Functional diversity of plant communities

The year 2014 was globally the warmest since records started and thus represents the (provisional) peak of the general trend of global warming that is expected to continue, which has severe negative effects on biodiversity and ecosystem processes. In order to understand the causes and predict or even mitigate consequences of these impacts, it is mandatory to study present patterns of biodiversity and to quantify ecological responses of communities to environmental changes such as increasing temperatures. Spatial gradients such as those along mountain slopes as well as re-visitations of sites where historical vegetation surveys had been conducted represent powerful long-term and large-scale study systems to estimate effects of climate change on ecosystems. The diversity, characteristics, distribution, and relative abundance of functional plant traits in communities reveal information on community assembly and ecosystem functioning. In contrast to vegetative and life-history traits, such information remains largely unknown for flower traits despite their essential roles for important ecological processes such as sexual reproduction of plants and pollinator diversity. In the proposed study, the advantages of the altitudinal gradient of the Austrian Alps as well as historical vegetation surveys will be exploited to fill that important gap. The plant species present in communities located between 1500 and 2600 m a.s.l. will be phenotyped by a large set of vegetative but most importantly floral functional traits including the morphology, phenology, scent emissions and color. Additionally, the phylogenetic composition of the communities as well as the flower-visitor interactions will be considered. This extensive and comprehensive dataset will allow testing hypotheses on community assembly, the link between functional plant diversity and flower visitor diversity, and the functional responses of plant communities and interaction patterns to altitude and climate change. The anticipated results and conclusions will therefore provide a novel perspective on community ecology and assembly with implications for climate change and the vulnerability of natural ecosystems and the conservation of the alpine flora and fauna.

The last years were globally the warmest since records started and thus represent the (provisional) peak of the general trend of global warming that is expected to continue, which has severe negative effects on biodiversity and ecosystem processes. In order to understand the causes and predict or even weaken consequences of these impacts, it is mandatory to study present patterns of biodiversity and to quantify ecological responses of communities to environmental changes such as increasing temperatures. Spatial gradients such as those found along mountain slopes represent powerful long-term and large-scale study systems to estimate effects of temporal gradients (i.e. climate change) on ecosystems. The diversity, characteristics, distribution and relative abundance of functional plant traits in communities located along gradients reveal information on community assembly and ecosystem functioning. In contrast to vegetative and life-history traits, such information remains largely unknown for flower traits despite their essential roles for important ecological processes such as sexual reproduction of plants and pollinator diversity. In the finalized study, the advantages of the altitudinal gradient of the Austrian Alps were exploited to fill that important gap. The plant species present in communities located between 1200 and 2550 m a.s.l. were phenotyped by a large set of vegetative but most importantly floral functional traits including the morphology, phenology, scent emissions and color. Additionally, the phylogenetic composition of the communities as well as the flower-visitor interactions were recorded. Our results clearly show that plant and pollinator communities strongly respond to temperature differences, both on small on large scales. Additionally, the structure of plant-pollinator interactions, measured as networks, varies with a temperature gradient. These variations are mediated by different functional compositions of plant communities, i.w. flower traits responded to temperature as well. These results and conclusions provide a novel perspective on community ecology and assembly with implications for climate change and the vulnerability of natural ecosystems and the conservation of the alpine flora and fauna.