Productivity and Costs of White Algarrobo (Prosopis alba) Thinning in Santiago del Estero, Argentina

An Initial Approach

Abstract

Operation of forest thinning in two experimental plantations of white mesquite (Prosopis alba) was analyzed in the irrigation area of the Santiago del Estero province in Argentina, through a study of time and motion for operational productivity and costs of chainsaw felling process. Effective and operative times were measured, and volume with bark, efficiency, productivity, and direct cost of thinning were calculated. The 83 sampled trees completed a volume of 5.66 m3 . The average operating time was 2.66 min/tree, while the average effective time was 1.36 min/tree. High dimensional variability of the sampled trees, and a high degree of variability in work times were found. A strong correlation between the uptime of the machine and the variables diameter and tree volume was verified. Operational efficiency was 51 %. Productivity in the felling was 1.54 m3 /h (22.56 tree/h). The cost of thinning was 12.18 US$/m3 , equivalent to 64.56 $/m3 (US$ 1 = $ 5.30 in may 2013). The results for efficiency, productivity, and cost of thinning are preliminary; and they are the first record in the area.