312 



FORESTRY AND IRRIGATION 



July 



logical formation interferes with tree 

 growth. Such areas, however, are 

 small and unimportant when com- 

 pared with those whose open condition 

 we attribute to the interference of 

 man. 



TYPES. 



According to cover, we may readily 

 distinguish three types of public lands 

 whose formation has been effected by 

 artificial means and is, therefore, in- 

 constant. These are : Closed forest, 



forested, but subsequently cleared, 

 planted, and are now abandoned and 

 reverting back to forest cover. 



The first tree species to appear are 

 usually of little value as timber pro- 

 ducers, but, as we shall see later, serve 

 their purposes well as fosters. 



"Cogonales" may be called an early 

 "parang" stage. They are lands free 

 at first of tree growth and heavily set 

 with "cogon" (Imperata anuidinacea), 

 a perennial grass from three to five 



Parang. 



semi-open or "parang" and open grass 

 lands or "cogonales." 



This paper will not attempt to deal 

 with the first type, but will briefly con- 

 sider the more open lands. 



Vidal, who was the first to adopt the 

 Tagal word "parang" as a technical 

 term, defines it as "land covered with 

 brushwood and invading species which 

 have substituted the original forest 1 

 species." These areas in general rep- 

 it tracts which were originally 



feet high. The relative proportion of 

 these areas is quite variable. In cer- 

 tain provinces the open lands are in- 

 significant, while in others they may 

 occupy as much as 30 per cent, of the 

 total area. Having been selected pri- 

 marily for the growing of crops, such 

 soils represent the most fertile portion 

 of the non-cultivated areas, and, as a 

 rule, occupy the low rolling foothills 

 adjacent to the cultivated plains, which 

 they separate from the upland forests. 



