APPLICATION OF PHYTOSOCIOLOGICAL TECHNIQUES 303 



we had not ascertained. On this basis, 206 (95.37 per cent) of the 216 species 

 are phanerophytic. The largest sub-class is mesophanerophytic, although 49 

 species (22.69 per cent) are megaphanerophytic, exceeding 30 m. height. Ac- 

 cording to the initial lists of Murga Pires, the plot contained 173 species of 

 trees that were 1 dm. or more in diameter. Our measurement of the trees 

 of the plot reduced this number somewhat by elimination of trees that did 

 not quite reach 1 dm. d.b.h. (diameter at 4.5 feet above the ground), but all 

 of them do attain tree size elsewhere, if not on the plot. Such data not only 

 show the reality of the phanerophytic dominance, taxonomically as well as 

 physiognomically, but affirm Raunkiaer's designation of a phanerophytic cli- 

 mate for the constantly humid tropics. Although there is an impressive num- 

 ber of lianas (28 species, 12.84 per cent), terra firme rain forest of this type 

 is not as rich in them as some other types. High forest is likewise not as rich 

 in vascular (or for that matter, cryptogamic) epiphytes as are some other 

 types, especially those of the coastal mountains. No climbing was done to 

 obtain epiphytes from the forest crown, and many species may have been 

 missed, but heavy storms had brought down many branches bearing epiphytes, 

 so that our list is probably representative. 



Turning now to leaf-size classes, we find a strong predominance in the 

 mesophyll class (149 species, 68.35 per cent). Species with large leaves of the 

 macrophyll class have a fair representation (24 species, 11 per cent), and the 

 class of largest leaves, megaphylls, is completely missing. Comparing the two 

 highest life-form classes, we find a consistent tendency for the leaves to be 

 somewhat smaller in the megaphanerophytic class than in the mesophanero- 

 phytic class: leptophylls, 4.06 to 1.87 per cent; nanophylls, 2.03 to 0.93 per 

 cent; microphylls, 16.35 to 14.02 per cent; mesophylls, 75.55 to 68.22 per 

 cent. Consistently, the class with the largest leaves is smaller in the highest 

 stratum: 2.03 to 14.95 per cent. Although the percentages are somewhat 

 different when the lianas and epiphytes are not distributed according to 

 phanerophytic sub-classes, the same relationship is clear (table 15). 



The excellent book "The Tropical Rain Forest" by Richards (1952) shows 

 the predominance of mesophyll leaves in rain forest. In the wet evergreen 

 forest of the Shasta Reserve, Nigeria, 84 per cent of the leaves are mesophyll. 

 In the evergreen seasonal forest of Trinidad the emergent trees are 86 per 

 cent mesophyll and the trees of the lower story have 80 per cent in that class. 

 Quoting from Brown (1919), in the Philippine Islands the dipterocarp tropi- 

 cal rain forest of Mt. Maquiling has 86 per cent mesophyll leaves; the sub- 

 montane rain forest has 97 per cent; and the montane mossy rain forest has 

 50 per cent mesophyll leaves. The latter type has 50 per cent microphyll 

 leaves. For the evergreen seasonal forest of Trinidad, Beard (1946; Richards, 

 1952) showed that the emergent trees have a higher percentage of species 

 with mesophyll leaves than do the canopy species, while lower-story trees are 

 intermediate. 



