01468naa a2200217 a 450000100080000000500110000800800410001910000170006024501250007726000090020252008490021165000150106065000130107565000160108865300220110465300240112665300110115070000200116170000140118177300550119521651592024-06-26       1950    bl uuuu     u00u1 u    #d1 aBLACK, G. A.  aSome attempts to estimate species diversity and population density of trees in Amazonian forests.h[electronic resource]  c1950  aCounts of trees with trunks more than 10 (or 20) cm. in diameter have been made on three 1-hectare (100 x 100 m.) plots in the vicinity of Belem, state of Pera, and at Tefe, state of Amazonas. The species were delimited with the assistance of native tree specialists, and whenever possible identified by vernacular as well as by scientific names. On the three plots 60, 87, and 79 species have been recorded among 564, 423, and 230 individuals, respectively. 2. Analysis of the data with the aid of PRESTON'S (6) "octave" method suggests that we have encountered probably no more than half the species which exist in the associations studied. Most of the rare, and some of the moderately common, species are missing on our plots. The population densities of many species of trees in the Amazonian Hylea are less than one individual per hectare.  apopulation  aEspécie  aPopulação  aAmazonian forests  aFloresta Amazônica  aSpecie1 aDOBZHANSKY, TH.1 aPAVAN, C.  tBotanical Gazettegv. 111, n. 4, p. 413-425, 1950.