Dissertation Research: Investigating the Role of a Cryptic Life Stage in Fern Evolution and Community Assembly

点击翻译按钮获取中文摘要

Ferns represent a successful and diverse lineage, unified by a unique life cycle that has persisted for hundreds of millions of years. Unlike bryophytes or seed plants, the haploid gametophyte and diploid sporophyte of ferns are capable of occurring largely independent of one another, and thus represent distinct ecological entities. Current knowledge of fern ecology is based almost exclusively on the larger, easily observable sporophyte stage; fern gametophytes in contrast have been mostly ignored by ecologists due to their small size (typically 1 cm) and lack of morphological characters for reliable species identification. The gametophyte represents the sexual phase responsible for reproduction, however, and is thus critically important to understanding fern ecology. Recent advances in DNA barcoding methods now allow for the reliable identification of fern gametophytes, and have opened new avenues for research into this neglected area of plant biology. This study will leverage an extensive DNA barcode library of the ferns of Moorea, French Polynesia to identify field-collected gametophytes and compare the distribution and ecological adaptations of fern gametophytes and sporophytes in a broad evolutionary context. This project will provide benefits to multiple groups including both the local community on Moorea and university students in the U.S., and will have important implications for fern conservation. Outreach activities including a multilingual museum display on fern biodiversity are planned for the Atitia community center on Moorea. In addition, data for this research will be partially generated by undergraduates trained at Harvard University. Knowledge of biodiversity will be increased by adding to museum holdings and describing new species. Finally, investigations into species? gametophyte distribution will reveal distribution patterns that will be important to consider when designing conservation programs for endangered fern species.