Abstract Detail

Pteridology

Quinlan, Alexandria Shayne [1], Kuo, Li-Yaung [2], Hu, Jer-Ming [3].

Ferns on ferns: an exploration of low-trunk epiphytic fern gametophytes growing on tree ferns in Taiwan.

Tree ferns have been documented as significant hosts for epiphytes, often composed of distinct communities that are considerably different from other hosts. Particularly, exclusive growth of epiphytic fern species has been exhibited on tree ferns, however, this fern-on-tree-fern epiphytism has yet to be substantially explored for the gametophyte generation. This study focused on epiphytic fern gametophytes growing on low trunks of a tree fern species, Alsophila spinulosa (Cyatheaceae), and nearby angiosperm hosts. Fern gametophyte surveys were conducted in two seasons, during the months of June and October, in a subtropical forest in Taiwan. These surveys sought to understand what factors make tree ferns optimal habitats for gametophytes, and whether there are notable differences between the composition of fern gametophyte communities on tree ferns compared with other hosts. For each season, 3 circular plots were established along either side of a stream (6 plots total), where gametophytes were collected beneath 1m on tree fern and angiosperm hosts, and sporophyte species were recorded to observe proximity to gametophytes. Gametophytes were identified using an Illumina Miseq approach which involved sequencing multiplexed trnL-F amplicons derived from tissue-direct PCR. Environmental surveys were conducted for each season, including recording relative humidity (RH), and measuring canopy openness and light availability. Overall, October had a higher abundance of individuals in the epiphytic gametophyte community which could be a phenological association. Tree ferns harbored a significantly higher abundance and species richness of gametophytes than angiosperm hosts, and hosted more cordiform gametophytes that were mostly from accidental and facultative fern epiphytes. In comparison, angiosperms had a higher abundance of non-cordiform individuals. In addition, two independent gametophytes were found on the surveyed hosts, Callistopteris apiifolia and a Haplopteris yakushimensis species. Generally, plots with a higher species richness of sporophytes also had a higher richness of gametophytes. Results from the environmental survey showed that the RH for all surveyed hosts was most frequently over 95%, however angiosperms spent considerably more time below 95% and 85% RH than tree ferns. The stable RH revealed on the tree fern trunks, which presumably results from the moist root mantle, allowed for a high diversity of fern gametophytes. There was overall no statistical significance with gametophyte diversity and canopy openness, however, in each season, the plot with the highest total light also had highest species richness and abundance for fern gametophytes. Importantly, this study is among the first insights of epiphytic gametophyte communities on tree ferns.

1 - National Taiwan University, Institute of Ecology and Evolutionary Biology, No. 1, Section 4, Roosevelt Rd., Da’an District, Taipei City, 10617, Taiwan
2 - National Tsing Hua University, Institute Of Molecular & Cellular Biology, Room 327, 3F, Life Science Building One, No.101, Sec., East, Hsinchu, HSZ, 30013, Taiwan
3 - National Taiwan University, Institute Of Ecology And Evolutionary Biology, Rm1227 Life Science Building, 1 Roosevelt Road Sec 4, Taipei, TPE, 106, Taiwan

Keywords:
Cyatheaceae
tree ferns
epiphytes
gametophytes
multiplexed amplicon sequencing
tissue-direct PCR
relative humidity
trnL-F.

Presentation Type: Oral Paper
Number: PTR1006
Abstract ID:436
Candidate for Awards:None