Plant resource-use strategies: the importance of phenotypic plasticity in response to a productivity gradient for two subalpine species |
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Authors: | Fabrice Grassein Ir��ne Till-Bottraud Sandra Lavorel |
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Affiliation: | Laboratoire d''écologie alpine, CNRS UMR 5553, Université Joseph Fourier, BP53, 38041 Grenoble, Cedex 9, France |
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Abstract: | Background and AimsFunctional traits are indicators of plant interactions with their environment and the resource-use strategies of species can be defined through some key functional traits. The importance of genetic variability and phenotypic plasticity in trait variations in response to a common environmental change was investigated in two subalpine species.MethodsTwo species with contrasted resource-use strategies, Dactylis glomerata and Festuca paniculata, were grown along a productivity gradient in a greenhouse experiment. Functional traits of different genotypes were measured to estimate the relative roles of phenotypic plasticity and genetic variability, and to compare their levels of phenotypic plasticity.Key ResultsTrait variability in the field for the two species is more likely to be the result of phenotypic plasticity rather than of genetic differentiation between populations. The exploitative species D. glomerata expressed an overall higher level of phenotypic plasticity compared with the conservative species F. paniculata. In addition to different amplitudes of phenotypic plasticity, the two species differed in their pattern of response for three functional traits relevant to resource use (specific leaf area, leaf dry matter content and leaf nitrogen content).ConclusionsFunctional trait variability was mainly the result of phenotypic plasticity, with the exploitative species showing greater variability. In addition to average trait values, two species with different resource-use strategies differed in their plastic responses to productivity. |
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Keywords: | Plant functional traits genetic variability Dactylis glomerata Festuca paniculata subalpine grasslands |
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