Abstract Detail

Conservation Biology

Reatini, Bryan [1], Valdebenito, Hugo [2], Torres, Maria de Lourdes [2], Vision, Todd [4].

Extinction by demographic swamping? A case study from the Galápagos islands.

When prezygotic barriers are weak and postzygotic barriers are strong, frequent interspecific pollen exchange can result in the demographic collapse of plant populations due to wasted reproductive effort. Such demographic swamping, as it is called, may pose a threat of extinction when it occurs between numerically skewed native and invasive lineages. Oceanic islands around the globe have been subjected to an alarming number of plant invasions within recent decades, providing substantial potential for reproductive interference – and potentially demographic swamping – between formerly isolated endemic and invasive congeners. In the Galápagos islands, for example, roughly a third of all native plant genera now contain at least one introduced species. One of the most problematic invasive lineages in the archipelago is common guava (Psidium guajava), which co-occurs with a closely related endemic species (P. galapageium) on all four human inhabited islands. Here I investigate the strength of pre- and postzygotic reproductive barriers between these species, and present evidence that reproductive interference due to frequent interspecific pollen exchange with invasive guava may be leading to demographic swamping and the local extinction of P. galapageium.

1 - University of North Carolina at Chapel Hill, Biology, 120 South Road, Chapel Hill, North Carolina, 27599-3280, USA
2 - Universidad San Francisco de Quito, Biology Department, Diego de Robles s/n y Pampite, Cumbayá, Quito, Ecuador
3 - Universidad San Francisco de Quito, Biology Department, Diego de Robles s/n y Pampite, Cumbayá, Quito, Ecuador
4 - Department Of Biology, Campus Box 3280, Chapel Hill, NC, 27599, United States

Keywords:
demographic swamping
extinction
reproductive isolation
reproductive interference
Galapagos.

Presentation Type: Poster
Session: P, Conservation Biology Posters
Location: Arizona Ballroom/Starr Pass
Date: Monday, July 29th, 2019
Time: 5:30 PM This poster will be presented at 6:15 pm. The Poster Session runs from 5:30 pm to 7:00 pm. Posters with odd poster numbers are presented at 5:30 pm, and posters with even poster numbers are presented at 6:15 pm.
Number: PCB004
Abstract ID:327
Candidate for Awards:None