Abstract

Warming can have dramatic effects on plant phenology and reproduction, with important consequences for reproductive output, plant survivorship, or species dispersal. In seagrasses, vegetative growth through clonal expansion is generally the dominant strategy for meadow maintenance, expansion and recovery, with sexual reproduction strongly differing amongst species, being rare for some, and some times associated with disturbance. Even rarer is the occurrence of pseudovivipary, an uncommon phenomenon in the plant realm, which has only been reported twice before in the marine environment as highly localized phenomena associated with environmental stress. Pseudovivipary is an asexual reproduction strategy whereby plantlets replace sexual reproductive structures, leading to the maintenance of the maternal clones. In summer of 2022, the Mediterranean Sea underwent unprecedented warming, and, associated with it, we observed extensive flowering (100% of sites) as well as pseudovivipary across numerous (>85 % of 36 sites) Posidonia oceanica meadows along the Balearic Islands. Our results support the notion that P. oceanica flowering is triggered under high warming but also, and importantly, this is the first time ever that pseudovivipary is reported across so many locations in a marine plant, and the fate of these plantlets is being monitored by assessing development, survivorship and dispersal through time. Considering the negative impacts that warming can have on seagrass ecosystems, the discovery of widespread pseudovivipary is a critical aspect to consider for understanding mechanisms of resilience in seagrasses.

TREC: a scientific voyage to address environmental challenges

Dr Kiley West Seitz - EMBL

TREC (TRaversing European Coastlines) is the European Molecular Biological Laboratory’s flagship Scientific expedition to study coastal ecosystems at molecular level. The expedition studies coastal regions which are known for their extremely rich biodiversity and plays a critical role in the stability and sustainability of ecosystems at planetary scale. These ecosystems are drastically affected by global changes & local human impacts making the study of them critical to understanding the climate crisis. For the TREC expedition, we employ a holistic cross sectional sampling approach along the land-sea gradient using highly standardized protocols. This systematic approach allows us to study the coastal ecosystems at the molecular level across pollution gradients, organismal scales, life complexity and time scales. 

The TREC expedition started in April 2023 and is expected to last until end of July 2024. During that time, the researchers will be gathering biological samples and environmental data along the European coastline at more than 120 land-sea transects. Mallorca is one of the sampling sites of the expedition, and IMEDEA is hosting and supporting the TREC team during their campaign on the island.

As part of this seminar you will learn about the project and you will visit the traveling labs parked at IMEDEA.