Technical and economic analysis of Stone pine (Pinus pinea L.) maintenance in urban areas

Abstract

The Italian Stone pine (Pinus pinea L.) is one of the most common ornamental trees in towns with Mediterranean climates. For example, in the city of Rome (Italy), Pinus is the most common genus, with more than 51,000 trees. This study investigates technical and economic features of maintenance operations of Stone pines and evaluates the productivity and costs of the observed work sites. Pruning and felling are the most frequent management operations of trees in towns and this study analyzes the features of these operations carried out in 17 work sites. The operations were carried out either with aerial platforms (20 trees) or ascending the crown by tree-climbing (8 trees). The operations were sampled with time studies (12 trees for pruning and 16 for felling). Work time was measured from the beginning of operations to the transport of the residual biomass to the collection and loading point, using centesimal stopwatches and video recording. The total residual biomass was weighed or assessed. Total observation time amounted to 84.1 h. Cost calculation for each site considered the fixed and the variable costs and the costs for the labor force. Multiple Linear Regression models which utilize regressors easily evaluable before the work, were adopted to predict the gross time of the operations and the cost per tree. This paper can contribute to optimize tree maintenance methods in urban sites and to assess the potential residual wood biomass attainable from urban forestry maintenance in the city of Rome.

Keywords

• Urban forestry
• Work analysis
• Residual biomass
• Pruning costs