An inland population of Azorina vidalii (Watson) Feer (Campanulaceae) near Capelo, Faial island, and the special habitat are described. The origin is discussed

Schäfer, Hanno

Repositório da Universidade dos Açores

 93 SHORT COMMUNICATION AN INLAND POPULATION OF Azorina vidalii  (WATSON) FEER ON FAIAL ISLAND HANNO SCHÄFER SCHÄFER, H. 1999. An inland population of Azorina vidalii  (Watson) Feer at Faial Island. Arquipélago. Life and Marine Sciences 17A: 93-95. Ponta Delgada. ISSN 0873-4704. An inland population of Azorina vidalii (Watson) Feer (Campanulaceae) near Capelo, Faial island, and the special habitat are described. The origin is discussed. SCHÄFER, H. 1999. Uma população terrestre de Azorina vidalii (Watson) Feer na Ilha do Faial. Arquipélago. Ciências Biológicas e Marinhas 17A: 93-95. Ponta Delgada. ISSN 0873-4704. É descrito o habitat especial de uma população Feer (Campanulaceae) terrestre de Azorina vidalii (Watson) perto do Capelo, Ilha do Faial. A origem é discutida. Hanno Schäfer, AG Geobotanik, Institut  für  Botanik, Universität Regensburg, 93040 Regensburg, Germany. e-mail: HannoSchaefer99@hotmail.com  INTRODUCTION Azorina  (Campanulaceae) is an endemic genus of the Azorian archipelago. The only species, Azorina vidalii (Watson) Feer (syn. Campanula vidalii Watson) is reported from coastal rocks at Corvo, Flores, Pico, São Jorge, Terceira, São Miguel and Santa Maria (FRANCO 1984, ORMONDE & PAIVA 1973, PALHINHA 1966, PINTO DA SILVA & PINTO DA SILVA 1974, SJÖGREN 1984). There is also an early but doubtful record for Faial (SAMPAIO 1904).  Azorina vidalii is a very attractive plant that was frequently used for ornamental reasons and therefore planted in gardens. Today, the origin of many populations is unknown but at least those at Pico, S. Jorge, Flores and Corvo seem to be natural (SJÖGREN 1984).   At Faial, no natural population has been known. Two small coastal populations at Monte da Guia and Porto do Castelo Branco are probably of recent introductions (Eduardo Dias pers. comm.). A third population on the coast south of Ribeira da Cabo (LÜPNITZ 1975) could not be detected despite several days of searching. However, it may still exist and its origin is unknown. During fieldwork for a project dealing with the distribution of introduced plants on Faial, a new Azorina population was discovered in June 1999 in a volcanic crater, quite a distance from the sea. THE LOCATION The plants were found at Caldeirão, a small crater situated between Cabeço do Canto and Cabeço Verde north of Capelo at an altitude of 320 to 350 m (Fig. 1).  The exact position was determined by GPS: N 38°35'66'', WO 28°48'26'' (UTM 034285 / 427337).  The shortest distance to the coast at Capelo is about 2 km.   94   Fig. 1. Distribution of Azorina vidalii at Faial island. THE HABITAT Caldeirão is a basaltic crater and one of the oldest in the western part of Faial (ZBYSZEWSKI et al. 1959). The slopes are covered by dense shrubs of Myrica faya and Erica azorica. Other plants include Myrsine africana, Hypericum foliosum, Viburnum tinus ssp. subcordatum, Picconia azorica, Hedera helix ssp. canariensis, Rubia peregrina ssp. agostinhoi, Platanthera micrantha, Thymus caespititius, Solidago sempervirens, Carex peregrina, Carex vulcani, Brachypodium sylvaticum, Pteridium aquilinum and the neophytics Pittosporum undulatum, Hydrangea macrophylla, Hedychium gardneranum and Sporobolus africanus. Inside the crater, there are nearly vertical walls in the north and south. The other sides are less steep and covered by Pittosporum undulatum. On the ground Hydrangea macrophylla and Rubus ulmifolius form a hardly penetrable thicket.   Azorina occurs only in the northwest exposed vertical wall on the southern side of the crater. About 50 plants of different ages, including seedlings, were found.  In an area of 5 m length and 5 m height were recorded the species presented in table 1: (14.09.1999; alt.: ca. 330 m; exp.: NW; almost vertical, basaltic wall). Table 1 Species recorded in an area of 5 m length and 5 m height (14.09.1999; alt.: ca. 330 m; exp.: NW; almost vertical, basaltic wall) Polypodium macaronesicum + Cyrtomium falcatum 1 Erica scoparia + Hypericum foliosum + Thymus caespititius + Azorina vidalii 1 Leontodon taraxacoides + Leontodon filii + Gnaphalium luteo-album + Tolpis succulenta + Conyza canadensis + Umbilicus horizontalis + Daucus carota + Apium graveolens + Centaurium erythraea + Lythrum hyssopifolia + Holcus rigidus  + Brachypodium sylvaticum 1 Polypogon maritimus + Agrostis cf. congestiflora 1  The presence of Tolpis succulenta is remarkable, as it is probably the last population of this species at Faial Island. About 20 plants were found in the whole area. At the foot of the wall a few plants of Euphorbia azorica, another coastal species occurs.  THE ORIGIN The question whether the presented Azorina population is natural or not, can not be answered conclusively, but some facts suggest a natural origin. The locality is difficult to reach. Only a small part of the population is accessible from a recently constructed walking trail around the rim of the crater. Most of the plants are certainly older than this path. The major part of the population is not accessible at all, as the wall is steep and the basaltic rock not very solid. Observations had to be made by telescope.  95 According to M. Ávila Gomes, Azorina was not introduced to the Caldeirão by the Direcção Regional do Ambiente. An introduction in former times at this inaccessible place without any surrounding gardens or other cultivation seems very unlikely. At the "Parque Florestal" near Capelo, the author saw several cultivated endemic species but no Azorina. Nor rare there any Azorina plantations in the gardens of the nearest settlements Capelo and Norte Pequeno.  The presence of other mainly coastal species like Apium graveolens and Polypogon maritimus indicates very special ecological conditions in the area. Unfortunately, it was not possible to carry out any further ecological investigations. However, the presence of three typically coastal species in a crater more than 300 m high is amazing. The fact, that no other botanist ever mentioned one of these species from the Caldeirão region is rather surprising and some doubts about the origin remain. CONCLUSIONS The vegetation of the walls of Caldeirão consists of a very interesting combination of coastal and mountain species although the origin of some of them is not certain. It should be protected by invasion of neophythics and any other harmful impacts. In the future, it would be very interesting, to carry out ecological surveys of the environment at Caldeirão. Especially the influence of sea winds could be considered as an important factor. ACKNOWLEDGEMENTS J. Pereira and Eng. M. Ávila Gomes, Direcção Regional do Ambiente, visited the locality and discussed the origin of the plants with the author. Prof. dr. E. Dias, Universidade dos Açores, gave some advice by email. The "Erich Oberdorfer - Stiftung" and the "Studienstiftung des deutschen Volkes" funded the fieldwork of the author on Faial island. REFERENCES FRANCO, J.A. 1984. Nova Flora de Portugal (Continente e Açores). II:  Clethraceae - Compositae. Lisboa. 660 pp. LÜPNITZ, D. 1975. Geobotanische Studien zur natürlichen Vegetation der Azoren unter Berücksichtigung der Chorologie innerhalb Makaronesiens. Beiträge zur Biologie der Pflanzen 51: 149-319. ORMONDE, J. & J.A.R. PAIVA 1973. Additiones et Adnotationes Florae Azoricae - I. Anuario da Sociedade Broteriana 39: 39-71. PALHINHA, R.T. 1966. Catálogo das Plantas vasculares dos Açores. Texto revisto e preparado para publicação por A. R. PINTO DA SILVA. Lisboa. 186 pp. PINTO DA SILVA, A.R. & Q. PINTO DA SILVA 1974. Ferns and flowering plants of the Azores. Agronomia Lusitana 36: 5-94. SAMPAIO, A.S. 1904. Memórias sobre a Ilha Terceira. Angra do Heroísmo. SJÖGREN, E. 1984. Açores: Flores. (ed. Direcção Regional de Turismo in Horta, Faial). Uppsala.176 pp. ZBYSZEWSKI, G., F. DE A. MOITINHO & O DA V. FERREIRA 1959. Carta Geológica de Portugal. Notícia explicativa da folha Faial (Açores). 25 pp.  Accepted 18 October 1999  

Uma população terrestre de Azorina vidalii (Watson) Feer na Ilha do Faial.

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Uma população terrestre de Azorina vidalii (Watson) Feer na Ilha do Faial.

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