Non-vascular photoautotrophs, including bryophytes, lichens, algae, and cyanobacteria, are widely distributed in all terrestrial habitats around the globe. They occur growing on and within rocks, epiphytically on plants, and growing on soil they often form so-called biological soil crusts. Despite their often small stature, these organisms (together with the microbiomes and cyanosphere they host) play a significant role in key ecological processes such as water, carbon, and nitrogen cycling, as well as the regulation of atmospheric and belowground processes. Yet, these critical organisms remain underrepresented in ecological research. Because non-vascular photoautotrophs are highly responsive to changes in environmental conditions, understanding and quantifying their functional roles is becoming increasingly important under rapid global change. Encouragingly, a growing body of data, such as functional traits, microbiome information, and greenhouse gas quantifications, is now emerging for non-vascular vegetation across diverse ecosystems, which has opened new avenues for linking to ecosystem functions in the context of climate change. However, significant challenges remain. These include limited quantitative understanding of how non-vascular photoautotrophs mediate interactions between the atmosphere, vegetation, soil, and associated microbial communities; mismatches in temporal and spatial scales of available observations and ecosystem-level processes; and difficulties in scaling physiological and community-level processes from local measurements to regional and global ecosystem functions.
To address these challenges, this session aims to bring together cutting-edge research that examines non-vascular photoautotrophs as crucial drivers of ecosystem functioning and to raise awareness of their inclusion in ecosystem function research frameworks within the field of ecology. We welcome all studies investigating the roles of bryophytes, lichens, cyanobacteria, algae, and their associated microorganisms, both individually and as communities in ecosystem processes, with particular interest in water, carbon, nitrogen, and other biogeochemical cycles. Contributions may make use of conceptual, observational (in-situ or remote sensing), experimental, and modelling approaches, and may cover a range of scales from organismal ecophysiology to community, ecosystem, regional, and global dynamics.