Invasive species

Part of my thesis investigation deals with invasive species in the Galapagos, which is a fascinating subject to me. 


Alien, introduced or exotic species are those that are found outside of their native range or ecosystem, most often being transported by humans deliberately; some of those species may negatively affect the new ecosystem, being then termed as invasive species.

Many of the current invasive species were brought to the Galapagos Islands for agricultural purposes by the colonists. Some of the more common plant examples include rose apple (Syzygium jambos), guava (Psidium guajava), blackberry (Rubus niveus), cuban cedar (Cedrela odorata), citrus (Citrus spp), cuban hemp (Furcraea hexapetala) and red quinine (Cinchona pubescens). Guézou et al. (2010) performed an extensive survey of the inhabited area of Santa Cruz, San Cristobal, Isabela and Floreana islands and recorded 754 alien plant species, whose most common use was ornamental. 

But today the main concern is the introduction and spread of these species from the inhabited areas into the NP; it is estimated that roughly 1,14% of the area of NP is occupied by  invasive plant species (CEPROEC-IAEN & SENPLADES, 2014).

According to my (somewhat simple) calculation of their spread in the next 10 years, the area covered by invasive species will be as shown in the map below.

The projected spread of invasive species on Isabela Island (shown in red and yellow) in the next 10 years.

Bibliography
Gardener, M. R., Trueman, M., Buddenhagen, C., Heleno, R., Jäger, H., Atkinson, R., & Tye, A. (2013). A Pragmatic Approach to the Management of Plant Invasions in Galapagos. In L. C. Foxcroft, P. Pyšek, D. M. Richardson, & P. Genovesi (Eds.), Plant Invasions in Protected Areas (pp. 349–374). Dordrecht: Springer Netherlands. 

Guézou, A., Trueman, M., Buddenhagen, C. E., Chamorro, S., Guerrero, A. M., Pozo, P., & Atkinson, R. (2010). An Extensive Alien Plant Inventory from the Inhabited Areas of Galapagos. PLoS ONE, 5(4), e10276.
 
CEPROEC-IAEN, & SENPLADES. (2014). Diagnóstico y análisis biofísico para evaluación y formulación de escenarios de desarrollo en el Archipiélago de Galápagos (No. Informe Técnico CEPROEC IT2014_01) (p. 402). Quito: IAEN, Senplades.