FORESTS AND FORESTRY IN PUERTO RICO AND 

 THE VIRGIN ISLANDS 



The trees native to Puerto Kico and the Virgin 

 Islands, some 500 species, were found at the time 

 of discovery in extoisive and luxuriant forests. 

 Whereas such forests have subsequently all but dis- 

 appeared, there is every reason to believe that at 

 the time of Columbus' arrival the dominant vege- 

 tation throughout the islands, with the possible 

 exception of a few small marshes, was forest. The 

 reports of early voyageurs (7, 8, 25) all describe 

 the islands as forest covered. Furthermore, in 

 other regions of similar climate and soil the vege- 

 tation is forest wherever it has not been modified 

 by man. The natural vegetation of Puerto Rico, 

 including forests and plant successions, has been 

 described by Gleason and Cook {12, 6) . 



THE VIRGIN FORESTS 



Description of the virgin forests of Puerto Rico 

 and the Virgin Islands can now be only very ap- 

 proximate, since few relics remain in Puerto Rico 

 and none in the Virgin Islands. Wlierever partial 

 cutting or complete deforestation has once talcen 

 place, even where forests are subsequently allowed 

 to redevelop, the relative abundance of the differ- 

 ent species suffers a marked change. The brief 

 description here presented is based upon a study 

 of a few remaining virgin forests in Puerto Rico 

 (38) and upon published descriptions of similar 

 forests in nearby islands, particularly those by 

 Beard (3). 



The eight climax forest types or forest regions 

 shown in figure 2 are described below with lists 

 of the common trees. Reference is made primarily 

 to Puerto Rico, and some species mentioned are 

 not in the Virgin Islands. However, the general 

 character of the vegetation there was apparently 

 as here described. 



The more important differences in the natural 

 vegetation of Puerto Rico and the Virgin Islands 

 reflect variations in topography, climate, and soil. 

 The vegetation of the coastal plains was unlike 

 that of the steeper upper slopes, and a still differ- 

 ent type of forest clothed the uppermost peaks. 

 Differences in tlie total amount and seasonal dis- 

 tribution of precipitation produced extreme differ- 

 ences between the forests of the eastern mountains 

 of Puerto Rico and those of the southwest coast. 

 Reduced moisture availability due to shallow soils, 

 particularly in the limestone regions, is manifest 

 in the gi'owth of trees on such areas. The contrasts 

 among the various vegetative types are striking 

 because of the extreme range of conditions with- 



in short distances. Elevations range from sea 

 level to 4,398 feet, precipitation from 30 to 180 

 inches annually, and soils from deep to very shal- 

 low, and from fine clays to coarse sands. 



Along the wind-swept .seacoasts was a low scrub- 

 by littoral woodland so narrow and so small in 

 area that it is not shown in figure 2. Most of the 

 trees in this woodland were small and of poor form 

 due to extreme exposure to salt winds. On dry 

 rocky slopes facing the southern or southwestern 

 coasts, on Ai^gada, on Mona, and on other small 

 outlyin<T islands the littoral woodland assumed the 

 form of cactus scrub. In the more pi'otected loca- 

 tions, particularly on tlie north coast of Puerto 

 Rico, grew trees of good timber species such as 

 maria {Calophylhnn bt-mlUense), ausubo (Manil- 

 latra bidentata), roble (Tabebuia heterophyUa), 

 and toi'tugo amarillo {SideroxyJon foetidissi- 

 mum). One of the most prominent species near 

 the shore was uva de playa {Coccoloba uvifera). 



Along the shores of protected bays, lagoons, and 

 estuaries in an area too restricted to show in figure 

 2 were dense stands of mangrove, tlie trees of only 

 four species growing to a height of 60 feet or more. 

 Five public forests bordering the coast, mapped in 

 figure 3, still contain mangroves. In the water it- 

 self was mangle Colorado {Rhizophora nmngJe). 

 On the adjacent area normally subject to tidal 

 flooding were mangle bianco (LaguncuJaria race- 

 mom) and mangle negro {Avicenma nhlda). On 

 the landward side was mangle boton {Coimcarpiis 

 erect us). The strong durable timbers of mangle 

 Colorado and mangle boton were much used for 

 construction. 



On the coastal plain and lower slopes, up to an 

 elevation of 500 feet or more in Puerto Rico, and 

 to the tops of most mountains of the Virgin Islands 

 grew a di-y forest which was largely evergreen but 

 with some deciduous species, particularly in the 

 drier coastal areas. At its best development, on 

 the northern coastal plain of Puerto Rico, this 

 forest attained 80 feet or more in height. Else- 

 where, in the moist limestone region and on the 

 south coast of Puerto Rico, and in the Virgin 

 Islands, it was apparently shorter, from 40 to 60 

 feet tall. This forest consisted of two tree stories, 

 each composed of distinct species. The lower story 

 constituted a forest within a forest and depended 

 upon the upper canopy for its existence. The veg- 

 etation varied in composition from place to place 

 but it was everywhere a mixture of species. At 

 least 200 tree sjjecies were present somewhere with- 

 in the natural distribution of this forest. 



12 



