Project 004 Description: Our group has an ongoing research program to determine the detectability of biocrusts on exoplanets. Biocrusts — communities that may be composed of any configuration of soil surface-dwelling cyanobacteria, eukaryotic algae, lichens, mosses or liverworts, and support assemblages of decomposers and a faunal food web — are one of the first kinds of biotic material to inhabit a newly available cological niche, including on the early Earth, and thus may be reasonable examples of primitive life on other planets. An undergraduate research student would continue our work on cultivating and measuring properties of biocrusts that can be remotely sensed, including spectral signatures and gas fluxes. Alternately, a student might instead work on our ongoing project of modeling the effects of three-dimensional life forms (e.g., trees) on photometric signals obtained by JWST and future observatories.