phenotypic plasticity of metabolic rate in J. cirratus populations is not related to latitude. In turn, thermal breadth is explained by the temperature variability each population experiences. Furthermore, we found clinal variation with a poleward decrease of the critical thermal minimum, suggesting that episodic extreme low temperatures represent a ubiquitous selective force on the lower thermal limit for ectotherms. Across our study gradient, plasticity patterns indicate that populations at the equatorial extreme are more vulnerable to a warming climate, while populations located in the biogeographic transitional zone (i.e. high environmental heterogeneity), on the centre of the gradient, display higher levels of phenotypic plasticity and may represent a genetic buffer for the effects of ocean warming. Together, our results suggest the existence of a fitness trade-off involving the metabolic cost of plasticity and population density that is evident only across the vast latitudinal gradient examined.
AB - Our understanding of the plastic and evolutionary potential of ectothermic organisms and their populational impacts in the face of rapid global change remains limited. Studies attempting on the relationship between the magnitude of thermal variability across latitude and the degree of phenotypic plasticity exhibited by marine ectotherms are inconclusive. We state that the latter arises from the narrow range of thermal variability captured by the limited span of the latitudinal gradients studied to date. Using a mechanistic ecophysiological approach and a satellite-based assessment of the relevant environmental variables (i.e. temperature and food availability), we studied individuals of the intertidal barnacle Jehlius cirratus from seven local populations widely spread along the Humboldt current system that spanning two biogeographic regions. At the same time, we synthesized published information on the local abundance of our study species across a total of 76 sites representing 20° of latitude, and spanning from 18 to 42°S. We examined the effects of latitude and environmental variability on metabolic rate plasticity, thermal tolerance (thermal breadth and thermal safety margins) and their impacts on the abundance of this widespread marine invertebrate. We demonstrate that the phenotypic plasticity of metabolic rate in J. cirratus populations is not related to latitude. In turn, thermal breadth is explained by the temperature variability each population experiences. Furthermore, we found clinal variation with a poleward decrease of the critical thermal minimum, suggesting that episodic extreme low temperatures represent a ubiquitous selective force on the lower thermal limit for ectotherms. Across our study gradient, plasticity patterns indicate that populations at the equatorial extreme are more vulnerable to a warming climate, while populations located in the biogeographic transitional zone (i.e. high environmental heterogeneity), on the centre of the gradient, display higher levels of phenotypic plasticity and may represent a genetic buffer for the effects of ocean warming. Together, our results suggest the existence of a fitness trade-off involving the metabolic cost of plasticity and population density that is evident only across the vast latitudinal gradient examined.
KW - Jehlius cirratus
KW - abundance
KW - metabolism
KW - ocean warming
KW - plasticity
KW - reaction norm
KW - thermal breadth
UR - http://www.scopus.com/inward/record.url?scp=85106301210&partnerID=8YFLogxK
U2 - 10.1111/1365-2656.13514
DO - 10.1111/1365-2656.13514
M3 - Article
AN - SCOPUS:85106301210
SN - 0021-8790
VL - 90
SP - 1961
EP - 1972
JO - Journal of Animal Ecology
JF - Journal of Animal Ecology
IS - 8
ER -