In five years, from 2012 to 2017, the number of trees in Italy grew by 4.7%, reaching about 14 million hectares of land. The phenomenon, as reported by the ISPRA report, the higher institute for environmental protection and research, does not concern cities, but the most marginal areas. Liguria (80.7%), Calabria (67%) and Tuscany (60.8%) are the regions with the highest percentage of trees.
In the same period, according to the data released a few days ago, Italy has however reduced by 4% the areas with agricultural or grazing vegetation, turning them into urban centers or wooded areas. The loss of the agricultural area, which once divided the cities clearly from the woods, was often accompanied by the disappearance of the heterogeneity of the landscape, the entrance of alien species and the reduction of the biodiversity of many inland areas and even more of security food.
The Ispra report is titled "Territory. Processes and transformations in Italy ": a work that, analyzing the main transformations of Italian soil, aims to represent a national reference for conducting analyzes on the state of the territory and the landscape.
The dynamics of the transformations of the last decades, however, remain dominated by the growth of artificial areas to cope with new transport infrastructures, new buildings or other non-natural roofing, which, with a growth of over 180% compared to the 1950s, represents the evolution of greater entity. The state of abandonment of agricultural areas favors over the years the re-colonization by the wood that today affects 40% of the territory, especially in mountain areas, where the trees reach a total of 65% of the territory.
Compared to the past, when the re-colonization affected the pastures in a particular way, today we observe the expansion of the forest by shrubs, which in fact represent an intermediate step towards forest ecosystems. This expansion does not always lead to an increase in biodiversity, especially when there are invasive alien species such as Robinia pseudoacia and Ailanthus altissima, or the reduction of open spaces, clearings, and other habitats that play a fundamental role for conservation. of certain species.
Territory coverage of the territory at regional level: Liguria (80.7%), Calabria (67%) and Tuscany (60.8%), are the Regions with the highest coefficient of tree cover, considering also orchards, olive groves, arboriculture from wood and trees in urban environment. On the opposite side are Veneto and Lombardy (29.5% and 32.9%). The growth of recent years has mainly occurred at the expense of areas with herbaceous vegetation (agricultural, natural or semi-natural) in the mountains (+ 2%), but even more so in the hills (+ 2.5%), where the abandonment processes are still in progress.
Municipal coverage: among the cities, Reggio Calabria, with 54.5%, holds the highest percentage of land covered by trees, followed by Genoa (54%) and Messina (49.9%). The capital stands at 21.7%, while Milan and Palermo respectively at 10.7% and 33.4%.