Plastic Responses to Elevated Temperature in Low and High Elevation Populations of Three Grassland Species

Abstract

Local persistence of plant species in the face of climate change is largely mediated by genetic adaptation and phenotypic plasticity. In species with a wide altitudinal range, population responses to global warming are likely to differ at contrasting elevations. In controlled climate chambers, we investigated the responses of low and high elevation populations (1200 and 1800 m a.s.l.) of three nutrient-poor grassland species, Trifolium montanum, Ranunculus bulbosus, and Briza media, to ambient and elevated temperature. We measured growth-related, reproductive and phenological traits, evaluated differences in trait plasticity and examined whether trait values or plasticities were positively related to approximate fitness and thus under selection. Elevated temperature induced plastic responses in several growth-related traits of all three species. Although flowering phenology was advanced in T. montanum and R. bulbosus, number of flowers and reproductive allocation were not increased under elevated temperature. Plasticity differed between low and high elevation populations only in leaf traits of T. montanum and B. media. Some growth-related and phenological traits were under selection. Moreover, plasticities were not correlated with approximate fitness indicating selectively neutral plastic responses to elevated temperature. The observed plasticity in growth-related and phenological traits, albeit variable among species, suggests that plasticity is an important mechanism in mediating plant responses to elevated temperature. However, the capacity of species to respond to climate change through phenotypic plasticity is limited suggesting that the species additionally need evolutionary adaptation to adjust to climate change. The observed selection on several growth-related and phenological traits indicates that the study species have the potential for future evolution in the context of a warming climate.

Genetic differentiation and plasticity interact along temperature and precipitation gradients to determine plant performance under climate change

“…This pattern contrasts with expectations of previous studies, predicting and, in some cases, confirming that plants from extreme environments at higher elevations tend to be less plastic (e.g. Emery, Chinnappa & Chmielewski ; Eranen & Kozlov ; Frei, Ghazoul & Pluess ). All these studies only worked along elevational gradients, and did not explicitly test the effect of different climatic variables.…”

A review and meta‐analysis of intraspecific differences in phenotypic plasticity: Implications to forecast plant responses to climate change

“…Multiple studies have reported significant P × E for a wide suite of plant functional traits, particularly focusing on the adaptive role of plasticity for populations of specific life‐forms or ecoregions (see e.g., Matesanz & Valladares, and references therein; Bansal, Harrington, et al, ; Frei, Ghazoul, & Pluess, ; Wadgymar, Cumming, & Weis, ). Some studies have also discussed the sources of bias in estimates of population differentiation, including the difficulty in distinguishing genetic from plastic components of such differentiation (Merilä & Hendry, ), the effect of the experimental approach (Gibson, Espeland, Wagner, & Nelson, ) and the role of maternal effects (Bischoff & Müller‐Schärer, ).…”

Testing the niche‐breadth–range‐size hypothesis: habitat specialization vs. performance in Australian alpine daisies

“…In a study examining perennial grassland species (including Trifolium , Ranunculus , and Briza ), a low level of morphological plasticity in alpine species compared to mid‐elevation species was interpreted in terms of an increased level of canalization of traits in harsher conditions (Frei et al. ). However, the common Brachyscome we tested, which were also found in lowland environments, did not have consistently higher plasticity.…”