Compara??o da vegeta??o arbustivo-arbórea de uma área de cerrado rupestre na Chapada dos Veadeiros, Goiás, e áreas de cerrado sentido restrito do Bioma Cerrado

摘要

The floristic composition and the structure of a savanna on rocky soil (cerrado rupestre) tree-shrub community, including monocots, in the municipality of Alto Paraíso de Goiás, state of Goiás, were determined. Our objectives were: 1. To compare floristic and structural aspects between the tree-shrub community studied and 14 other cerrado sensu stricto areas, with and without monocots. 2. To evaluate phytogeography patterns of the 15 compared areas. We sampled 71 species, including five monocots (Velloziaceae/ =/ 3; Arecaceae/ =/ 2). Including monocots, the studied community was the most dense (1,977 individuals ha-1) and showed the second basal area (11.25/ m2/ ha-1) among the 15 compared areas. On the other hand, excluding monocots, density and basal area decreased to 892 individuals ha-1 e 7.55/ m2/ ha-1, respectively. The diversity and equability indices were low (H'/?=/ 2.81; J'/?=/ 0.66, respectively) when monocots were included; however, excluding species of this group, H' and J' increased to 3.63 and 0.86, respectively. Increases in richness, density and basal area, with the inclusion of monocots, suggested high importance of Velloziaceae and Arecaceae families in the studied community. The flora was mostly represented by deep-soil cerrado species. Nevertheless, five of the ten highest IV species are considered cerrado rupestre habitat specialists (Vellozia variabilis Mart. ex Schult. f., Wunderlichia cruelsiana Taub., Schwartzia adamantium (Cambess.) Bedell ex Giraldo-Ca?as, Hyptis pachyphylla Epling and Vellozia tubiflora (A. Rich.) Kunth). Moreover, the low floristic similarities between the studied community and the others suggest floristic particularity of the Alto Paraíso de Goiás rocky cerrado. The phytogeographical patterns revealed through cluster (UPGMA) and ordination (DCA) analyses indicated the influence of altitude, of geographical closeness between the areas and of their location in relation to the Cerrado neighboring biomes (Amazonian Forest, Atlantic Forest and Caatinga).