Abstract
Seagrasses form a unique group of submerged marine angiosperms capable of both sexual and asexual reproduction. The amounts of sexual and asexual reproduction differ within some species relying on geographic location and environmental factors. Here, we studied the reproductive strategies of different geographic Zostera japonica populations, S1 and S2 at Swan Lake lagoon (SLL), and H1 and H2 at Huiquan Bay (HQB), in northern China. The duration of flowering at SLL was longer than at HQB, whereas flowering initiation at HQB occurred earlier than at SLL. In addition, the timing of seed maturation at HQB occurred earlier than at SLL. The allocation to sexual reproduction at SLL was greater than at HQB. The maximum potential seed production was greatest at S1 (22228.52 ± 8832.46 seeds ⋅ m–2), followed by S2 (21630.34 ± 9378.67 seeds ⋅ m–2), H2 (7459.60 ± 1779.33 seeds ⋅ m–2), and H1 (2821.05 ± 1280.57 seeds ⋅ m–2). The seasonal changes in total shoot density and biomass were small at HQB. There was a relatively large number of overwintering shoots at HQB because of the higher average temperature during winter. The allocation to sexual reproduction was lower than at SLL, and no seedlings were observed at HQB during our study. Thus, the population of Z. japonica at HQB was maintained by asexual reproduction. Compared with HQB, the biomass of overwintering shoots at SLL was less than 30 g dry weight ⋅ m–2. The Z. japonica at SLL relied on asexual and sexual reproduction to maintain the population. The results show the necessity of understanding local reproductive strategies before starting restoration and management projects. The study provides fundamental information and guidance for the conservation and restoration of seagrass beds.
Highlights
Seagrasses form a unique group of angiosperms that have evolved a series of structural and genomic modifications to survive in the world’s oceans (Olsen et al, 2016)
We report the differences in reproductive strategies of Z. japonica under different geographic and environmental conditions in northern China
The seasonal changes in total shoot density and biomass were small in Huiquan Bay (HQB)
Summary
Seagrasses form a unique group of angiosperms that have evolved a series of structural and genomic modifications to survive in the world’s oceans (Olsen et al, 2016). Effective management programs and active restoration work are becoming increasingly important (Zhou et al, 2014; Unsworth et al, 2015; CullenUnsworth and Unsworth, 2016; van Katwijk et al, 2016; Lefcheck et al, 2017) Understanding their reproductive strategies is essential for the conservation, management, and restoration of seagrasses. It is usually assumed that the recruitment of seagrass populations occurs mainly through asexual reproduction (Williams, 1990; Procaccini and Mazzella, 1998; Rasheed, 2004). Rasheed (1999) found that the recolonization of artificially cleared plots in a seagrass meadow dominated by Zostera capricorni occurred principally by asexual growth from surrounding rhizomes. In which there is few remnant seagrass available, initial recolonization may occur by seeding (Marba and Walker, 1999; Greve et al, 2005; Lee et al, 2007)
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
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.
