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Epiphyllous bryophytes in the Azores Islands
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Abstract(s)
A vegetação epífila é típica das florestas tropicais húmidas. A presença extratropical de um grande número de briófitos epífilos nos arquipélagos da Macaronésia, Açores, Madeira e Canárias, torna-se, por isso, notável. Este artigo refere-se à flora e vegetação epífila dos Açores. O material em análise consiste em 963 amostras (568 epífilos) incluindo os epifilos preferenciais, na sua maioria hepáticas. Muitas destas espécies pertencem às famílias Lejeuneaceae e Radulaceae. As amostras foram colhidas entre 1965 e 1995, em todas as nove ilhas dos Açores. Estas amostras foram recolhidas de 30 plantas-suporte (ou forófitos) diferentes. Aqui fornece-se informação sobre a ecologia, sociologia e vulnerabilidade destas espécies de briófitos. Por outro lado, discute-se a sua alta frequência em locais já sugeridos para protecção, mas com base apenas em plantas vasculares endémicas. Entre as 89 espécies encontradas como epífilas, 21 são preferencialmente epífilas e 14 são endémicas, quer dos Açores, quer da Macaronésia, sendo membros mais ou menos frequentes da brio-comunidade epífila Cololejeuneo-Colurion: Cololejeuneetum azoricae Sjn. 78. As condições óptimas de habitat para estas espécies encontram-se entre os 700 a 1000 m de altitude (nas ilhas do grupo central). Dentro destes limites de altitude, tem sido encontrado o maior número de diferentes espécies forófitas colonizadas, bem como o maior número de espécies preferenciais epífilas associadas (médias de mais de 3,5 espécies). Os dados apontam como sendo forófitos preferenciais: (1) Blechnum, Trichomanes, Elaphoglossum (pteridófitos); (2) Ilex, Laurus (ávores/arbustos): (3) Hedera (herbaceas); (4) Thamnobryum (briófitos). Algumas áreas com floresta nativa endémica dos Açores (Juniperion brevifoliae), tem sido apontadas para áreas protegidas. A presença, nestas áreas, dos briófitos epífilos caracteriza-se por: (1) alta diversidade de espécies, (2) várias espécies de epifilos preferenciais também ocorrem como epífitos e como epixílicos, (3) um grande número de espécies forófitas, (4) possuírem um grande número de espécies endémicas açorico/macaronésicas, (5) possuírem um grande número de espécies com o status de rara, vulnerável ou em perigo, de acordo com o "Red Data Book of European Bryophytes" (algumas alterações o status são sugeridas neste artigo).
ABSTRACT: Epiphyllous vegetation is typical of tropical rainforests. The extratropical presence of a large number of epiphyllous bryophytes on the Macaronesian Island groups of the Azores, Madeira and the Canary Islands is thus remarkable. The present paper deals with Azorean epiphyllous flora and vegetation. The material treated consists of 963 samples (568 epiphyllous) with presence of preferentially epiphyllous bryophytes, mostly hepatics. Several species belong to the families Lejeuneaceae and Radulaceae (sampling time 1965-1995 on all nine Azorean islands). The epiphyllous samples originate from 30 different host plants or phorophytes. Information has been provided on ecology, sociology and vulnerability of the species. The high frequency of epiphyllous bryophytes in localities suggested for protection has been discussed, the selection being in many cases only founded on presence of endemic vascular plants. Among the 89 species recorded as epiphyllous, 21 species are preferentially epiphyllous and 14 species are endemic either to the Azores or to Macaronesia. They are more or less frequent members of the endemic epiphyllous bryo-community, the Cololejeuneo-Colurion: Cololejeuneetum azoricae Sjn. 78. Optimal habitat conditions for epiphyllous bryophytes are between 700-1000 m (central island group). Within that altitude range have been recorded the largest numbers of colonized phorophyte species and as well the largest numbers of associated preferentially epiphyllous species in the samples (means of more than 3.5 species). The phorophytes recorded as preferentially colonized by the epiphyllous bryophytes are: (1) Blechnum, Trichomanes, Elaphoglossum (pteridophytes); (2) Ilex, Laurus (trees/shrubs); (3) Hedera (herbs); (4) Thamnobryum (bryophytes). A few areas with endemic native forest (Juniperion brevifoliae) have been considered for preservation in the Azores. The presence within these forest areas of epiphyllous bryophytes is characterized by: (1) high diversity of species, (2) several preferentially epiphyllous species also occur as epiphytic and as epixylic, (3) a large number of different phorophyte species, (4) a large number of Azorean/Macaronesian endemic species, (5) a large number of species with status as rare, vulnerable or endangered according to "Red Data Book of European Bryophytes" (several changes of status suggested in this paper).
ABSTRACT: Epiphyllous vegetation is typical of tropical rainforests. The extratropical presence of a large number of epiphyllous bryophytes on the Macaronesian Island groups of the Azores, Madeira and the Canary Islands is thus remarkable. The present paper deals with Azorean epiphyllous flora and vegetation. The material treated consists of 963 samples (568 epiphyllous) with presence of preferentially epiphyllous bryophytes, mostly hepatics. Several species belong to the families Lejeuneaceae and Radulaceae (sampling time 1965-1995 on all nine Azorean islands). The epiphyllous samples originate from 30 different host plants or phorophytes. Information has been provided on ecology, sociology and vulnerability of the species. The high frequency of epiphyllous bryophytes in localities suggested for protection has been discussed, the selection being in many cases only founded on presence of endemic vascular plants. Among the 89 species recorded as epiphyllous, 21 species are preferentially epiphyllous and 14 species are endemic either to the Azores or to Macaronesia. They are more or less frequent members of the endemic epiphyllous bryo-community, the Cololejeuneo-Colurion: Cololejeuneetum azoricae Sjn. 78. Optimal habitat conditions for epiphyllous bryophytes are between 700-1000 m (central island group). Within that altitude range have been recorded the largest numbers of colonized phorophyte species and as well the largest numbers of associated preferentially epiphyllous species in the samples (means of more than 3.5 species). The phorophytes recorded as preferentially colonized by the epiphyllous bryophytes are: (1) Blechnum, Trichomanes, Elaphoglossum (pteridophytes); (2) Ilex, Laurus (trees/shrubs); (3) Hedera (herbs); (4) Thamnobryum (bryophytes). A few areas with endemic native forest (Juniperion brevifoliae) have been considered for preservation in the Azores. The presence within these forest areas of epiphyllous bryophytes is characterized by: (1) high diversity of species, (2) several preferentially epiphyllous species also occur as epiphytic and as epixylic, (3) a large number of different phorophyte species, (4) a large number of Azorean/Macaronesian endemic species, (5) a large number of species with status as rare, vulnerable or endangered according to "Red Data Book of European Bryophytes" (several changes of status suggested in this paper).
Description
Keywords
Flora Epífila Vegetação Epífila Epiphyllous Flora Epiphyllous Vegetation Açores Azores
Citation
"ARQUIPÉLAGO. Ciências Biológicas e Marinhas = Life and Marine Sciences". ISSN 0873-4704. Nº 15A (1997): 1-49