A synecological study of communities with Santolina corsica Jordan et Fourr.

S. corsica is endemic to Corsica (France) and Sardinia (Italy), with the main distributional area in central-northern Corsica. The distribution and floristic composition of the communities with S. corsica were studied in relation to different environmental parameters such as altitude, geology and soil. The data was analysed by numerical methods: two-way indicator species (TWINSPAN) and Canonical Correspondence Analysis (CCA). TWINSPAN classification of 39 relevés revealed seven different community groups which were interpreted as belonging to a new subassociation of Stachydi-Genistetum in the alliance Teucrion mari and to Helichryso-Santolinetalia. The floristic composition of the communities studied was significantly correlated with the gradient of soil evolution. Another important factor was interpreted to be substrate coherence/incoherence. The altitude/temperature gradient was not correlated with the floristic composition of the different communities. Several communities were regeneration stages after cultivation or grazing, and others seemed to be relatively unaffected by human activity. The ecological optimum for S. corsica was in the former, in codominance with Helichrysum italicum.