Physiognomy and structure of a caatinga with Cordia oncocalyx (Boraginaceae), a new type of community in Andrade-Lima's classification of caatingas

recently, the inclusion of physiognomies with cordia oncocalyx allem？o (boraginaceae) as a new type/unit within andrade-lima's classification of caatingas (alfpc) has been proposed. however, no study has quantitatively analyzed this proposal so far. in order to fill this gap, a phytosociological study was conducted in a caatinga with c. oncocalyx, and differences in structure and physiognomy in relation to compiled caatinga studies were verified. 1795 plants from 25 species and a total basal area of 35.26 m2 were found. c. oncocalyx and mimosa caesalpiniifolia benth. (fabaceae) had 48% of total importance index (iv). the physiognomy was characterized by the predominance of individuals of intermediate height (3？4 m) and the tallest ones accounted for the highest fraction of basal area. of the five species with highest iv, only one had high frequency among the species with highest iv in the compiled studies (16/35). only two of these compiled studies were comparable to the present study, and only one could be classified according to alfpc. a contrast between that study and the present one was found, as the first reports a dense community with high number of small diameter individuals accounting for most of the basal area. these findings suggest the suitability of including c. oncocalyx caatingas in low and medium caatinga forests as proposed in alfpc. however, the low number of comparable studies limits generalizations.