The vegetation of the blue clay slopes of the Maltese islands

Abstract

Blue Clay slopes are a characteristic feature of the Maltese Islands and are mostly found along the Upper Coralline plateaux of Malta and Gozo. The slopes are dynamic systems that are geomorphologically active and are subject to various disturbances. Thus, they support an ecosystem which is in a state of flux. Slope dynamics are influenced by intensity of rainfall which promotes soil erosion. Sixty-seven macrophytic species were recorded in the clay slopes investigated. The slope community is steppic in character, although enclaves of maquis and garigue communities occur frequently where springs emerge. Vegetation characteristic of disturbed ground was found near the main paths. Vegetational diversity is generally low and a small number of species predominate in terms of abundance. Lygeum spartum is the most widely occurring plant. The slope community also comprises various opportunistic species such as Oxalis pes caprae which exploit transient gaps in the community. Such gaps are the result of disturbances including soil creep and trampling. The vegetation is characterised by a distinct seasonal succession. This is due to the entry into and departure from the community of a small number of species. This succession 1s dependent on frequency and intensity of precipitation and is therefore allogenic.