Abstract Detail

Bryology and Lichenology

Clark, Theresa An [1].

Can Arid Land Mosses Hide from Climate Change?

Although many arid land mosses are renowned for their ability to survive in arid ecosystems by drying without dying (i.e. desiccation tolerance), laboratory research indicates the rate at which these small plants desiccate and the amount of time they spend hydrated after precipitation events are critical to preventing lethal damage. Current projections for further climate change predict that arid environments like the Mojave Desert Ecoregion, will become hotter and drier with altered rain patterns; such emerging climatic stressors have already been linked to increased mortality and reduced fitness in several Mojave Desert moss species. However, it has been hypothesized that habitat structure (topography and microhabitat) may lower the vulnerability of mosses to desiccation stress by protecting them from the brunt of climatic extremes, a process called habitat buffering. It follows that such protective buffering could prolong moss cushion hydration periods and slow their drying rates, potentially reducing desiccation stress. Therefore, we implemented a nested, three-scaled sampling design to quantify the capacity of elevational life zone, NNE vs SSW aspect, and sun exposure to (1) buffer the extremes of macroclimate experienced by common arid land moss species (Grimmia anodon, Syntrichia ruralis, and Syntrichia caninervis), and (2) to influence critical moss cushion water dynamics. Across a 2500 m elevation gradient, we systematically selected 48 moss microsites spanning the Joshua tree/black brush, pinyon-juniper, and ponderosa pine communities of the Desert National Wildlife Refuge, 35 miles northwest of Las Vegas. Using macroclimate data (from climate stations at each site) and microclimate data (from sensors placed adjacent to moss cushions), we estimated habitat buffering in several ways. Lastly, we recorded the length and frequency of moss hydration periods (i.e. hydroperiods) using time-lapse photography. In this poster presentation, preliminary data will reveal current trends characterizing (1) variation in mean microhabitat buffering at the three habitat scales (life zone, topographical aspect, microhabitat exposure), and (2) relationships between microhabitat type (soil vs rock), microclimate, buffering capacity, and the length of moss hydroperiod. Broad implications of my research include the potential importance of microhabitat buffering in the protection of other small, desiccation-tolerant microorganisms (e.g. algae, cyanobacteria, fungi, lichens, and microinvertebrates) at risk from a changing climate. Our data will be used in future research to help inform predictions for moss species range shifts as part of a formal vulnerability assessment of these small but important plants in a changing natural world.

1 - University Of Nevada, Las Vegas, Biology, 4505 S Maryland Parkway, Las Vegas, NV, 89154, USA

Keywords:
moss
climate change
microhabitat
microhabitat buffering
desiccation tolerance
water relations.

Presentation Type: Poster
Session: P, Bryology and Lichenological Section/ABLS Posters
Location: Exhibit Hall/Savannah International Trade and Convention Center
Date: Monday, August 1st, 2016
Time: 5:30 PM This poster will be presented at 5:30 pm. The Poster Session runs from 5:30 pm to 7:00 pm. Posters with odd poster numbers are presented at 5:30 pm, and posters with even poster numbers are presented at 6:15 pm.
Number: PBR003
Abstract ID:904
Candidate for Awards:None