La storica corona olivata di Sassari. Analisi diacronica dei rapporti citta campagna

The Sassari green belt of olive trees. Diachronic analysis of urban-rural relationships The historical peri-urban olive groves of Sassari, the fifth largest municipality in Italy, are investigated in the following three dates: 1920-1928, using the “Nuovo Catasto Terreni”, 1977 and 2013, through color orthophotos analysis. The olive groves are classified into four density classes: Residual (≤50 plants/ha), Sparse (51÷100 plants/ha), Historic (101÷200 plants/ha) and Intensive (>200 plants/ha). The “Nuovo Catasto” records 5,075 ha which reduced to 4,965 in 1977 and 4,436 in 2013. Photointerpretation notes the prevalence of Historical Olive groves (3,841 ha in 1977 versus 3,090 in 2013), followed by Intensive (545 and 580 ha), Sparse (518 and 677 ha) and Residual (60 and 88 ha). In particular, 435 ha of Historic Olive groves, 11% of those present in 1977, are classified in 2013 as Anthropized Territories, with definitive loss of 65,000 olive trees. A further 210 hectares of Historic olive groves are reclassified as Sparse, with loss of 15,700 olive trees. The diachronic analysis allows to assess the magnitude and direction of changes for each type of olive groves. Between 1920 and 2013, the periurbanization of Sassari has eliminated about 100,000 olive trees.