Local ecotypic and species range-related adaptation influence photosynthetic temperature optima in deciduous broadleaved trees

Abstract

Given prior evidence for local ecotypic and species-specific adaptation in trees, we hypothesized that: (1) Acer rubrum and Quercus rubra provenances with different climate origins should differ in photosynthetic temperature optimum (T opt ) even after long-term growth in a common environment; (2) congeneric species Populus tremuloides and Populus deltoides with differing but overlapping ranges should not differ in T opt when co-occurring, due to the likelihood of both ecotypic thermal adaptation and phenotypic thermal acclimation. To address these questions, we investigated the temperature responses of pairs of A. rubrum and Q. rubra provenances planted in a common garden and the temperature responses of P. tremuloides and P. deltoides at four sites where the species ranges overlap in Minnesota, USA. Both studies showed significant signals of temperature adaptation. The provenances of both A. rubrum and Q. rubra that originated from northern sites with lower ambient temperature had lower T opt . This supported the hypothesis about the dominance of local ecotypic adaptation of photosynthesis to temperature despite opportunity for both long-term (12-year) acclimation to the common-garden temperature regime and short-term temperature acclimation. However, acclimation capacity to the temperatures experienced in the days and weeks before the gas exchange measurements differed among the contrasting provenances suggesting that the observed differences in T opt could be due to either fixed genotypic differences (e.g., adaptive T opt ), acclimation of T opt , or both. In contrast, the Populus species with the colder home range, P. tremuloides, showed significantly (P \ 0.05) lower T opt on average than co-occurring P. deltoides. Thus, despite the opportunity for both ecotypic adaptation and local acclimation, phylogenetic inertia still constrained the species with the colder overall range to a different temperature optimum than the one with a warmer overall range. Our results also imply that rapid but modest climate change may create mismatches between photosynthetic physiology and local climate because of lags in population or species-level adaptation.Electronic supplementary material The online version of this article

Ecotypic differentiation in photosynthesis and growth of Eriophorum vaginatum along a latitudinal gradient in the Arctic tundra

“…Beginning with the seminal work of Mooney and Billings (1961) on the Arctic plant species Oxyra digyna, studies have demonstrated intraspecific genetic differentiation in key plant physiological processes, including photosynthesis (Arntz and Delph 2001;Chapin and Oechel 1983;Flood et al 2011;Mooney and Billings 1961;Robakowski et al 2012;Teramura and Strain 1979). Our results support these previous experiments, demonstrating intraspecific variation in photosynthetic performance for E. vaginatum.…”

Photosynthesis of temperate Eucalyptus globulus trees outside their native range has limited adjustment to elevated CO2 and climate warming

“…Slope differences between J max / V cmax ratios as a function of leaf temperature were tested via a linear regression using dummy variables, where a significant interaction between leaf temperature and the assigned dummy variable indicates a difference between slopes (Neter et al ., ). As a measure of the recent growth temperature environment of plants, we used the average temperature for the week prior to measurements (Atkin & Tjoelker, ; Lee et al ., ; Ow et al ., ; Robakowski et al ., ). Increasing the growth temperature period to running time lengths between 1 and 2 weeks yielded very similar results to those shown in our analysis.…”

Impacts of local adaptation of forest trees on associations with herbivorous insects: implications for adaptive forest management

“…; Robakowski et al. ; Sork et al. ), and studies that target multiple provenance trial locations are required to separate genetic and environmental contributions to provenance phenotypes (Tack et al.…”

“…This requires better understanding of the relative contributions of host plant genotype and other ecological factors to the tree phenotypes exposed to herbivores . Geographical patterns of local adaptation and tree phenotypic variation have only been mapped in a tiny minority of species (Savolainen et al 2007;Robakowski et al 2012;Sork et al 2013), and studies that target multiple provenance trial locations are required to separate genetic and environmental contributions to provenance phenotypes . While our study was based on a single trial, the oak phenotypic traits we analysed have been shown to be highly heritable in the sampled provenances (Sinclair 2012), so we expect the provenance effects we found to contain a significant genetic component.…”