Ecomorphology and phenomorphology of Mediterranean heathlands (SW Iberian Peninsula)
Latorre, Andrés Vicente Pérez; Gavira, Oscar; Cabezudo, Baltasar
The ecomorphology and phenomorphology of heathlands bordering the Strait of Gibraltar (S. Spain) have been studied in what constitutes the southern limit of this type of vegetation in Europe and which is characterised by other floristic and phytosociological singularities. Despite the high rainfall of its habitat, this heathland shows typical Mediterranean adaptations, which has resulted in a mixture of Euro-Atlantic species adapted to summer drought, and Mediterranean endemisms. The phenophasic calendar of the heathland is as follows: maximum flower bud formation, flowering and growth in spring; fruit setting between spring and summer; dolichoblast leaf shedding in summer, and seed dispersal between summer and autumn. The phenophasic index RVA (balance between reproductive and vegetative phenophases) is very low in some species of the heathland and contributes to the differentiation of this vegetation from other Mediterranean communities studied. Although these heathlands are similar in some of their phenophasic aspects to other shrublands ("matorrales") of the Mediterranean Basin (similar seasons for seed dispersal, dolichoblast leaf shedding, brachyblast vegetative growth and APC index = period of active phenophases in the community) they can be ecomorphologically differentiated by their stratification into two sub-layer, lower leaf area, longer leaf duration and lower estimated biomass. Furthermore these South-Iberian heathlands have a greater diversity of coenomorphs (group of species with similar morpho-functional strategies) than other Mediterranean communities studied, which suggests that functional groups of species have converged in this area, where they develop different adaptations to the same environmental conditions. Some species of the heathland studied stand out from the rest due to their peculiar phenophasic and ecomorphological characteristics: e.g. Drosophyllum lusitanicum, Argantoniella salzmanii and Polygala microphylla.