A vegetation survey of Wied Dalam, Birżebbuġa, Malta, for October 2024 to May 2025

Abstract

The valley of Wied Dalam (Birżebbuġa, Malta) was surveyed four times (from October 2024 till May 2025), to investigate the plant species composition, species density, and the most dominant species in each habitat type, following ecological restoration and management initiatives carried out in the locality in recent years. This was carried out using a belt transect (3 m) with a quadrat (1 × 1 m), and results were analysed using the Braun-Blanquet Scale. The western side of the valley had a higher species richness of maquis undergrowth species, especially at high densities of Arundo donax L. and Ceratonia siliqua L., while the eastern side of the valley had more ruderal and arid-tolerant species typical of open ground. Species composition and abundance differed due to seasonal conditions and recent anthropogenic disturbance. The rare Allium triquetrum L., and the scarce Glebionis segetum (L.) Fourr., Poa annua L., and Scandix pecten-veneris L. were noted. Numerous plant species that were recorded in past studies were not observed during the surveys, while several invasive plant species still persist throughout the valley. These findings highlight the current situation regarding vegetation composition as present at Wied Dalam throughout the sampling year 2024–2025, as well the importance of long-term vegetation monitoring following ecological restoration actions, such as those undertaken in this location.