Pro.Ce.Di

The work was divided into two parts:

• the first, silvicultural, aims to describe and characterize the phenomenon of chestnut stumps’ overturning to define the factors of greatest risk;
• the second is to evaluate the stability of wooded slopes, through a model applied at different forest management conditions.

The study area was located in Valcuvia in the municipality of Brenta where in recent years there have been incidents of landslides along wooded slopes (mostly made of aged chestnut coppice).

The results obtained regarding the overturning show that the aging of the stumps leads to a significant increase in the risk. The factors that most affect the extent of the phenomenon is side’s slope, the precise location of overturned trees, their diameters and their ages. In particular, it has been shown that, for the examined area and its slope (about 30°), the critical age for the loss of efficiency of the stumps in terms of stability is about 35 years, and that is about three times the usual turn.

From the point of view of prevention of superficial landslides, the results lead to less clear conclusions. Despite the big difference observed in the distribution of the roots between aged and managed coppice, the differences in terms of prevention capacity (expressed in terms of additional cohesion) are not appreciable. It was further highlighted that the Copse’s roots, although aged, are always able to guarantee a certain stability. The stability of the slope fails only if the water content of the soil is very high (between 60 and 90%).

From a management point of view, therefore, it is possible to conclude that the coppicing conducted within 30 years offers guarantees that, even on very steep slopes (30-35 °), rollovers are after all limited. This solution is instead substantially indifferent from the point of view of stability of slopes, which is guaranteed in any case, except for the situations of maximum saturation of the soil and the maximum slope.

The results in terms of quantity and methodology are of interest to all the technicians who work in forestry and hydrogeological, while those of a general nature, and management information are also of is of interest to policy makers.

Some of the results are also of interest to the international scientific community to add data and information in a poorly studied area.

In terms of concrete products, the project makes available a database on rollovers, the resistance of the roots and their density for the chestnut coppice subject to abandonment.

Publications

1. Bassanelli C., Bischetti G.B., Chiaradia E.A.,· Rossi L., Vergani, C. (2013) “The contribution of chestnut coppice forests on slope stability in abandoned territory: a case study”, Journal of Agricultural Engineering, June 2013, 06/2013; 44(2s). DOI:10.4081/jae.2013.s2.e13
2. Vergani, C., Bassanelli C., Rossi L., Chiaradia E.A.,· Bischetti G.B., “The effect of chestnut coppice forests abandon on slope stability: a case study”, poster presented at EGU Conference 2013; 04/2013
3. C., Bassanelli C., Rossi L., Chiaradia E.A.,· Bischetti G.B., Nicoloso A., Pividori M., ”Dissesto idrogeologico e copertura forestale: il ruolo dei cedui di castagno abbandonati”, Quaderni della Ricerca, n. 152, giugno 2013. Download the PDF or get more info by clicking here.