Abstract
Marine 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.
Highlights
Seagrasses are declining worldwide due to human and natural causes (Waycott et al 2009), leading to loss of their important ecosystem functions (Hemminga and Duarte 2000)
Summary: Marine flowering plants can reproduce sexually and clonally, and the relative contribution of these two modes can be dependent on the environmental conditions
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
Summary
Seagrasses are declining worldwide due to human and natural causes (Waycott et al 2009), leading to loss of their important ecosystem functions (Hemminga and Duarte 2000). Clonal propagation is the major mode of space occupation for many seagrasses (Marbà and Duarte 1998), under some environmental conditions sexual reproduction can be very important in population persistence and in particular for recovery from disturbances (Greve et al 2005, Bell et al 2008, Park et al 2011). Hughes and Stachowicz 2004, Massa et al 2013, Evans et al 2017) These studies report that higher genotypic diversity can have several positive effects on the response to perturbations, including increased resistance to loss and faster recovery. A better understanding of how seagrass meadows recover from extreme events and of the relative role of sexual versus clonal propagation (i.e. genotypic diversity) may be an important concern in conservation and management decisions (Reusch et al 2005, Qin et al 2014). This paper aims to focus on understanding the relationship between sexual versus clonal propagation and disturbance over a multi-year time scale
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
