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Corresponding author: Leandro Freitas ( leandro@jbrj.gov.br ) Corresponding author: Rafaela Forzza ( rafaela@jbrj.gov.br ) Academic editor: Reyjane Patricia Oliveira
© 2016 Leandro Freitas, Alexandre Salino, Luiz Menini Neto, Thais Almeida, Sara Mortara, Joao Stehmann, André Márcio Amorim, Elsie Guimaraes, Marcus A. Nadruz Coelho, Ana Zanin, Rafaela Forzza.
This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Citation:
Freitas L, Salino A, Neto LM, Almeida TE, Mortara SR, Stehmann JR, Amorim AM, Guimarãe EF, Coelho MN, Zanin A, Forzza RC (2016) A comprehensive checklist of vascular epiphytes of the Atlantic Forest reveals outstanding endemic rates. PhytoKeys 58: 65-79. https://doi.org/10.3897/phytokeys.58.5643
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Knowledge of the geographic distribution of plants is essential to underpin the understanding of global biodiversity patterns. Vascular epiphytes are important components of diversity and functionality of Neotropical forests but, unlike their terrestrial counterparts, they are under-represented in large-scale diversity and biogeographic analyses. This is the case for the Atlantic Forest - one of the most diverse and threatened biomes worldwide. We provide the first comprehensive species list of Atlantic Forest vascular epiphytes; their endemism patterns and threatened species occurrence have also been analyzed. A list with 2,256 species of (hemi-)epiphytes - distributed in 240 genera and 33 families - is presented based on the updated Brazilian Flora Checklist. This represents more than 15% of the total vascular plant richness in the Atlantic Forest. Moreover, 256 species are included on the Brazilian Red List. More than 93% of the overall richness is concentrated in ten families, with 73% represented by Orchidaceae and Bromeliaceae species alone. A total of 78% of epiphytic species are endemic to the Atlantic Forest, in contrast to overall vascular plant endemism in this biome estimated at 57%. Among the non-endemics, 13% of epiphytic species also occur either in the Amazon or in the Cerrado - the other two largest biomes of Brazil – and only 8% are found in two or more Brazilian biomes. This pattern of endemism, in addition to available dated phylogenies of some genera, indicate the dominance of recent radiations of epiphytic groups in the Atlantic Forest, showing that the majority of divergences dating from the Pliocene onwards are similar to those that were recently reported for other Neotropical plants.
Angiosperms, canopy, ferns, lycophytes, hotspots, life-forms, monocots, tropical forests
Geographic distribution of vascular plant species forms the framework to understand terrestrial diversity patterns, their relationship to environmental and historical factors and the ecological and evolutionary mechanisms underlying these patterns (
The high abundance of vascular epiphytes constitutes a remarkable characteristic of tropical forests. These plants may exceed 50% of local vascular plant richness in some montane forests (
The Atlantic Forest, one of the floristic diversity centres in the Neotropics (
This paper provides the first comprehensive species list of vascular epiphytes for the Brazilian Atlantic Forest, identifying: (i) taxonomic representativeness, (ii) geographic distribution and endemism, and (iii) occurrence of threatened species among epiphytes of this biome. This study is the first approach to the analysis of epiphyte diversity patterns in the Neotropics involving the mechanisms underlying floristic diversity in tropical forests.
Raw data for this study were obtained from the database developed by
All facultative and holoepiphytes, as well as all primary and secondary hemiepiphytes were listed, but accidental and heterotrophic epiphytes were excluded following the concept provided by
Our compilation recorded 2,256 species of epiphytes distributed in 33 vascular plant families (Suppl. material
Number of vascular taxa for the Brazilian Atlantic Forest. Compiled from the
Taxonomic group | Families | Genera | Species | |
---|---|---|---|---|
All life-Forms | Angiosperms | 211 | 1,975 | 14,638 |
Ferns and lycophytes | 36 | 127 | 852 | |
Total - vascular plants | 247 | 2,102 | 15,490 | |
(Hemi-) Epiphytes | Angiosperms | 22 | 197 | 2,013 |
Ferns and lycophytes | 11 | 43 | 243 | |
Total - vascular plants (epiphytes/all life-forms) |
33 (13.4%) | 240 (11.4%) | 2,256 (15.4%) |
Representation of vascular epiphytes is highly concentrated in a few families, with the ten richest families accounting for around 93% of epiphyte diversity (Fig.
About three out of four vascular epiphytic species from the Atlantic Forest are endemic to this biome (Table
Distribution patterns of vascular (hemi-)epiphytes for Atlantic Forest along the four main Brazilian biomes, and the number of endangered species.
Number and percentage of species | |||
Angiosperms | Ferns and lycophytes | Vascular flora | |
Restricted to Atlantic Forest | 1,595 (79.2%) | 146 (60.1%) | 1,741 (77.2%) |
Atlantic Forest + Amazonia | 110 (5.5%) | 42 (17.3%) | 152 (6.7%) |
Atlantic Forest + Cerrado | 134 (6.7%) | 20 (8.2%) | 154 (6.8%) |
Atlantic Forest + Caatinga | 31 (1.5%) | 0 | 31 (1.4%) |
Wide (3 or more biomes) | 143 (7.1%) | 35 (14.4%) | 178 (7.9%) |
Endangered species | 237 (11.8%) | 19 (7.9%) | 256 (11.3%) |
Very high levels of vascular epiphytic species richness and endemism were found for the Atlantic Forest, with the vast majority of species being restricted to a small number of plant families. Taxonomic representation of vascular epiphytes for the Atlantic Forest is similar to that found for other tropical forests (
The high number of species and endemism rate of epiphytes found in the Brazilian Atlantic Forest follows the trend for this biome, one of the leading world hotspots for many groups of organisms including vascular plants (
Nevertheless, a recurrent question regarding the value of focusing on biodiversity hotspots revolves around the conflicting results that often arise when comparing different groups (
This high rate of epiphytic endemism in the Atlantic Forest is reinforced by the contiguity of the xeric Caatinga biome that harbours few epiphytic species and may act as a barrier to biotic exchanges between the Atlantic Forest and the rainforest in the Amazonia (
The historical discussion on geotemporal trajectories of plant diversification in Neotropical biomes has focused on two alternative models: the museum hypothesis, highlighting an ancient history of steady accumulation of diversity, and the cradle model, favouring more recent diversification and high speciation rates (reviewed in
The very high endemism rates found for Atlantic Forest epiphytes, in particular for predominantly holoepiphytic groups of angiosperms are in accordance with the idea of predominant recent diversification. This is the case of Bromeliaceae native to the Atlantic Forest, which rates of net diversification are especially high in the bromelioid tank epiphyte clade (1.11 and 1.05 Mya for stem and crown rates, respectively) and the core tillandsioids (i.e., Tillandsioideae minus Catopsis Griseb. and Glomeropitcairnia Mez; 0.47 and 0.67 Mya) (
The Atlantic Forest holds the highest richness of fern and lycophyte species in Brazil (
Currently there are 78 fern and lycophyte species listed as threatened in Brazil (
Vascular epiphytes in the Atlantic Forest are possibly more prone to projected effects of global climate change in their area of occurrence, specifically with increased mean temperatures, and higher frequency of drastic events such as long dry periods (
Vascular epiphytes are a characteristic feature of Neotropical forests, however, our understanding on biogeographical and floristic relationships of epiphytes as well as of the mechanisms that structure epiphyte communities are still rather poor (
This paper results from activities of the Atlantic Forest Epiphytes’ Network, an initiative sponsored by the Coordenation for the Improvement of Higher Education Personnel (CAPES-PNADB, Brazil). A.M.A., A.S., J.R.S., L.F., and R.C.F. acknowledge the National Counsel of Technological and Scientific Development (CNPQ, Brazil) for their productivity scholarships.We also thank Daniela Zappi and Andrew Smith for the English revision; Jomar Gomes Jardim, Eric de Camargo Smidt and an anonymous reviewer for their constructive comments.
Species list of vascular (hemi-)epiphytes of Brazilian Atlantic Forest
Data type: species list.