An internet application for archiving spring phenological observations collected by a network of observers

The number of studies concerning the analyses of biological and climatic data is increasing year after year due also to the attention focused on global climate change impacts on species distribution and phenology. As regard the project "Gilia - Spring Signals", issued by theInstitute of Biometeorology of Florence, an Internet application system was developed and used to record phenological data which had been collected by a network of observers. This paper describes the architecture of the system and the criteria used for the network creation and for the data classification. Four years of phenological data are presented and discussed, particularly data related to first arrival sighting of Barn swallow (Hirundo rustica L.)