Leaf defoliation and Tabernaemontana rotensis (Asterids: Gentianales: Apocynaceae) flower induction and fruit development
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Abstract
Tabernaemontana rotensis (Kaneh.) P.T. Li is an attractive small tree that is endemic to the islands of Guam and Rota. Conservation efforts of the threatened population are constrained by lack of research. Understanding the ecology of flower and fruit development is fundamental to successful conservation of threatened angiosperms. This study determined the extent of flower induction following tropical cyclone defoliation, tested the efficacy of 10% urea sprays as a defoliant to induce flowering, and quantified the resulting fruit expansion to determine ontogeny traits. A total of 512 inflorescences were observed, half following tropical cyclones and half following defoliation with urea. Fruit length was measured every five to seven days until seed dispersal. The mean length of time between defoliation and initial flower anthesis was 29 days, and did not differ between tropical cyclone defoliation and urea solution aerosol defoliation. Four stages of observable fruit development were identified following anthesis. Linear increases in ovary length occurred for two weeks, maximum ovary length occurred at about day 30, color break from green to orange began at about day 60, and seed dispersal occurred at about day 90. Defoliation treatment did not influence the timing of these stages. The results indicated that tropical cyclone and urea solution defoliation consistently generated mast flowering after about one month with mast seeding about three months later. Conservationists may use this new knowledge to predictably schedule seed harvests at about four months following a natural or anthropogenic defoliation event. Many Tabernaemontana species are exploited for traditional medicine, and the use of defoliation to manipulate phenology of these species may benefit the practitioners of this trade.
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References
Beech, E., M. Rivers, S. Oldfield & P.P. Smith (2017). GlobalTreeSearch: The first complete global database of tree species and country distributions. Journal of Sustainable Forestry 36: 454–489. https://doi.org/10.1080/10549811.2017.1310049
BGCI (2021). State of the World’s trees. https://www.bgci.org/resources/bgci-tools-and-resources/state-of-the-worlds-trees. Downloaded on 12 May 2023.
Bogdziewicz, M., D. Ascoli, A. Hacket-Pain, W.D. Koenig, I. Pearse, M. Pesendorfer, A. Satake, P. Thomas, G. Vacchiano, T. Wohlgemuth & A. Tanentzap (2020a). From theory to experiments for testing the proximate mechanisms of mast seeding: an agenda for an experimental ecology. Ecology Letters 23: 210–220. https://doi.org/10.1111/ele.13442
Bogdziewicz, M., J. Szymkowiak, R. Calama, E.E. Crone, J.M. Espelta, P. Lesica, S. Marino, M.A. Steele, B. Tenhumberg, A. Tyre, M. Żywiec & D. Kelly (2020b). Does masting scale with plant size? High reproductive variability and low synchrony in small and unproductive individuals. Annals of Botany 126: 971–979. https://doi.org/10.1093/aob/mcaa118
Bogdziewicz, M. (2022). How will global change affect plant reproduction? A framework for mast seeding trends. New Phytologist 234: 14–20. https://doi.org/10.1111/nph.17682
Caujapé-Castells, J., A. Tye, D.J. Crawford, A. Santos-Guerra, A. Sakai, K. Beaver, W. Lobin, F.B. Vincent Florens, M. Moura, R. Jardim, I. Gomes & C. Kueffer (2010). Conservation of oceanic island floras: present and future global challenges. Perspectives in Plant Ecology, Evolution and Systematics 12: 107–129. https://doi.org/10.1016/j.ppees.2009.10.001
Chapman, K.R., J. Saranah & B. Paxton (1979). Induction of early cropping of guava seedlings in a closely planted orchard using urea as a defoliant. Australian Journal of Experimental Agriculture 19: 382–384. https://doi.org/10.1071/EA9790382
Chao, K.-J., Y.-C. Lin, G.-Z.M. Song, C.-H. Liao, Y.-L. Kuo, C.-F. Hsieh & E.W. Schupp (2022). Understorey light environment impacts on seedling establishment and growth in a typhoon-disturbed tropical forest. Plant Ecology 223: 1007–1021. https://doi.org/10.1007/s11258-022-01255-4
Enquist, B.J., X. Feng, B. Boyle, B. Maitner, E.A. Newman, P.M. Jørgensen, P.R. Roehrdanz, B.M. Thiers, J.R. Burger, R.T. Corlett, T.L.P. Couvreur, G. Dauby, J.C. Donoghue, W. Foden, J.C. Lovett, P.A. Marquet, C. Merow, G. Midgley, N. Morueta-Holme, D.M. Neves, A.T. Oliveira-Filho, N.J.B. Kraft, D.S. Park, R.K. Peet, M. Pillet, J.M. Serra-Diaz, B. Sandel, M. Schildhauer, I. Šímová, C. Violle, J.J. Wieringa, S.K. Wiser, L. Hannah, J.-C. Svenning & B.J. McGill (2019). The commonness of rarity: Global and future distribution of rarity across land plants. Science Advances 5: eaaz0414. https://doi.org/10.1126/sciadv.aaz0414
Kaiser-Bunbury, C.N., A. Traveset & D.M. Hansen (2010). Conservation and restoration of plant–animal mutualisms on oceanic islands. Perspectives in Plant Ecology, Evolution and Systematics 12: 131–133. https://doi.org/10.1016/j.ppees.2009.10.002
Koenig, W.D. (2021). A brief history of masting research. Philosophical Transactions of the Royal Society 376: B3762020042320200423. https://doi.org/10.1098/rstb.2020.0423
Marler, T.E. (2001). Tropical cyclones and perennial species in the Mariana Islands. HortScience 36: 264–268. https://doi.org/10.21273/HORTSCI.36.2.264
Marler, T.E. (2013). The intersection of a military culture and indigenous peoples in conservation issues. Communicative & Integrative Biology 6: e26665. https://doi.org/10.4161/cib.26665
Marler, T.E. (2014). Pacific island tropical cyclones are more frequent and globally relevant, yet less studied. Frontiers in Environmental Science 2: 42. https://doi.org/10.3389/fenvs.2014.00042
Marler, T.E. (2017). Horticultural research crucial for plant conservation and ecosystem restoration. HortScience 52: 1648–1649. https://doi.org/10.21273/HORTSCI12423-17
Marler, T.E. (2021). Leaf elemental concentrations, stoichiometry, and resorption in Guam’s coastal karst forests. Diversity 13: 545. https://doi.org/10.3390/d13110545
Marler, T.E., A. Cascasan & J.H. Lawrence (2015). Threatened native trees in Guam: short-term seed storage and shade conditions influence emergence and growth of seedlings. HortScience 50: 1049–1054. https://doi.org/10.21273/HORTSCI.50.7.1049
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: 3. https://doi.org/10.4172/2167-0587.1000178
Marler, T.E. & A.J. Lindström (2020). Diel patterns of stem CO2 efflux vary among cycads, arborescent monocots, and woody eudicots and gymnosperms. Plant Signaling & Behavior 15: 1732661. https://doi.org/10.1080/15592324.2020.1732661
Marler, T.E., C. Musser, A.N.J. Cascasan, G.N. Cruz & B.E. Deloso (2021). Adaptive management lessons for Serianthes nelsonii conservation. Horticulturae 7: 43. https://doi.org/10.3390/horticulturae7030043
Naidoo, C.M., Y. Naidoo, Y.H. Dewir, H.N. Murthy, S. El-Hendawy & N. Al-Suhaibani (2021). Major bioactive alkaloids and biological activities of Tabernaemontana species (Apocynaceae). Plants 10: 313. https://doi.org/10.3390/plants10020313
Nic Lughadha E., S.P. Bachman, T.C.C. Leão, F. Forest, J.M. Halley, J. Moat, C. Acedo, K.L. Bacon, R.F.A. Brewer, G. Gâteblé, S.C. Gonçalves, R. Govaerts, P.M. Hollingsworth, I. Krisai-Greilhuber, E.J. de Lirio, P.G.P. Moore, R. Negrão, J.M. Onana, L.R. Rajaovelona, H. Razanajatovo, P.B. Reich, S.L. Richards, M.C. Rivers, A. Cooper, J. Iganci, G.P. Lewis, E.C. Smidt, A. Antonelli, G.M. Mueller & B.E. Walker (2020). Extinction risk and threats to plants and fungi. Plants, People, Planet 2: 389–408. https://doi.org/10.1002/ppp3.10146
Pereira, H.M., L.M. Navarro & I.S. Martins (2012). Global biodiversity change: The bad, the good, and the unknown. Annual Review of Environment and Resources 37: 25–50. https://doi.org/10.1146/annurev-environ-042911-093511
Rieger, M. (2006). Introduction to Fruit Crops. Taylor & Francis, Oxfordshire, United Kingdom, 520 pp.
Rivers, M., A.C. Newton, S. Oldfield & Global Tree Assessment Contributors (2022). Scientists’ warning to humanity on tree extinctions. Plants, People, Planet 4: 1–17. https://doi.org/10.1002/ppp3.10314
Samant, D., K. Kishore & G.C. Acharya (2020). Efficacy of some chemicals for crop regulation in Allahabad Safeda guava under coastal Indian conditions of Odisha. Indian Journal of Horticulture 77: 94–100. https://doi.org/0.5958/0974-0112.2020.00008.0
Silveira, D., A.F. de Melo, P.O. Magalhães & Y.M. Fonseca-Bazzo (2017). Tabernaemontana species: Promising sources of new useful drugs. pp. 227–289. In: Atta-ur-Rahman (ed.). Studies in Natural Products Chemistry. Volume 54. Elsevier, Amsterdam, The Netherlands, 428 pp.
Singh, G.; A.K. Singh, S. Rajan & S.R. Bhriguvanshi (2002). Strategy for crop regulation in guava (Psidium guajava L.) through foliar urea sprays and its effect on different N-forms in leaves. Journal of Applied Horticulture 4: 93–98.
Singh, N., D.P. Sharma, S. Kumari & K. Kalsi (2018). Techniques for crop regulation in guava-a review. International Journal of Farm Sciences 8: 131–135. https://doi.org/10.5958/2250-0499.2018.00068.X
Staude, I.R., L.M. Navarro & H.M. Pereira (2020). Range size predicts the risk of local extinction from habitat loss. Global Ecology and Biogeography 29: 16–25. https://doi.org/10.1111/geb.13003
Stone, B.C. (1971). America’s Asiatic flora: The plants of Guam. American Scientist 59: 308–319.
Taesotikul, T., A. Panthong, D. Kanjanapothi, R. Verpoorte & J.J.C. Scheffer (1990). Pharmacological activities of Tabernaemontana pandacaqui. Planta Medica 56: 688–688.
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.
United States Fish & Wildlife Service (2020). Tabernaemontana rotensis 5-Year Review Summary and Evaluation. https://ecos.fws.gov/docs/five_year_review/doc6641.pdf. Downloaded on 12 May 2023.
Vacchiano, G., M.B. Pesendorfer, M. Conedera, G. Gratzer, L. Rossi & D. Ascoli (2021). Natural disturbances and masting: from mechanisms to fitness consequences. Philosophical Transactions of the Royal Society 376: B3762020038420200384. https://doi.org/10.1098/rstb.2020.0384
Zhang, J., T. Heartsill-Scalley & R.L. Bras (2022). Forest structure and composition are critical to hurricane mortality. Forests 13: 202. https://doi.org/10.3390/10.3390/f13020202