Eusebio Cano

The endemic flora in the south of the Iberian Peninsula: taxonomic composition, biological spectrum, pollination, reproductive mode and dispersal

Summary The taxonomical composition and four ecological characteristics (life form, seed-dispersal, pollination and reproductive mode) of the 553 endemic species occurring in the south of the Iberian Peninsula have been investigated. A comparative analysis of the results reveals that this endemic flora does not comply with the general patterns previously observed in local floras, Mediterranean regional floras and floras of temperate latitudes. Predominant life forms are chamaephytes (45%) and hemicryptophytes (33%). By contrast, therophytes (11%) and phanerophytes (1%) are relatively infrequent. This spectrum of life forms mirrors the altitudinal distribution of the endemic species, their seed-dispersal strategy and the type of phytocoenoses in which they occur. As far seed-dispersal is concerned, 44% of the endemic species lack any noteworthy adaptive feature. However, the results clearly suggest that this limitation in their disseminative potential has only encouraged endemicity among the therophytes inhabiting lowlands. Among chamaephytes and hemicryptophytes of medium and high altitude, there is a relatively high frequency of exozoochory and anemochory, an adaptation that has contributed to the survival of small plant populations. 91% of the endemic species are pollinated by animals (insects), and only 3 species are dioecious. The dichotomies that the above mentioned characteristics produce (herbaceous vs woody life form, animal-assisted vs abiotic seed-dispersal, animal-assisted vs abiotic pollination and dioecious vs hermaphrodite reproductive mode), have been used to plot statistically significant associations. These are three: Pollination mode is linked with the seed-dispersal strategy, life form with pollination mode, and pollination mode with the reproductive mode. These associations contrast distinctly with results of previous surveys on whole floras, a contrast which makes the singularity of the endemic flora of the Southern Iberian peninsula even more remarkable.

Endemic flora biodiversity in the south of the Iberian Peninsula: altitudinal distribution, life forms and dispersal modes

The south of the Iberian Peninsula, with an altitudinal range varying from sea level to 3482 m and annual average rainfall ranging from 206 to 2223 mm, has 516 vascular endemic species or subspecies, that is, an endemicity rate of 13%. This survey deals with parameters such as species richness, originality, life forms and dispersal modes of these plants, in relation to altitudinal and rainfall gradients. Although most of the endemic plants occur between 600 and 1400 m a.s.l. and in the range of 600–1000 mm annual average rainfall, floristic originality (rate of endemic taxa per area unit) increases exponentially with altitude. The biological spectrum of this endemic flora does not follow the usual patterns observed either in local floras in the south of the Iberian Peninsula or in other regions of the Mediterranean Basin. Chamaephytes (46.08%) and hemicryptophytes (31.37%) are very abundant, whereas therophytes (11.96%) and phanerophytes (0.98%) are comparatively rare. There is a statistically significant correlation between life form and both altitudinal and rainfall gradients. Chamaephytes reach their highest density rates within 1400–2000 m a.s.l., but these records tend to decrease as rainfall rates increase. Abundance of hemicryptophytes is directly dependent on rainfall rates and inversely dependent on temperature. The altitudinal distribution pattern of therophytes is opposite to that of hemicryptophytes, but there is no clear correlation as far as rainfall gradient is concerned. Considering both the endemic plants as a whole and each of the life form groups, the relationships between the dispersal modes used and the altitudinal and rainfall gradients are analysed. Up to 44.51% of the endemic plants do not present evident adaptations to promote the dispersion of their diaspores. However, only in the group of therophytes, whose occurrence is positively related to areas of minor altitude, does this difficulty of dispersion play a significant role in the maintenance of stenochory.

Distribution of Central American Melastomataceae: biogeographical analysis of the Caribbean islands

Abstract We have studied the geological history of Central America, particularly the Caribbean, in order to discover the impact of other areas on the islands in the Caribbean Sea. The study of the distribution of 675 Melastomataceae species led us to establish the biogeographical ranks of Subregion, Superprovince, Province and Subprovince. We also suggest a biogeographical typology for the Caribbean Islands. In order to discover the relationships between the 16 territories under study, we collected the endemic Melastomataceae taxa occurring in each of them and applied the Jaccard index. Finally, we establish the Caribbean Subregion, with the Western Antilles Superprovince, which in turn includes the Provinces of Florida and Cuba. In this latter, we define two subprovinces, Cuba and Jamaica. The Central—Eastern Antilles Superprovince includes the provinces of Eastern Antilles and Hispaniola. The research involved the implementation of a floristic and distributional study of the Melastomataceae endemic taxa of the Caribbean Islands, particularly on Hispaniola; for this latter, finally the study revealed the existence of two large areas, one siliceous and another of a carbonated character.

Phytosociological study of the Pinus occidentalis forests in the Dominican Republic

Abstract The article deals both with the Pinus occidentalis pine tree forests growing on high mountain limestones and siliceous substrates, and with the copses growing on serpentines in Dajabón (Cibao Valley), Dominican Republic. The samplings carried out in these forests reveal the occurrence of numerous endemic species and, consequently, the habitats can be considered as endemic, priority habitats of the Antilles. The article relies on some previous surveys carried out by us, Cano E, Velóz Ramirez A, Cano-Ortiz A, Esteban FJ. (2009b). Analysis of the Pterocarpus officinalis forests in the Gran Estero (Dominican Republic). Acta Botanica Gallica 156(4):559–570, that made use of the data provided by 87 weather stations of the Dominican Republic. With the values of the Ci, Oi, Cti, etc. indexes, we make a bioclimatical proposal for Hispaniola. Our preliminary analysis of the studies published on the vegetation of the Island of Hispaniola and nearby islands, along with the samples taken by us, lead us to propose two new alliances: Ilici tuerckheimi–Pinion occidentalis and Phyllario mummularioidi–Leptogonion buchi, and three new associations: Dendropemon phycnophylli–Pinetum occidentalis, Cocotrino scopari–Pinetum occidentalis and Leptogono buchi–Pinetum occidentalis.

Synopsis of aquatic plant-communities of the class Potametea in the southern Iberian Peninsula

Abstract By means of phytosociological techniques and 254 relevés taken both from bibliography (162) and specific field sampling (92), a review of the rooted aquatic vegetation in the south of the Iberian Peninsula was carried out. The survey has led to the recognition of 17 plant associations, 7 of which had not so far been described: Myriophyllo alterniflori-Potametum natantis, Callitricho brutiae-Ranunculetum saniculifolii, Callitricho brutiae-Ranunculetum peltati, Ranunculetum trichophylli, Callitricho lusitanicae-Ranunculetum penicillati, Callitricho lusitanicae-Ranunculetum pseudofluitantis and Zannichellietum contortae. The research has also provided new floristic, ecological and biogeo- graphical data concerning associations either unknown or little mentioned in the area under study. Each recognised community is classified in a syntaxonomical synopsis and characterised by its main ecological parameters.

Analysis of the Pterocarpus officinalis forests in the Gran Estero (Dominican Republic)

Abstract This paper deals with the geological, historical, bioclimatic and floristic aspects of the northern sector of the Caribbean—Atlantic Subprovince. By means of phytosociological vegetation samples, we focussed our attention on the edaphohygrophilous Pterocarpus officinalis forests and megaforbic plant communities formed by large helophytes. Our paper presents a new endemic association for Hispaniola, the Roystoneo hispaniolanae—Pterocarpetum officinalis nova. Since this association cannot be included in any of the alliances belonging to the class Chrysobalano-Annonetea glabrae Borhidi & Muñiz in Borhidi, Muñiz & Del—Risco 1979, order Tabebuio-Bucidetalia (Lvov 1967) Borhidi & Del- Risco in Borhidi, Muñiz & Del—Risco 1979, we propose a new alliance, Marcgravio rubrae—Pterocarpion officinalis nova, floristically characterised by Pterocarpus officinalis, Philodendron angustatum, Cecropia schreberiana, Cissus verticillata, Dalbergia berterii, Ficus velutina, Inga vera, Palicourea crocea. All the edaphohigrophilous and occasionally hygrophilous forests found in swampy sites either with fresh or slightly saline water should be included in this endemic alliance.

La vegetación edafohigrófila del distrito Guadiciano-Bastetano (Granada-Jaén, España)

Se realiza un estudio fitosociologico, sinfitosociologico y geosinfitosociologico de la vegetacion edafohigrofila desarrollada en las zonas humedas del distrito Guadiciano-Bastetano (sector Guadiciano-Bacense, subprovincia Betica, provincia Betica). Se reconocen dos geoseries y una microgeoserie de vegetacion que contienen un total de 46 fitocenosis. La peculiaridad de este distrito radica en su relacion con otras zonas semiaridas del centro, este y sudeste peninsular, que se refleja en la presencia de numerosas comunidades vegetales compartidas con los territorios aragoneses, manchegos y murciano-almerienses. No obstante, tambien contiene fitocenosis y taxones endemicos que aumentan su originalidad.

Study of seasonal and daily variations in airborneOlea europaea L. pollen in Jaén (Spain), 1993–1995

A study is made of the seasonal and daily variations in the concentrations of pollen ofOlea europaea L. over three consecutive years (1993–1995) in the atmosphere of Jaén (southern Spain). A Burkard volumetric spore trap was used for sampling. The results show that the highest concentrations of airborne olive pollen occur during May and the first 2 weeks of June, when levels often exceed 500 grains/m3 and occasionally reach nearly 5000 grains/m3 (the levels of allergenic pollen in the atmosphere of Jaén are among the highest in Europe). Over the 3-year study period a significant seasonal variation was detected, not only in the development of the principal pollination period, but also in the value of the maximum pollen concentrations recorded.

Comparative analysis between the mangrove swamps of the Caribbean and those of the State of Guerrero (Mexico)

Abstract The aim of this study is to know the diversity and state of conservation of the mangrove swamps of Central America. The study area is the State of Guerrero and the Dominican Republic and more precisely the sites of Tres Palos, Laguna de Coyuca, Majagua, Punta Arena (Sabana de la Mar), Barracote, Bahía de Samaná, Playa Las Cejas, Playa Morón, Playa El Alemán, Portillo, Laguna Redonda, Boca de Nisibón, Playa del Macao, Laguna de Bávaro, Punta Aljibe (Bahía Catalina), Isla Catalinita, Boca del Soco and Laguna de Oviedo. With the plant samples taken in the above mentioned sites, we created a synthetic table out of 16 phytosociological tables belonging to 6 original associations and 9 associations obtained from the bibliographical study. With the purpose of obtaining a similarity gradient (matching) between the associations under study, we carried out a statistical analysis (clustering, principal component analysis and Jaccard similarity/dissimilarity analysis). Our phytosociological approach relied on criteria such as biogreography and dynamic-catenal contact. Our sampling analysis has led us to propose the following syntaxa: Machaerio lunati-Rhizophoretum manglis; Rhabdadenio biflorae-Laguncularietum racemosae; Sthalio monospermae-Laguncularietum racemosae; Lonchocarpo pycnifolii-Conocarpetum erecatae; Lonchocarpo sericei-Laguncularietum racemosae; Crataevo tapiae-Conocarpetum erectae. We also propose a new alliance and a change of status: Phyllantho elsiae-Laguncurion racemosae; Dalbergio-Rhizophorion manglis (Borhidi 1991) status novo. The mangrove swamps of Central America are arranged in three vegetation bands corresponding to different plant associations. The analysis of the three sampled area not only revealed the degradation of the vegetation but also the causative factors.

Contribution to the knowledge of the plant communities of the Caribbean-Cibensean Sector in the Dominican Republic

Abstract The Caribbean-Cibensean Sector (Eastern Coastal Plain) is situated in the east of Santo Domingo (Dominican Republic). Despite intense tourist activity and farming, two types of forest can still be found in this area. This survey analyses the phytosociological profile of these forests. As a result of the heavy water losses in the underlying coral limestones, both the primary and the secondary forest undergo water stress and, consequently, there is no doubt that they are edaphoxerophilous. However, growing on deeper soils, the Chrysophyllo oliviformi-Sideroxyletum salicifolii primary forest undergoes less intense water stress than the Zamio debilis-Metopietum toxiferi secondary forest, which is a development of the former and appears as a result of the outcropping of coral limestones. Both forest formations are located in a pluviseasonal tropical, subhumid, infratropical macrobioclimate, but as a result of the xericity induced by the porous coral substrate and high potential evapotranspiration, these forests occasionally behave ambivalently, that is, either as climatophilous or edaphoxerophilous. The great number of endemic species and the high endangered level of some, such as Goetzea ekmanii O. E. Schulz, Peresquia quisqueyana Alain and Cubanola domingensis Aiello, lead us to propose that these two forest types be regarded as habitats worthy of preservation.