Journal Article

Micro-climatic controls and warming effects on flowering time in alpine snowbeds

Petraglia, Alessandro, Tomaselli, Marcello, Perucco, Francesco, Bernareggi, Giulietta, Carbognani, Michele

2016

Overview

Alpine snowbed communities are among the habitats most threatened by climate change. The warmer temperature predicted, coupled with advanced snowmelt time, will influence flowering phenology, which is a key process in species adaptation to changing environmental conditions and plant population dynamics. However, we know little about the effects of changing micro-climate on flowering time in snowbeds and the mechanisms underlying such phenological responses. The flowering phenology of species inhabiting alpine snowbeds was assessed with weekly observations over five growing seasons. We analysed flowering time in relation to micro-climatic variation in snowmelt date, soil and air temperature, and experimental warming during the snow-free period. This approach allowed us to test hypotheses concerning the processes driving flowering phenology. The plants were finely tuned with inter-annual and intra-seasonal variations of their micro-climate, but species did not track the same micro-climatic feature to flower. At the growing-season time-scale, the air surrounding the plants was the most common trigger of the blooming period. However, at the annual time-scale, the snowmelt date was the main controlling factor for flowering time, even in warmer climate. Moreover, spatial patterns of the snowmelt influenced the developmental rate of the species because in later snowmelt sites the plants needed a lower level of heat accumulation to enter anthesis. Phenological responses to experimental warming differed among species, were proportional to the pre-flowering time-span of plants, and did not show consistent trends of change over time. Finally, warmer temperature produced an overall increase of flowering synchrony both within and among plant species.

• Publisher: Springer Science + Business Media,Springer Berlin Heidelberg,Springer,Springer Nature B.V
• Subject: air / Air temperature / Alpine ecosystems / alpine plants / Biomedical and Life Sciences / Climate Change / Ecology / Ecosystem / Environmental changes / Environmental conditions / environmental factors / flowering / Flowers / GLOBAL CHANGE ECOLOGY – ORIGINAL RESEARCH / Global temperature changes / Growing season / habitats / heat / Hydrology/Water Resources / Life Sciences / Microclimate / Phenology / Plant populations / Plant Sciences / Plant species / Population biology / population dynamics / Seasonal variations / Seasons / Snow / Snowmelt / soil air / Temperature / Weather forecasting