Experimental climate change impacts on Baltic coastal wetland plant communities

Abstract

Coastal wetlands provide a range of important ecosystem services, yet they are under threat from a range of stressors including climate change. This is predominantly as a result of alterations to the hydroregime and associated edaphic factors. We used a three-year mesocosm experiment to assess changes in coastal plant community composition for three plant communities in response to altered water level and salinity scenarios. Species richness and abundance were calculated by year and abundance was plotted using rank abundance curves. The permutational multivariate analysis of variance with Bray–Curtis dissimilarity was used to examine differences among treatments in plant community composition. A Non-metric Multi-dimensional Scaling analysis (NMDS) was used to visualize the responses of communities to treatments by year. Results showed that all three plant communities responded differently to altered water levels and salinity. Species richness and abundance increased significantly in an Open Pioneer plant community while Lower and Upper Shore plant communities showed less change. Species abundances changed in all plant communities with shifts in species composition significantly influenced by temporal effects and treatment. The observed responses to experimentally altered conditions highlight the need for conservation of these important ecosystems in the face of predicted climate change, since these habitats are important for wading birds and livestock grazing.

Halophytic Clonal Plant Species: Important Functional Aspects for Existence in Heterogeneous Saline Habitats

“…Agrostis stolonifera can be found in different successional zones of the beach plain with various flooding-salinity regimes, even being dominant in some of them [31]. In the Baltic coastal wetlands, A. stolonifera is the most abundant species on the lower shore, being abundant also on the upper shore and present in open pioneer communities [19]. With a frequency of 33%, the species occurs in Central European inland salt marshes at maximum soil salinity EC e 118.0 dS m −1 [30].…”

“…In the Netherlands, three subspecies of F. rubra have been recognized depending on the location of their habitat [171]. In Baltic coastal wetlands, F. rubra is one of the most abundant species in lower-shore and upper-shore communities [19]. In Central European inland salt marshes, the species occurs with a relatively high frequency (17%) and can be found on soils with a maximum salinity of EC e 25.7 dS m −1 [30].…”

“…For example, when coastal habitats, associated with strandlines, are considered, it is stressed that strandline "colonist species" (plants being able to establish in these habitats) in the majority are "clonal perennials with extensive rhizomatous or stoloniferous growth" [16]. As salinity is one of the major factors controlling species distribution and abundance in coastal habitats [17][18][19], it would be logical to ask how salinity affects aspects of clonal growth in coastal species. Surprisingly, the presence of clonal growth characteristics is largely a neglected aspect in plant salinity tolerance studies, and so far, no study has focused in particular on halophytic clonal plant species.…”

Dual-season comparison of OBIA and pixel-based approaches for coastal wetland classification

“…Most of the studies use only one image date to map and classify wetlands. However, the landscape of coastal wetlands is dynamic, showing strong seasonal fluctuations in water levels and growth and senescence of vegetation (Daí et al, 2019;Bergamo et al, 2022). Both backscatter in SAR images and reflectance in optical images are strongly affected by these seasonal changes (Furtado et al, 2016;Prudente et al, 2022), justifying the importance of dual-season analysis.…”

A cross-continental analysis of the habitat requirements for stable Black-tailed Godwit (Limosa l. limosa) populations in Europe

“…Sites ranged from 32.8 to 86.2 ha, all managed through AES requirements by cattle grazing (at least 50% of short swards) and known to be key wader breeding areas (Estonian Environmental Agency 2019). We identified four plant communities commonly occurring in Estonian coastal meadows, which have been previously described in detail: Lower shore (LS), Upper shore (US), Open pioneer (OP) and Tallgrass (TG; Bergamo et al, 2022;Burnside et al, 2007;Villoslada et al, 2021). The composition and distribution of plant communities in Estonian coastal meadows are mainly driven by the brackish conditions in the Baltic Sea and seasonal flooding driven by storm surges (Ward et al 2016).…”