Microsatellite data of 14 Avicennia marina populations from Mozambique Channel area
Triest, Ludwig (2020), Microsatellite data of 14 Avicennia marina populations from Mozambique Channel area, Dryad, Dataset, https://doi.org/10.5061/dryad.8pk0p2nkt
Mangrove forests are dynamic ecosystems found along sheltered low-lying coastal plains in warm-temperate, tropical and subtropical regions, predominantly on tidal flats, deltas, estuaries, bays, but also on oceanic atolls. These landforms present varied hydrodynamic and geomorphological settings for mangroves to establish and could influence the extent of propagule transport and subsequent regeneration. In this study, we examined whether these landform characteristics influence the genetic diversity and structure of Avicennia marina, one of the most abundant and widespread mangrove species. To do so, we considered 14 populations located in estuarine and coastal bay environments spread across the Western Indian Ocean region. A transect approach was considered to estimate kinship-based fine-scale spatial genetic structure using fifteen polymorphic microsatellite markers in 475 adult A. marina trees from 14 different populations. No overall significant difference was found in the levels of allele or gene diversities between coastal bay and estuarine populations. However, some South African estuarine populations showed strong inbreeding levels that are most likely due to the recurrent closing of the river mouth, lowering the chance of external propagule input. Elevated kinship values and significant fine-scale spatial genetic structure up to 30 m, 60 m or 90 m distance were detected in all coastal bays, indicating a topographic setting suitable for propagule retention and establishment within a neighborhood. Slopes of a linear regression over restricted distance within 150 m were significantly declining in each sheltered transect. Contrastingly, such a spatial structure could not be detected for transects along the rivers of the estuarine systems considered, suggesting that recruitment here is governed by unrelated carried-away mixed-origin propagules. In general, we have shown that A. marina populations can locally experience different modes of propagule movement, explained from their position in estuaries. Thus, the resilience and natural regeneration of mangroves is achieved by different mechanisms for settings with different hydrodynamic conditions, which can be important information for their management and protection within the variety of coastal environments.