Natalia Sanhueza1, Milen Duarte2, Fadia Tala3, Julio Vasquez3, Alejandra V. González1
1Departamento de Ciencias Ecológicas, Facultad de Ciencias, Universidad de Chile, 2Instituto de Ecología y Biodiversidad, Facultad de Ciencias, Universidad Austral de Chile. Campus Isla Teja. Valdivia, 3Departamento de Biología Marina, Centro de Investigación y Desarrollo Tecnológico en Algas (CIDTA), Instituto Milenio en Socioecología Costera (SECOS), Facultad de Ciencias del Mar, Universidad Católica del Norte
The kelps Lessonia spicata and L. berteroana are ecosystem engineers that dominated the Chilean intertidal zone. They support important artisanal fisheries and provide many other ecosystem services and raw materials. As such it is crucial that we assess the impacts of climate change on these species. We use ecological niche modelling to predict shifts in species distributions under different climate change scenarios, assessing refugia, loss, and expansion areas using both, currents, and future distribution, under four scenarios (RCP 26, 45, 60 y 85). The models predicted distributions that were consistent with the current empirical and genetic distributions. The results showed largely spatially isolated distributions between the 2 species but included overlapping distributions in central Chile (30°-33°S). The modelling predicted that the future range for both species would be dramatically affected: L. berteroana, distributed from 15°-30ºS will shift its distribution with 66.62% reduction, 33.38% refuge, and an expansion of 225 km2. In 2050, only the central Chile area could act as climatic refuges (24º-31ºS) with dramatic reduction of northern areas (from Ica-Perú to Taltal-Chile). For L. spicata, which are distributed south of 29ºS, the model predicts a 54.79% reduction, with a refuge area of 45.21%, and 2,765 km2 of the expansion area. The central-south zone of Chile is predicted to be the best climatic refuge for L. spicata (35º-41ºS). These results are an important baseline for managing and conserving species under intense harvesting, and future planning for repopulation and restoration, to reduce the vulnerability to environmental fluctuations.
Funding: FONDEF ID20I10167, Packard 2021-73304