Diversity of vascular epiphytes in two high altitude biotopes of the Brazilian Atlantic Forest

Montane environments create unique conditions that favour the development of remarkably rich and endemic biotas. The Serra da Mantiqueira is an important Brazilian mountain range and is recognised globally for certain groups of living organisms, whereas gaps in knowledge exist for other groups, such as epiphytes, which have been poorly studied in the region. The Serra da Mantiqueira contains rare fragments of a vegetation formation, the mixed ombrophilous forest (MOF), which is typical of the Southern Region of Brazil and is very threatened. The present study aimed to analyse the epiphytic communities occurring on individuals of Podocarpus lambertiiKlotzsch ex Endl. (Podocarpaceae) in two biotopes: natural patches and continuous alluvial forest. We sampled 60 phorophytes, equally divided between the sites, and established five strata according to stem ramification. This phorophyte species is ecologically relevant, since it harbours 92 species and 19 families, and a single individual may support up to 30 % of the total richness of the studied community. The Shannon diversity index was 3.86, which is comparable to that found in other studies dealing with several phorophyte species and is the highest found to date for the MOF. The biotopes and strata did not show significant differences in the calculated diversity indices, except in richness (80 species in the alluvial forest and 60 in the patches). The most representative ecological categories were characteristic holoepiphytes (73 species) and accidental holoepiphytes (nine species). The present study shows the importance that a single species can have in an ecosystem and contributes to our knowledge concerning epiphytic synusia in mountainous environments.