Spatial distribution of Araceae on phorophytes in different areas of submontane rainforest, Santa Catarina Island (SC), Southern Brazil

Araceae is well represented in Brazil but there are few studies on spatial distribution of species on phorophytes. Aiming to analyze vegetation variations, four different areas of submontane rainforest were studied: bottom of valley (BV); middle slope (MS); mountaintop (M); and rocky mountaintop (RM) in Santa Catarina Island, southern Brazil. To study the aroids, the quadrant points method with 60 phorophyte sampled by area was used. Each phorophyte was divided in 2-m-height intervals to obtain the vertical distribution. Eight species of aroids belonging to four genera were recorded, among which Anthurium Schott and Philodendron Schott were the most representative. Species richness, Shannon diversity, and evenness index were the highest in MS and the lowest in RM. The most similar areas were MS and M ( J = 0.88). Most species of aroids showed low horizontal and vertical frequency; however, the aroids were present in 35.4 % of the phorophytes surveyed; 60 % of families and 50 % of phorophyte species sampled; and 8.9 % of the height intervals sampled. The occurrence of the species in the strata close to the ground and intermediates may be related to the prevalence of nomadic vine species. Species of aroids showed no specificity for host tree.