Phenological response of grassland species to manipulative snowmelt and drought along an altitudinal gradient

Abstract

Plant communities in the European Alps are assumed to be highly affected by climate change, as the temperature rise in this region is above the global average. It is predicted that higher temperatures will lead to advanced snowmelt dates and that the number of extreme weather events will increase. The aims of this study were to determine the impacts of extreme climatic events on flower phenology and to assess whether those impacts differed between lower and higher altitudes. In 2010, an experiment simulating advanced and delayed snowmelt as well as a drought event was conducted along an altitudinal transect approximately every 250 m (600–2000 m above sea level) in the Berchtesgaden National Park, Germany. The study showed that flower phenology was strongly affected by altitude; however, there were few effects of the manipulative treatments on flowering. The effects of advanced snowmelt were significantly greater at higher than at lower sites, but no significant difference was found between both altitudinal bands for the other treatments. The response of flower phenology to temperature declined through the season and the length of flowering duration was not significantly influenced by treatments. The stronger effect of advanced snowmelt at higher altitudes may be a response to differences in treatment intensity across the gradient. Consequently, shifts in the date of snowmelt due to global warming may affect species more at higher than at lower altitudes, as changes may be more pronounced at higher altitudes. These data indicate a rather low risk of drought events on flowering phenology in the Bavarian Alps.

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

“…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).…”

Five years of phenological monitoring in a mountain grassland: inter-annual patterns and evaluation of the sampling protocol

“…Additionally, experimental studies indicate that subalpine meadows are sensitive to climate change manipulations, reporting either community or species-specific responses (Cornelius et al 2013; Dunne et al 2003). …”

“…Field work for data collection and/or analysis usually represents a big effort for researchers, so a key question would be which experimental protocol (number and distribution of observation units) is required to track IAV of a given phenological variable and, among different observational approaches, which are more suitable to investigate IAV in the context of a long-term monitoring programme. Reducing sampling effort is laudable especially in the monitoring of remote areas (Cornelius et al 2011). Previous sample size analyses suggest that a sample size of 15 sampling units and a fortnightly frequency is the minimum requirement for tracking a seasonal phenological trajectory in deciduous forest ecosystems (Morellato et al 2010).…”

Predicting Effects of Climate Change on Habitat Suitability of Red Spruce (Picea rubens Sarg.) in the Southern Appalachian Mountains of the USA: Understanding Complex Systems Mechanisms through Modeling

“…Long-term records indicate that earlier phenological development [3,4], range shifts [5,6] and shrinking habitats [7] are all in progress now.…”