Asexual reproduction via specialized propagules that contain both fungal and algal components occurs throughout the diverse lineages that comprise lichens, and is one of the most interesting aspects of lichen biology. Although lichens that reproduce this way represent up to ~50% of lichen biodiversity in any given area they have been chronically neglected. This project implements a novel methodology to remedy this problem using a revision of the lichen genus Lepraria in North America as a case study. This methodology relies on extensive field observations to reconcile the results of analyses of molecular data against those based on traditional characters such as morphology and chemistry. Lepraria is a unique group that has lost the ability to reproduce sexually yet continued to diversify.
This project addresses a significant knowledge gap in lichenology by producing the first comprehensive treatment of Lepraria on a continental scale and introducing the first standardized morphological terminology for any group of sterile crustose lichens. Field studies in boreal/arctic North America will substantively increase the functionality of this treatment. Similarly, newly generated molecular data will shed light on the evolution of asexual reproduction in lichenized fungi while providing taxonomic placement for numerous species currently orphaned within Lepraria. Most notably the methodology implemented here is broadly applicable to other sterile lichens, providing a timely and cost-effective way to document and describe the biodiversity of this highly speciose but chronically neglected group. The project will train a doctoral student and results of the study will be disseminated through the development of websites, videos, and mass media public outreach activities.
This award supported improvements to the dissertation of a PhD student to facilitate scientific understanding of a poorly understood group of crustose lichens. Lichens represent a diverse group of fungi that are presumed to have critical roles in land-based ecosystems throughout North America and abroad. The lichen genus Lepraria, which was the focus of this award, represents an extreme case of a phenomenon seen in many lichens wherein species evolve to reproduce asexually through fragmentation. Although many would assume this to be a limiting factor for an organism, Lepraria is a dominant member of shaded habitats throughout North America. Remarkably, its species have continued to diversify chemically and morphologically. Because these species lack sexual fruiting bodies they have been neglected by most researchers. The research carried out under this award led to significant advances in our understanding of Lepraria, as well as the discovery of several species new to science. Specific products were: 1) the first fully illustrated guide to the morphology of the genus, a work that has already improved communication between researchers and other biologists by providing a standard language through which Lepraria can be described. 2) A series of studies using DNA sequence data to examine and define species of Lepraria, resulting in the description of multiple new North American endemics. 3) A new protocol was developed using DNA sequence data to aid in the recognition and description of sterile crustose lichens, a highly diverse group that includes Lepraria and many unrelated species. 4) A formal scientific revision of Lepraria that led to the recognition that it included members of four families, including a previously unrecognized order that was new to science. 5) Thousands of new specimens were collected in Canada (Ontario, Quebec, Yukon), the Appalachian Mountains (North Carolina, Pennsylvania, Tennessee) and Tasmania, providing substantial new information on the lichens of these regions. 6) The first fully illustrated taxonomic revision of Lepraria in North America with keys and distribution maps, which will be published online and available for free to the general public. 7) Public outreach in the form of presentations to multiple groups (scientists, botanical clubs, undergraduate students) in the United States and Canada, attendance of Workshops as an expert referee, and hands-on study in the field with local biologists and lichenologists in the United States, Canada, and Tasmania. Collectively the products of this award have shown that lichen species, have discrete morphologies and geographic distributions and biogeographic affinities, and that they are frequently poorly understood due to a fundamental lack of basic information (i.e., collections and field observations). These findings are relevant in the context of an ongoing extinction crisis and provide support for the immediate need to fund large scale studies of biodiversity in North America so that we can document and understand what lives in our own backyard before it disappears.