Biogeography pattern of the marine angiosperm Cymodocea nodosa in the eastern Mediterranean Sea related to the quaternary climatic changes

Abstract

We investigated the population dynamics of a highly clonal marine angiosperm, Cymodocea nodosa , in the eastern Mediterranean Sea, to identify the historical dynamics, demography, and connectivity of the species in the area. Eighteen microsatellite loci were used in conjunction with coalescent methods to investigate the genetic structure and demographic history of C. nodosa meadows. Approximate Bayesian computation (ABC) modeling was used to examine the pattern of divergence over time in the context of environmental change over the course of the Quaternary period. ABC analysis revealed an initial split of the C. nodosa populations between the north‐western, northern, and north‐eastern Aegean Sea during the Pleistocene epoch, followed by a more recent divergence of the north‐western population and the central‐western part of the Aegean Sea. According to the results, the most parsimonious historical scenario is that of a pervasive genetic signature of the effects of the drop in sea level during the Pleistocene epoch. This scenario supports the isolation of the north‐western, north, and north‐eastern area, and the subsequent recolonization after post‐glaciation sea level rise that may explain the north‐western differentiation as well present‐day detected dispersion of C. nodosa .

Salinity as a Key Factor in Structuring Macrophyte Assemblages in Transitional Water Bodies: The Case of the Apulian Coastal Lagoons (Southern Italy)

“…Besides the crucial role of salinity, the topology of T-WBs, also involving their degree of fragmentation and their size, may influence the Species Richness of macrophytes. In fact, we observed that the sampling stations placed in uninterrupted and/or wider T-WBs (such as LE1, LE2, LE3, VA, PC, MP1 and MP2) had a higher number of macrophyte species with respect to sampling stations placed in patchy and smaller T-WBs (this is the case of TG, PU and CE), confirming the role of habitat fragmentation and habitat size in enhancing biodiversity, as proved in previous studies [74,75]. Moreover, the degree of confinement of T-WBs, besides influencing the qualitative composition of macrophyte assemblages (see above), can also play a role in affecting Species Richness, even at a sampling station scale.…”

Predictive Mapping of Mediterranean Seagrasses-Exploring the Influence of Seafloor Light and Wave Energy on Their Fine-Scale Spatial Variability

“…Studies that aimed at correlating various abiotic environmental parameters, such as light [44][45][46], temperature, and nutrients [47], to the growth and spatial distribution of the P. oceanica meadows indicated that light limitation is the main driver differentiating their distribution at large-scale local and sub-ecoregional levels. Similar efforts addressing the biogeographic patterns and assessing the natural drivers affecting the marine angiosperm C. nodosa can be found in [48,49]. Temperature and salinity seem to be the main limiting factors for C. nodosa [50], while it has considerable resilience to light deprivation due to its intrinsic arrangement of the pigment pool [51,52].…”

Effects of flooding on the Mediterranean Cymodocea nodosa population in relation to environmental degradation

“…Shoots from Vrasidas exhibited more sun-adapted behaviour under both conditions than Nea Karvali shoots, which showed more shade-adapted characteristics. Since the treated shoots are derived from genetically identical populations (Vrasidas and Nea Karvali; Konstantinidis et al 2022), this variation in the shoots' ability to capture light could be explained by phenotypic plastic differences as the plant can modify its physiology, biochemistry, behaviour, and morphology in response to environmental changes (Bulleri et al 2018).…”

“…Temperature but mainly salinity affect multiple biological levels, from molecular to sub-cellular and physiological, decreasing the species' growth and fitness (Tsioli et al 2022). The evolutionary implications of differential transcriptome genotypes of osmotic and temperature stress (Malandrakis et al 2017), along with the significant diversity among different geographical areas in the Eastern Mediterranean Sea (Gkafas et al 2016, Konstantinidis et al 2022 showed the genotypespecific strategy of the species for colonization and adaptation to habitats. However, in the Mediterranean Sea and the Canary Islands, Cymodocea nodosa meadows (Tuya et al 2014) are declining because of light and nutrient availability and turbidity caused by anthropogenic pressures (Hemminga and Duarte 2000, Papathanasiou et al 2016, Papathanasiou and Orfanidis 2018, Najdek et al 2020.…”