Nicole Acosta-Vásconez
Invasive plants are one of the greatest threats to the biodiversity of the Galapagos Islands (Riegl et al., 2023; Tye, 2006), and are recognised as one of the greatest threats to biodiversity worldwide (Roy et al., 2023). Despite the recognised importance of rural ecosystems for several endemic plants and animals, there is a lack of research on the rate of spread of invasive plants. This knowledge gap limits the capacity of conservation projects and neglects the urgency of addressing the problem.
In the past century, rapid agricultural expansion in the Galapagos has resulted in the invasion of native ecosystems in the rural highland zone by non-indigenous species. In 1961, around 94% of Santa Cruz Island's unprotected area was covered by native vegetation, but by 2018, this had reduced to only 7% (Alomía Herrera et al., 2022). Presently, the islands are home to over 870 non-native plant species, with approximately 10% classified as invasive, posing a significant threat due to their rapid spread and ability to dominate the ecosystem (Guézou et al., 2010).
In rural areas, invasive plants thrive primarily on abandoned agricultural land where native vegetation has already been cleared. These invasive plants have also spread into the surrounding reserve, but the exact rate of spread in both the unprotected and the surrounding reserve is still unknown.
The reimagining patches of native vegetation in the rural areas are relevant for the survival of many endemic species. Some examples are the plants Scalesia pedunculata and Miconia robinsoniana, and endemic birds such as the Galapagos rail, Laterallus spilonota, and the Galápagos petrel, Pterodroma phaeopygia.
We will use unmanned aerial vehicles (UAVs), machine learning and participatory modelling to map the vegetation cover of the rural zone and the surrounding protected area. The resulting map will be compared with previous information to estimate the rate of spread of invasive plants and changes in native vegetation patches. (all article references available on request).