Quantifying phenological plasticity to temperature in two temperate tree species

Abstract

Summary1. Phenotypic plasticity allows large shifts in the timing of phenology within one single generation and drives phenotypic variability under environmental changes, thus it will enhance the inherent adaptive capacities of plants against future changes of climate. 2. Using five common gardens set along an altitudinal gradient (100-1600 m asl.), we experimentally examined the phenotypic plasticity of leaf phenology in response to temperature increase for two temperate tree species (Fagus sylvatica and Quercus petraea). We used seedlings from three populations of each species inhabiting different altitudes (400, 800 and 1200 m asl.). Leaf unfolding in spring and leaf senescence in autumn were monitored on seedlings for 2 years. 3. Overall, a high phenological plasticity was found for both species. The reaction norms of leaf unfolding date to temperature linearly accelerated for both species with an average shift of )5AE7 days per degree increase. Timing of leaf senescence exhibited hyperbolic trends for beech due to earlier senescence at the lowest elevation garden and no or slight trends for oak. There was no difference in the magnitude of phenological plasticity among populations from different elevations. For both species, the growing season length increased to reach maximum values at about 10-13°C of annual temperature according to the population. 4. Since the magnitude of phenological plasticity is high for all the tested populations, they are likely to respond immediately to temperature variations in terms of leaf phenology. Consequently the mid-to high-elevation populations are likely to experience a longer growing season with climate warming. The results suggest that climate warming could lengthen the growing season of all populations over the altitudinal gradient, although the low-elevation populations, especially of beech, may experience accelerated senescence and shorter growing season due to drought and other climate changes associated with warming.

Alteration of the phenology of leaf senescence and fall in winter deciduous species by climate change: effects on nutrient proficiency

“…Modeling predicts advances in leaf appearance of 5-9 days during this century (Morin et al, 2009). The modeling of leaf senescence in winter deciduous species is less satisfactory, and the results are good for some species but not for others (Vitasse et al, 2010).…”

Phenotypic plasticity facilitates resistance to climate change in a highly variable environment

“…Migration of individual species might, however, be limited by dispersal rates (Aitken et al 2008), by the lack of suitable habitat in fragmented landscapes (Jackson and Sax 2010), or by dispersal barriers such as high mountain ranges. In the Alps, low-elevation provenances of Fagus sylvatica have been shown to be more vulnerable to increased temperature and drought than midor high-elevation provenances (Vitasse et al 2010). Because dispersal barriers might limit the arrival of new species in mountainous regions, forest persistence might be threatened at lower elevations.…”

Estimating the ability of plants to plastically track temperature‐mediated shifts in the spring phenological optimum

“…Temperate plants often exhibit pronounced temperature-mediated plasticity in their spring phenology, as documented via longitudinal studies of individuals (Vitasse et al, 2010;www.trackatree.org.uk), geographic transplants (Kramer, 1995) and experimental approaches (Franks et al, 2014). Such plastic phenological responses are often assumed to be adaptive, allowing plants to track spatial and temporal variation in the onset of benign environmental conditions.…”