Date of Award


Degree Name

MS in Biological Sciences


Biological Sciences


College of Science and Mathematics


Nishanta Rajakaruna

Advisor Department

Biological Sciences

Advisor College

College of Science and Mathematics


Lichens are an underrepresented group of organisms when it comes to both research and conservation efforts. At the same time, lichens face increasing threats from anthropogenic sources including wildfires, climate change and urbanization. With this thesis, I seek to ascertain and publish ecological data on a critically endangered lichen to inform future conservation designations and efforts to preserve and protect the species in perpetuity.

In Chapter 1, I provide an ecological overview of the known range of Sulcaria isidiifera and assess the status of Sulcaria isidiifera via a population count. Sulcaria isidiifera occurs in maritime chaparral habitat in the Los Osos-Baywood Park-Morro Bay area of San Luis Obispo County, California. Although apparently similar maritime chaparral is known from a much larger range along the coast of California, S. isidiifera has never been found outside of this extremely local population area. Population data collected during the study determined there are an estimated 3,588-7,772 mature individuals of S. isidiifera range-wide. Chapter 1 also characterizes the vascular plant vegetation community, microclimate parameters, and lichen community assemblage in which S. isidiifera occurs. The elegant fringe lichen (Leucodermia leucomelos) was found to be a strong indicator for the presence of S. isidiifera. Chamise (Adenostoma fasciculatum), buck brush (Ceanothus cuneatus), and Morro manzanita (Arctostaphylos morroensis) were the most common shrub species on which S. isidiifera was found.

In Chapter 2, conservation translocation was tested as a mitigation strategy for the previously observed population decline of S. isidiifera. Whole thalli were translocated while attached to their original substrate to adjacent shrubs in suitable habitat that was not occupied by S. isidiifera. The vitality of translocated thalli was tested using chlorophyll fluorescence techniques. After 13.5 months, I report 100 percent survival of translocated thalli with no significant negative impacts to thallus health. The S. isidiifera transplants will continue to be monitored indefinitely. Guidance on future conservation translocations for S. isidiifera is provided and these methods will continue to be updated as further observations and results are gathered.