THE PHILIPPINE FORESTS 9 



everywhere that tide water covers the land except on exposed 

 beaches. Frequently these tide flats are a mile or more in width. 

 In composition these forests are very simple, the majority of the 

 stand belonging to a single family rhizophoraceae. Frequently 

 some of the different species occur in pure stands, although gen- 

 erally there are a half dozen or so mixed together. Nearly all 

 of them are relatively small growing kinds in normal mature 

 stands ranging from 6 inches to 30 inches in diameter and from 

 40 to 50 feet in height. There is relatively little undergrowth 

 except near the upper limits of tidewater where this type mingles 

 with fresh water ones. These mangrove swamp forests produce 

 great quantities of fire wood, while the bark of many species 

 is gathered as tan bark. In addition to the trees described above, 

 a palm known locally as "nipa" grows along streams in many 

 parts of the tide flats. The leaves of the nipa palm are one 

 of the most important products of the Islands to the natives, 

 since they are used almost exclusively for thatching roofs and 

 sides of the native houses. 



The beach type of forest grows on sandy beaches and beach 

 flats lying above high water. The stand is very complex, con- 

 taining a great many species, but the type is not especially 

 valuable. 



The pine type of forest occupies the high mountainous region 

 of northern Luzon, nearly all of which is over 3,000 feet in eleva- 

 tion. Throughout this region pine (pimts mstdaris) groves 

 in nearly pure stands. Occasionally these are dense, running 

 up to 10,000 or 20,000 feet per acre, but more often they are 

 very open and scattered. In the pure stands of pine there is 

 very little undergrowth except grass and ferns. Strange to say, 

 the common fern growing in this region belongs to the same 

 genus as does the brake fern so common in portions of the 

 United States. In the stream bottoms and on the moister slopes 

 broad-leaved species occur, often forming dense jungles not un- 

 like that in other forest types. In general appearance the open 

 pine forests are not greatly different from the yellow pine forests 

 in the western United States. The trees grow to large size and 

 produce a fair grade of timber which is rather inclined to be 

 pitchy. This type of forest is practically the only one which is 

 liable to be killed by forest fires. The grass, which during the 

 wet season grows in great profusion, dries out in the dry part 

 of the year and with the needles that have accumulated, 

 burns fiercely, doing great damage to reproduction and often 

 to mature trees. Apparently it is the forest fires that have pre- 

 vented the pine from producing dense stands. With fire pro- 

 tection the region would probably support a fairly uniform and 

 heavy stand of timber, possibly 15,000 or 20,000 feet B. M. 

 per acre. Scattered pine trees are also found in two other locali- 

 ties aside from the mountainous area of northern Luzon one in 



