**5. Discussion**

*buchii* [28]. In the rest of the territory, the potential forest consists of *Swieteania mahagoni* and *C. diversifolia*. An important feature in this area is the presence of the Gran Estero, developed in the last 400–500 years from deposits of materials from the Northern Cordillera. This area is subject to frequent flooding, and is home to a forest of *P. officinalis* belonging to the associa‐ tion *Roystoneo hispaniolanae‐Pterocarpetum officinalis* Cano, Veloz, Cano‐Ortiz & Esteban 2009. It represents the outer edge of the mangrove forests of *R. mangle* that are typical in the broad

**BA‐A4**. The Samaná Peninsula was isolated from the rest of the territory until 300–400 years ago. It constitutes a geomorphological unit dominated by karstic and limestone materials, with schists and marbles. The thermotype is infratropical and the ombrotype is subhumid‐humid. The presence of escarpments (cliffs) has led to the installation of eda‐ phoxerophilous communities that must be considered as dry forest, owing to the pre‐ dominance of *P. polygonus, Z. debilis, A. antillarum, Eugenia samanensis* Alain*, B. simaruba, Capparis flexuosa* L.*, Ficus velutina* H. & B. ex Willd.*, E. maleolens, O. dilenii, Comocladia dodo‐ naea* (L.) Britt.*, Stigmaphyllom emarginatum* (Cav.) A. L. Juss. and *C. linearis.* This area has

**BA‐A5**. The Eastern Cordillera is the oldest range in this biogeographical territory, and has a frequent presence of limestone, karstic landscapes, tufas, alluvial deposits and foothills. It serves as a separation from the great eastern coastal plain, with sporadic intrusions of Palaeozoic slates and basalts. The thermotype ranges from infra to mesotropical; the mac‐ robioclimate is rainy and the ombrotype is subhumid to hyperhumid. The subhumid forest with a semi‐deciduous character represents the transition between the dry and ombrophilous

**Figure 9.** Vegetation catena of the Samaná Peninsula. 1. Coconut cultivation. 3. Broadleaf forest. 2. Community of *Cocco‐ thrinax gracilis* and *Bursera simaruba*. As. *Coccotrino gracili‐Burseretum simarubae* [31]. 4. Cloud forest of *Prestoea montana*.

5. Forest of *Pterocarpus officinalis.* As. *Roystoneo hispaniolanae‐Pterocarpetum officinalis*.

channels and in Samaná Bay [23].

180 Plant Ecology - Traditional Approaches to Recent Trends

over 60 species of flora **Figure 9**.

The island of Hispaniola is characterised by its abrupt differences in altitude—from 0 to 3175 m on Pico Duarte in the Central Cordillera—[38], the wide diversity of substrates and a plu‐ viometric gradient that ranges from 400 to 4600 mm [35]. These three parameters, in combina‐ tion with the isolation to which the various territories have been subjected, are key factors in explaining the existence of the current vegetation. For the study of this vegetation, we have established several large areas based on rainfall and temperature—dry, subhumid, humid‐ hyperhumid areas and high‐mountain zones—as highlighted in [22, 23]. The bioclimatic anal‐ ysis reveals the presence of several macrobioclimates on Hispaniola: tropical xeric, tropical pluviseasonal and tropical pluvial; all of which are reflected in different vegetation units: dry forest, subhumid broadleaf forest, cloud forest and high‐mountain forest (pine forest) [35].

The dry areas have a tropical xeric macrobioclimate with a high rate of endemic species. These zones correspond closely to the study areas A3, A9 and A12 [39]. The vegetation in all the semiarid and dry areas is physiognomically very similar; it is dominated essentially by plants from the families *Agavaceae* and *Cactaceae* among others: *Lemaireocereus hystrix* (Haw.) B.&R., *Cylindropuntia caribae* (B.&R,) Kunth*, Consolea moniliformis* (L.) Haw., *Leptochloopsis virgata* (Poir.) Griseb., *Pilosocereus polygonus* (Lam.) B.& R., *Opuntia dillenii* (Fer.‐ Gawl) Haw., *Leptocereus weingartianus* (Hartm.) Britt. & Rose*, Acacia skleroxyla* Tuss., *Agave antilla‐ rum* Descourt. and *Pithecellobium unguis‐cati* (L.) Mart. In the southwest of the island (A12), we establish two types of dry forest: first, the forest of Pedernales‐Ceitillan (Procurrente de Barahona), growing on dogtooth limestone substrates. We highlight as endemic species *Melocactus pedernalensis* (Ait.) M. Mejía & R. García*, Galactia dictyophylla* Urb., *Coccoloba incras‐ sata* Urb., *Caesalpinia domingensis* Urb. and *Guettarda stenophylla* Urb. The dry forest in area A9 with an *Io* = 2.7 has a somewhat lower rate of endemics. The most notable endemics and those which mark the difference with the dry forest of Pedernales are *Melocactus lemairei* (Monv.) Miq. *Neoabbottia paniculata* (Lam.) Britt. & Rose and *Coccotrinax spissa* Bailey. In area A3, located in the northwest of the island, there is a dry forest differentiated from the previous forests by the presence of a floristic contingent of endemic species, including *Salvia montecristina* Urb. & Ekm., *Mosiera urbaniana* Borhidi*, Croton poitaei* Urb., *Croton sidaefolius* Lam., *Guettarda tor‐ tuensis* Urb. & Ekm. and *Coccoloba buchii* Urb. The most representative plant communities in the dry areas belong to the following endemic habitats: *Lepotogono buchii‐Leptochloopsietum virgatae* Cano et al. [24, 25], included in the serpentinicolous endemic alliance *Tetramicro canaliculatae‐Leptochloopsion virgatae* Cano, et al. [24, 25]; *Crotono astrophori‐Leptochloopsietum virgatae* Cano, et al. [24, 25], *Melocacto pedenalensi‐Leptochloopsietum virgatae* Cano, et al. [24, 25], *Solano microphylli‐Leptochloopsietum virgatae* Cano et al. [24, 25], included in the endemic alliance *Crotono poitaei‐Leptochloopsion virgatae* Cano et al. [24, 25]; the dry forests published in Ref. [29], and the pine forests on serpentines of *Leptogono buchii‐Pinetum occidentalis* Cano, Veloz & Cano‐Ortiz 2011, which we include in the endemic alliance *Phyllario mummularioidi‐ Leptogonion buchi* Cano, Veloz, & Cano‐Ortiz 2011.

Most of Hispaniola has a pluviseasonal tropical macrobioclimate and a predominantly sub‐ humid ombrotype, with rainfall ranging from 1000 to 2000 mm and an ombrothermic index of *Io* = 3.7–4.3 (Parque Nacional del Este); *Io* = 4 (El Seibo); *Io* = 6.2 (Miches); *Io* = 5.4 (Jarabacoa) and *Io* = 5.9 (Mayaguana) (A7). The dominant vegetation in these areas is a subhumid broad‐ leaf forest subjected to a dry season from December to April, which is why the floristic compo‐ sition includes deciduous tree species due to water stress, such as *Bursera simaruba* (L.) Sarg. and *Swietenia mahagoni* (L.) Jacq., along with other species such as *Metopium toxiferum* (L.) Krug & Urb., *Krugidendron ferreum* (Vahl) Urb., *Acacia macracantha* H. & B. ex Willd., *Coccoloba diversifolia* Jacq. and *Bucida buceras* L. These formations contain important endemic elements such as the climber *Aristolochia bilobata* L. and the tree element *Melicoccus jimenezii* (Alain) Acev. Rodr., in addition to scrubland plants such as *Lonchocarpus neurophyllus* Benth., along with the other scrubland formations that become dominant and act as dynamic substitution stages. This is the case of *Zamia debilis* L., which coexists with the endemic species *Pereskia quisqueyana* Alain and *G. ekmanii* O.E. Schulz.

established several large areas based on rainfall and temperature—dry, subhumid, humid‐ hyperhumid areas and high‐mountain zones—as highlighted in [22, 23]. The bioclimatic anal‐ ysis reveals the presence of several macrobioclimates on Hispaniola: tropical xeric, tropical pluviseasonal and tropical pluvial; all of which are reflected in different vegetation units: dry forest, subhumid broadleaf forest, cloud forest and high‐mountain forest (pine forest) [35].

The dry areas have a tropical xeric macrobioclimate with a high rate of endemic species. These zones correspond closely to the study areas A3, A9 and A12 [39]. The vegetation in all the semiarid and dry areas is physiognomically very similar; it is dominated essentially by plants from the families *Agavaceae* and *Cactaceae* among others: *Lemaireocereus hystrix* (Haw.) B.&R., *Cylindropuntia caribae* (B.&R,) Kunth*, Consolea moniliformis* (L.) Haw., *Leptochloopsis virgata* (Poir.) Griseb., *Pilosocereus polygonus* (Lam.) B.& R., *Opuntia dillenii* (Fer.‐ Gawl) Haw., *Leptocereus weingartianus* (Hartm.) Britt. & Rose*, Acacia skleroxyla* Tuss., *Agave antilla‐ rum* Descourt. and *Pithecellobium unguis‐cati* (L.) Mart. In the southwest of the island (A12), we establish two types of dry forest: first, the forest of Pedernales‐Ceitillan (Procurrente de Barahona), growing on dogtooth limestone substrates. We highlight as endemic species *Melocactus pedernalensis* (Ait.) M. Mejía & R. García*, Galactia dictyophylla* Urb., *Coccoloba incras‐ sata* Urb., *Caesalpinia domingensis* Urb. and *Guettarda stenophylla* Urb. The dry forest in area A9 with an *Io* = 2.7 has a somewhat lower rate of endemics. The most notable endemics and those which mark the difference with the dry forest of Pedernales are *Melocactus lemairei* (Monv.) Miq. *Neoabbottia paniculata* (Lam.) Britt. & Rose and *Coccotrinax spissa* Bailey. In area A3, located in the northwest of the island, there is a dry forest differentiated from the previous forests by the presence of a floristic contingent of endemic species, including *Salvia montecristina* Urb. & Ekm., *Mosiera urbaniana* Borhidi*, Croton poitaei* Urb., *Croton sidaefolius* Lam., *Guettarda tor‐ tuensis* Urb. & Ekm. and *Coccoloba buchii* Urb. The most representative plant communities in the dry areas belong to the following endemic habitats: *Lepotogono buchii‐Leptochloopsietum virgatae* Cano et al. [24, 25], included in the serpentinicolous endemic alliance *Tetramicro canaliculatae‐Leptochloopsion virgatae* Cano, et al. [24, 25]; *Crotono astrophori‐Leptochloopsietum virgatae* Cano, et al. [24, 25], *Melocacto pedenalensi‐Leptochloopsietum virgatae* Cano, et al. [24, 25], *Solano microphylli‐Leptochloopsietum virgatae* Cano et al. [24, 25], included in the endemic alliance *Crotono poitaei‐Leptochloopsion virgatae* Cano et al. [24, 25]; the dry forests published in Ref. [29], and the pine forests on serpentines of *Leptogono buchii‐Pinetum occidentalis* Cano, Veloz & Cano‐Ortiz 2011, which we include in the endemic alliance *Phyllario mummularioidi‐*

Most of Hispaniola has a pluviseasonal tropical macrobioclimate and a predominantly sub‐ humid ombrotype, with rainfall ranging from 1000 to 2000 mm and an ombrothermic index of *Io* = 3.7–4.3 (Parque Nacional del Este); *Io* = 4 (El Seibo); *Io* = 6.2 (Miches); *Io* = 5.4 (Jarabacoa) and *Io* = 5.9 (Mayaguana) (A7). The dominant vegetation in these areas is a subhumid broad‐ leaf forest subjected to a dry season from December to April, which is why the floristic compo‐ sition includes deciduous tree species due to water stress, such as *Bursera simaruba* (L.) Sarg. and *Swietenia mahagoni* (L.) Jacq., along with other species such as *Metopium toxiferum* (L.) Krug & Urb., *Krugidendron ferreum* (Vahl) Urb., *Acacia macracantha* H. & B. ex Willd., *Coccoloba diversifolia* Jacq. and *Bucida buceras* L. These formations contain important endemic elements such as the climber *Aristolochia bilobata* L. and the tree element *Melicoccus jimenezii* (Alain)

*Leptogonion buchi* Cano, Veloz, & Cano‐Ortiz 2011.

182 Plant Ecology - Traditional Approaches to Recent Trends

When these subhumid forests are located on perforated reef limestone, the territory acts as dry owing to the intense water losses from the soil, and present the floristic elements *P. polygonus, P. unguis‐cati, L. weingartianus* and *Hylocereus undatus* (Haw.) Britt. & Rose. These formations connect with the dry forest in the southwest of the island. A similar phenomenon occurs in the rocky escarpments of Samaná, where there is a widespread frequent presence of *B. simaruba, Coccothrinax gracilis* Burret*, A. antillarum, L. weingartianum* and *O. dilleni*. These habitats tend to contain deciduous species due to water stress and correspond to the associa‐ tions recently proposed by us [30]: *Chrysophyllo oliviformi‐Sideroxyletum salicifolii* Cano & Veloz 2012 and *Zamio debilis‐Metopietum toxiferi* Cano & Veloz 2012. In dry and subhumid areas, the serpenticolous vegetation is of great interest for conservation [28].

Humid areas have a tropical pluvial macrobioclimate, and there is therefore no dry season. Rainfall exceeds 2000 mm. These humid areas tend to be located in the mountain ranges of the Northern Cordillera, Central Cordillera, Sierra de Bahoruco, Eastern Cordillera, Los Haitises and on the Samaná Peninsula, all of which concentrate the humid rainy formations, namely broadleaf ombrophilous forests whose physiognomy varies from one place to another. In the Loma La Herradura (Eastern Cordillera), the dominant plants are *Sloanea berteriana* Choisy*, Ormosia krugii* Urb., *Didymopanax morototoni* (Aubl.) Dcne. & Planch. and *Oreopanax capitatus* (Jacq.) Dcne. & Planch. Towards the stream beds, there is a presence of the sierran palm for‐ est of *P. montana* (Grah.) Nichol*,* whose associated flora are *Guarea guidonia* (L.) Sleumer*, D. morototoni, Alchornea latifolia* Sw. and *Eugenia domingensis* Berg [11].

In the Central Cordillera (A16), for example, in the Ébano Verde Science Reserve, the ombroph‐ ilous forest is dominated by species from the genus *Magnolia*, which are endemic to the island: *Magnolia pallescens* Urb. & Ekm. and *Magnolia domingensis* Urb., along with the 'palo de viento' *Didymopanax tremulus* Krug & Urb., *Ocotea leucoxylon* (Sw.) Lanessan*, Persea oblongifolia* Kopp, *Cyrilla racemiflora* L.*, Cecropia schreberiana* Miq. and *Dendropanax arboreus* (L.) Decne. & Planch. This forest is home to the endemic species *Myrsine nubicola* A. Liogier*, Odontadenia polyneura* (Urb.) Woods*, Marcgravia rubra* A. Liogier*, Pinguicula casabitoana* J. Jiménez and *Tabebuia vinosa* A. Gentry. As in the Loma La Herradura, the sierran palm forest of *P. montana* can be found in the most humid gorges. When these plant communities become altered and their coverage decreases, they are quickly superseded by tropical fern or herb formations of *Dicranopteris pectinata* (Willd.) Underw. and *Gleichenia bifida* (Willd.) Spreng. [9].

In the Loma Humeadora, the cloud forest of 'palo de viento' *D. tremulus* grows at an alti‐ tude of 1100–1315 m, and this species is associated with *Clusia clusioides* (Griseb.) D'Arcy*, C. racemiflora, Ocotea foeniculacea* Mez*, Lyonia alainii* W. Judd and *P. montana*. Descending to 850–1100 m on slopes with a gradient of 45–60° but with abundant litterfall that effectively retains water, and in gorges, *P. montana* becomes dominant associated with *A. latifolia, O. leu‐ coxylon, Bombacopsis emarginata* (A. Rich.) A. Robins.*, S. berteroana, Mora abbottii* Rose & Leon., *Turpinia occidentalis* (Vent.) G. Don*, Bactris plumeriana* Mart. and *Ditta maestrensis* Borhidi [8].

In the relevés taken both in the Central Cordillera and in Sierra Bahoruco, in addition to the existence of different substrates, the broadleaf forest shows clear floristic differences, with *M. pallescens* and *M. domingensis* in the Central Cordillera and *Magnolia hamorii* Howard in the Sierra de Bahoruco. The forest of *M. hamorii* and *D. tremulus* has a large number of associ‐ ated endemic species such as *Lasianthus bahorucanus* Zanoni*, Psychotria guadalupensis* (DC.) Howard*, H. domingensis* Urb. *Mecranium ovatum* Cog. (local endemic), *Vriesea tuercheimii* (Mez.) L.B. Smith*, Macrocarpaea domingensis* Urb. *Cestrum daphnoides* Griseb. *Hypolepis hispan‐ iolica* Maxon*, Columnea domingensis* (Urb.) Wiehler and *Ilex tuerckheimii* Loes. This vegetation was included in Ref. [22] in the classes *Ocoteo‐Magnolietea* Borhidi & Muñiz in Borhidi, Muñiz & Del Risco 1979 and in *Weinmannio‐Cyrilletea* Knapp 1964.

The study of high‐mountain areas took place in the Central Cordillera (A16), crossing the mountain from Constanza to San José de Ocoa, and in the Sierra de Bahoruco (A12). From the physiognomic point of view, the plant formations sampled between 1203 m (Sierra Bahoruco) and 2383 m (Central Cordillera) are similar, corresponding to a pine forest of *Pinus occiden‐ talis* Sw. These are territories with lower rainfall, as the sea of clouds from the trade winds originating the broadleaf forest lies beneath. The temperature may drop to 0°C in winter. The xericity and the low temperatures in the high mountains result in the presence of a pine for‐ est of *P. occidentalis*, which in the Central Cordillera is accompanied by endemic species, with 8–10 endemic plants per sampling unit. This is also the case in the Sierra de Bahoruco, where the pine forest has an average of 20 endemic species per sampling. The endemic character of these two mountains is caused by their former isolation.

In the Central Cordillera, these forests grow on siliceous substrates and are home to a large number of endemic species such as *I. tuerckheimii, Ilex fuertesiana* (Loes.) Loes. *Garrya fadye‐ nii* Hooker*, Mikania barahonensis* Urb.*, Myrica picardae* Krug & Urb., *Rubus eggersii* Rydberb., *Tetrazygia urbaniana* (Cogn. in Urb.) Croizat ex Moscoso and *Fuchsia pringsheimii* Urb.; the endemic and specific parasitic species *P. occidentalis, Dendropemon pycnophyllus* Krug & Urb. and *Dendropemon constantiae* Krug & Urb. are of particular importance. In the understorey of this forest, there is a high frequency of the grass *Isachne rigidifolia* (Poir.) Urb., and when the pine forest is cleared, it is substituted by a formation of single‐culm grasses dominated by *D. domin‐ gensis* Hack. & Pilg., which occupies large extensions above 1800 m in the Central Cordillera.

The pine forest of *P. occidentalis* growing on limestone in the Sierra de Bahoruco has a dif‐ ferent floristic composition, in which the endemic species *Coccothrinax scoparia* Becc., *Agave intermixta* Trel., *Senecio barahonensis* Urb.*, Cestrum brevifolium* Urb., *Eupatorium gabbii* Urb., *Lyonia truncatula* Urb., *Sideroxylon repens* (Urb. & Ekm.) TD. Pennington*, Cordia selleana* Urb., *Narvalina domingensis* Cass. and *Galactia rudolphiodes* (Griseb.) Benth. & Hook. *var. haitiensis* Urb. are of particular interest, along with some other endemic herbs such as *Pilea spathulifo‐ lia* Groult*, Tetramicra ekmanii* Mansf., *Artemisia domingensis* Urb., *Gnaphalium eggersii* Urban and *Polygala crucianelloides* DC. High‐mountain pine forests that have been diagnosed by us as endemic habitats of Hispaniola [26] are *Dendropemom phycnophylli‐Pinetum occidentalis* Cano, Veloz & Cano‐Ortiz 2011 and *Cocotrino scopari‐Pinetum occidentalis* Cano, Veloz & Cano‐Ortiz 2011.

### **5.1. Distribution analysis of endemic species**

In the relevés taken both in the Central Cordillera and in Sierra Bahoruco, in addition to the existence of different substrates, the broadleaf forest shows clear floristic differences, with *M. pallescens* and *M. domingensis* in the Central Cordillera and *Magnolia hamorii* Howard in the Sierra de Bahoruco. The forest of *M. hamorii* and *D. tremulus* has a large number of associ‐ ated endemic species such as *Lasianthus bahorucanus* Zanoni*, Psychotria guadalupensis* (DC.) Howard*, H. domingensis* Urb. *Mecranium ovatum* Cog. (local endemic), *Vriesea tuercheimii* (Mez.) L.B. Smith*, Macrocarpaea domingensis* Urb. *Cestrum daphnoides* Griseb. *Hypolepis hispan‐ iolica* Maxon*, Columnea domingensis* (Urb.) Wiehler and *Ilex tuerckheimii* Loes. This vegetation was included in Ref. [22] in the classes *Ocoteo‐Magnolietea* Borhidi & Muñiz in Borhidi, Muñiz

The study of high‐mountain areas took place in the Central Cordillera (A16), crossing the mountain from Constanza to San José de Ocoa, and in the Sierra de Bahoruco (A12). From the physiognomic point of view, the plant formations sampled between 1203 m (Sierra Bahoruco) and 2383 m (Central Cordillera) are similar, corresponding to a pine forest of *Pinus occiden‐ talis* Sw. These are territories with lower rainfall, as the sea of clouds from the trade winds originating the broadleaf forest lies beneath. The temperature may drop to 0°C in winter. The xericity and the low temperatures in the high mountains result in the presence of a pine for‐ est of *P. occidentalis*, which in the Central Cordillera is accompanied by endemic species, with 8–10 endemic plants per sampling unit. This is also the case in the Sierra de Bahoruco, where the pine forest has an average of 20 endemic species per sampling. The endemic character of

In the Central Cordillera, these forests grow on siliceous substrates and are home to a large number of endemic species such as *I. tuerckheimii, Ilex fuertesiana* (Loes.) Loes. *Garrya fadye‐ nii* Hooker*, Mikania barahonensis* Urb.*, Myrica picardae* Krug & Urb., *Rubus eggersii* Rydberb., *Tetrazygia urbaniana* (Cogn. in Urb.) Croizat ex Moscoso and *Fuchsia pringsheimii* Urb.; the endemic and specific parasitic species *P. occidentalis, Dendropemon pycnophyllus* Krug & Urb. and *Dendropemon constantiae* Krug & Urb. are of particular importance. In the understorey of this forest, there is a high frequency of the grass *Isachne rigidifolia* (Poir.) Urb., and when the pine forest is cleared, it is substituted by a formation of single‐culm grasses dominated by *D. domin‐ gensis* Hack. & Pilg., which occupies large extensions above 1800 m in the Central Cordillera. The pine forest of *P. occidentalis* growing on limestone in the Sierra de Bahoruco has a dif‐ ferent floristic composition, in which the endemic species *Coccothrinax scoparia* Becc., *Agave intermixta* Trel., *Senecio barahonensis* Urb.*, Cestrum brevifolium* Urb., *Eupatorium gabbii* Urb., *Lyonia truncatula* Urb., *Sideroxylon repens* (Urb. & Ekm.) TD. Pennington*, Cordia selleana* Urb., *Narvalina domingensis* Cass. and *Galactia rudolphiodes* (Griseb.) Benth. & Hook. *var. haitiensis* Urb. are of particular interest, along with some other endemic herbs such as *Pilea spathulifo‐ lia* Groult*, Tetramicra ekmanii* Mansf., *Artemisia domingensis* Urb., *Gnaphalium eggersii* Urban and *Polygala crucianelloides* DC. High‐mountain pine forests that have been diagnosed by us as endemic habitats of Hispaniola [26] are *Dendropemom phycnophylli‐Pinetum occidentalis* Cano, Veloz & Cano‐Ortiz 2011 and *Cocotrino scopari‐Pinetum occidentalis* Cano, Veloz &

& Del Risco 1979 and in *Weinmannio‐Cyrilletea* Knapp 1964.

184 Plant Ecology - Traditional Approaches to Recent Trends

these two mountains is caused by their former isolation.

Cano‐Ortiz 2011.

The study of the 19 areas in Hispaniola shows a wide distribution of endemic species, but with three nuclei of particular interest due to their high rate of endemic plants, as highlighted by the comparative treatment between the total number of endemic species present in an area and the endemic species that are exclusive to this area. There are a total of 2094 endemic species in the 19 areas, of which 1162 are exclusive. The difference between 2094 − 1162 = 932, confirming the high number of endemic species distributed all over the island. The highest concentrations are found in areas A12, A16, A13 (**Table 1**), whereas the rest of the areas have a lower number of endemic species, with a slight increase in areas A4 and A9. These areas continue to be of interest as they contain endemic species that are exclusive to the territory, and even endemic genera, as occurs in A18 and A19 (**Figure 11**).


**Table 1.** Comparative analysis of the total endemic species in each area with the number of endemic species exclusive to that area.

### **Relationship between the relation of endemic taxa (total number) to exclusive endemic taxa per study area**

**Figure 11.** Ratio of total endemic species in each area to endemic species exclusive to that area.

## **6. Conclusions**

Hispaniola has recently been elevated by us to the rank of biogeographical province [2, 22, 24], having previously been treated with the rank of biogeographical sector [4] and included in the province of the Antilles. In previous studies, we raised it to the rank of superprovince of the Central‐Eastern Antilles and included Hispaniola in it, which along with a group of small neigh‐ bouring islands—Beata, Saona, Gonave and Tortuga—constitute the province of Hispaniola. In the current study, we propose a biogeographical typology with the rank of district for both coun‐ tries (Dominican Republic and Republic of Haiti) in the biogeographical province of Hispaniola, in which we establish five biogeographical territories (sectors) and 19 areas (districts), in the Caribbean‐Mesoamerican region. This proposal is based on geological, climatic and bioclimatic aspects and on studies of the flora and vegetation.

The high number of genera and endemic species in areas A12, A13 and A16 justifies their proposed designation as being of special interest for conservation.

Superprovince of the Central‐Eastern Antilles. Province of Hispaniola. 1. **Central subprovince**. 1.1. Central BT. BA‐A16. Central‐Eastern. 2. **Caribbean‐Atlantic subprovince**. 2.1. Bahoruco‐ Hottense BT. BA‐A12. Bahoruco‐La Selle. BA‐A13. Hottense. 2.2. Neiba‐Matheux‐North‐east‐ ern BT. BA‐A14. Neiba‐Matheux. BA‐A15. North‐western. BA‐A17. Central‐Western. BA‐A19. Tortuga Island. 2.3. BT Azua‐ San Juán‐Hoya Enriquillo‐Port au Prince‐Artiobonite‐Gonaivës. BA‐A9. Azua‐Sán Juán‐Hoya Herniquillo. BA‐A10. Central Plain. BA‐A11. Port au Prince‐ Arbiobonite‐Gonaives. BA‐A18. Gonave Island. 2.4. Caribbean‐Cibense BT. BA‐A3. Cibao Valley. BA‐A7. Eastern Caribbean. BA‐A8. Yamasense. 2.5. Northern BT. BA‐A1. Northern Cordillera. BA‐A2. Coastal Atlantic. BA‐A4. Samanense. BA‐A5. Eastern. BA‐A6.Haitiense **Figure 12**.

**Figure 12.** Map of biogeographical areas (districts) of Hispaniola. A1. Northern Cordillera. A2. Coastal‐Atlantic District. A3. Cibao Valley. A4. Samanense. A5. Eastern. A6. Haitiense. A7. Eastern‐Caribbean. A8. Yamasense. A9. Azua‐Sán Juan‐ Lago Herniquillo. A10. Central Plain (Haiti). A11. Port au Prince‐Ariobonite‐Gonaivës. A12. Bahoruco‐La Selle. A13. Hottense. A14. Neiba‐Matheux. A15. Northwest Haiti. A16. Central‐Eastern. A17. Central‐western (Massif du Nord). A18. Gonave Island. A19 Tortuga Island.
