**5. Conclusions**

A new updated beta version of WorldClim has recently been released for the 1971–2000 time period. This "Version 2" (http://worldclim.org/version2), along with the need for carefully evaluating the quality of records used for modelling and keeping climate databases up-to-date, is an essential requirement for the adequate development of tools and informative systems. The lack of reliability on MAP values can be seen as the main shortcoming of the WorldClim database in Europe and elsewhere. However, precipitation is much more di fficult to interpolate, given its low spatial and temporal autocorrelation as well as the lack of statistical relationships with some of the main physiographic parameters, such as elevation. Further research should focus on this parameter, seeking more significant determinants of MAP, given its importance in climate change scenarios where drought stresses are predicted to be the most relevant issue.

**Author Contributions:** Conceptualization, M.W., M.B. and M.M.; methodology, M.M. and M.W.; software, M.M.; validation, M.M., I.S. and M.W.; formal analysis, M.M.; investigation, M.M., M.B. and M.W.; resources, M.B.; data

curation, M.M., I.S. and M.W.; writing—original draft preparation, M.M. and M.W.; writing—review and editing, M.M., I.S., M.B. and M.W.; visualization, M.M.; supervision, M.B. and M.W.; project administration, M.W. and M.B.; funding acquisition, M.M., M.W. and M.B.

**Funding:** Maurizio Marchi was funded by EU, in the framework of the Horizon 2020 B4EST project "*Adaptive BREEDING for productive, sustainable and resilient FORESTs under climate change*", UE Grant Agreement 773383 (http://b4est.eu/). Marjana Westergren and Iztok Sinjur were funded by the Slovenian Research Agency, Research programme Forest Biology, Ecology and Technology P4-0107.

**Acknowledgments:** We thank Gregor Vertaˇcnik from National Meteorological Service of Slovenia and Athanasios D. Sarantopoulos from the Hellenic National Meteorological Service Division of Climatology for contributing data.

**Conflicts of Interest:** The authors declare no conflict of interest.
