Figure 7
Schematic diagrams illustrating the main factors controlling the N isotope values in sediment OM of Laguna Matanzas. N input from the watershed depends on human activities and land cover type. Agriculture practices and cattle farms (grassland development) contribute more N to the lake than native forest and plantations. Periods of higher productivity tend to deplete the 14N in dissolved inorganic N, leading to higher δ15N values on OM. Post-burial denitrification processes are more effective during periods of anoxic conditions associated with higher lake levels.
