In order to face the lack of existing data on the distribution of poplar plantations (currently available until 2017), an update of the mapping to 2021 has been planned and implemented for the Lombardy Region. The action also involved an analysis of the capacity of poplar plantations to mitigate climate change, both in relation to the soils and the contribution made by Harvested Wood Products (HWP), of which post-harvest processes were also considered.
The characterization of the existing tree plantations in Lombardy was carried out by Rete Clima through bibliographic research from different sources and existing scientific databases.
FLA with the support of the company Bluebiloba (spinoff of the University of Florence) has therefore updated the mapping of poplar plantations, through the analysis of Sentinel-2 satellite images of the multispectral sensor (MSI) and of the vegetation indices (such as NDVI).
The mapping of the poplars has identified the areas of poplar plantations with a surface greater than 0.5 ha and an age greater than 4 years in the areas close to the Po Valley (Piedmont, Emilia-Romagna, Veneto and Friuli Venezia-Giulia). 2020, 2019, 2018 and 2017 have been the years investigated, while a specific focus only on Lombardy made it possible to obtain data updated to 2021.
In a second phase of work, an analysis was carried out by Università della Tuscia to investigate and quantify the potential of poplar plantations in mitigating climate change, through the capture of CO₂ from the atmosphere and the consequent storage in the soil.
To achieve the purpose of the survey, the organic carbon stock contained in the soil of poplar plantations in the region or in pedoclimatic conditions similar to those of the Lombardy region was derived from the scientific literature, using the most common research sources, and a classification was carried out. For the analysis of the carbon stock in the HWPs from the region under examination, a production accounting approach was adopted, using the available databases and the field data collected within the study region by CREA. The analysis was carried out by dividing the value chain into two fundamental parts: from the standing trees to the raw materials delivered to the processing plants and from the raw material to the raw finished product, to be used for the various applications.
The characterization of the plantations in the focus area, carried out by reviewing existing data at the regional and national level, led to the creation of a specific database of the types of plantations in Lombardy. The analysis showed, despite the scarcity of data, that the different poplar species are the most represented tree species in all the studies, covering almost 60% of the selected points. The remaining 40% covers a large number of species, with the walnut (Juglans regia) second in terms of representativeness.
The updating of the mapping of poplar plantations to 2020 in the areas of the Po Valley, has confirmed that Lombardy is the region with the largest poplar surface. The highest values ​​of poplar areas mapped are found in the southernmost areas of the region. Literature research to analyze the soil carbon mitigation potential of poplar plantations has shown that few studies are available on the specific sustainable techniques used for poplar cultivation. Although the analysis is based on a small set of data, the northern Mediterranean climate present also in Lombardy appears to be one of the most promising in terms of soil carbon accumulation. The analysis conducted on the carbon stock of HWP demonstrates how wood products can play a significant role in maintaining the carbon sequestered by poplar plantations.
These results will be useful for the continuation of the project activities, such as the insertion of these maps in the GIS-FARMs that are being created and, for some selected poplar farms, they will also be useful for the purpose of investigating the organic carbon content in the soil.
