Linking altitudinal gradients and temperature responses of plant phenology in the Bavarian Alps

Abstract

Global climate change influences ecosystems across the world. Alpine plant communities have already experienced serious impacts, and will continue to do so as climate change continues. The aim of our study was to determine the sensitivity of woody and herbaceous species to shifts in temperature along an altitudinal gradient. Since 1994, park rangers have been making phenological observations at 24 sites from 680 to 1425 m a.s.l. Each year 21 plant species were observed once or twice weekly from March to July; with a main focus on flowering and leaf unfolding. Our study showed a very high degree of dependence of phenophases and species on inter-annual temperature variation and altitude. Averaged over all species and phenophases, there was a delay of 3.8 days with every 100 m increase in altitude and, across all elevations, an advance of phenophases of 6 days per 1 °C increase in temperature. Temperature lapse rates assessed indirectly by phenology, as the quotient of altitudinal to temperature response coefficients, were higher than directly calculated from March to July mean temperatures, most likely due to snow effects. Furthermore, a significant difference in sensitivity to temperature change was found between growth forms (herbs versus trees). Sensitivity was less pronounced in events occurring later in the season. Our results show that species reactions will differ in magnitude during global warming. Consequently, impacts of shifts in the timing of phenological events on plant migration and plant-pollinator interactions due to rising temperatures should be considered at the species level.

Traits and climate are associated with first flowering day in herbaceous species along elevational gradients

“…Also, Cornelius, Estrella, et al. (2013) detected differences in phenological responses between observational sites in the Alps. Hopkins law states that species should delay their phenology by 3.3 day 100/m (Fitzjarrald, Acevedo, & Moore, 2001; Vitasse, Delzon, et al., 2009) yet only three species reacted almost as strongly as predicted.…”

“…C. defloratus shifted its phenology by 3.28 day 100/m, P. orbiculare by 3.26 day 100/m, and T. pratense by 3.06 day 100/m, the other species were less responsive. Other observational studies in alpine grasslands showed an average delay of 3.8 day 100/m (Cornelius, Estrella, et al., 2013; Cornelius, Leingärtner, et al., 2013). Interestingly, for A. foetida and M. perennis, the reaction was much less pronounced compared to the observations on these species reported by Cornelius, Estrella, et al., 2013 and Cornelius, Leingärtner, et al., 2013; 2.19 day 100/m instead of 3.7 day 100/m for A. foetida and 0.85 day 100/m compared to 3.5 day 100/m for M. perennis , respectively).…”

“…Typically, studies report the onset of a phenological stage as day of the year, that is, first flowering day, FFD (e.g., Cornelius, Estrella, Franz, & Menzel, 2013; Cornelius, Leingärtner, et al., 2013; Fitter & Fitter, 2002). A complementary approach would be to measure the temperature accumulation reached to start flowering, or more specifically, the growing degree days to start FFD (GDD FFD ; de Réaumur, 1735).…”

Effects of Different Methods on the Comparison between Land Surface and Ground Phenology—A Methodological Case Study from South-Western Germany

“…Apart from the mean GP-SOS and its trends, the early detecting LSP-SOS in form of 20% amplitude and 3rd derivative were also able to capture the high inter-annual variability of early species GP-SOS (understory) occurring before 90th day of the year (Supplementary Figure S6). These early species are limited by the frost period and hence show higher response to temperature fluctuations and therefore a higher inter-annual variability in their SOS [45,46]. The lower correlations of early understory species' GP-SOS with LSP-SOS could be due to the short time series of data or may be due to artefacts introduced in smoothing of early season NDVI.…”

Variación morfo-anatómica de Ribes ciliatum a lo largo de un gradiente altitudinal en el norte de la Sierra Nevada, México

“…La variabilidad ambiental se relaciona con factores tales como la radiación solar, la temperatura del aire, las propiedades del suelo y el défi cit hídrico (Molina-Montenegro, 2008; Molina-Montenegro y Cavieres, 2010;Cornelius et al, 2013). En consecuencia, las plantas modulan 19° 26' 55.4" 98° 46' 39.3" 2 3,366 19° 26' 16.2" 98° 45'10.0" 3 3,386 19° 26' 19.0" 98° 44' 55.9" 4 3,545 19° 24' 43.3" 98° 44' 59.3" Cuadro 1.…”