P2012-01: Vegetative and reproductive fitness of apomictic and sexual Ranunculus kuepferi in response to climatic constraints along an altitudinal gradient

Project leader :

Apomictic taxa show latitudinally and altitudinally larger distribution ranges than their sexual relatives and tend to colonize more frequently previously glaciated areas – a phenomenon termed as geographical parthenogenesis.

The elevated ploidy of apomictic plants might be an important factor to establish better under the stressful conditions of alpine environments. A further advantage of apomicts is the ability to reproduce via single individuals, whereas sexual relatives are usually self-incompatible and are thus dependent on pollinators and mating partners.

Comparative investigations on vegetative and reproductive fitness of alpine apomictic and sexual plants are largely missing. In our study, transplanted apomictic and sexual individuals of Ranunculus kuepferi are subjected to a climatic gradient along an altitudinal transect of 1000 m in the Stubai Alps (Austrian Central Alps). We investigate the influence of the date of snowmelt and site temperatures on the timing of vegetative and reproductive development, growth performance of above-ground organs, and reproductive fitness (seed set, seed mass).

The study should reveal whether fitness variation along a climatic gradient can explain the geographical pattern of apomictic and sexual R. kuepferi.