Understanding Terrestrial Carbon Exports To Freshwater Ecosystems In The American Tropical Region

About 5 Billion Tons Of Carbon Are Manually Transported From Terrestrial To Aquatic Ecosystems, Which Is About Half Of The Anthropogenic Carbon Emissions. These Fluxes Are Poorly Constrained For Tropical Areas, Although Carbon Exports From Some Tropical Areas Are Among The Highest Measured. Furthermore, Our Ideas On How Land Use Changes And Climate Change Exports Of Carbon From Tropical Ecosystems Are Not Well Understood. The Objective Of This Project Is To Improve Our Understanding Of These Carbon Fluxes. In Particular, We Want To Explore The Importance Of Climatic Variations And Of Land Use On These Fluxes. Field Data Will Be Collected From Three Watersheds In Costa Rica And Ecuador With Good Research Records. These Watersheds Represent Mixed Land Uses In Different Climatic Zones. These Watersheds Will Be Intensively Monitored, And The Carbon Fluxes In The Rivers Will Be Quantified. The Dissolved Organic Carbon Production In Different Land Use Forms Will Be Measured From Soil Water, And We Will Apply State-Of-The-Art Methodologies To Determine The Role Of Different Land Uses. These Include Innovative Uses Of Light Absorption Spectra Of Organic Carbon, Natural Abundances Of Stable Isotopes, As Well As Process-Based Modelling. To Put Our Work Into A Global Context, We Will Also Undertake A Global Analysis Of Published Carbon Flux Data From Published Data Sources And The Grey Literature. The Work Will Be Done In Close Collaboration With Three Latin American Research Institutions, Which Have Already Collected Extensive Data From Our Sample Areas. We Expect That Our Research Results In A Vastly Improved Understanding Of How Changing Climate And Land Use Changes Modulate The Exports Of Carbon In Tropical Ecosystems. The Results Have Implications In The Calculation Of Carbon Balances; They Contribute To A Better Understanding Of How Land Use Changes Affect The Ecology Of Aquatic Ecosystems. Furthermore, They Are Important For Management Of Watersheds For The Production Of Drinking Water.