Title: Diversity and Biology of Annual Mosses
Instructor: Bernard Goffinet & William Buck
Dates: June 18–24, 2023
Description: All bryophytes have a life cycle dominated by the vegetative gametophyte, but the gametophyte is not necessarily perennial. Mosses from across the diversity of the acrocarpous Bryopsida (those mosses with arthrodontous peristomes aiding in spore release) have adopted a shortened life cycle, whereby gametophytes reach sexual maturity rapidly, and develop a sporophyte, which may also exhibit an accelerated maturation. Some short-lived annual species complete their life cycle, from spore to spore, within a few weeks. Annual mosses occur on short-lived or seasonal habitats, and only on soil. Shortening of the life cycle is typically achieved by the simplification of the plant body, i.e., a reduction in architectural complexity, such that annual species develop un- or barely branched vegetative plants, and sporophytes may be simplifed to immersed capsules lacking peristomes but with a differentiated mode of dehiscence. We aim for participants being able to study plants of the various lineages, primarily from collections made during the spring and during local excursions. The laboratory will focus on the identification of the species as well as provide an opportunity to survey the diversity of putative adaptations characterizing annual moss species. The laboratory time will be complemented with lectures highlighting the phylogenetic and ecological diversity of annual mosses and other bryophytes, and recent advances in our understanding of moss development and its relevance to understanding annual life cycles.
