Logging operations in high value hardwood mixed plantations

In Italy some agricultural areas have been planted with high value hardwood mixed plantations (mainly walnut or cherry trees) realized with a technique that provides benefits also for the presence of accessory species. The purpose of this work is to study intermediate cutting operations in mixed plantations. Two different plantations of walnut (with poplar and other fitting trees), situated in Lombardia region (Northern Italy), were investigated. In Casal Buttano plantation walnut has a planting distance of 10x14 m and it is combined with poplar (5x14 m distance). Between the two species there are two shrub rows (cob hazel and elder) and a common European alder row. In walnut rows, the main species is alternated with Eleagnus umbellata shrubs. In San Matteo delle Chiaviche plantation the planting distance between trees is 3x3.5 m. Trees species are walnut, poplar, common European alder and a shrub (Eleagnus umbellata). During intermediate cutting operation poplar needs to be felled providing no damages to standing walnuts. Because of the different distance between species in the two stands, different logging methods were needed. Time studies were carried out to analyse two different logging methods. In Casal Buttano plantation cob hazel shrubs were cut with a cutting-chipper machine that provided biomass for heating. During poplar logging an operator with chainsaw felled the trees assisted by an excavator equipped with a loading grapple; the trees were then forwarded on a tractor bunk. In San Matteo delle Chiaviche plantation a chainsaw operator felled poplar in the right direction supported by an operator with felling lever; the trees were skidded by tractors. Productivity and costs of the two methods were calculated. Both adopted logging methods did not cause any damage to the standing walnuts. First method might be suitable when rows of poplar and walnuts are separated by an accessory species row, in order to avoid damages caused by the excavator. Second method is advisable in stands where rows of poplar and walnuts are adjacent, without any accessory species in the middle.