A Study Contrasting Two Congener Plant Species: Psidium guajava (Introduced Guava) and P. galapageium (Galapagos Guava) in the Galapagos Islands

  • Hugo ValdebenitoEmail author
Part of the Social and Ecological Interactions in the Galapagos Islands book series (SESGI)


The genus Psidium in Galapagos presents the unique condition of having both an endemic (P. galapageium) and an invasive introduced species (P. guajava). The aim of this study was to evaluate the community structure, morphology, and phenology of both species in San Cristobal Island, which is essential for informing conservation actions.

There are clear morphological differences between the species studied. Flowers and their parts, buds, fruits, and leaves were on average smaller in P. galapageium var. howellii than in P. guajava, and the interspecies population variation was greater than within-individual variation in the same species.

The community-level characterization showed different plant community structures. While plots with P. guajava were dominated by herbaceous species, shrubby species were dominant in the P. galapageium areas. Species composition between plots with P. guajava and P. galapageium showed similarity in the absolute numbers as well as relative proportions of native, endemic, and introduced species over plots of both species. In contrast, species diversity was significantly different, being lower in plots with P. guajava.

Regarding phenology, both P. guajava and P. galapageium displayed similar phenological flowering and fruiting patterns. A complex assortment of floral buds, open flowers, fruitlets, and fruits of varying sizes was found on both species during similar periods.

Finally, a larger array of ecological and biological attributes should be investigated in P. galapageium and P. guajava. It is important to study the species’ reproductive biology, and we need to know if these species are interfertile and produce fertile progeny. In addition, extant populations of both species need to be screened using both morphological and molecular data.


Galapagos Psidium galapageium Psidium guajava Endemic plant species Introduced plant species 



This research was funded by a grant from GAIAS–Universidad San Francisco de Quito. A research permit (PC-61-14) was granted by the Galapagos National Park that allowed this research to be conducted. I acknowledge Nefi Vélez, Annette Olaya, and Génesis Ponce for their assistance in the fieldwork and data analyses as well as special thanks to the Instituto de Geografïa USFQ (Patricia Martínez and Carlos F. Mena) for the help in designing the maps and to an anonymous reviewer for valuable comments on this manuscript. Thanks to María de Lourdes Torres and Carlos F. Mena for inviting me to participate in this book. Carlos F. Mena and Steve Walsh of the Galapagos Science Center (USFQ/UNC) for their valuable support during the fieldwork. Thanks to all the personnel from GAIAS and the Galapagos National Park Service (specially to Ms. Maryuri Yépez and Mr. Jeffreys Málaga) for their support in the field.


  1. Anderson MS, de Vicente CM (2010) Gene flow between crops and their wild relatives. The John Hopkins University Press, BaltimoreGoogle Scholar
  2. Bleeker W, Schmitz U, Ristow M (2007) Interspecific hybridisation between alien and native plant species in Germany and its consequences for native biodiversity. Biol Conserv 137:248–253CrossRefGoogle Scholar
  3. Brodie C, Miller C, Pippard H, Kami T (2016) Species conservation in the Pacific Islands: taking effective steps forward. Pac Conserv Biol 22(3):201–202CrossRefGoogle Scholar
  4. Cedeño W (1990) Estudio fenológico de especies vegetales introducidas y nativas en la isla Santa Cruz-Galápagos. Tesis de grado, Universidad Técnica Luis Vargas Torres. Estación Científica Charles DarwinGoogle Scholar
  5. Celesti-Grapow L, Bassi L, Brundu G, Camarda I, Carli E, D’Auria G, Del Guacchio E, Domina G, Ferretti G, Foggi B, Lazzaro L, Mazzola P, Peccenini S, Pretto F, Stinca A, Blasi C (2016) Plant invasions on small Mediterranean islands: an overview. Plant Biosyst 150(5):1119–1133CrossRefGoogle Scholar
  6. Gardener MR, Trueman M, Buddenhagen C, Heleno R, Jäger H, Atkinson R, Tye A (2013) A pragmatic approach to the management of plant invasions in Galápagos. In: Foxcroft LC, Pyšek P, Richardson DM, Genovesi P (eds) Plant invasions in protected areas. Springer, Dordrecht, Netherlands, pp 349–374CrossRefGoogle Scholar
  7. Guézou A, Chamorro S, Pozo P, Guerrero AM, Atkinson R, Buddenhagen C, Jaramillo Díaz P, Gardener M (2016) CDF Checklist of Galapagos Introduced Plants - FCD Lista de especies de Plantas introducidas de Galápagos. In: Bungartz F, Herrera H, Jaramillo P, Tirado N, Jiménez-Uzcátegui G, Ruiz D, Guézou A, Ziemmeck F (eds) Charles Darwin Foundation Galapagos Species Checklist - Lista de Especies de Galápagos de la Fundación Charles Darwin. Charles Darwin Foundation/Fundación Charles Darwin, Puerto Ayora, Galápagos. Last updated 03 Aug 2016. Accessed 28 Nov 2016Google Scholar
  8. Helmstedt K, Shaw J, Bode M, Terauds A, Springer K, Robinson S, Possingham H (2016) Prioritizing eradication actions on islands: it’s not all or nothing. J Appl Ecol 53(3):733–741CrossRefGoogle Scholar
  9. Itow S (2004) Zonation pattern, succession process and invasion by aliens in species-poor insular vegetation of the Galapagos Islands. Global Environ Res 7(1):39–58Google Scholar
  10. Jäger H, Kowarik I, Tye A (2009) Destruction without extinction: long-term impacts of an invasive tree species on Galapagos highland vegetation. J Ecol 97:1252–1263CrossRefGoogle Scholar
  11. Jorgensen PM, León-Yáñez S (eds) (1999) Catalogue of the vascular plants of Ecuador, Monographs in systematic botany, vol 75. Missouri Botanical Garden, MissouriGoogle Scholar
  12. Lehman A, Pender R, Morden C, Wieczorek AM (2014) Assessment of persistence of hybrids between alien pima cotton, Gossypium barbadense (Malvaceae), and endemic Hawaiian cotton, G. tomentosum, in Hawai’i. Pac Sci 68(1):85–96CrossRefGoogle Scholar
  13. Magee J, McMullen CK, Reaser JK, Spitzer E, Struve S, Tufts C, Tye A, Woodruff C (2001) Green invaders of the Galápagos Islands. Science 294:1279–1280CrossRefGoogle Scholar
  14. Pasquet RS, Peltier A, Hufford MB, Oudin E, Saulnier J, Paul L, Knudsen JT, Herren HR, Gepts P (2008) Long-distance pollen flow assessment through evaluation of pollinator foraging range suggests transgene escape distances. Proc Natl Acad Sci U S A 105:13456–13461CrossRefGoogle Scholar
  15. Porter D (1969) Psidium (Myrtaceae) in the Galapagos Islands. Ann Missouri Bot Gard 55:368–371CrossRefGoogle Scholar
  16. Randell R, Howarth DG, Morden CW (2004) Genetic analysis of natural hybrids between endemic and alien Rubus (Rosaceae) species in Hawaii. Conserv Genet 5:217–230CrossRefGoogle Scholar
  17. Rentería JL, Atkinson R, Guerrero AM, Mader J (2006) Manual de Identificación y Manejo de Malezas. Fundación Charles Darwin y Servicio Parque Nacional GalápagosGoogle Scholar
  18. Rentería JL, Gardener MR, Panetta FD, Atkinson R, Crawley MJ (2012) Possible impacts of the invasive plant Rubus niveus on the native vegetation of the Scalesia forest in the Galápagos Islands. PLoS One 10:e48106. CrossRefGoogle Scholar
  19. Solarte E, Insuasty O, Melgarejo LM 2014 Calendario fenológico de la guayaba en la Hoya del río Suárez. Parte 01 Cap02.pdf. Accessed 29 Jan 2017
  20. Stoops G (2014) Soils and Paleosoils of the Galapagos Islands: what we know and what we don’t know, a meta-analysis. Pac Sci 68(1):1–17CrossRefGoogle Scholar
  21. Tye A (2000) Plantas amenazadas y acciones de manejo en varias islas del archipiélago. Informe Galápagos 1999–2000. Fundación NaturaGoogle Scholar
  22. Tye A (2002) Revisión del estado de amenazas de la flora endémica de Galápagos. Informe Galápagos 2001–2002. Fundación Natura, pp 116–122Google Scholar
  23. Tye A (2006) Can we infer island introduction and naturalization rates from inventory data? Evidence from introduced plants in Galapagos. Biol Invasions 8:201–215CrossRefGoogle Scholar
  24. Walsh S, McCleary A, Mena CF, Shao Y, Tuttle JP, González A, Atkinson R (2007) QuickBird and hyperion data analysis of an invasive plant species in the Galapagos Islands of Ecuador: implications for control and land use management. Special issue on earth observation for biodiversity and ecology. Remote Sensing of Environment, Douglas M. Muchoney, Senior Scientific Expert, GEO Secretariat, Guest EditorGoogle Scholar
  25. Walsh S, Mena C (2016) Interactions of social, terrestrial, and marine sub-systems in the Galapagos Islands, Ecuador. Proc Natl Acad Sci U S A 113(51):14543–14543CrossRefGoogle Scholar

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© Springer International Publishing AG 2018

Authors and Affiliations

  1. 1.Colegio de Ciencias Biológicas y Ambientales, Herbario QUSFUniversidad San Francisco de Quito USFQQuitoEcuador
  2. 2.Galapagos Science Center UNC—USFQSan CristobalEcuador

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