Title: A global meta-analysis on fire effects in seed survival, germination and dormancy
Fire is a major disturbance shaping plant traits and vegetation dynamics worldwide. The effects of fire on seed germination and dormancy break are well-established in some ecosystems, but to date there is no attempt to evalute fire effects on regeneration from seed at the global level. I will present the results of a global meta-analysis aiming to determine the effects of high temperatures, smoke and their interactions on seed survival, germination and dormancy. Effect sizes will be compared across ecosystems (forests, savannas, mediterranean-like ecosystems and grasslands), life-forms (grasses, herbs, shrubs, trees and climbers), life-history (annuals vs perennials), regeneration strategy (seeder vs resprouter), seed bank type (soil vs canopy), seed dormancy classes and seed size. Our study has the potential to contribute to a better understanding of regeneration ecology and evolutionary responses of species living in a world with increasing fire frequency.
Fernando Silveira is Professor of Plant Ecology at the Federal University of Minas Gerais, Brazil. He is a broadly trained plant ecologist with a focus on the ecology of seeds. He has developed empirical, theoretical and meta-analytical studies on seed germination, dormancy, dispersal and soil seed banks. His main research line aims to determine the functional role of seeds in structuring plant communities. His study models are ancient, nutrient-poor vegetation associated with rocky outcrops, where he is also trying to use knowledge on seed ecology to better inform restoration practices.
Title: All Seasons Seed Mix - Molecular and Physiological Mechanisms of Seed and Fruit Ecology
Plant seeds are nature's packages that deliver the next generation of plant life across space and time. The team of Prof Gerhard Leubner conducts interdisciplinary research with crop, wild and weed diaspores (seeds and fruits) by integrating approaches from molecular biology and biomechanical engineering to diaspore ecology and environmental simulation. Examples from the Brassicaceae family for the diversity in germination, dormancy and longevity mechanisms will be provided which evolved as adaptations to seasons and erratic weather. Aethionema arabicum provides an excellent model system for studying the role of diaspore bet-hedging to survive unpredictable environments. The large genus Lepidium (cress) provides a diversity of very fascinating mechanisms by which the fruit coat (pericarp) mechanically or chemically imposes dormancy and controls the germination of crop and weed diaspores. Ambient temperature and moisture regimes drive hormonome, epigenome and transcriptome changes underpinning diaspore responses to abiotic and biotic stresses.
Gerhard Leubner is the Chair of Plant Biochemistry and Head of the Seed Science and Technology Group at Royal Holloway University of London. He has more than 25 years’ experience in seed research and is the curator of 'The Seed Biology Place' (www.seedbiology.eu) website. He is the lead PI of the ERA-CAPS Consortium SeedAdapt on dimorphic fruits, seeds and seedlings as bet-hedging adaptation mechanisms to abiotic stress and unpredictable environments (www.seedadapt.eu). More applied projects are into weed ecophysiology and improving crop seed quality and seedling performance is crucial for plant/food value supply chain resilience to climate change.
Title: Is pollen like a haploid seed?
The dispersal units of plants are seeds but pollen is also dispersed and there are many similarities to be found between these two types of diaspores, especially in their environmental interactions. The economy of natural processes suggests that nature would not ‘‘re-invent the wheel’’ and indeed there are many similarities, if not identical types of mechanisms, in the metabolic activities of seed and pollen responses to environmental conditions. The main differences regard scale and the responses/mechanisms available to bi-or tri-cellular systems compared to those operating at cytological or organ level. Besides pollen has no dormancy. Intriguing parallels will be highlighted implying also the homologies.
Ettore Pacini is retired full Prof.c/o Dept of Life Sciences at Siena University. He always worked in all aspects of higher plant reproduction: pollen and seed development and their dispersal modalities.