SITE GUIDE Caribbean National Forest, Puerto Rico James W. Wiley and Gerald P. Bauer LOCATION: Caribbean National (200 inches) per year at the highest slopes.These forestsare now largely Forest:Luquillo Mountainsof northeast- peaks,and is greatestduring spring and goneowing to their valuabletimber and ern Puerto Rico (18ø10'N, 65ø30'W) fall. Most showers are short but intense. the pastneed for agriculturalland. (Fig. 1). Much of the lower forest is timber The palo colorado,or uppermontane plantationsand reclaimed agricultural rain forest,ranges from 600 to 900 me- DESCRIPTION: The 11,500-hectare land, with a mixture of exotic and native ters (1970-2950 feet) in the valleysand (28,000-acre) Caribbean National Forest trees,ferns, and vines, and a widevariety gradualslopes, and is characterizedby (Fig. 2) is the only tropicalrain forestin of naturalizedflowering plants. Except Micropholischrysophylloides, M. gar- the UnitedStates National Forestsystem, for modifications around roads and rec- ciniaefolia,and Cyrilla racemifiora(palo and offers the traveler a convenientop- reation areas, the relict pre-Columbian colorado). The palo colorado, which portunityto visit a lush and exotic eco- forestof the uppermountains remains in dominatesthis zone, also grows as a short systemand observeits birdlife. the same state as when Europeansfirst tree or shrubin the titi swampsof the Extreme climate, steep topography, landedon PuertoRico nearly 500 years southeasternUnited States. However, m cascadingstreams, and luxuriantvegeta- ago. Four distinctforest types comprise the PuertoRican mountainsit growsas a tion characterizethe forest(Fig. 3). Ele- thevirgin forest:the tabonuco,palo colo- huge,canopy-forming tree with circum- vationranges from approximately100 to rado, palm, and dwarf forests. ferencesup to 6.3 meters(20.7 feet;F•g 1075 meters (330-3530 feet) above sea The tabonucotype, or lower montane 5). level, with threepeaks rising above 1000 rain forest, lies below 600 meters (2000 The palm forest, or brake, occurson meters(3281 feet). Daily temperatures feet) and is characterizedby Dacryodes steepslopes and arroyos above 600 me- average25.5øC (77.9øF) at the lowest excelsa(tabonuco), Sloanea berteriana, tersand is characterizedby a near-mono- elevation, and about 18.5øC (65.3øF) and Manilkara bidentata. The straight culture of sierra palm (Prestoea mon- above 1000 meters.Mean monthly tem- white trunks of the dominant tabonuco tana). The forest has few vines and a peraturevaries annually from 3 to 3.5øC are clear of branches for more than one- sparseunderstory, making it moreopen (5 4-6.3øF).Clouds often coverthe up- half the tree's height. This createsan than the other forest types. perforest, with solarradiation at El Yun- openmid-section in the forest (Fig. 4). The dwarf forest, or elfin woodland, que Peakaveraging only 60% of that for Originally, tabonuco towered to more occurson summitsand ridge tops above the coast,10 kilometersaway. Rain falls than 30 meters (100 feet) and covered 850 meters(2790 feet) and is character- nearly daily, averaging500 centimeters most of Puerto Rico's lower mountain izedby dense stands of stunted,contorted shrubsand small trees. Usually bathed in mistsand clouds(Fig. 6), this forestre- ceivesrain nearly 350 days each year The vegetation,as well as the forest floor, is festoonedwith bryophytesand mosses,and overburdenedwith vines, PuertoRico lianas, and bromeliads. The Caribbean National Forest has beendesignated as an ExperimentalFor- est and a Biosphere Reserve in the UNESCO Man and the BiospherePro- CARIBBEAN gram(MAB). To preservegenetic diver- NATIONAL sity and remnantvirgin tractsrepresent- FOREST ingthe four forest types indigenous to the Fig. 1. Map of PuertoRico and the CaribbeanNational Forest. The Commonwealth of Puerto area, an 850-hectare(2070-acre) "Bafio Rtcois the smallestand easternmostof the GreaterAntilles. It is locatedabout 1600 kilometers de Oro" Research Natural Area has been (1000 mi.) southeastof Miami, Florida. established. An additional area has been 12 American B•rds, Spring 1985 Fig. 2. North(Atlantic) slope of theCaribbean National Forest. El YunquePeak is in thebackground. Photos/Gerald P. Bauer. proposedas the E1 CaciqueWilderness a recentlydiscovered twig-like species (A. but only four are common.Perhaps the Area occultus).Small litter-dwelling Sphaero- forestis bestknown as the lastrefuge of Vegetativediversity of the Caribbean dactyluslizards can often be seenon the the formerlyabundant Puerto Rican Par- NationalForest, although not as great as trails. Only one snakeoccurs commonly rot (Fig. 7). If one follows the sugges- a continentaltropical forest, is greaterper in the low and middle elevations of the tionsgiven below under the heading."B•g umt areathan in any otherUnited States forest--a spectacularboa (Epicrates in- Tree Trail", there is a good chancefor National Forest. Two hundred and twen- Ornatus)that attainsa maximumlength seeinga pair or small flock of theseex- ty-fivetree species are nativeto the for- of about4 meters(13 feet). Amphibians quisitegreen birds as they fly over the est, 23 endemic. An additional47 have are mostlyrepresented by 12 speciesof forestcanopy. been introduced. The Caribbean National smallfrogs of the genusEleutherodacty- Forestharbors 88 rare tree species,more lus.They are locally called coqu[because ACCESS: Puerto Rico's close associ- thanany othernational forest. The rain of their delightfulpiping of "co-qui, co~ ation with the United States makes travel forestcontains about 50 speciesof native qui" vocalizations.The coqu[sare abun- to andaround the islandeasy and without orchidsand 150 ferns, the largest of dant throughoutthe forest and are most the complicationsof currencyexchange which, the tree fern Cyathea arborea, vocalat nightduring rainy weather.They ratesor a needfor passportsand visasfor growsto 12 meters(40 feet) high. offer a bedtime concert for those who UnitedStates citizens. Spanish is the of- chooseto camp. ficial language, although English •s About 100 vertebratespecies inhabit Puerto Rico hosts 269 bird species widelyspoken and accepted. A smalllan- theCaribbean National Forest. Although throughoutthe year, of which 106 breed guageguide may prove useful for those a number of mammals once inhabited the and11 are endemic; 66 speciesrepresent- who planto travelthroughout the island •sland,including a largeground sloth, the ing 22 familiesoccur in the NationalFor- Major American and foreign airlines only nativemammals now inhabitingthe est(Table 1). Especiallyinteresting birds serve Puerto Rico several times daily forestare 11 speciesof bats. The forest includethe Puerto Rican Tody, oneof the The Isla Verde InternationalAirport •n fauna is dominated.by lizards and birds five membersof the Todidae, a family the San Juanmetropolitan area is about by day andfrogs by night. Eight species endemic to the Greater Antilles, and the 40 kilometers(25 miles) west of the Na- of Anolis lizard are found within the for- PuertoRican Tanager, sole member of an tionalForest. Tour and cruiseships also est, including the 36-centimeter (14- endemicgenus. Seventeen species of mi- make Puerto Rico one of their regular tach)giant tree anole (Anolis cuvieri) and grant warblersregularly use the forest, ports of call. Volume 39, Number I 13 Fig. 2. North(Atlantk') slope of theCaribbean National Forest. El YunquePeak is in thebackground. Photos/Gerald P. Bauer. proposedas the El CaciqueWilderness a recentlydiscovered twig-like species (A. but only four are common. Perhapsthe Area. occultus).Small htter-dwellingSphaero- forestis bestknown as the last refugeof Vegetativediversity of the Caribbean daco'luslizards can often be seenon the the formerly abundantPuerto Rican Par- National Forest, althoughnot as great as trails. Only one snakeoccurs commonly rot (Fig. 7). If one follows the sugges- a continentaltropical forest, is greaterper in the low and middle elevations of the tionsgiven below under the heading "Big unit areathan in any otherUnited States forest--a spectacularboa (Epicrates in- Tree Trail", there is a good chancefor National Forest. Two hundred and twen- ornatus) that attainsa maximum length seeinga pair or small flock of theseex- ty-fivetree species are nativeto the for- of about4 meters(l 3 feet). Amphibians quisite green birds as they fly over the est, 23 endemic. An additional 47 have are mostly representedby 12 speciesof forestcanopy. been introduced. The Caribbean National smallfrogs of the genusE!eutherodacty- Forestharbors 88 rare tree species,more !us.They arelocally called coqui because ACCESS: Puerto Rico's close associ- thanany othernational forest. The rain of their delightfulpiping of "co-qui, co- ation with the United States makes travel forestcontains about 50 speciesof native qui" vocalizations.The coquisare abun- to andaround the islandeasy and without orchids and 150 ferns, the largest of dant throughoutthe forest and are most the complicationsof currencyexchange which. the tree fern Cyathea arborea, vocalat nightduring rainy weather.They ratesor a needfor passportsand visas for growsto 12 meters(40 feet) high. offer a bedtime concert for those who UnitedStates citizens. Spanish is the of- chooseto camp. ficial language, although English is About 100 vertebratespecies inhabit Puerto Rico hosts 269 bird species widelyspoken and accepted. A small lan- the CaribbeanNational Forest.Although throughoutthe year, of which 106 breed guageguide may prove useful for those a number of mammals once inhabited the and I