Acknowledgements
We would like to express our thanks to the many people who collaborated in fieldwork, sample processing and data analysis over time. Research in this paper is based on the PASTUS database, which was compiled from different funding sources over time, the most relevant being: the EU Interreg III- A Programme (I3A- 4- 147- E) and the POCTEFA Programme/Interreg IV- A (FLUXPYR, EFA 34/08); the Spanish Science Foundation FECYT- MICINN (CARBOPAS: REN2002- 04300- C02- 01; CARBOAGROPAS: CGL2006- 13555- C03- 03 and CAPAS: CGL2010- 22378- C03- 01); the Foundation Catalunya- La Pedrera and the Spanish Institute of Agronomical Research INIA (CARBOCLUS: SUM2006- 00029- C02- 0). This work was funded by the Spanish Science Foundation FECYT- MINECO (BIOGEI: GL2013- 49142- C2- 1- R) and the University of Lleida (PhD Fellowship to AR).