Ecophysiology of the endemic plants of the Balearic Islands in the Mediterranean context

Abstract

Galmes, J., Conesa, M.A., Cifre, J., Gulías, J., Medrano, H., Ribas-Carbó, M., Flexas, J. (2010). Ecophysiology of the endemic plants of the Balearic Islands in the Mediterranean context. Ecosistemas 19(1):10-23.

Many endemic species in the West Mediterranean usually inhabit rocky, open, and highly stressful environments with low interespecific competition. In the Balearic Islands, in  addition to such geologic-edaphic dimension, endemic species are subject to geographic isolation. Regardless of these two constraints, geologic-edaphic distribution and geographic restriction, studies reporting physiological factors as being the general causes of the limited distribution of endemic species are scarce. This fact suggests that the geographic distribution of endemisms of the Balearic Islands is mainly limited by historical filters, whereas their habitat distribution would fit a ‘refugee hypothesis’, i.e. the endemic species only inhabit environments whose high level of stress excludes the presence of generalist species. The low interespecific competence in these environments permits the survivorship of certain endemic species with particular traits, which would be potentially disadvantageous in other environments. Finally, the analysis of three specific cases of endemicity (Crepis triasii, Lysimachia minoricensis and Digitalis minor) illustrates that low phenotypic plasticity of endemic species is not a general trend, and that some of the Balearic endemisms present a high capacity to adapt to changing environments, in particular to water stress. An improved knowledge of the physiological basis for the lack of ecological success of endemic species may be necessary as a tool for a correct management of biodiversity in these areas.