383 
very high mountain regions that low temperature is likely to bring the 
chresard below the danger point. The saturation deficit is the direct 
measurement of the influence of the temperature on the condition of the 
atmospheric moisture, so it is not necessary again to consider it in this 
connection. 
However, independently of the chresard and of the atmospheric humid- 
ity, heat influences the transpiration and thus may effect ecological 
structure. ‘The chresard and saturation defiicit remaining constant, a 
raising or lowering of the temperature respectively will increase or 
decrease the transpiration. A reference to the tables will show a con- 
tinually lower temperature on the slopes of the mountain as compared 
with that at the base.** It is believed that this element, together with 
the lower saturation deficit and the greater rainfall, must be taken into 
consideration to explain the almost evergreen character of the forests on 
the mountain slopes, as compared with their decidedly deciduous aspect 
at the base of the mountain. 
Aside from its ecological aspect, temperature has a profound influence 
on the floristic character of the vegetation, so that the upper regions of the 
mountain under consideration have floristic elements different from 
those of the region near the level of the sea. This contrast will clearly 
be shown when the plant formations are considered in detail. 
Wind.—Wind is another factor affecting ecological distribution. In 
the absence of proper instruments no record of wind velocity was kept 
at Lamao. ‘The effect of wind on vegetation, especially in exposed situa- 
tions, will be discussed in another connection. 
TABLE XI. —Monthly and annual averages of the daily volocity of wind in Manila during 
the period 1885-1898, in kilometers. 
| Jan, Feb. | Mar. | Apr. | May. | June.) July. |) Aug. | Sept. 
| 
| | 
| 
| 
| 
| 165.9 192.8 | 224.8 
| Oct. | Noy. Dee. | 
280. 0 
= | - 
232.7 | 281.4 | 284.5 | 273.8 | 296.0 | 182.3 
Average, 217.8. 
SOIL. 
The soil of the Lamao Reserve is remarkably uniform in its physical 
texture and chemical composition. With the exception of that on the 
beach, it is all of a residual nature from the andesitic rocks which form 
the core of Mount Mariveles. It is usually a heavy clay, more or less 
impregnated with iron, which resembles laterite. However, it is not 
at all the laterite of Burma,’® which is remarkable for its deficiency 
"For literature on the effect of air temperature on transpiration see Burger- 
stein, l. ¢., 115 to 121, especially Eberdt, O. Die Transpiration der Pflanzen und 
ihre Abhingigkeit von fiusseren Bedingungen (1889). 
* Schimper, I. ¢., 379. 
