Within the area described are four distinct forest 

 regions or ecological provinces, each giving rise 

 to a distinct type of forest. These regions or prov- 

 inces, designated as moist coast, moist limestone, 

 dry coast, and dry limestone, are shown in figiire 2. 



The more common or characteristic species of 

 the moist coastal forest included the following: 



more hardy rejilace these. The trees of the dry 

 limestone forest include : 



Acrocomia media 

 Nectandra coriacea 

 Hemandia sonora 

 Hymenaea courbanl 

 Andira inermis 

 Pterocarpus officinalis 

 Zanthoxylum 



mnrtinicense 

 CaJophyllum 



hrasiJien.te 

 Mammea americana 



Psidium guajava 

 Manilkara Mdentata 

 Sideroxylon 



foetidissimuin 

 C itharexylum 



fr%iMcosum 

 Petitia domingensis 

 Tahehxda heterophylla 

 Genipa americana 

 Guettarda srahra 

 Randia aculeata 



The moist limestone forest was similar to that 

 along the coast and had many of the same species. 

 The chief differences appear to be due to the drier 

 soils on the well-drained limestone hills and the 

 greater humidity in the protected areas between 

 the hills, especially in the southern part of this 

 area which is close to the central mountains. The 

 tree species of the moist limestone forest include : 



Montezuma 



speciosissima 

 Ochroma pyramidale 

 Chisia rosea 

 Bueida bucera.s 

 Tetrazygia eleagnoides 

 Dipholis salicifolia 

 Sideroxylon 



foetidissimurn 

 Guettarda scahra 

 Tereiraria resinosa 

 Randia aculeata 



Aiphanes 



acanthophyUa 

 Gauss ia aftenuata 

 CoccoJoha diversifolia 

 Coccoloia pubescens 

 Licaria salicifolia 

 Zanthoxylum, 



fnarfinicense 

 Bursera simaniba 

 Cedrela odorata 

 Hyeronima clusioides 

 Sapiu7)i lauroce-rasus 

 Thouinia striata 



On the southern, di-y side of Puerto Rico the 

 more adverse moisture conditions excluded many 

 of the tree species common on the north side. In 

 their places grew a few other species especially 

 adapted to such conditions. The tree species of 

 the dry coastal forest include : 



Coccoloha venosa Polygala cowelUi 



Capparis cynophallo- Ceibo, pentandra 



phora Guasuma ulmifolia 



Stahlia monosperma Canella lointeranxi 



Lonxihocarpus domin- Bueida huceras 



gensis Rauvolfia nitida 



Pictetia aculeata Cordia nitida 



Erythroxylon areola- Citharexylum 



turn finiticosmn 

 Guaiocum officinale 



In the limestone region of the south coast, as on 

 the north coast, excessive soil drainage accentuates 

 the dryness of the environment to a point that some 

 species of trees cannot subsist. Others which are 



Pixonia alhida 

 Capparis cynophallo- 



phora 

 Pictetia acxdeata 

 Guaiocum, officinale 

 Guaiacum sanctum 

 A my ins elemifera 

 Bursera simaruha 

 Gymnanthes htcida 



Thouinia portoricensis 

 Coluhrina ar-borescens 

 Satcomphalus reticula- 



fus 

 Crphalocereus royenii 

 Opuntia rubescens 

 Bueida buceras 

 Dipholis salicifolia 

 Pliimeria alba 



The coastal forests of Puerto Rico and the Vir- 

 gin Islands, unlike those of the other Greater 

 Antilles, contained no mahogany (Svnetenia ma- 

 hagoni). Widespread use of the wood and early 

 introduction of the tiee to these islands has led to 

 a general impression that this species is native. 

 However, whereas the young trees develop abun- 

 dantly in Puerto Rico beneath or near planted 

 trees of this species, they are never encountered in 

 native forest at any distance from .such trees. Had 

 the s]3ecies been native, there would still be young 

 trees throughout the coastal forests of the island 

 without relation to the location of planted trees. 

 It is extremely unlikely that it could ever have 

 been exterminated, since aceitillo (Zanthoxylum 

 flctvnm) , a tree in greater demand and with much 

 weaker reproductive capacity than mahogany, is 

 still to be found in remote forests. 



Typical mountain forests are confined to Puerto 

 Rico, although a small i)atch of similar but unique 

 forest is found on the top of Sage Mountain. Tor- 

 tola. Between about 500 to 2,000 feet elevation in 

 the eastern moiuitains, known as Luquillo Moun- 

 tains, and to 3,000 feet in the central mountains or 

 Central Cordillera, slightly higher on the south 

 slope than on the north, was probably the most 

 magnificent forest of Puerto Rico. Much of the 

 original vegetation of this area is described as 

 tropical moist forest ; in the wettest areas it is trop- 

 ical rain forest. At its maximum development this 

 forest reached 110 feet in height, with trees to 8 

 feet in diameter. Three forests of distinct size and 

 composition grew together here, each forming a 

 separate story of vegetation. Throughout the 

 range of this type of forest there were probably 

 about 170 tree species. 



Within the mountain area are two forest regions 

 or ecological provinces and corresponding distinct 

 forest types. These provinces are designated as 

 lower dordillera and lower Luquillo. It is seen 

 in figure 2 that the lower Cordillera province in- 

 clucles both the north and south lower slopes of 

 the central mountains of Puerto Rico and the 

 Sierra de Cayey and also the upper slopes of the 

 disconnected "Sierra de Atalaya in the northwest. 

 The Luquillo Mountains are separate both geo- 

 graphically and ecologically from the Central 

 Cordillera. 



The trees of the lower Cordillera forest include 

 the following: 



13 



