Selvagens

The Selvagens Islands bryofl ora and its relation with islands of the Madeira and Canary Islands Archipelagos

Manuela Sim-Sim1, 2, Susana Fontinha3, Leena Luís1, 2, Carlos Lobo4 and Michael Stech5

1 Universidade de Lisboa, Faculdade de Ciências de Lisboa, DBV, Centro de Biologia Ambiental, C2, Campo Grande, 1749-016 Lisboa, Portugal (corresponding author: [email protected])

2 Museu Nacional de História Natural, Jardim Botânico/CBA, Rua da Escola Politécnica, n° 58, 1250-102 Lisboa, Portugal

3 Centro de Estudos da Macaronésia (CEM), Universidade da Madeira, Campus da Penteada, 9000-390 Funchal, Madeira, Portugal

4 Jardim Botânico da Madeira-Eng° Rui Vieira/CEM, Quinta do Bom Sucesso, 9064-512 Funchal, Madeira, Portugal;

5 Netherlands Centre for Biodiversity Naturalis, section Nationaal Herbarium Nederland, Leiden University, P. O. Box 9514, 2300 RA Leiden, The Netherlands

With 4 fi gures and 2 tables

Abstract: The bryofl ora of the Selvagens Archipelago is characterised and updated based on results from recent fi eldwork, and compared with those of Madeira and Canary Islands. The bryofl ora of Selvagens Islands includes 16 taxa, four of which are reported for the fi rst time for these islands. As a result of its small area and strong saline infl uence, low habitat diversity is present on Selvagens Archipelago determin-ing most of its bryophyte diversity, which is dominated by acrocarpous mosses and mainly by species adapted to stressful conditions. Due to its topography, the Selvagens bryofl ora is quite distinct from the other islands of Madeira Archipelago. Cluster analysis revealed closest relationships with the driest islands of Madeira Archipelago (Desertas Islands and Porto Santo), and with the Canary Islands of Fuerteventura and Lanzarote. Recent revisions in the course of this comparison also revealed new taxa for the bryofl ora of Desertas and Porto Santo, namely one and eight species, respectively.

Key words: Bryofl ora, Canary Islands, dry areas, Madeira Archipelago, Selvagens Islands

Introduction

The uninhabited Selvagens Archipelago is situated in the North Atlantic at approximately 300 km south of Madeira Island and 180 km north of the Canary Archipelago (Fig. 1). It consists of a group of small islands of volcanic origin, Selvagem Grande, Selvagem Pequena and Ilhéu de Fora, which originated from the same volcanic hotspot as the Canary Islands and have an estimated age of 27 Myr (e.g., Geldmacher et al. 2005). This archipelago constitutes the southernmost part of the Portuguese territory and is administrated by the Madeira Autonomous Region.

Nova Hedwigia, Beiheft 138, 187–199 ArticleStuttgart, November 2010

© 2010 J. Cramer in Gebr. Borntraeger Verlagsbuchhandlung, Stuttgart, Germany www.borntraeger-cramer.de 1438-9134/2010/0138-0187 $ 3.25

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188 M. Sim-Sim et al.

Selvagens Islands are protected since 1971 as a strict Nature Reserve; therefore the use of the terrestrial and marine areas is very restricted. In 1997 the European Diploma for Protected Areas Category A was awarded to Selvagens Islands, hereby placing them under the auspices of the Council of Europe. More recently they were included as a site of the Natura 2000 Network (SPNM 2004).

The knowledge concerning the bryofl ora of the Selvagens Archipelago is scarce. Only a small number of researchers have published some data records for these islands during the last 68 years. The fi rst seems to be by Luisier (1942), who refers the collection of Heterocladium heteropterum (Brid.) Schimp. by Custódio Fernandes in Selvagem Pequena, representing the only reference to this small island. Afterwards Nóbrega (1955) refers seven mosses and only one liverwort to Selvagem Grande, then Eggers (1982) indicates seven taxa for that island. More recently Sérgio et al. (2008) published a list of the bryophytes of Madeira, referring nine taxa (eight mosses and one liverwort) to the Selvagens Archipelago. During the last years several plant sociological rele-vés have been made by Kürschner et al. (2008a, b) on the Madeira Archipelago (Madeira , Porto Santo and Deserta Grande) resulting in an increase in the number of bryophyte taxa in relation to the latest bryophyte list (Sérgio et al. 2008).

The main aim of this work is to present an updated list of the bryofl ora of Selvagens Archi-pelago. In addition, a characterization of its bryofl ora, concerning the main taxonomical groups (mosses and liverworts) and phytogeographic affi nities (including endemics) is presented. We also analyse the bryofl ora of Selvagens comparatively to the other Islands of Madeira Archi-pelago concerning their bryophyte richness and composition, with a brief overview of its rela-tionships with the bryofl ora of Canary Islands, the geographically and geomorphogically closest archipelago.

Fig. 1. Location of the Selvagens Archipelago.

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189The Selvagens Islands bryofl ora

Material and methods

Study area. The Selvagens Archipelago is situated between 30° 01′ 35″ and 30° 09′ 10″ N, 15° 52′ 15″ and 16° 03′ 15″ W in the Atlantic Ocean (Fig. 1). It is composed of three small islands and several islets, in total about 2.73 km2. Geologically the islands are of volcanic origin and have never been part of the African continent (Carvalho & Brandão 1991).

The highest altitude is Pico da Atalaia (163 m a.s.l.) on the Selvagem Grande. This island has an area of approximately 245 ha, is roughly pentagonal in shape and crowned by a plateau that is about 100 m a.s.l. In general, the landscape is rugged and the coastline made of sheer drops resulting from sea erosion (SPNM 2004). The other two small islands are located at about 20.37 km southwest of Selvagem Grande: Selvagem Pequena, with an area of 20 ha and the highest peak at 49 m a.s.l., and Ilhéu de Fora, with an area of 8.1 ha and the highest peak at 18 m a.s.l. The islands represent remains of volcanic peaks and their area almost doubles at low tide (SPNM 2004).

Selvagem Grande is made up from porous scoria, which due to erosive processes gave rise to a brittle terrain and a soil with a vitrifi ed surface and a nicrolitic structure. Its visible base is composed of foralite and nephelinite, upon which a thick layer of yellowish calcareous sand was deposited (Carvalho & Brandão 1991). On this island, there is an extensive subterranean gallery, where a bed of lime sulphate of saccharoid crystallization was deposited. There are also various shell beds dating back to different geological epochs, from the Miocene up to more recent times (Carvalho & Brandão 1991).

A subtropical maritime climate is prevailing. Although the islands are under the infl uence of the dominant northeasterly trade winds, their low altitude does not favour cloud condensation. Nevertheless, it seems that in the past, these islands must have been infl uenced by higher humid-ity conditions, which can be inferred from the presence of a great profusion of sub-fossil shells of land snails. Occasional westerly winds carry dust from the Sahara desert as well as high tem-peratures to the islands (SPNM 2004).

The present plant cover is mainly composed by herbaceous, saxicolous halophytes, some endemics [e.g., Misopates salvagense D. A. Sutton, Argyranthemum thalassophilum (Svent) Humphries], within ecosystems in an unaltered state (Selvagem Pequena and Ilhéu de Fora), which have remained untouched by human activities. The vascular fl ora is comprised by approxi-mately 105 taxa of which 7 are endemic to this group of islands. In fact, Selvagens Archipelago presents the highest density of endemic species per km2 in the entire Macaronesian region. Of these species, we point out, Monanthes lowei (Paiva) Pérez et Acebes (an endemic species to Selvagens and endemic genus to Macaronesia) and Euphorbia anachoreta Svent., existing only on Ihéu de Fora (Press & Short 1994).

Fieldwork and herbarium studies. In order to study the bryofl ora of Selvagens Archipelago, fi eldwork was carried out in Selvagens Islands, namely on Selvagem Grande (at least once a year between February 2002 and August 2008). Bryophyte material was collected all over Selvagem Grande Island, in rock crevices and fi ssures as well as on soil depressions on the top where hu-midity is high enough for the development of small bryophyte populations. Although the bryo-phytes are not abundant on the island, a higher frequency of bryophytes was observed on soil depressions, where some water accumulates during short periods, especially in winter time. The specimens revised are deposited in LISU, MADJ and MADS herbaria. Aditionally, the speci-mens from Porto Santo and Desertas are also deposited in LISU, MADJ and MADS herbaria.

Data analysis. In order to clarify the relation of Selvagens bryofl ora to the other islands of Madeira Archipelago as well as of Canary Islands, data concerning the species referred for each island were gathered. The Madeiran Archipelago bryofl ora is compiled in Sérgio et al. (2006,

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2008). Subsequent additions were made by Luís et al. (2007, 2008, 2010), Stech et al. (2007), Blockeel (2008), Kürschner et al. (2008a, b), Lobo (2008), Fontinha et al. (2010), Sim-Sim et al. (2008, 2010). Relating to Canary Islands, we considered the list of bryophytes published by González-Mancebo et al. (2008), excluding the doubtful taxa. Nomenclature follows Ros et al. (2007) for liverworts and Hill et al. (2006) for mosses, except for Isothecium prolixum (Mitt.) Stech, Sim-Sim, Tangney & D. Quandt, which follows Stech et al. (2008), and for families Frey & Stech (2009).

Collection data were subjected to a cluster analysis based on presence and absence data for each taxon in each island of Madeira, Selvagens, and Canary Islands Archipelagos. Euclidean distance was used as a distance measure and weighted pair group average as the linkage method. Cluster analysis was performed in Statistica 9.0 (StatSoft 2009).

Results and discussion

New data on the bryofl ora of Selvagens Archipelago

The bryofl ora from Selvagens Archipelago comprises 16 species. Four species are new to Selvagens bryofl ora, namely Bryum dichotomum, Riccia atlantica, Riccia lamellosa and Tortula solmsii, indicated by an asterisk in the list below.

MARCHANTIOPHYTA

Ricciaceae*Riccia atlantica Sérgio & PeroldSelvagens Archipelago: Selvagem Grande, Pico dos Tornozelos, N and NE sided, 30° 08′ 54.485″ N, 15° 51′ 57.079″ W, 136 m, on rock cracks and under the rocks on coastal exposed areas, April 2005, Silva (MADJ), (LISU), s.n.

*Riccia lamellosa RaddiSelvagens Archipelago: Selvagem Grande, Topo, 30° 08′ 54.581″ N, 15° 52′ 09.772″ W, 100 m, exposed, dry and rocky area, Febr. 2005, Silva (MADJ),(LISU) s.n; Selvagem Grande, plateau between Pico dos Tor-nozelos and Pico Atalaia, 30° 08′ 54.581″ N, 15° 52′ 09.772″ W, 100 m, exposed, dry and rocky area, Aug. 2008, Fontinha & Sim-Sim (MADJ), (LISU), s.n.; Selvagem Grande, plateau between Pico dos Tornozelos and Pico Atalaia, 30° 08′ 54.581″ N, 15° 52′ 09.772″ W, 100 m, exposed, dry and rocky areas, Aug. 2008, Fontinha & Sim-Sim (MADJ), (LISU) s.n.

Riccia sorocarpa Bisch.Selvagens Archipelago: Selvagem Grande (Nóbrega 1955); Selvagem Grande, Pico Atalaia (N), 30° 08′ 49.567″ N, 15° 52′ 25.022″ W, 153 m, exposed, dry, windy and rocky area, Apr. 2006, Fontinha (MADJ), (LISU), s.n.; Selvagem Grande, Topo, 30° 08′ 54.581″ N, 15° 52′ 09.772″ W, 100 m, exposed, dry and rocky area, Febr. 2005, Silva (MADJ), (LISU) s.n; Selvagem Grande, plateau between Pico dos Tor-nozelos and Pico Atalaia, 30° 08′ 54.581″ N, 15° 52′ 09.772″ W, 100 m, exposed, dry and rocky area, Aug. 2008, Fontinha & Sim-Sim (MADJ), (LISU), s.n.

BRYOPHYTA

BryaceaeBryum caespiticium Hedw.Selvagens Archipelago: Selvagem Grande (Nóbrega 1955, Eggers 1982).

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Bryum canariense Brid.Selvagens Archipelago: Selvagem Grande (Nóbrega 1955).

*Bryum dichotomum Hedw.Selvagens Archipelago: Selvagem Grande, Pico Atalaia (N), 30° 08′ 49.567″ N, 15° 52′ 25.022″ W, 153 m, exposed, dry, windy and rocky area, Apr. 2006, Fontinha (MADJ), (LISU), s.n.; Selvagem Grande, Topo, 30° 08′ 54.581″ N, 15° 52′ 09.772″ W, 100 m, exposed, dry and rocky area, Febr. 2005, Silva (MADJ), (LISU) s.n.; Selvagem Grande, Pico dos Tornozelos (N, NE), 30° 08′ 54.485″ N, 15° 51′ 57.079″ W, 136 m, rock cracks and under the rocks, Apr. 2005, Silva (MADJ), (LISU), s.n.; Selvagem Grande, Pico dos Tornozelos (N), 30° 08′ 54.485″ N, 15° 51′ 57.079″ W, 136 m, Aug. 2008, Fontinha & Sim-Sim (MADJ), (LISU), s.n.; Selvagem Grande, plateau between Pico dos Tornozelos and Pico Atalaia, 30° 08′ 54.581″ N, 15° 52′ 09.772″ W, 100 m, exposed, dry and rocky area, Aug. 2008, Fontinha & Sim-Sim (MADJ), (LISU), s.n.; Selvagem Grande, Topo, 30° 08′ 54.581″ N, 15° 52′ 09.772″ W, 100 m, exposed, dry and rocky coastal area, Aug. 2008, Fontinha & Sim-Sim (MADJ), (LISU), s.n.; Selvagem Grande, Topo, 30° 08′ 54.581″ N, 15° 52′ 09.772″ W, 100 m, exposed, dry and rocky area, Aug. 2008, Fontinha & Sim-Sim (MADJ), (LISU) s.n.

FissidentaceaeFissidens sublimbatus GroutSelvagens Archipelago: Selvagem Grande, Pico dos Tornozelos, N and NE sided, 30° 08′ 54.485″ N, 15° 51′ 57.079″ W, 136 m, on rock cracks and under the rocks on coastal exposed areas, 30 Apr. 2005, Silva (MADJ), (LISU), s.n.; Selvagem Grande, plateau between Pico dos Tornozelos and Pico Atalaia, 30° 08′ 54.581″ N, 15° 52′ 09.772″ W, 100 m, exposed, dry and rocky areas, Aug. 2008, Fontinha & Sim-Sim (MADJ), (LISU) s.n. (Fontinha et al. 2010).

Fissidens viridulus (Sw. ex anon.) Wahlenb. var. incurvus (Starke ex Röhl.) Waldh.Selvagens Archipelago: Selvagem Grande (Nóbrega 1955, Eggers 1982).

PottiaceaePottia lanceolata (Hedw.) Müll.Hal.Selvagens Archipelago: Selvagem Grande (Nóbrega 1955, Eggers 1982).

Pottiopsis caespitosa (Brid.) Blockeel & A. J. E. Sm.Selvagens Archipelago: Selvagem Grande, Topo, 30° 08′ 54.581″ N, 15° 52′ 09.772″ W, 100 m , exposed, dry and rocky area, Febr. 2005, Silva (MADJ), (LISU), s.n. (Sim-Sim et al. 2010).

Tortella fl avovirens (Bruch) Broth.Selvagens Archipelago: Selvagem Grande (Nóbrega 1955, Eggers 1982); Selvagem Grande, Pico dos Tor-nozelos (N, NE), 30° 08′ 54.485″ N, 15° 51′ 57.079″ W, 136 m, rock cracks and under the rocks, Apr. 2005, Silva (MADJ), (LISU), s.n.; Selvagem Grande, plateau between Pico dos Tornozelos and Pico Atalaia, 30° 08′ 54.581″ N, 15° 52′ 09.772″ W, 100 m, exposed, dry and rocky areas, Aug. 2008, Fontinha & Sim-Sim (MADJ), (LISU) s.n.

Tortula atrovirens (Sm.) Lindb.Selvagens Archipelago: Selvagem Grande (Nóbrega 1955, Eggers 1982).

Tortula muralis Hedw.Selvagem Grande (Nóbrega 1955, Eggers 1982).

Tortula pallida (Lindb.) R. H. ZanderSelvagens Archipelago: Selvagem Grande, Pico Atalaia (N), 30° 08′ 49.567″ N, 15° 52′ 25.022″ W, 153 m, exposed, dry, windy and rocky area, Apr. 2006, Fontinha (MADJ), (LISU), s.n.; Selvagem Grande, Topo, 30° 08′ 54.581″ N, 15° 52′ 09.772″ W, 100 m, exposed, dry and rocky area, Febr. 2005, Silva (MADJ), (LISU) s.n.; Selvagem Grande, Pico dos Tornozelos (N, NE), 30° 08′ 54.485″ N, 15° 51′ 57.079″ W, 136 m,

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rock cracks and under the rocks, Apr. 2005, I. Silva (MADJ), (LISU), s.n.; Selvagem Grande, Pico dos Tornozelos (N), 30° 08′ 54.485″ N, 15° 51′ 57.079″ W, 136 m, Aug. 2008, Fontinha & Sim-Sim (MADJ), (LISU), s.n.; Selvagem Grande, plateau between Pico dos Tornozelos and Pico Atalaia, 30° 08′ 54.581″ N, 15° 52′ 09.772″ W, 100 m, exposed, dry and rocky area, Aug. 2008, Fontinha & Sim-Sim (MADJ), (LISU), s.n.; Selvagem Grande, Topo, 30° 08′ 54.581″ N, 15° 52′ 09.772″ W, 100 m, exposed, dry and rocky coastal area, Aug. 2008, Fontinha & Sim-Sim (MADJ), (LISU), s.n.; Selvagem Grande, Topo, 30° 08′ 54.581″ N, 15° 52′ 09.772″ W, 100 m, exposed, dry and rocky area, Aug. 2008, Fontinha & Sim-Sim (MADJ), (LISU) s.n. (Luís et al. 2010).

*Tortula solmsii (Schimp.) Limpr.Selvagens Archipelago: Selvagem Grande, Pico dos Tornozelos, N and NE sided, 30° 08′ 54.485″ N, 15° 51′ 57.079″ W, 136 m, on rock cracks and under the rocks on coastal exposed areas, Apr. 2005, Silva (MADJ), (LISU), s.n.

HeterocladiaceaeHeterocladium heteropterum Bruch & Schimp.Selvagens Archipelago: Selvagem Pequena (Luisier 1942, Eggers 1982).The citation by Luiser (1942) about the presence of Heterocladium heteropterum on Selvagem Pequena should be considered doubtful since the name of the collect locality could be a mistake. Due to the characteristics of this species and the lack of any fountain in this island its occurrence at Selvagem Pequena is very unlikely, and the species has never been collected or identifi ed by one of the authors (S. Fontinha) who visited Selvagens at least once a year since 2002.

New data on the bryofl ora of Desertas and Porto Santo Islands

As a result of recent revisions, new taxa are referred to the bryofl ora of Desertas and Porto Santo islands, namely one and eight taxa, respectively.

MARCHANTIOPHYTA

AytoniaceaeAsterella africana (Mont.) A. EvansPorto Santo: Pico Ana Ferreira, 33° 02′ 57″ N, 16° 22′ 04″ W, 94–150 m, crevices and rock base, March 2007, Fontinha & Sim-Sim (MADJ), (LISU) s.n.; Pico Castelo, 33° 04′ 50″ N, 16° 20′ 01″ W, 360–437 m, crevices and rock base, March 2007, Fontinha & Sim-Sim (MADJ), (LISU) s.n.

RicciaceaeRiccia atlantica Sérgio & PeroldPorto Santo: Pico Ana Ferreira, 33° 02′ 57″ N, 16° 22′ 04″ W, 94–150 m, crevices and rock base, March 2007, Fontinha & Sim-Sim (MADJ), (LISU) s.n.

TargioniaceaeTargionia lorbeeriana Müll.Frib.Porto Santo: Pico Ana Ferreira, 33° 02′ 57″ N, 16° 22′ 04″ W, 94–150 m, crevices and rock base, March 2007, Fontinha & Sim-Sim (MADJ), (LISU) s.n.

LophocoleaceaeLophocolea bidentata (L.) Dumort.Porto Santo, Pico Ana Ferreira, 33° 02′ 57″ N, 16° 22′ 04″ W, 94–150 m, on crevices and rock base, March 2007, Fontinha & Sim-Sim (MADJ), (LISU) s.n.; Rocha de Nossa Senhora, 33° 04′ 50″ N, 16° 20′ 01″ W, 360–437 m, crevices and rock base, March 2007, Fontinha & Sim-Sim (MADJ), (LISU) s.n. This taxon was found on two new localities though it was already referred to the island (Lobo 2008).

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BRYOPHYTA

BryaceaeBryum radiculosum Brid.Deserta Grande: top of Vale da Castanheira, 32° 3′ 39,24″ N, 16° 31′ 33,11″ W, 400–444 m, on soil between grasses, March 2007, Fontinha & Sim-Sim, (MADJ), (LISU) s.n.

LeucobryaceaeCampylopus brevipilus Bruch & Schimp.Porto Santo: Pico Ana Ferreira, 33° 02′ 57″ N, 16° 22′ 04″ W, 94–150 m, crevices and rock base, March 2007, Fontinha & Sim-Sim (MADJ), (LISU) s.n.

DitrichaceaeCeratodon purpureus (Hedw.) Brid.Porto Santo: Pico Castelo, 33° 04′ 50″ N, 16° 20′ 01″ W, 360–437 m, crevices and rock base, March 2007, Fontinha & Sim-Sim (MADJ), (LISU) s.n.

FunariaceaeEntosthodon obtusus (Hedw.) Lindb.Porto Santo: Rocha de Nossa Senhora, 33° 04′ 50″ N, 16° 20′ 01″ W, 360–437 m, crevices and rock base, March 2007, Fontinha & Sim-Sim (MADJ), (LISU) s.n.

GigaspermaceaeOedipodiella australis (Wager & Dixon) DixonPorto Santo: Pico Castelo, 33° 04′ 50″ N, 16° 20′ 01″ W, 360–437 m, crevices and rock base, March 2007, Fontinha & Sim-Sim (MADJ), (LISU) s.n.

PottiaceaeLeptophascum leptophyllum (Müll.Hal.) J. Guerra & M. J. CanoPorto Santo: Pico Castelo, 33° 04′ 50″ N, 16° 20′ 01″ W, 360–437 m, crevices and rock base, March 2007, Fontinha & Sim-Sim (MADJ), (LISU) s.n.

Comparison of the bryofl ora of Selvagens and Madeira Archipelagos

The Selvagens bryofl ora is represented mainly by mosses (81 %) and to a lesser extent by liver-worts (19 %). No hornworts were found (Table 1, Fig. 2). Compared with the islands of Madeira Archipelago, the mosses are higher represented and the liverworts show the lower represen-tativity (Fig. 2). For example, in Porto Santo the liverworts are highly represented (53 %) and

Table 1. Number of bryophyte taxa present in Madeira and Selvagens Archipelagos.

Madeira Island Porto Santo Desertas Selvagens

Hornworts 6 4 4 –Liverworts 176 70 30 3Mosses 359 59 63 13Total 541 133 97 16

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Fig. 2. Proportion of mosses (�), liverworts (�) and hornworts (�) in Selvagens Archipelago and the other islands of Madeira Archipelago.

Table 2. Madeiran endemic bryophyte taxa on each island of Madeira and Selvagens Archipelagos. × present.

Madeira Region

Taxa Madeira Island

Porto Santo Desertas Islands

Selvagens Islands

Brachythecium percurrens Hedenäs × – – –Brachythecium rutabulum (Hedw.) Schimp. var.

atlanticum Hedenäs× – – –

Bryoxiphium madeirense A. Löve & D. Löve × – – –Echinodium setigerum (Mitt.) Jur. × – – –Fissidens microstictus Dixon & Luisier × – – –Fissidens nobreganus Luisier & P.de la Varde × – – –Frullania sergiae Sim-Sim et al. – × × –Nobregaea latinervis Hedenäs × – – –Porella inaequalis (Gottsche ex Steph.) Perss. × – – –Riccia atlantica Sérgio & Perold × × × ×Thamnobryum fernandesii Sérgio × – – –Tylimanthus madeirensis Grolle & Perss. × – – –

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mosses have the lowest representativity (44 %), while hornworts are represented by four species (3 %). The different patterns of representation of liverworts and mosses may be explained by the distinct environmental conditions and variability of the habitats in the different islands of the Madeira Archipelago.

The 12 acrocarpous mosses found in the bryofl ora of Selvagens Archipelago represent 75 % of its total bryofl ora, followed by the thallose liverworts (3 taxa, representing 19 %), and only one pleurocarpous moss (Fig. 3). The acrocarpous mosses are included in three families, namely the Pottiaceae Schimp. (7 taxa), Bryaceae Schwägr. (3 taxa) and Fissidentaceae Schimp. (2 taxa), which are adapted to the xeric and saline conditions that prevail on Selvagens, as is the particular case of Tortula pallida.

A comparative analysis revealed that the proportion of the acrocarpous mosses in Selvagens is closer to the one observed for Desertas (51 %), followed by Madeira Island (47 %), but distinct from Porto Santo, where the foliose liverworts (37 %) are more highly represented than the ac-rocarpous mosses (32 %) (Fig. 3).

There is only one species of pleurocarpous mosses referred to Selvagens, namely, Heterocla-dium heteropterum. However, this taxon cited by Luiser (1942) to Selvagem Pequena is consid-ered a doubtful species for that island, as it is generally associated with hygrophilous conditions that are not found in Selvagem Pequena habitats.

The Riccia spp. are the only liverworts able to develop in the unstable and xeric conditions of the Selvagens habitats (Fig. 3). In fact, the thallose liverworts occur also in the other Madeira

Fig. 3. Proportion of acrocarpous mosses (�) and pleurocarpous mosses ( ), thallose liverworts (�), fo-liose liverworts (�) and hornworts (�) in Selvagens Archipelago and the other islands of Madeira Archi-pelago.

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Archipelago islands, revealing a lower incidence in Madeira Island, where the pleurocarpous mosses showed their highest representativity.

The topographical characteristics of Selvagens Archipelago determine a particular bryofl ora composition, which distinguishes Selvagens from all other islands of Madeira Archipelago, more closely related concerning the proportion of the bryophyte groups considered. Of the 12 bryo-phyte taxa endemic to Madeira (Table 2), only one, Riccia atlantica Sérgio & Perold, was found in Selvagens Archipelago. This species is also referenced to Porto Santo Island, extending the distribution to all islands of Madeira Archipelago (Table 2).

Phytogeographic affi nities of the Selvagens bryofl ora

In order to analyse the differences in bryophyte species composition between the Selvagens Ar-chipelago and the islands of Madeira and Canary Islands Archipelagos, a Cluster Analysis was performed (Fig. 4).

Five species were found to be present in all analysed islands, namelly Bryum dichotomum Hedw., Riccia sorocarpa Bisch., Tortella fl avovirens (Bruch) Broth., Tortula atrovirens (Sm.) Lindb., and Tortula muralis Hedw. Although 13 of the 16 species present in Selvagens are in common with the Madeiran bryofl ora, the strong xeric and saline ecological conditions of the Selvagens make its bryofl ora quite distinct from the one found in Madeira Archipelago. The Madeira Archipelago bryofl ora is very rich and diverse, and results from the existence of a high diversity of habitats, which are due to the particular geographical, geological and ecological conditions found mainly on Madeira Island. This diversity explains the great differences between

Fig. 4. Dendrogram showing the similarities between the bryofl ora of Selvagens, Madeira and Canary Is-lands, based on species presence and absence data, using the options group average linkage and Euclidean distance.

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its bryofl ora from the one observed on the other islands of the Madeira Archipelago, as well as from the bryofl ora of Selvagens Archipelago and also from Canary Islands (Fig. 4). On Madeira Island most of the endemics with oceanic affi nities are found, mainly liverworts with neotropical affi nities (Sim-Sim et al. 2005; Stech et al. 2006, 2010; Vanderpoorten et al. 2007; Aigoin et al. 2009). The Paleo-endemic Echinodiaceae whose origins date back from the European Tertiary period (Stech et al. 2008) can also be included in this group. The highest representativity of taxa with Atlantic and Mediterranean Europe affi nities is also found in Madeira Island, where habitat diversity and factors such as altitude (and thus climate) differ.

The bryofl ora of Selvagens Archipelago is closest to the driest islands of Madeira Archipelago, namely Desertas and Porto Santo. These islands have seven species in common, namely Bryum dichotomum, Heterocladium heteropterum, Riccia atlantica, Riccia sorocarpa, Tortella fl avovi-rens, Tortula atrovirens and T. muralis. It is closer, however, to the Desertas bryofl ora, having one more species in common, namely T. solmsii. Concerning the Canary Islands, Selvagens bryofl ora is closest to the bryofl ora of Fuerteventura and Lanzarote, the two islands of the east-ern group closer to mainland Africa. These islands are the oldest of the archipelago and present smaller altitudinal ranges. Their bryofl ora is also the less rich of the Canary Islands Archipelago, and has ten species in common with the Selvagens bryofl ora, namely Bryum canariense, B. dichotomum, Fissidens sublimbatus, Riccia lamellosa, Riccia sorocarpa, Tortella fl avovirens, Tortula atrovirens, T. lanceolata R. H. Zander, T. muralis and T. solmsii.

Analysing the new data on the bryofl ora of Selvagens, as well as Porto Santo (eight new taxa), a concordance was observed with the results obtained by González-Mancebo et al. (2008). How-ever, future studies especially in the Island of Porto Santo may contribute to a better knowledge of its bryofl ora and to clarify the proportion between mosses and liverworts.

Concluding remarks

The lowest diversity of Madeira´s bryofl ora occurs on the Selvagens Archipelago, which is un-der strong xerophytic and saline contraints due to its geographical position and climate. This defi nitely infl uences the composition and structure of the Selvagens bryophyte fl ora. The topo-graphical characteristics as already mentioned by Nóbrega (1955) for the vascular plant vegeta-tion, are also important, being characterised by premature growth, predominance of xerophytic characteristics, succulence, less chloroplasts, and the psammophilous or halophilous character of some species.

Nevertheless, the natural habitats of the Selvagens take on signifi cant importance and value for the maintenance of biological diversity in the Macaronesian Region and consequently in the World. The animals and plants endemic to Selvagens are confi ned to an extremely restricted geographical area, which, according to present IUCN criteria, makes them inherently threatened.

Acknowledgements

Thanks are due to the directors of the Natural Park of Madeira and the Selvagens Nature Reserve for the permission to land and to collect the plant material, as well as for the hospitality and help during the fi eld work. Special thanks are owing to the Nature Warden Isamberto Silva for collect-ing bryophytes at the Selvagem Grande Island.

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References

Aigoin, D. A., N. Devos, S. Huttunen, M. S. Ignatov, J. M. González-Mancebo & A. Vanderpoorten (2009): And if Engler was not completely wrong? Evidence for multiple evolutionary origins in the moss fl ora of Macaronesia. – Evolution 63: 3248–3257.

Blockeel, T. (2008): Cheilolejeunea cedercreutzii (H. Buch & Perss.) Grolle on Madeira Island. – J. Bryol. 30: 159–161.

Carvalho, A. M. G. & J. B. Brandão (1991): Geologia do Arquipélago da Madeira. – Museu Nac. História Nat., Univ. Lisboa, Lisboa.

Eggers, J. (1982): Artenliste der Moose Makaronesiens. – Cryptogamie, Bryol. Lichénol. 3: 283–335.Fontinha, S., C. Lobo, L. Luís & M. Sim-Sim. (2010): Fissidens sublimbatus Grout. – In: New national and

regional records from bryophytes. – J. Bryol. (submitted).Frey, W. & M. Stech (2009): Marchantiophyta, Bryophyta, Anthocerotophyta. – In: FREY, W.: Syllabus of

Plant Families, Part 3: 9–263. – Gebr. Borntraeger; Berlin, Stuttgart.Geldmacher, J., K. Hoernle, P.v.d. Bogaard, S. Duggen & R. Werner (2005): New 40Ar/39Ar age and geo-

chemical data from seamounts in the Canary and Madeira volcanic provinces: support for the mantle plume hypothesis. – Earth Planet. Sci. Lett. 237: 85–101.

González-Mancebo, J., F. Romaguera, R. Ros, J. Patiño & O. Werner (2008): Bryophyte fl ora of the Canary Islands: an update compilation of the species list with an analysis of distribution patterns in the context of the Macaronesian Region. – Cryptogamie, Bryol. 29: 315–357.

Hill, M. et al. (19 authors) (2006): An annotated checklist of the mosses of Europe and Macaronesia. – J. Bryol. 28: 198–267.

Kürschner, H., S. Fontinha, M. Sim-Sim & W. Frey (2008a): The Mannio-Exormothecetum pustulosae ass. nov., a xerophytic bryophyte community from Madeira and the Canary Islands/Macaronesia. – Nova Hedwigia 86: 445–468.

Kürschner, H., W. Frey, S. Lobo, L. Luís, S. Fontinha & M. Sim-Sim (2008b): New data on bryophytes from the Ilhas Desertas (Madeira Archipelago). – Nova Hedwigia 87: 529–543.

Lobo, C. (2008): Contribution to the study of the bryofl ora of Pico Branco – Porto Santo Island. – Bol. Mus. Mun. Funchal 58 (318): 5–18.

Luís, L., J. Váňa & M. Sim-Sim (2007): New data on small liverworts from Madeira island bryofl ora. – Port. Acta Biol. B, Sist. 22: 157–158.

Luís, L., M. Sim-Sim, S. Fontinha & D. T. Holyoak (2008): New data on riparian bryophytes of Madeira. – Cryptogamie, Bryol. 29: 393–396.

Luís, L., M. Sim-Sim & S. Fontinha (2010): Tortula pallida (Lindb.) R. H. Zander. In: New national and regional records from bryophytes. – J. Bryol. (submitted).

Luisier, A. (1942): Les mousses de l’Archipel de Madère et en general des Îles Atlantiques. – Brotéria, Ci. Nat. 11: 29–41.

Nóbrega, M. (1955): Notas botânicas sobre a Selvagem Grande. – Bol. Mus. Munic. Funchal 8: 22–32.Press J. R. & Short M. J. (1994): Flora of Madeira. – HMSO, LondonRos et al. (26 authors) (2007): Hepatics and Anthocerotes of the Mediterranean, an annotated checklist. –

Cryptogamie, Bryol. 28: 351–437.Sérgio, C., M. Sim-Sim & M. Carvalho (2006): Annotated catalogue of Madeiran Bryophytes. – Bol. Mus.

Munic. Funchal 10: 5–163.Sérgio, C., M. Sim-Sim, S. Fontinha & R. Figueira (2008): Os briófi tos (Bryophyta) dos arquipélagos da

Madeira e das Selvagens. – In: Borges, P. A. V. et al. (10 authors) (eds.): Listagem dos fungos, fl ora e fauna terrestres dos arquipélagos da Madeira e Selvagens, pp. 123–156. – Direcção Regional do Am-biente da Madeira e Universidade dos Açores, Funchal e Angra do Heroísmo.

Sim-Sim, M., M. G. Esquível, S. Fontinha & M. Stech (2005): The genus Plagiochila (Dumort.) Dumort. (Plagiochilaceae, Hepaticophytina) in Madeira Archipelago – Molecular relationships, ecology, and bio-geographic affi nities. – Nova Hedwigia 81: 449–461.

Sim-Sim, M., L. Luís, C. Garcia, S. Fontinha, C. Lobo, S. Martins & M. Stech (2008): New data on the status of threatened bryophytes of Madeira Island. – J. Bryol. 30: 226–228.

Sim-Sim, M., L. Luís & S. Fontinha (2010): Pottiopsis caespitosa (Brid.) Blockeel & A. J. E. Sm. In: New National and Regional records from bryophytes. – J. Bryol. (submitted).

F-01.indd 198 27.10.2010 08:16:32


SPNM – Serviço do Parque Natural Da Madeira (2004): As Ilhas Selvagens. – Governo Regional da Ma-deira, Secretaria Regional do Ambiente e dos Recursos Naturais, Funchal.

StatSoft, Inc. (2009): STATISTICA (data analysis software system), version 9.0. – www.statsoft.com.Stech, M., S. Osman, M. Sim-Sim & W. Frey (2006): Molecular systematics and biogeography of the liver-

wort genus Tylimanthus (Acrobolbaceae). Studies in austral temperate rain forest bryophytes 33. – Nova Hedwigia 83: 17–30.

Stech, M. et al. (12 authors) (2010): Molecular, phytochemical, and morphological characterisation of the liverwort genus Radula in Portugal (mainland, Madeira, Azores). – Syst. Biodiv. 8: 257–268.

Stech, M., M. Sim-Sim & J.-P. Frahm (2007): Campylopus (Leucobryaceae, Bryopsida) on Madeira Island – Molecular relationships and biogeographic affi nities. – Nova Hedwigia, Beih. 131: 91–100.

Stech, M., M. Sim-Sim, M. G. Esquível, S. Fontinha, R. S. Tangney, C. Lobo, R. Gabriel & D. Quandt (2008): Explaining the‘anomalous’distribution of Echinodium (Bryopsida: Echinodiaceae): Independent evolution in Macaronesia and Australasia. – Org. Divers. Evol. 8: 282–292.

Vanderpoorten, A., F. J. Rumsey & M. A. Carine (2007): Does Macaronesia exist? Confl icting signal in the bryophyte and pteridophyte fl oras. – Am. J. Bot. 94: 625–639.

F-01.indd 199 27.10.2010 08:16:32

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