A phytogeographic analysis of cloud forests and other forest subtypes amidst the Atlantic forests in south and southeast Brazil

Abstract

In a previous study near the summit of Mt. Cuscuzeiro (Ubatuba, SP) (820–1270 m), on the SE Brazilian coast, we found two floristically different forests, one above 1120 m, that appears to have a number of features typical of cloud forests, and another on the lower altitude slopes below. Taking these two forests as reference points, we addressed two questions: (1) What are their floristic relationships with other Atlantic forest subtypes in S-SE Brazil?; (2) Do the cloud forests in this region constitute a particular floristic-phytogeographic formation or are they a subset of their surrounding community? Species from 109 surveys (including Mount Cuscuzeiro) of 83 locations in S-SE Brazil were compiled into a binary (presence-absence) floristic matrix. Analyses of similarity among these samples using clustering (UPGMA, TWINSPAN) and ordination (DCA, PCO and CA) methods were performed. The surveys were divided into six main groups: (1) Cloud Forests; (2) “Salesopolis” group (3) Coastal Forests, subdivided between (a) Slope Forests and (b) Coastal Plain (“Restinga”) Forests and Mountaintop Forests (not included in the Cloud Forests group); (4) Araucaria Forests; (5) Inland Seasonal Forests (from below ca. 700 m); and (6) Inland Montane Forests (from above ca. 700 m). The preferential and indicator species of the Cloud Forest group produced by TWINSPAN are presented. The Mount Cuscuzeiro forests from above and from below 1120 m were clustered with the Cloud Forests and the coastal Slope Forests groups, respectively. We concluded that Cloud forests comprise a distinct phytogeographic formation in Brazilian S-SE region.