CARIBBEAN LANDSCAPES AND THEIR

Ariel E. Lugo, Eileen H. Helmer and Eugenio Santiago Valentín

SUMMARY

Both the biodiversity and the landscapes of the forests, and built up land. Recent land cover changes from ag- have been greatly modified as a consequence of human activity. ricultural to urban cover have allowed for the proliferation of In this essay we provide an overview of the natural landscapes novel forests, where introduced plant species have naturalized and biodiversity of the Caribbean and discuss how human ac- and play important ecological roles that appear compatible with tivity has affected both. Our Caribbean geographic focus is on native and endemic . the insular Caribbean and the biodiversity focus is on the flora,

PAISAJES CARIBEÑOS Y SU DIODIVERSIDAD Ariel E. Lugo, Eileen H. Helmer y Eugenio Santiago Valentín RESUMEN Tanto la biodiversidad como los paisajes del Caribe han diversidad es la flora, bosques y tierras construidas. Cambios sido extensamente modificados como consecuencia de la activi- recientes en la cobertura de las tierras, de cobertura agrícola a dad humana. En este ensayo se presenta una visión global de urbana, han permitido la proliferación de nuevos bosques, don- los paisajes naturales y la biodiversidad del Caribe y se dis- de las especies de plantas introducidas se han naturalizado y cute cómo la actividad humana ha modificado a ambos. Nues- juegan importantes papeles ecológicos que parecen compatibles tro enfoque caribeño es en el Caribe insular y el foco sobre la con la flora nativa y endémica.

Introduction masses, is defined in a vari- watersheds draining into the Greater , the Lesser ety of ways. Geographically, Caribbean and the Gulf Antilles, and . The Caribbean, a the area known as the Great- of . The Caribbean The date with over one thousand is- er Caribbean includes all the belong to three dif- back to about 45my, while lands and continental land- islands plus those continental ferent archipelagoes: the portions of the Greater Antil-

KEYWORDS / Biodiversity Hotspots / Endemism / Introduced Species / Land Cover Change / Novel Ecosystems / Species Naturalization / Received: 11/21/2011. Modified: 09/07/2012. Accepted: 09/11/2012.

Ariel E. Lugo. Ph.D. in Plant USDA Forest Service. Ad- Eileen H. Helmer. Ph.D. in For- Eugenio Santiago Valentín. Ecology, University of North dress: Calle 1201, Jardín est Ecology, Oregon State Uni- Ph.D. in Plant Taxonomy, Uni- Carolina at Chapel Hill, USA. Botánico Sur. Río Piedras versity, USA. Research Ecolo- versity of Washington, USA. Director, International Institute 00926-1119, . e- gist, International Institute of Professor, University of Puerto of Tropical Forestry (IITF), mail: [email protected] Tropical Ecology, Puerto Rico. Rico at Río Piedras.

SEP 2012, VOL. 37 Nº 9 0378-1844/12/09/705-06 $ 3.00/0 705 PAISAGENS DO CARIBE E SUA BIODIVERSIDADE Ariel E. Lugo, Eileen H. Helmer e Eugenio Santiago Valentín RESUMO Tanto a biodiversidade como as paisagens do Caribe têm sido bosques e terras construídas. Mudanças recentes da cobertu- extensamente modificadas como consequência da atividade hu- ra das terras, de cobertura agrícola a urbana, têm permitido mana. Neste ensaio se apresenta uma visão global das paisa- a proliferação de novos bosques, onde as espécies de plantas gens naturais e a biodiversidade do Caribe e se discute como a introduzidas têm se naturalizado e desempenham importantes atividade humana tem modificado ambos. Nosso enfoque caribe- papéis ecológicos que parecem compatíveis com a flora nativa nho é no Caribe insular e o foco sobre a diversidade é a flora, e endêmica.

les (e.g., ) contain frag- region: the Central American plant genera endemic to Ca- species in the endemic gen- ments that date back as far and the Antillean sub-re- ribbean Islands, sensu stricto. era. Fifty one percent of the as 1000my and the Bahamian gions. The Antillean sub-re- These genera belong to 47 endemic genera are unispe- Islands date back about gion (our focus) is subdivided families. Francisco Ortega et cific (Francisco Ortega et al., 200my (Acevedo Rodríguez into three groups: the al. (2007) reported 8000 en- 2007). The geographic area and Strong, 2008). As a Bahamas, the Greater Antil- demic vascular plant species that these authors analyzed group, the Caribbean Islands les, and the Lesser Antilles. in the Caribbean and 727 excludes south but it are also known as the West Only 28% of the na- includes the Nether- Indies or Antilles. The Less- tive seed plant flora TABLE I lands Antilles and the er Antilles, separated from in the Caribbean is ESTIMATES OF THE NUMBER OF Venezuelan Antilles the by the shared with other INTRODUCED TAXA TO THE CARIBBEAN north of . Passage, extend geographic of ISLANDS Among the islands, from Sombrero Island on the the world, as the re- Cuba has the largest Taxon Native Introduced north to on the maining 72% is en- number of species South. None of the Caribbean demic to the West Families of seed plants 205 26 and highest number Islands is in contact with Indies (Acevedo Ro- Genera of seed plants 1447 500 and proportion of en- surrounding continental land- dríguez and Strong, Species of seed plants 10948 1899 demic plants. Aceve- masses. Our emphasis will be 2008). The vascular Floating or submerged plants 4 do Rodríguez and on the terrestrial biodiversity plant flora for the Ca- Cattails 1 Strong (2008) found of Caribbean Islands with the ribbean Islands in- Climber/vines 17 that 105 of the 181 en- Ferns 5 objective of highlighting the cluding introduced demic plant genera oc- Grasses 28 effects of land cover change and cultivated plants Herbs 35 cur on a single island, on the flora. is estimated at 12847 Sedges 1 this and the fact that species in about 231 Shrubs 16 80% are unispecific, The Caribbean Biodiversity families (Acevedo Ro- Trees 220 make the genera vul- Hotspot dríguez and Strong, Crustaceans 2 nerable to land cover 2008), of which 7868 Earthworms 1 change. In the Lesser The Caribbean Islands species, or about Insect 90 Antilles, a third of the (Myers et al., 2000) and ad- 2.3% of the world’s 1 endemic seed plant jacent marine waters (Rob- total, are endemic to Mites 8 taxa are single-island erts et al., 2000) are global the region. Mollusks 17 taxa, a third occur on biodiversity hotspots. A Of the 231 seed Solifuguds 1 two to three islands, hotspot is a region with ex- plant families in the Tunicates 1 and the rest are dis- ceptional concentration of , 205 are 8 tributed on four or endemic species and experi- indigenous. None of Birds 20 more islands (Acevedo encing exceptional habitat these families is en- Fish 37 Rodríguez and Strong, loss. The Caribbean Islands demic to the Carib- 20 2008). Torres Santana contain at least 2% of the bean, most are shared 15 et al. (2010) estimated world’s endemic plant and with other regions of Fungi 2 that there were 156 vertebrate species on only the Neotropics, and Diseases 2 single-island endemic 0.4% of the ’s land sur- 17 are endemic to the The first three rows are from Acevedo Rodríguez and pteridophyte species face (Myers et al., 2000). Neotropics. These 17 Strong (2008) and the rest are from Kairo et al. (2003). in the Caribbean. Kai- families represent Empty cells mean the information is not available in the ro et al. (2003) report- Botanical biodiversity about 49% of the en- publications cited. However, information for some of the ed that 40% of Carib- seed plant taxa is available in the following website: demic seed plant fam- http://botany.si.edu/antilles/WestIndies/query.cfm bean butterflies are The West Indian flora is a ilies in the Neo- And also in www.sil.si.edu/smithsoniancontributions/ known only from a subset of the Neotropical flo- . Francisco Botany/ single island, which ra (Acevedo Rodríguez and Ortega et al. (2007) The numbers from Kairo et al. add up to 552 species further highlights the (327 plants, 121 invertebrates, 100 vertebrates, and 4 Strong, 2008). Borhidi (1991) and Acevedo Rodrí- fungi and diseases). Kairo et al. also combined the spe- vulnerability of en- identified two phytogeograph- guez and Strong cies according to habitat: 479 terrestrial, 55 freshwater, demic taxa in these ical units in the Caribbean (2008) listed 181 seed and 18 marine. islands.

706 SEP 2012, VOL. 37 Nº 9 TABLE II TABLE III NUMBER OF INTRODUCED PERCENT URBAN, FOREST, AND VEGETATION COVER OF VARIOUS PLANT AND ANIMAL SPECIES CARIBBEAN ISLANDS IN 2000 TO VARIOUS ISLANDS OF Island area THE CARIBBEAN Island Urban Forest Vegetation (ha) Source Anegada 2.8 64.8 67.0 3990 Kennaway et al., 2008 Island Number of Species † 20.9 17.1 42.8 43431 Helmer et al., 2008 186 British † 7.0 75.2 80.6 15412 Kennaway et al., 2008 Puerto Rico 182 Dominican Republic*† 1.5 49 99.2 4797317 Hernández and Pérez., 2005 Bahamas 159 Grenada† 8.8 51.1 58.0 31341 Helmer et al., 2008 102 3.2 82.7 89.1 1036 Kennaway et al., 2008 73 7.2 49.2 88.9 9311 Helmer et al., 2008 63 NPCG ** 1.4 70.2 80.4 1077 Kennaway et al., 2008 & 61 Puerto Rico† 15.4 44.8 82.4 886951 Kennaway and Helmer., 2007 Barbados 60 St. Croix 14.4 56.7 80.7 21795 Kennaway et al., 2008 Cuba 60 St. Eustatius 7.0 45.1 83.2 2029 Helmer et al., 2008 - 45 St. Johns 5.9 89.0 90.4 5090 Kennaway et al., 2008 US Virgin Islands 42 St. Kitts† 7.0 46.2 61.3 16695 Helmer et al., 2008 Curacao 41 St. Thomas 22.5 69.0 72.9 8170 Kennaway et al., 2008 Grenada 37 10.6 79.8 85.6 6847 Kennaway et al., 2008 37 Trinidad 8.2 70.9 90.7 483186 Helmer et al., 2012 St. Lucia 37 Tobago 7.9 83.6 90.7 30102 Helmer et al., 2012 34 Trinidad & Tobago† 8.2 71.6 90.6 513288 Helmer et al., 2012 St. Vincent 32 US Virgin Islands† 15.9 69.8 87.1 35055 Kennaway et al., 2008 31 Virgin Gorda 7.9 78.2 85.3 2462 Kennaway et al., 2008 26 * Urban includes only high density urban. 9 ** Norman, Peter, Cooper, Ginger Islands. 9 Agriculture and golf course covers are excluded from the vegetation cover data. For islands with a Turks-Caicos Islands 8 ‘†’ Kairo et al. (2003) gives the number of naturalized introduced species. 7 St. Kitts-Nevis 5 5 (Francis and Liogier, Acevedo Rodríguez and the Lesser Antilles (Table II). 4 1991; Whittaker, 1998; Strong (2008) report that the The species-area relationship St. Martin 2 Kairo et al., 2003). percent of the total number of between both introduced and Aves 0 The magnitude of seed plant taxa represented by naturalized species and island Leeward Is- 0 these changes due to ex- introduced taxa was 11, 26 area for ten Caribbean Islands lands tinctions, extirpation, or and 15% for families, genera, was significant (p= 0.003 and Navassa 0 introduction of species is and species, respectively (Ta- 0.001, respectively) for log- difficult to assess for the ble I). For Puerto Rico, which transformed data. All data are from Kairo et al. (2003). Kairo region as a whole. How- has benefited from intensive Available information on et al. caution that the list is incomplete. Is- lands are arranged in descending order of ever, the changes are taxonomic activity, the present the richness of Caribbean bio- introductions. evident for particular number of taxa for trees (Lit- ta shows that the flora and places or groups of or- tle et al., 1974), monocotyle- of the islands is today ganisms studied by sci- donous plants (Acevedo Ro- richer than it was before they Anthropogenic Effects on entists. One example is the dríguez and Strong, 2005), experienced significant human the Caribbean Biota extinction and extirpation vines and climbing plants activity. As we will see be- events in the bird and mam- (Acevedo Rodríguez, 2005), low, the success of introduced Humans have lived in the mal ferns (Proctor, 1989), orchids species in the Caribbean may Caribbean for millennia caus- (Brash, 1987; Woods, 1996). (Ackerman, 1996), aquatic be related to land cover ing considerable modification Documenting extinction and invertebrates (Williams et al., changes, particularly the in- to the landscape and its biota. extirpation of species is harder 2001), fish (Kwak et al., crease in built-up and degrad- The early people in the Carib- to do than documenting intro- 2007), birds (Raffaele, 1989; ed lands. These land cover bean affected land cover and ductions of species, because Biaggi, 1997), ants (Torres changes create new environ- introduced human settlements the introduced species that and Snelling, 1997), amphibi- mental conditions to which to the region, but their main survive are in plain sight, ans and reptiles (Rivero, native species are poorly effect on the biota was not which is not the case for those 1998), and earthworms (Borg- adapted to, thus giving a due to extensive deforestation that disappeared before a sci- es, 1996), are higher than be- competitive edge to intro- and land cover changes. In- entific record of their presence fore humans arrived. Kairo et duced taxa (Francis and Lio- stead, before their contact on the Islands existed. al. (2003) compiled data for a gier, 1991; Hobbs et al., with Europeans, the people of Today, Caribbean island variety of taxa (Table I) and 2006). the Caribbean had an impor- contain more taxa than found that the number of in- tant effect on the species they did before humans ar- troduced species varied with Anthropogenic Effects on composition of the biota. rived to the region. The in- the size and location of the Caribbean Landscapes They did so by causing the crease is due to the large island. The larger islands of extinction of organisms and number of species introduc- the Greater Antilles had more Large-scale land cover moving plant and animal spe- tions and naturalizations. For introduced species than those changes in the Caribbean cies from one place to another the West Indies as a whole, of the smaller Bahamas and were the legacy of European

SEP 2012, VOL. 37 Nº 9 707 settlers. They did so is proportionally to exploit forest re- high in compari- sources, for mining son with activities, and for in the . agriculture. At the Kennaway and turn of the 20th cen- Helmer (2007) tury it was difficult aged the forests of to identify pristine Puerto Rico and forest cover any- found that be- where in the Carib- tween 1991 and bean (Zon and Spar- 2000 most of the hawk, 1923; Gill, forests cleared for 1931). In fact, Gill development (55%) asserted that Trini- were 1 to 13 years dad, Haiti, Puerto old, reflecting the Rico, and most of recent abandon- Cuba were ‘almost ment and coloni- forest-less lands’. zation of agricul- Gill (1931, p. 66) tural lands. Only wrote: “The wood- 13% of the forests lands of Porto Rico cleared for devel- are only a memory”. opment were older He attributed much than 41 years old. of the anthropogenic They found that effects as high grad- the tendency for ing of forests, i.e., to urban development the repetitive and se- was on flat lands lective removal of or lands with easy the best timbers, access, regardless with dramatic effects of land cover (for- on forest composi- est or agricultur- tion and structure. al). Helmer (2004) Outright deforesta- found that the tion for agricultural likelihood of ur- purposes was the ban development other major anthro- in Puerto Rico pogenic effect on was positively re- Caribbean forests. lated to proximity Any objective to urban areas, analysis of Caribbe- size of urban area, an landscapes leads proximity to roads to two fundamental and surrounding observations: 1. The proportion of pas- landscapes of the ture. It was nega- Caribbean, like any tively related to other landscape in elevation, percent the world, reflect the slope, alluvial intensity and types Figure 1a. Land cover maps of several Caribbean Islands (Kennaway and Helmer 2007; Helmer substrate relative of human activity et al., 2008; Kennaway et al., 2008). to other sub- prevailing on them strates, and sur- (Lugo, 1996); the land cov- Rico with the decline of ag- landscapes had experienced rounding proportion of ers in the Caribbean during riculture and the expansion a dramatic change in land shrubs plus low canopy den- the early to mid 20th century of urban built-up land cover as a result of declin- sity forests. Helmer (2004) reflected the prevailing agri- (Lugo, 2002; Kennaway and ing agricultural activity and also found that pasture is cultural activities of humans, Helmer, 2007). Helmer et al. increasing urbanization. more likely to undergo de- and these activities coupled (2008) showed that this pat- These changes are reflected velopment than shrubland to charcoal production re- tern of land cover change in the land cover data in plus forest with low canopy sulted in reductions in forest from agricultural to urban Table III and Figure 1. Al- density, and that most land areas (Lugo et al., 1981). 2. and forests also happened in though the data cover a development occurs in the Because human activities other Caribbean Islands. small fraction of the Carib- least protected ecological change over time, land cover bean Islands and mostly zones. and land uses change, and Recent Land Cover in the those of the Lesser Antilles, By the end of the 20th thus it is possible for land- Caribbean the general pattern is clear: century, built-up land due to scapes to change dramati- forest cover and vegetation urbanization had become a cally in a period of decades; By the end of the 20th account for a large fraction determinant factor in the this happened in Puerto century, Caribbean Island of the land, and urban cover outcome of land cover

708 SEP 2012, VOL. 37 Nº 9 change. Like to- in Table III was pography, built- significantly re- up land became a lated to the num- correlate of for- ber of natural- est clearing and ized species per landscape frag- unit land area mentation, much (p= 0.016; adjust- like road access ed r2= 0.59). The to forestlands urban cover is a was at the turn proxy for the lev- of the 20th cen- el of human ac- tury. This pattern tivity responsi- of land conver- ble for diversi- sion is only pos- fying the land- sible in an ener- scape and in- gy-rich society creasing the op- whose machines portunities for allow conversion the naturaliza- of lands that be- tion of species. fore were topo- In summary, graphically inac- for millennia the cessible. This Caribbean Islands new reality is have been a hot what makes the bed of human ac- endemic biota of tivity, which has the Caribbean continuously vulnerable to ur- transformed the banization and landscape and its other land cover biodiversity. The changes. Howev- appearance of the er, the land-cover landscape, as data of Helmer et measured by al. (2008) show changing land recovery of veg- covers, has etation, including changed signifi- forests, on aban- cantly several doned agricul- times from land- tural lands such scapes dominated that there is by natural vege- more vegetation tation cover with and forest cover native species, to in the Caribbean fragmented and today than dur- deforested agri- ing the first half cultural land- of the 20th cen- scapes with both tury. This rever- native and intro- sal of land cover duced species, and forest area Figure 1b. Land cover maps of several Caribbean Islands (Kennaway and Helmer 2007; Helmer et al., and more recently will likely have 2008; Kennaway et al., 2008). urbanizing land- important eco- scapes with a logical consequences for the Introduced species initially nomenon (Marris, 2009): a mosaic of small fragments of future. colonize abandoned and de- natural response to environ- vegetation cover composed of graded lands; they form mental change triggered by native, introduced, and natu- Ecological Consequences even age monospecific anthropogenic activity. Re- ralized species. In spite of all and Future Trends stands and at first appear to search on the functioning of the changes in land cover, exclude native species. How- novel forests of the Carib- the fundamental original pat- The abandonment of agri- ever, over time, these stands bean is just beginning to terns of natural vegetation cultural lands and the natu- are invaded by native tree take shape, but the species composition has not changed ral recovery of vegetation on species and they diversify diversification of these for- and the Islands remain a those lands has not only re- and increase the number of ests represents a mitigating hotspot of terrestrial biodi- sulted in the greening of species per area (Lugo, effect in relation to the ef- versity, particularly Cuba and Caribbean Islands, but also 2004). These forests are new fects of deforestation and , as are the adja- has led to a change in spe- forest types on the land- urbanization. In fact, we cent marine waters in terms cies composition in the re- scape, i.e., novel forests sen- found that the percent urban of marine biodiversity. Hu- sulting secondary vegetation su Hobbs et al. (2006). Their cover in eight Caribbean Is- mans have added complexity (Lugo and Helmer, 2004). emergence is a global phe- lands identified with an ‘†’ to the native biota by intro-

SEP 2012, VOL. 37 Nº 9 709 ducing species to the Carib- Acevedo Rodríguez P, Strong MT narine S (2012) Forest tree Lugo AE, Helmer E (2004) (2008) Floristic richness and communities for Trinidad and Emerging forests on aban- bean with mixed results in affinities in the West Indies. Tobago mapped with multisea- doned land: Puerto Rico’s new relation to the expectations of Bot. Rev. 74: 5-36. son Landsat and multiseason forests. Forest Ecol. Manag. the introductions. However, Ackerman JD (1996) The matura- fine-resolution imagery. Forest 190: 145-161. Ecol. Manag. 279: 147-166. land cover changes induced tion of a flora: Orchidaceae of Lugo AE, Schmidt R, Brown S by changing Caribbean econ- Puerto Rico and the Virgin Hernández S, Pérez M (2005) (1981) Tropical forests in the omies have allowed natural Islands. Ann. N. Y.Acad. Sci. Land Cover Map of the Do- Caribbean. Ambio 10: 318-324. 776: 55-64. minican Republic from Land- processes of species natural- sat ETM+ Imagery Circa Marris E (2009) Ragamuffin earth. ization, dispersal, growth, Biaggi V (1997) Las Aves de Nature 460: 450-453. Puerto Rico. 4th ed. Universi- 2000. Secretaría de Estado de and self organization to pro- dad de Puerto Rico. Rio Pie- Medio Ambiente y Recursos Myers N, Mittermeir RA, Mitter- duce a suite of novel ecosys- dras, PR. 389 pp. Naturales. , meir CG, da Fonseca GA, Dominican Republic. tems such as the extensive Borges S (1996) The terrestrial Kent J (2000) Biodiversity Spathodea campanulata for- oligochaetes of Puerto Rico. Hobbs RJ, Arico S, Aronson J, hotspots for conservation pri- ests in Puerto Rico, where Ann. N. Y.Acad. Sci. 776: Baron JS, Bridgewater P, Cra- orities. Nature 403:853-858. 239-248. mer VA, Epstein PR, Ewel JJ, 75% of the forest area con- Klink CA, Lugo AE, Norton Proctor GR (1989) Ferns of Puerto tain novel combinations of Borhidi A (1991) Phytogeography D, Ojima D, Richardson DM, Rico and the Virgin Islands. tree species (Brandeis et al., and Vegetation Ecology of Sanderson EW, Valladares F, The New York Botanical Gar- den, New York, NY, USA. 2009). These novel forests Cuba. Akadémiai Kiadó. Bu- Vila M, Zamora R, Zobel M dapest, Hungary. 857 pp. (2006) Novel ecosystems: the- 389 pp. now appear as natural on the Brandeis, TJ, E Helmer, H Mar- oretical and management as- Raffaele HA (1989) A guide to the Caribbean landscape as do cano Vega, AE Lugo (2009) pects of the new ecological birds of Puerto Rico and the their predecessor native eco- Climate shapes the novel plant world order. Global Ecol. Bio- Virgin Islands. Princeton Uni- geogr. 15: 1-7. systems. The net result is communities that form after versity Press, Princeton, NJ, that the Caribbean Islands deforestation in Puerto Rico Kairo M, Ali B, Cheesman O, USA. 259 pp. are now richer in species and and the U.S. Virgin Islands. Haysom K, Murphy ST (2003) Forest Ecol. Manag. 258: Rivero JA (1998) Los Anfibios y Invasive species threats in the nd community types than they 1704-1718. Caribbean region: report to Reptiles de Puerto Rico. 2 were prior to human habita- the Nature Conservancy. ed. Universidad de Puerto Brash AR (1987) The history of Rico, Río Piedras, PR. tion but the cover of natural avian extinction and forest CABI. Curepe, Trinidad & ecosystems (including the conversion on Puerto Rico. Tobago. 132 pp. Roberts CM, McClean CJ, Veron novel ones) is now less than Biol. Cons. 39: 97-111. Kennaway T, Helmer EH (2007) JEN et al (2002) Marine bio- it was before people. Humans Francisco Ortega J, Santiago Va- The forest types and ages diversity hotspots and conser- now occupy spaces previ- lentín E, Acevedo Rodríguez cleared for land development vation priorities for tropical P, Lewis C, Pippoly JIII, in Puerto Rico. GISci. Rem. reefs. Science 295:1280-1284. ously occupied by natural Sens. 44: 356-382. ecosystems. The vulnerability Merrow AW, Maunder M Torres JA, Snelling, RR (1997) (2007) Seed plant genera en- Kennaway TA, Helmer EH, Lefsky Biogeography of Puerto Rican of all Caribbean ecosystems demic to the Caribbean island MA Brandeis TA, Sherrill KR ants: a non-equilibrium case? to unwanted anthropogenic biodiversity hotspot: a review (2008) Mapping land cover Biodiv. Cons. 6: 1103-1121. effects is now higher than and a molecular phylogenetic and estimating forest structure Torres Santana CW, Santiago Va- ever and requires judicious perspective. Bot. Rev. 73: using satellite imagery and 183-234. coarse resolution lidar in the lentín E, Levia Sánchez AT, conservation measures to as- Peguero B, Clubbe C (2010) Francis JK, Liogier HA (1991) Virgin Islands. J. Appl. Rem. Conservation status of plants sure that the Caribbean con- Naturalized Exotic Tree Spe- Sens. 2: 023551-023527. in the Caribbean island biodi- tinues to function as one of cies in Puerto Rico. General Kwak TJ, Cooney PB, Brown CH the world’s premiere hotspots Technical Report SO-82. (2007) Fishery Population versity hotspot. Fourth Global of biodiversity. USDA Forest Service, South- and Habitat Assessment in Botanic Gardens Congress. ern Forest Experiment Sta- Puerto Rico Streams: Phase 1 Dublin, Ireland. pp. 1-15. tion. New Orleans, LO, USA. Final Report. Marine Resourc- Avai­lable at www.bgci.org/ ACKNOWLEDGEMENTS 12 pp. es Division, Puerto Rico De- files/Dublin2010/papers/Tor- res-Santana-Christian.pdf Gill T (1931) Tropical Forests of partment of Natural and Envi- The authors thank Thom- the Caribbean. Tropical Plant ronmental Resources. San Williams EHJr, Bunkley WL, as S. Ruzycki for assistance Research Foundation / Charles Juan, PR. 196 pp. Lilyestrom CG, Ortiz-Corps with figures and Mildred Lathrop Pack Forestry Trust. Little EL, Woodbury RO, Wad- EA (2001) A review of recent Alayón for editing the man- Baltimore, MD, USA. 318 pp. sworth, FH (1974) Trees of introductions of aquatic in- Helmer EH (2004) Forest conser- Puerto Rico and the Virgin vertebrates in Puerto Rico uscript. This study was con- Islands, Vol. 2. Agriculture ducted in collaboration with vation and land development and implications for the man- in Puerto Rico. Lands. Ecol. Handbook N° 449 USDA For- agement of nonindigenous the University of Puerto 19: 29-40. est Service. Washington, DC, species. Caribb. J. Sci. 37: Rico. USA. 1024 pp. 246-251. Helmer EH, Kennaway TA, Pedre- ros DH, Clark ML, Marcano- Lugo AE (1996) Caribbean island Whittaker RJ (1998) Island Bioge- REFERENCES Vega H, Tieszen LL, Ruzycki landscapes: indicators of the ography: Ecology, Evolution effects of economic growth on TR, Schill SR, Carrington and Conservation. Oxford Acevedo Rodríguez P (2005) CMS (2008) Land cover and the region. Env. Dev. Econ. 1: 128-136. University Press. Oxford, Vines and Climbing Plants of forest formation distributions . 285 pp. Puerto Rico and the Virgin for St. Kitts, Nevis, St. Eusta- Lugo AE (2002) Can we manage Islands. Contr. U.S. Natl. tius, Grenada and Barbados tropical landscapes? An an- Woods CA (1996) The land mam- Herb. N° 51. 483 pp. from decision tree classifica- swer from the Caribbean per- mals of Puerto Rico and the tion of cloud-cleared satellite spective. Lands. Ecol. 17: Virgin Islands. Ann. N. Y. Acevedo Rodríguez P, Strong MT Acad. Sci. 776: 131-148. (2005) Monocotyledons and imagery. Caribb. J. Sci. 44: 601-615. Gymnosperms of Puerto Rico 175-198. Lugo AE (2004) The outcome of Zon R, Sparhawk WN (1923) For- and the Virgin Islands. Con- Helmer EH, Ruzycki TS, Benner alien tree invasions in Puerto est Resources of the World. tr. U.S. Natl. Herb. N° 52. J, Voggesser SM, Scobie BP, Rico. Front. Ecol. Env. 2: McGraw-Hill. New York, NY, 415 pp. Park C, Fanning DW, Ram- 265-273. USA. 997 pp.

710 SEP 2012, VOL. 37 Nº 9