The Northern Andes hold the highest plant biodiversity on earth, and a suite of ecosystems that range from lowland moist tropical forests to Alpine paramo, including dry associations. This great diversity results, in part, from the spatial and temporal variability of precipitation that relates to its origin as evaporation. The study of moisture sources through stable isotopes allow to track the connection between different processes like evaporation and precipitation from terrestrial sources as well as the influence of large scale hydroclimatic phenomena, for example the seasonal migration of the InterTropical Convergence Zone (ITCZ). This study characterizes the isotopic composition of Northern Andes and the Caribbean in South America moisture sources, according to the available observations of stable isotopes in precipitation (δ18O, δ2H) from the Global Network of Isotopes in Precipitation (2004-2007) and contrast them with results from the Lagrangian FLEXPART model that uses input from ERA-Interim reanalysis.
Results/Conclusions
Our results indicate that most precipitation in the region comes from terrestrial sources including recycling (>30% monthly all year), the northern Amazon (up to 17% monthly for June, July and August) and Orinoquia (up to 28% monthly for April) basins; followed by oceanic sources such as the Tropical South Pacific (up to 30% monthly in October, November, December) and Tropical North Atlantic (up to 30% monthly for January). Our results highlight the connections between ecosystems, such that changes in the structure and dynamics of one (i.e deforestation in the Amazon), can result in remote alterations in other regions such as the Northern Andes, with important impacts on biodiversity, ecosystem function and ecosystem services.