2 88 CAIN, DE OLIVEIRA CASTRO, PIRES, AND DA SILVA 



Table 9. Tree species having the largest basal area on a sample plot of equatorial 



rain forest at Mucambo 



Species 



Basal area, 

 sq. dm. 



Relative basal area, 

 per cent of total 



Vochysia guianensis 



Goupia glabra 



Echweilera odora 



Trattinikia sp.? "Sucuruba" 

 Eschweilera krukovii 



Parkia pendiila 



Anacardinm giganteum . . . 



Vantanea cupidaris 



Protium sp.? "Breu mescla" 

 Chimarrhis turbinata 



Caryocar microcarpum . . . . 



Protimn trifoliolatum 



Pourouma myrmecophila . . 



Piptadenia suaveolens 



Protium nodulosum 



Sterculia pruriens 



Vouacapoua americana .... 

 Pithecolobium jupunba . . . . 



Protium carnosum 



Qualea albiflora 



Neea sp.? 



Enterlobium schomburgkii . 



Trattinikia rhoifolia 



Caryocar villosum 



Sapotaceae, Gen. sp.? 



of all species (table 10). By the use of relative measures it becomes possible 

 to add up the otherwise disparate data of number (density), basal area (dom- 

 inance), and occurrence (frequency). Although calculations have been made 

 for all the species on the 2-hectare plot, these tables show in each case only 

 the relatively small number of leading species. Only 25 species have a relative 

 density of more than 1 per cent and a relative basal area of more than 1 per 

 cent. Only 18 species have frequencies in classes D and E and exceed relative 

 frequencies of about 1.25 per cent. 



