23, i Merrill: Distribution of Dipterocarpaceae 9 



of these from above that altitude. On the authority of Mr. A. 

 D. E. Elmer, we find in Mindanao Parashorea warburgii Bran- 

 dis, .Shorea squamata Dyer (= S. palosapis Merr.), and S. sp. 

 at 1,000 meters altitude, and Vatica mindanensis Foxw. at 1,100 

 meters altitude. 



In connection with the altitudinal range of the Dipterocarpa- 

 ceae in the Philippines, it is interesting to compare the data com- 

 piled by Brown 9 in the midmountain forests of central Luzon ; 

 that is, between 600 and 900 meters altitude. At an altitude 

 of 700 meters a plot 50 meters square was selected with the 

 same slope and exposure as those of the plot surveyed in the 

 dipterocarp forest at 450 meters altitude. In this plot he found 

 five hundred seventy-eight individual trees, representing thirty- 

 nine species, but the Dipterocarpaceae were entirely absent. 

 However, most of the species found in this plot occur also in 

 the dipterocarp forest at lower altitudes. In other words, 

 Brown definitely shows that the Dipterocarpaceae are strictly 

 limited as to their altitudinal range, while representatives of 

 many other families and genera, which are associated with the 

 Dipterocarpaceae and form the complex, low-altitude forests of 

 the Philippines, thrive at altitudes distinctly higher than the 

 Dipterocarpaceae themselves. 



Brown states that in the transition from the dipterocarp to 

 the midmountain forest the change from one association to 

 another is usually gradual and is marked by intermediate con- 

 ditions. The tall trees characteristic of the Dipterocarpaceae 

 that form the upper story of the typical dipterocarp forest 

 gradually disappear, and the first story of the Quercus-Neolitsea 

 association of the midmountain forest is approximately of the 

 same height and composed largely of the same species as the 

 second story of the dipterocarp forest. There is no marked 

 change in the composition of the minor elements in the transi- 

 tion zone. 



In reference to the altitudinal range of the dipterocarps out- 1 

 side of the Philippines, Mr. I. H. Burkill, Director of the Botanic 

 Gardens, Singapore, informs me under date of January 8 that, 

 on the main range of the Malay Peninsula in the neigborhood 

 of Semangkok Pass, he and Mr. Holttum found that they dis- 

 appear at an altitude of about 1,050 meters without apparent 

 dwarfing. The forest here at an altitude of about 1,200 meters 



•Brown, W. H., The Vegetation of Philippine Mountains (1919) 76-97. 



