The gardens of Villa A at Olpontis through pollen and phytolith analysis of soil samples

Pollen analysis of a soil sample from room 20 in Villa A at Oplontis revealed the presence of a garden with peculiar characters with respect to the other gardens of the Pompeian region, all dated to the A.D. 79. The age of the soil level analyzed in this study is still under determination but it is certainly older that the A.D. 79. At that time, the garden of room 20 was characterized by the significant presence of myrtle and lemon while the analysis of the A.D. 79 levels of room 93 in the same Villa as well as those of the other Pompeian villas, revealed the constant occurrence of olive trees and vines. This fact could indicate either the change in composition of gardens from the I century B.C. (presumed age of the analyzed sample) to the I century A.D. or the occurrence of contamination of more modern pollen grains in the soils of room 20. However, it cannot be excluded that, being olive and vine insect-pollinated, their pollen did not reach room 20, which is a rather restricted room within Villa A. The presence of probably cultivated vegetables (cabbage) indicates the vicinity of vegetable gardens. This is in agreement with the traditional way of Roman land use and management where small vegetable gardens were cultivated close or within gardens or orchards. Phytolith analysis was performed for the first time in a garden of Roman age. The most interesting result consists in the abundance of bulliform cells which could indicate either dry summer conditions or exceptional water availability related to irrigation in the garden.