An investigation of the vegetation of Wied Għollieqa (Malta) with a plan for its restoration as a protected area

Abstract

Wied Ghollieqa was declared a Bird Sanctuary in January 1994. This study involves a detailed description of the vegetation found at Wied Ghollieqa to assess the vegetational communities present. Line transects and quadrats were employed to identify the dominant, and other species in various parts of the valley. l'rees higher than 1.5m were lndlvldually mapped. Soll and wale1 !>ample!> we1e aho used to assess the abiotic factors present in the valley. The soil depths of various areas of the pond were also taken to determine if this was acting as a limiting factor for growth in size of certain species. Species were classified according to Raunkiaer's Life Forms. The number of very abundant species was found by calculating Hill's Dominance Indices for the raw data obtained. Over half of the species present in the valley were found to be typical of disturbed or degraded areas (ruderals). In all the areas sampled, more than half of the most dominant species were found to be ruderals. Some like Galactites tomentosa were common throughout. Several of the species present are typical pests of agricultural land. Most of the valley was extensively cultivated in the past, and some areas are still being used today. The valleybed had the greatest proportion of native/archaeophytic trees, including Ceratonia siliqua and Crataegus monogyna. Lianes, such as Hedera helix and Clematis cirrhosa are also very common. It also supports a very rich population of fungi, one of which is Aurificaria indica, for which this valley provided the first record from Europe. The fungal population has declined over these last fifteen years, mainly as a direct result of disturbance. A pond exists which fills up throughout the winter, supporting several hydrophytes like Rumex conglomeratus. Several native trees were also introduced by Arbor for reforestation, including Populus alba. A plan for the restoration of the valley was then prepared. This involved the division of the valley in various sections and a restoration plan made for each area according to the habitat available. Eventually plans for the construction of an Oak woodland, Alerce woodland, Riparian woodland, maquis and garigue were prepared. This was accompanied by a management plan which involved the setting up of a wardening system to control the management within the valley, together with the construction of a series of nature trails which would bring visitors closer to the reconstructed ecosystems.