292 CAIN, DE OLIVEIRA CASTRO, PIRES, AND DA SILVA 



Table 12. The leading tree species of equatorial rain forest at Mucambo arranged 

 by families and the sums of the importance value indexes of the species 



Family Number of species Importance value 



Burseraceae 



Lecythidaceae 



Vochysiaceae 



Leguminosae 



Sapotaceae 



Celastraceae 



Myristicaceae 



Sterculiaceae 



Anacardiaceae 



Guttiferae 



Moraceae 



Humiriaceae 



Icacinaceae 



Caryocaraceae 



Rubiaceae 



Dichapetalaceae 



Olacaceae 



Rosaceae 



Nyctaginaceae 



19 families 44 



been known that the vegetation of equatorial humid regions — the various 

 types of rain forest — is predominantly woody, with many medium and tall 

 trees. This is the vegetation of phanerophytic dominance that exists in 

 Raunkiaer's "phanerophytic climate." Our analysis of the vegetation at Mu- 

 cambo is given in table 15, where it is seen that 74.3 per cent of the known 

 flora of the sample plot is made up of true phanerophytes. When the lianas 

 and vascular epiphytes are distributed among the sub-classes of phanerophytes 

 according to the maximum height they attain, the percentage of total phan- 

 erophytes jumps to 95.37 per cent. The sub-class of tall trees (exceeding 30 

 m.) contains 22.48 per cent of the flora; that of medium-sized trees (8 to 

 30 m.) contains 39.45 per cent; small trees (2 to 8 m.) make up only 1.38 

 per cent; and shrubs (0.25 to 2 m.) are 11.01 per cent. Lianas and epiphytes 

 are fairly abundant, being 12.84 per cent and 8.25 per cent, respectively. 

 The other classes in which the perennating buds receive progressively more 

 protection are all so small as to be essentially insignificant, and annuals 

 (therophytes) are completely missing from among the total of 218 species 

 on the plot that have been analyzed for life form. 



