Southern Patagonia Freshwater Ecosystems Affected by Invasive Species: A Case of Study of CH4 and CO2 Emission from Beaver Dams in Tierra del Fuego

In 1946, beaver was introduced in the pristine wilderness of southern Patagonia, specifically at Tierra del Fuego Island. Since their introduction, it has been estimated that beaver's population has grow dramatically (ca. 95 000 to 168 000 individuals), spreading to other islands through the southern American continent. Therefore, beaver is considered an invasive species that is causing important alterations in the landscape by building dams; negatively impacting both native forest and peatlands, as well as flooding riparian areas. In this study, we have been; (i) analyzing carbon greenhouse gas emissions from five beaver dams (as study models), (ii) conducting respirometric assays at distinct temperatures using sediments from different beaver dams, and (iii) determining spatiotemporal distribution of beavers throughout the chilean portion of Tierra del Fuego. Our results indicate that beaver expansion modifies more than 20 ha y^-1 of the surface biome of Tierra del Fuego. In addition, by flooding riparian areas CH₄ emission has increased while CO₂ emission has been reduced due to the creation of anoxic environments. Our study is looking into the myriad of carbon greenhouse gas emissions provoked by the disturbance of introduction of beaver in the unique biome located between 47°S and 56°S on Earth.