Analysis of two vegetation maintenance operations in a historical park in Florence

Lawn mowing and hedge pruning are two important operations in urban green areas maintenance. The aim of the current work is monitoring and characterize these operations in an historical park in term of required time, energy and quality. Lawn mowing has been characterized in two cuts and two different machines (with a manual 2-stroke engine brush cutter for finishing). Mowing conditions and working area affect the time required for the work. It ranged between the minimum of 56.3 m2/min and the maximum of 81.75 m2/min. Consistently, energy consumptions ranged between the minimum of 0.012 MJ/m2 and the maximum of 0.041 MJ/m2. On the other hand, the brush cutter worked at the constant value of about 8.0 m2/min. The hedge pruning has been characterized on plants pruned 18 months and 12 months ago. Two different hedge trimmers have been tested: an electric trimmer and a 2-stroke engine trimmer. First of all, the following parameters have been measured: working times, removed biomass, energy consumption. Then, a methodology for the evaluation of the working quality of trimmers, based on visual assessment, has been developed. The time required for the pruning of 1 m of hedge was about 30 s for both machines. On the other hand, energy consumptions were strongly different. The electric trimmer required 2.73 KJ/m while the 2-stroke one 111.03 KJ/m. Cut quality was not affected by the used hedge trimmer. On the other hand, the 18 months hedge was less damaged by the cutting than the 12 months one.