Selective thinning in artificial populations of Pinus nigra

LIFE13 BIO/IT/000282

The selective thinning in artificial stands of Austrian pine, which are dense and not very stable because they are never thinned out or almost from the moment of planting. The strong shading of the foliage strongly limits the biodiversity to the soil in these stands.

PROJECT REFERENT
Cantiani Paolo

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To demonstrate how the selective thinning in pine forests of artificial origin of Austrain pine, by modifying the horizontal and vertical structural diversity, and, therefore, the coverage of the canopies, determines a different regime of light, water and temperature on the ground, contributing to increase the settlement of herbaceous vegetation - arboreal, mycological and microbiological diversity, and the creation of additional habitats.

The selective thinning implemented by SelPiBioLife project is an innovative treatment for artificial reforestation areas with conifers. It is applied by choosing 100 plants per hectare (called candidates), then, for each candidate, by identifying the immediate competitors on the dominant level which will then be cut down.

A fundamental phase of the good practice is the choice of candidate plants for which, in this type of stands, the following aspects must be evaluated:

• the specific composition;
• tree vigour conditions;
• the degree of mechanical stability;
• mechanical and/or pathological damage (if any);
• the stability cores.

The thinning has the purpose of leaving free space for the crowns of the candidate plants. The effect consists of better lighting which leads to an increase in diameter growth and a greater development of the canopy. A new thinning operation must be carried out when the candidate plants have their foliage back in contact with new competing plants.

The selective thinning implmeneted by the SelPiBioLIFE project was applied in two different territorial and socio-economic contexts: Monte Amiata (SI) and Pratomagno (AR). The pine forests (average age from 44 to 59 years) have somewhat different environmental characteristics and cultural histories, but for this reason they can be considered more representative for many other thousands of hectares of reforested with Austrian pine present in the Apennines.

The reforestation of Austrian pine is widespread on over 200.000 ha in Italy (and more than 800.000 ha in Europe) and most of these are almost pure plantations, aged between 50 and 70 years and with a common problem: they have never ben thinned out from the plantation phase. The strong initial density led to the growth of plants with long and thin trunks, not very stable, and, today, even more at risk due to extreme events originating from climate change. Wherever these conditions are occurring, the intervention suggested by SelPiBioLIFE can be a solution to be pursued.

From the LIFE GoProFor database, in the final part of the sheet, it is possible to download some material relating to the project, including the technical manual entitled "Selective thinning. Increasing stability and biodiversity in artificial Austrian pine forests”, the bulletin n°2 dedicated to “The forestry interventions”, and the Layman's report.