APPLICATION OF PHYTOSOCIOLOGICAL TECHNIQUES 269 



the lianas and epiphytes. Terrestrial herbs were almost completely absent, 

 but tree reproduction was sometimes very dense in the ground layer. 



A certain amount of layering in the forest is readily apparent. As noted 

 before, the emergent Sumauma, Ceiba pentandra, often extends 10 m. or 



Table 3. Summary table of presence and life form of phanerophytes 

 of the tnata da varzea, Arapari Island, Para 



Number of species in each presence class 



Presence Mega- Meso- Micro- 

 class phanerophytes phanerophytes phanerophytes Total 



6/6 5 8 1 14 



5/6 7 7 ..14 



4/6 6 11 17 



3/6 5 8 . . 13 



2/6 4 8 . . 12 



1/6 15 17 7 39 



Total 42 59 8 109 



more above the general canopy of megaphanerophytes at the level of about 

 35 m. A layer below the general canopy is sometimes well marked by a local 

 abundance of Euterpe oleracea at about 15 to 20 m. A still lower layer at 

 about 5 to 8 m. is well marked by Theobroma cacao. Strata within the 

 general mesophanerophytic level are not apparent. The ground is generally 

 crowded by tree reproduction and nanophanerophytic shrubs intermixed at 

 levels from about 1 to 3 m. except in the wetter igapos where the soil is bare 

 or with a jumble of plank-like roots or snake-coiled masses of superficial 

 cylindrical roots and pneumatophores. 



PART II. COMPOSITION AND STRUCTURE OF TERRA FIRME 

 RAIN FOREST AT MUCAMBO. BELEM, PARA ^ 



Mucambo is a rather extensive tract of apparently primeval terra firme 

 rain forest on the grounds of the Instituto Agronomico do Norte on the 

 eastern side of Belem, Para, at about 1° 27" S. Lat. and 48° 27" W. Long. 

 Mucambo lies at a slight elevation above the varzea (flood plain) between 

 Igarape Calu and Igarape Agua Preta, which connect with the Rio Guama. 



In an easily accessible portion of the forest about a kilometer from one 

 of the Instituto service roads Dr. Murga Pires laid out a sample plot of 2 



* Stanley A. Cain, Gustavus M. de Oliveira Castro, and J. Murga Pires. 



