Adventitious rooting of mature Cycas micronesica K.D. Hill (Cycadales: Cycadaceae) tree stems reveals moderate success for salvage of an endangered cycad

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Thomas Edward Marler
Gil Naputi Cruz


Mature Cycas micronesica trees were among the forest trees that were destined to be removed from a 2012 construction site in northern Guam.  Forty-nine of these trees were cut at the base and transported to nursery conditions to determine if adventitious root development could be stimulated as a means of saving the trees.  Fungicide and auxin were applied to the base of each stem, and perlite was used as the container medium.  A nursery maintained by an experienced cycad horticulturist yielded 41% survival, but half of the rooted plants exhibited severe stem dieback.  A nursery maintained by general plant nursery specialists without cycad experience resulted in 100% mortality.  If numerous caveats are acknowledged, whole-tree stem cuttings may yield moderate success for saving C. micronesica trees from construction sites when adequate resources are appropriated to support the nursery phase with experienced cycad biologists. 

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Short Communications
Author Biographies

Thomas Edward Marler, Western Pacific Tropical Research Center, UOG Station, University of Guam, Mangilao, Guam 96923, USA

Terrestrial Ecologist in western Pacific oceanic island nations

Gil Naputi Cruz, 1,2 Western Pacific Tropical Research Center, UOG Station, University of Guam, Mangilao, Guam 96923, USA

Gil Cruz is Agricultural Research Technician Leader and has supported cycad projects for 15 years.


Bozzano, M., R. Jalonen, E. Thomas, D. Boshier, L. Gallo, S. Cavers, S. Bordács, P. Smith & J. Loo (eds.) (2014). Genetic Considerations in Ecosystem Restoration Using Native Tree Species. State of the World’s Forest Genetic Resources - Thematic Study. Rome, FAO and Bioversity International, 281pp.

Brummitt, N.A., S.P. Bachman, J. Griffiths-Lee, M. Lutz, J.F. Moat, A. Farjon, J.S. Donaldson, C. Hilton-Taylor, T.R. Meagher, S. Albuquerque, E. Aletrari, A.K. Andrews, G. Atchison, E. Baloch, B. Barlozzini, A. Brunazzi, J. Carretero, M. Celesti, H. Chadburn, E. Cianfoni, C. Cockel, V. Coldwell, B. Concetti, S. Contu, V. Crook, P. Dyson, L. Gardiner, N. Ghanim, H. Greene, A. Groom, R. Harker, D. Hopkins, S. Khela, P. Lakeman-Fraser, H. Lindon, H. Lockwood, C. Loftus, D. Lombrici, L. Lopez-Poveda, L. Lyon, K. Malcolm-Tompkins, L. Moreno, L. Murray, K. Nazar, E. Power, M.Q. Tuijelaars, R. Salter, R. Segrott, H. Thacker, L.J. Thomas, S. Tingvoll, G. Watkinson, K. Wojtaszekova & E.M.N. Lughadha (2015). Green plants in the red: A baseline global assessment for the IUCN sampled Red List Index for plants. PloS one 10(8): e0135152.

Calonje, M., D.W. Stevenson & L. Stanberg (2017). The world list of cycads, online edition. 2013–2017. Available from: Downloaded on 11 July 2017.

Cascasan, A.N. & T.E. Marler (2016). Publishing trends for Cycadales, the most threatened plant group. Journal of Threatened Taxa 8(3): 8575–8582;

Cibrian-Jaramillo, A., A.C. Daly, E. Brenner, R. DeSalle & T.E. Marler (2010). When north and south don’t mix: genetic connectivity of a recently endangered oceanic cycad, Cycas micronesica, in Guam using EST-microsatellites. Molecular Ecology 19: 2364–2379.

Donaldson, J.S. (ed.) (2003). Cycads. Status Survey and Conservation Action Plan. IUCN/SSC Cycad Specialist Group. IUCN, Gland, Switzerland and Cambridge, UK, ix+86pp.

Donnegan, J.A., S.L. Butler, W. Grabowiecki, B.A. Hiserote & D. Limtiaco (2004). Guam’s Forest Resources, 2002. Resour. Bull. PNW-RB-243.

Portland, OR: U.S. Department of Agriculture, Forest Service, Pacific Northwest Research Station, USA, 32pp.

Fragniere, Y., S. Bétrisey, L. Cardinaux, M. Stoffel & G. Kozlowski (2015). Fighting their last stand? A global analysis of the distribution and conservation status of gymnosperms. Journal of Biogeography 42(5): 809–820.

Haynes, J. (2012). Transplanting a large cycad. The Cycad Newsletter 35(3): 22–23.

Marler, T.E. (2001). Tropical cyclones and perennial species in the Mariana Islands. Hortscience 36: 264–268.

Marler, T.E. (2012). Cycad aulacaspis scale invades the Mariana Islands. Memoirs New York Botanical Garden 106: 20–35.

Marler, T.E. (2013). Increased threat of island endemic tree’s extirpation via invasion-induced decline of intrinsic resistance to recurring tropical cyclones. Communicative & Integrative Biology 6: e223611–e223616.

Marler, T.E., J. Haynes & A. Lindström (2010). Cycas micronesica. In: IUCN 2014. IUCN Red List of Threatened Species. Version 2014.2. Available at: Downloaded on 11 July 2017.

Marler, T.E. & J.H. Lawrence (2012). Demography of Cycas micronesica on Guam following introduction of the armoured scale Aulacaspis yasumatsui. Journal of Tropical Ecology 28: 233–242; http://doi. org/10.1017/S0266467412000119

Marler, T.E., J.H. Lawrence & G.N. Cruz (2016). Topographic relief, wind direction, and conservation management decisions influence Cycas micronesica K.D. Hill population damage during tropical cyclone Journal of Geography & Natural Disasters 6: 178;

Marler, T.E. & A. Moore (2011). Military threats to terrestrial resources not restricted to wartime: a case study from Guam. Journal of Environmental Science & Engineering 5: 1198–1214.

Marler, T.E. & I. Terry (2013). The continuing demise of Cycas micronesica. The Cycad Newsletter 36(1): 22–26.

Moore, A., T. Marler, R.H. Miller & R. Muniappan (2005). Biological control of cycad aulacaspis scale on Guam. The Cycad Newsletter 28(5): 6–8.

Norstog, K.J. & T.J. Nicholls (1997). The biology of the cycads. Cornell University Press, Ithica, New York, xi+363pp.

Stopes, M.C. (1910). Adventitious budding and branching in Cycas. New Phytologist 9: 235–241.

United States Fish & Wildlife Service (2015). Endangered and threatened wildlife and plants; endangered status for 16 species and threatened status for 7 species in Micronesia. Federal Register 80: 59424–59497.

Yokomizo, H., T. Takada, K. Fukaya & J.G. Lambrinos (2017). The influence of time since introduction on the population growth of introduced species and the consequences for management. Population Ecology 59: 89–97;