An integrated analysis of coastal dune vegetation patterns on sandy substrates

Abstract

The aim of this study was to analyse the current state of vegetation patterns on Maltese sandy substrates, namely coastal dune environments. Another goal of this study was to assess the relationship between soil granulometric properties and the distribution and extent of various plant species occurring along these sandy substrates. By applying a combination of classical and modern techniques, a thorough survey of vegetation patterns along the remaining sand dune environments and other sandy substrates locally was conducted, addressing a considerable data gap locally. Results indicate that populations of dune-specific plant species are on the decline when compared to other records from studies carried out in the late 20th and early 21st centuries. An increase in both natural and anthropogenic pressures has been observed to continually restrain these coastal biotopes, further constraining biotope growth, hence lowering population size and evenness. With respect to the granulometric properties, various substrates were found to contain an abundance of artificial material, suggesting that anthropogenic influence on these substrates is much greater than anticipated. The presence in large quantities of these materials often stimulated the growth of ruderal and invasive species. The expansive occurrence of these invasive species has driven out native dune specific species out of most coastal dune environments locally. Only a handful of sites are still capable of supporting relatively intact dune ridge morphology and the associated vegetation populations. As highlighted in other parts of the study, these results provide a baseline for local researchers and authorities to monitor and manage these fragile coastal environments. Whilst results obtained address a critical information gap, the field of study is very vast; hence other surveys must be carried out further to this study to continue to further understand the complex relationship of both biotic and abiotic processes interacting along these dune environments.