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- Sexual reproduction vs. clonal propagation in the recovery of a seagrass meadow after an extreme weather eventPublication . Paulo, Diogo; Diekmann, Onno; Ramos, Ana; Alberto, Filipe; Serrao, EsterMarine flowering plants can reproduce sexually and clonally, and the relative contribution of these two modes can be dependent on the environmental conditions. Zostera marina, a seagrass widely distributed in the northern hemisphere, can form annual and perennial meadows with different proportions of sexual versus clonal propagation depending on the environmental disturbance regime. We study the hypothesis that the contribution of sexual propagation varies during the recovery of a seagrass meadow. In this case study, we compare the proportion of sexual versus clonal propagation of a perennial Z. marina meadow before its disappearance due to winter storms and after recovery. Before disturbance, genotypic diversity was high, indicating frequent sexual reproduction events likely to create an abundant seed bank. Seedling germination allowed the population to recover after the extreme disturbance. As months passed, seedlings became rare and finally absent, giving place to adult shoots. In an advanced stage of colonization, the shoots colonized the area by vegetative growth, which lowered the genotypic diversity. Despite this reduction over time, the genotypic diversity of the new meadow is still high, demonstrating the importance of sexual reproduction in meadow recovery and persistence.
- Less is more: seagrass restoration success using less vegetation per areaPublication . Mourato, Carolina; Padrão, Nuno; Serrao, Ester A.; Paulo, DiogoSeagrass restoration in open coast environments presents unique challenges. Traditional sod transplant designs, though relatively successful in these environments, are impractical for large-scale restoration due to high biomass requirements. Here, we develop the checkers design, which aims to optimise the usage of biomass by transplanting fewer sods in a checkerboard pattern. We established six plots (9 m2 each) for each species (Zostera marina and Zostera noltei), with 25 sods in each plot. The area, percent cover, density, and leaf length were measured at 1, 6, and 12 months. The plots located on the seaward end of the transplant design vanished over the winter, suggesting location-dependent survival influenced by winter storms. Nevertheless, both species exhibited increased percentages of cover, density, and vegetated area after one year, with variations between species. Z. noltei showed a slower expansion but greater resilience to winter, while Z. marina displayed a higher density and cover over the first 6 months but experienced area loss during the winter. Despite these differences, both species survived and increased vegetated areas after one year, indicating the viability and promise of the checkers method for large-scale restoration. However, careful consideration of location or storm-mitigating measures is essential for the successful implementation of this method.