Species richness and geographical distribution of montane pteridophytes of Costa Rica, Central America

Abstract

AbstractA list of 342 montane pteridophyte species of Central America, occurring at elevations higher than 2500 m a.s.l. is presented, including their geographical and altitudinal distribution. For Costa Rica a total of 1099 species are registered, but only 282 species occur in the higher montane area. More than 50% of the montane species have a wide altitudinal distribution and can be found at 1000m and even below. Only 56 species are restricted to the montane area, 22 of which are endemic. The altitudinal distribution for Costa Rica shows the strongest regression of species at 3000 to 3400 m, repesenting the timber‐line. Of the 25 montane pteridophyte families the Polypodiaceae, Adiantaceae, Hymenophyllaceae, Lomariopsidaceae, Lycopodiaceae, Aspleniaceae and Dryopteridaceae are contributing 70% of the species. At the generic level the most frequent ones are Grammitis (31 spec.), Elaphoglossum (29 spec.), Lycopodium (28 spec.), Hymenophyllum (17 spec.), Asplenium (13 spec.), Polypodium (13 spec.) and Thelypteris (12 spec.). Highest species richness was found in the ‘Cordillera de Talamanca’ and on the ‘Barva’ volcano. For this volcano 104 species were observed on an area of only 19 km2 in the last 45 years. Many of the species of older collections (before 1950) were not found again, indicating the influence of human activities.