Llo R. Stark

University of Nevada Las Vegas


My lab studies the ecology and physiology of the trait vegetative desiccation tolerance (DT) in mosses. Desiccation tolerance (DT) is the ability of an organism or structure to survive drying in equilibration with dry air, and among plants is most well developed among the bryophytes.

In my lab, various species of mosses are cultured and bred, with experiments on DT normally based on single clonal lines. We are interested in determining the instrinsic ecological strategy of DT employed by a species; this strategy resides along an inducibility gradient, from weakly inducible to nearly constitutive.

Experimental topics include the DT of vegetative and reproductive phases, the physiology and timelines of hardening and dehardening phenomena, how different life phases of mosses (shoots, asexual propagules, antheridia, juvenile structures) exhibit variation in response to desiccation stress, and the length of time structures can tolerate continuous desiccation. Specifically, my laboratory is investigating how the four components of desiccation tolerance, (i) the rate of drying, (ii) the equilibrating relative humidity experienced, (iii) the duration spent in the dried state, and (iv) the rate of rehydration, affect the capacity of a plant to tolerate desiccation.

Recent research highlights include an illustration that desert mosses were employing an inducible strategy of DT (2013), the first experimental assessment of dehardening in mosses and the implications for mechanistic studies in the field of DT (2014), the first demonstration that the model moss Physcomitrella patens was desiccation tolerant (2014), the first demonstration that different life phases of a single species exhibit different intrinsic strategies of DT (2016), the first study to show that mosses, specifically in the genus Syntrichia, are in fact not constitutively protected but exhibit a complex inducible strategy of DT (2017), the first demonstration that antheridia of mosses are DT (2016), and soon the first demonstration of how prehydration rescues a moss from severe desiccation (2018).

Current funded projects include (1) an NSF grant exploring DT in the genus Syntrichia, (2) a US Golf Association grant exploring stress effects on a moss that inhabits golfing greens, and (3) a floristic project for Grand Staircase Escalante National Monument. Prospective graduate students should have a background in bryophytes and an interest in moss ecophysiology.



Stark Lab Members on the 3D Moss Project

Theresa Clark – PhD Candidate

Joshua Greenwood – Post-doc

John Brinda – PhD

Mandy Slate – Post-doc


Selected Publications

Stark, L. R., J. L. Greenwood, M. L. Slate, and J. C. Brinda. 2017. Syntrichia norvegica shoots exhibit a complex inducible response to desiccation: separating the effects of rate of drying and water content. Botany, in press. doi: 10.1139/cjb-2016-0263  Google Scholar Link

Brinda, J. C., L. R. Stark, T. A. Clark, and J. L. Greenwood. 2016. Embryos of a moss can be hardened to desiccation tolerance: effects of rate of drying on the timeline of recovery and dehardening in Aloina ambigua (Pottiaceae). Annals of Botany 117: 153–163. doi: 10.1093/aob/mcv136 Google Scholar Link

Stark, L. R., D. N. McLetchie, J. L. Greenwood, and S. M. Eppley. 2016. Moss antheridia are desiccation tolerant: rehydration dynamics influence sperm release in Bryum argenteum. American Journal of Botany 103: 856–864. doi:10.3732/ajb.1600026 Google Scholar Link

Stark, L. R., J. C. Brinda, and J. L. Greenwood. 2016. Propagula and shoots of Syntrichia pagorum (Pottiaceae) exhibit different ecological strategies of desiccation toleranceBryologist 119: 181-192. doi:http://dx.doi.org/10.1630/0007-2745-119.2.181 Google Scholar Link

Stark L. R. and J. C. Brinda. 2015. Developing sporophytes transition from an inducible to a constitutive ecological strategy of desiccation tolerance in the moss Aloina ambigua: effects of desiccation on fitness. Annals of Botany 115: 593–603, doi: 10.1093/aob/mcu252 Google Scholar Link

Raudenbush, Z., S. J. Keeley, and L. R. Stark. 2015. A review: establishment, dispersal, and management of silvery-thread moss (Bryum argenteum Hedw.) in putting greens. Crop, Forage & Turfgrass Management, doi: 10.2134/cftm2014.0094 Google Scholar Link

Stark, L. R., J. L. Greenwood, J. C. Brinda, and M. J. Oliver. 2014. Physiological history may mask the inducible desiccation tolerance strategy of the desert moss Crossidium crassinerve. Plant Biology 16: 935–946. DOI: 10.1111/plb.12140 Google Scholar Link

Greenwood, J. L. and L. R. Stark. 2014. The rate of drying determines the extent of desiccation tolerance in Physcomitrella patens. Functional Plant Biology 41: 460–467. DOI: 10.1071/FP13257 Google Scholar Link

Stark, L. R., J. L. Greenwood, J. C. Brinda, and M. J. Oliver. 2013. The desert moss Pterygoneurum lamellatum exhibits inducible desiccation tolerance: effects of rate of drying on shoot damage and regeneration. American Journal of Botany 100: 1522–1531. Google Scholar Link

Selected Awards

2014 Sullivant Award, outstanding paper published in The Bryologist in 2013, “An experimental demonstration of rhizautoicy, self-incompatibility, and reproductive investment in Aloina bifrons (Pottiaceae).” $1000 award, Botanical Society of America meeting, Boise, Idaho, July 2014 [coauthor John Brinda].