D. Nicholas McLetchie

mclet's picture
  • Associate Professor
  • Biology
  • Ecology and Evolutionary Biology
  • Plant Sciences
102 MDR #3
(859) 257-6786
Research Interests:

Ph.D. Ecology, Univ. of Tennessee, Knoxville, 1993
BS in Botany, Howard University, 1984


Please see 'Lab website' link (on left side and below contact phone number ) for more recent and complete information.


There are few greater obstacles to sexual reproduction than the rarity or absence of one sex. Limited or no sexual reproduction can result in a species inability to adapt to a changing environment, leading to population declines and eventually species extinction. Yet among plants, specifically bryophytes, rarity or absence of one sex occur frequently. An illustration of this pattern occurs in the liverwort Acrobolbus ciliatus Mitt. which is found as males in Japan and females in the Appalachian mountains in the USA . Although intriguing, the underlying causes of these patterns have infrequently been investigated. My research program focuses on elucidating the factors resulting in an entire species or population being dominated by one sex. Such factors include variation in offspring sex ratios and sex differences in clonal expansion that are a function of differential growth, asexual reproduction, colonization and survival as well as sex differences in sex expression.

To study the causes and consequences of sex ratio variation we use an unusually broad array of techniques, including molecular-genetic analysis, physiological methods, greenhouse and growth chamber experiments, field experiments and monitoring, and mathematical modeling. We consider the structure and dynamics of individuals, local clusters of individuals (patches), and patch assemblages, and interactions among them and the environment.

Selected Publications: 

Publications since 2009 SEE 'LAB WEBSITE' LINK (upper right in the 'CONNECT' box) FOR MORE RECENT INFORMATION

  1. Moore J.D., L. Kollar D.N. McLetchie (In Press) Does selection for gamete dispersal and capture lead to a sex difference in clump water-holding capacity? American Journal of Botany doi:10.3732/ajb.1600096
  2. Rose M., J. Burton D.N. McLetchie. 2016. Sex differences and plasticity in dehydration tolerance: insight from a tropical liverwort. Annals of Botany doi: 10.1093/aob/mcw102
  3. Stieha C., G García-Ramos, D.N. McLetchie, P. Crowley. 2016. Maintenance of the Sexes and Persistence of a Clonal Organism in Spatially Complex Metapopulations.  Evolutionary Ecology DOI 10.1007/s10682-016-9841-8
  4. Stark L. R, D. N. McLetchie, S. M. Eppley and J. L. Greenwood. 2016. Moss Antheridia are Desiccation Tolerant: Rehydration Dynamics Influence Sperm Release in Bryum argenteum (Bryaceae) American Journal of Botany doi:10.3732/ajb.1600026
  5. Stieha C., A. Middleton, J. Stieha; S. Trott, D. N. McLetchie. 2014 The dispersal process of asexual propagules and the contribution to population persistence in Marchantia (Marchantiaceae) American Journal of Botany 101:348-356. doi:10.3732/ajb.1300339
  6. Brzyski, J. R., W. Taylor, D. N. McLetchie. 2014. Reproductive allocation between the sexes, across natural and novel habitats, and its impact on genetic diversity. Evolutionary Ecology 28: 247-261. 10.1007/s10682-013-9672-9
  7. Brzyski, J., K. Adams, C. Walter, K. H. Gale, D. N. McLetchie. 2012 Characterization of 12 polymorphic microsatellite markers in the liverwort Marchantia inflexa (Marchantiaceae) American Journal of Botany (vol. 99 no. 11 e440-e442). http://www.amjbot.org/cgi/doi/10.3732/ajb.1200187
  8. Stark L. R., J C Brinda, D. N. McLetchie, M J Oliver. 2012 Extended periods of hydration do not elicit dehardening to desiccation tolerance in regeneration trials of the moss Syntrichia caninervis. International Journal of Plant Sciences 173 333-343. 10.1086/663970
  9. Reynolds, L. A., and D N. McLetchie. 2011 Short distance between extreme microhabitats do not result in ecotypes in Syntrichia caninervis, Journal of Bryology 33: 148-153 10.1179/1743282011Y.0000000004
  10. Benassi, M. L., L. R. Stark, J. C. Brinda, D. N. McLetchie, M. Bonine, and B.D. Mishler. 2011 Plant size, sex expression, and sexual reproduction along an elevation gradient in a desert moss. The Bryologist 114:277-288 10.1639/0007-2745-114.2.277
  11. Horsley K., L. R. Stark, and D. N. McLetchie. 2011 Does the silver moss Bryum argenteum exhibit sex-specific patterns in vegetative growth rate, asexual fitness, or prezygotic reproductive investment? Annals of Botany 107: 897-907 doi: 10.1093/aob/mcr027
  12. Stark L. R., J C Brinda, D. N. McLetchie 2011 Effects of increased summer precipitation and N deposition on Mojave Desert populations of the biological crust moss Syntrichia caninervis, Journal of Arid Environments 75: 457-463  doi:10.1016/j.jaridenv.2010.12.015
  13. Stark, L. R., D. N. McLetchie, and S. M. Eppley.. 2010 Sex ratios and the shy male hypothesis in the moss Bryum argenteum (Bryaceae) The Bryologist. 113: 788-797 (http://www.bioone.org/doi/full/10.1639/0007-2745-113.4.788)
  14. Groen, K. E., Stieha, C., Crowley, P. H., and McLetchie, D. N. 2010 Sex-specific plant responses to light intensity and canopy openness: implications for spatial segregation of the sexes. Oecologia 162: 561-570 doi:10.1007/s00442-009-1473-z
  15. Groen, K. E., Stieha, C., Crowley, P. H., and McLetchie, D. N. 2010 Sex-specific plant responses to two light levels in the liverwort Marchantia inflexa (Marchantiaceae). The Bryologist. 113: 81-89.
  16. Cole, C., Stark, L. R., Bonine M., and McLetchie, D. N. 2010. Transplant survivorship of bryophyte soil crusts in the Mojave Desert. Restoration Ecology 18: 198-205. doi:10.1111/j.1526-100X.2008.00445.x.
  17. Stark, L. R, Brinda, J. and McLetchie, D. N. 2009 An experimental demonstration of the cost of sex and a potential resource limitation on reproduction in the moss Pterygoneurum (Pottiaceae). American Journal of Botany 96: 1-11. doi:10.3732/ajb.0900084
  18. Stark, L. R, McLetchie D. N. and Roberts S. 2009. Gender differences and a new adult eukaryotic record for upper thermal tolerance in the desert moss Syntrichia caninervis Journal of Thermal Biology 34: 131-137.  cleardoi:10.1016/j.jtherbio.2008.12.001



PubMed Publications*: 
  • Moore, JD ;Kollar, LM ;McLetchie, DN "Does selection for gamete dispersal and capture lead to a sex difference in clump water-holding capacity?" American journal of botany 103, 8 (2016): 1449-57. Details. Full text
  • Marks, RA ;Burton, JF ;McLetchie, DN "Sex differences and plasticity in dehydration tolerance: insight from a tropical liverwort." Annals of botany 118, 2 (2016): 347-56. Details. Full text
  • Stark, LR ;McLetchie, DN ;Greenwood, JL ;Eppley, SM "Moss antheridia are desiccation tolerant: Rehydration dynamics influence sperm release in Bryum argenteum." American journal of botany 103, 5 (2016): 856-64. Details. Full text
  • , ;Adams, KJ ;Walter, CM ;Gale, KH ;McLetchie, DN "Characterization of 12 polymorphic microsatellite markers in the liverwort Marchantia inflexa (Marchantiaceae)." American journal of botany 99, 11 (2012): e440-2. Details. Full text
  • McLetchie, DN ;Stark, LR "Sporophyte and gametophyte generations differ in their thermotolerance response in the moss Microbryum." Annals of botany 97, 4 (2006): 505-11. Details. Full text
  • Fuselier, L ;McLetchie, N "Maintenance of sexually dimorphic preadult traits in Marchantia inflexa (Marchantiacae)." American journal of botany 89, 4 (2002): 592-601. Details. Full text
* Publications are automatically pulled from pubmed.gov based on a user-specific query. Results may include incorrect citations. See: Tutorial on improving PubMed results.
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