Changes in the hydrologic aspects of climate are of optimum importance. However, the details of past changes in the hydrologic cycle are difficult to reconstruct. In this report we show the firs results of the analyses of paleohydrological proxies (n-alkanes) that allow the reconstruction of multiple terms of the hydrologic budget in the GPNP. We analyzed a core from Lake Trebecchi (GPNP), and after the definition of the age-dating chronology, we measured the concentrations of n-alkanes and their major indexes (ACL, Paq, C27/C31) usually selected to infer information about hydrological evolution of the ecosystems.