Bryology in California- Recent Advances in Understanding the Large Contribution of our Small Plants (mosses, liverworts and hornworts)

Saturday, October 22 at 8:00-9:40 am, Donner Room

Session Description: Bryophytes (mosses, liverworts and hornworts) comprise more than 10% of California’s native plant species. This session focuses on our rapidly expanding knowledge of the floristics, biogeography, ecology and conservation priorities of these understudied but important native plants.

Session Chair: Ben Carter (San Jose State University, San Jose, CA, USA)

31.1    Ecology of dryland mosses and lessons in moss restoration to degraded systems

Jasmine Anenberg (Northern Arizona University, Flagstaff, AZ, USA), Matthew Bowker (Northern Arizona University, Flagstaff, AZ, USA), Anita Antoninka (Northern Arizona University, Flagstaff, AZ, USA), Philip Ramsey (MPG Ranch, Florence, MT, USA), Rebecca Durham (MPG Ranch, Florence, MT, USA), Kyle Doherty (MPG Ranch, Florence, MT, USA)

Drylands comprise approximately 41% of the world’s terrestrial land and face significant loss of ecosystem services due to land use change, so restoring function to dryland ecosystems is essential. Focusing on soil health to reduce dust emission, erosion, and water runoff creates immediate short- and long-term benefits to the ecosystem. Biocrusts, a living groundcover in drylands, can fix carbon and nitrogen, stabilize soil, and retain water. Their ability to provide habitat for microbial communities, nutrients for surrounding plants, and influence hydrology, sediment movement, and plant interactions, makes them a critical piece of dryland restoration. Restoration of biocrusts by cultivating and adding back to degraded field sites has had mixed success. Syntrichia ruralis is a common moss occurring in biocrust communities across the western United States that we have successfully cultivated. We chose this species to test two potential reintroduction methods for cultivated moss: pelletization and weed barrier fabric. Traditional broadcasting methods have led to loss of material being blown away from target sites, so pellets and weed fabric could improve retention of materials at the site while also suppressing exotic plants. To test pellets, we created eight combinations varying in recipe, size, and shape to determine the most effective micro-environment for moss growth. To test moss fabric, we grew S. ruralis on five different weed barriers, with the material ranging in life span from one month to 30 years, and then installed with the moss either facing up or down. Moss cover and weed suppression will be reported here from monitoring to occur in May 2022. Both experiments were installed at a retired rangeland site at MPG Ranch during October 2021. If we can find ways to rehabilitate mosses and other biocrust organisms on the landscape in an efficient and scalable way, we can provide restoration managers with an important tool for use in degraded dryland systems.

31.2    Bryophyte Ecoregions in California

John T. McLaughlin (San Jose State University, San Jose, CA, USA)

The biogeography of California’s vascular flora is better understood than nearly any region in North America, however, bryophytes are not typically included in biogeographic studies. Recent collecting efforts, digitization projects, and publication of regional floras have greatly increased the available information on bryophyte distributions across the state. In this study, we used three datasets to identify major biogeographic regions for Californian bryophytes and to test whether bryophyte distributions conform to the Jepson Ecoregions. We were specifically interested in whether the higher quality data in floras or the higher quantity of data with county recorded but not coordinates would yield different results from the standard practice of using only georeferenced herbarium records. We collected species lists from 32 florulas, as well as obtained distribution data from the Consortium of North America Bryophyte Herbaria. The collections data were analyzed based on presence across counties (N= 7.8×10^4) and across 0.5 degree grid cells (N=5.2×10^4). Each of these three datasets were subjected to hierarchical cluster analysis to identify major clusters (regions) based on shared species across floras, counties or grid cells, respectively. The three datasets provided generally consistent clustering patterns that were largely aligned with the Jepson Ecoregions. The most noteworthy difference was a tendency for southern areas in the CFP to cluster with the deserts rather than the coast ranges. We found several major and unexpected gaps in collecting efforts across the state, even in botanically interesting areas including Mendocino County and the Transverse Ranges, indicating that more collecting will likely improve our understanding of the state bryophyte flora.

31.3    Biogeographic patterns defined by turnover of species and lineages in the moss flora of California and western North America

Ben Carter (San Jose State University, San Jose, CA, USA)

The identification of biomes has long been of interest for understanding biogeographic and floristic patterns. This study used spatial data from herbarium records in conjunction with a phylogeny to document patterns of turnover in both species and in evolutionary lineages across the mosses of California and the rest of western North America. Patterns of nestedness (i.e. species-poor regions have assemblages that are subsets of the species in species-rich regions) vs. turnover (species-poor regions have unique species not found in species-rich regions) were analyzed to understand the extent to which these two patterns explain broad biogeographic patterns across the state, especially in the context of the latitudinal precipitation gradient. Biogeographic patterns as identified by species and by evolutionary lineages were generally concordant, with a few noteworthy exceptions. Similarly, patterns of nestedness vs turnover largely mirrored expectations, but deviations from expectations based on the vascular flora are present.

31.4    Conservation assessment of California mosses using spatial phylogenetic methods

Brent D. Mishler (University and Jepson Herbaria, Dept. of Integrative Biology, University of California, Berkeley, CA, USA), Israel T. Borokini (University and Jepson Herbaria, Dept. of Integrative Biology, University of California, Berkeley, CA, USA), Ben Carter (San Jose State University, San Jose, CA, USA)

California is recognized as one of the world’s biodiversity hotspots. It is also one of the places where biodiversity is most threatened, because of habitat loss, invasive species, and climate change. There is an urgent need to understand conservation priorities on the landscape of California for all groups of organisms, yet no such study has been made for mosses. Therefore, we pruned a larger spatial dataset of geo-referenced herbarium records for all of North America, as well as a matching phylogenetic data matrix, from Carter et al. (2022, Journal of Biogeography, 10.1111/jbi.14385) to make a California subset. A maximum likelihood phylogeny was constructed (both time-calibrated and not) and used along with newly produced species niche models to find regions of significant phylogenetic diversity and phylogenetic endemism within California, employing a spatial randomization. We also carried out a phylogenetic complementarity analysis to identify conservation priorities on the landscape that optimally increase protected biodiversity, using an algorithm that takes into account current land protection status and data on landscape intactness to identify priority sites containing concentrations of lineages that are evolutionarily unique, vulnerable due to small range size, and poorly protected across their ranges. We evaluated priorities using three different dimensions of phylodiversity (each measuring a different value): a phylogram (i.e., genetic divergence), a chronogram (i.e., evolutionary time), or a cladogram (i.e., speciation events). These three metrics yielded conservation priorities that agreed in many places but differed in others. We compared these results to those previously published for vascular plants of California (Kling et al. 2018, Phil. Trans. Roy. Soc. B, 374: 20170397). Several top priority regions of the state emerged from these comparisons.