Exploration of the diversity of tree ferns (Cyatheaceae, Dicksoniaceae - Polypodiopsida) along two elevational gradients in Indonesian New Guinea
Final Report Abstract
During a month-long expedition to the Indonesian part of New Guinea, the fern diversity was evaluated along two elevational transects in a joint effort between the University Zurich, the Indonesian LIPI, and the applicant. Partial transects in each province were combined to a transect reaching from the lowlands to the highest accessible forest (500-2000 m and 1500-3500 m, respectively). As predicted, fern diversity was highest at midelevations. New Guinea as a large, mountainous island has a high diversity in general, but a comparison with other islands shows that diversity is not directly correlated with an island’s surface. The applicant focused on inventorying the tree ferns and was able to collect almost all species of Dicksoniaceae (or “hairy tree ferns”; 7 of 8 spp.) and ca. 50 % of Cyatheaceae (or “scaly tree ferns”; 44 spp.) reported for New Guinea. This includes a new record for the island (Cyathea croftii Holttum), one reinstated species (Alsophila olivacea Brause) and at least two undescribed species of Cyatheaceae. The material collected yields good results in DNA extractions and sequencing of the chloroplast regions trnL-F, trnG-R and rpl16. The phylogenetic information in each region is relatively low, but combined sufficient for the planned analyses. A more variable primer set (cp, nuclear) is being searched for. We expect our results to ultimately serve for DNA fingerprinting of these CITES regulated taxa. Lab work continues; preliminary results indicate two strictly New Guinean radiations of higherelevation taxa in the genera Sphaeropteris s.s. and Alsophila. The hypothesis that New Guinea harbors the earliest divergences in the tree ferns could not be conclusively tested. Material and data generated with this grant are currently used in three students’ theses. A continuation of this project on a global scale is planned in a bilateral cooperation between the Universities of Bonn and Zurich.
