Martina Petrů(e-mail: Martina.Petru@bf.jcu.cz),

†††††† a PhD student in Plant Ecology at Department of Plant Ecology and Nature Conservation, University of Potsdam in Germany, supervised by Dr. Katja Tielbörger and Prof. Florian Jeltsch. Within the framework of the GLOWA Jordan River project I focus on plant population-level studies, particularly on changes in population dynamics of selected annuals under various scenarios of climate change.

†††††† The aim of my research is to investigate responses of annual plants to changing rainfall conditions via regulation of seed dormancy and germination strategies, while testing several theoretical predictions, and considering consequences of such behavior for species population dynamics and for adaptive strategies within an evolutionary context.

My field studies are among the first to empirically test for theoretical models about optimal germination rates of annual plants, such as the Cohenís models (Cohen 1966, 1967) predicting increase in germination rates with increasing precipitation.

I am also testing for maternal effects on seed germination, contradicting germination predicted by Cohen models, i.e. germination rates negatively related to previous yearís rainfall (Tielbörger & Valleriani, unpubl.) due to sibling competition.

I aim to separate effects of climate (Cohenís germination) and maternal effects on germination.

†††††† The seven study species overlapping among four sites along the precipitation gradient include different dormancy types. Dormancy tends to increase from grasses (Bromus fasciculatus, Stipa capensis), to Cruciferae (Biscutella didyma, Carrichtera annua, Reboudia pinnata) to Leguminosae (Hippocrepis unisiliquosa, Hymenocarpos circinatus).

I use seed-addition-plots in four field sites along a natural precipitation gradient and in plots with altered rainfall regime: artificially added rainfall pulses (irrigation) and artificially subtracted rainfall (rain-out shelters). I evaluate germination rates of the study species comparing between sites (testing for Cohen germination) and treatments (testing for maternal effects).

In controlled phytotron conditions I check for maximal germination rates of the species comparing between stations, treatments, years and dormancy types testing for both models.

To separate climatic effects from maternal effects, I grow plants from different climatic regions under the same conditions in an open greenhouse until seed production, while maternally induced germination rates of produced seeds will be investigated under controlled phytotron conditions.

       My research interests include plant ecology and field botany, plant demography, population and metapopulation ecology and conservation biology, seed and seedling ecology, evolutionary ecology; desert ecology; spatial and temporal processes in plant populations with respect to habitat heterogeneity, climate and disturbance; mechanisms of plant species interactions, competition and coexistence on individual and community levels, plant clonality, plant-animal interactions including pollination ecology, ecological modeling and related fields in plant ecology.

       I obtained BSc. and MS degrees in Biology and Plant Ecology at the Faculty of Biological Sciences, University of South Bohemia in České Budějovice, Czech Republic, under supervision of Prof. Jan Lepš, thesis on population ecology of Pedicularis palustris and P. sylvatica, two rare species of wet grasslands.

       MS thesis included 4 studies of the effects of experimental disturbances on microsites and plant demography. Two studies focused on rare Pedicularis sylvatica in wet meadows in the Czech Republic the other two studies on several endemic species in xeric scrub communities in inland Florida (advised by Dr. Eric S. Menges).