Productivity assessment of timber harvesting techniques for supporting sustainable forest management of secondary Atlantic Forests in southern Brazil

Abstract

Abstract. The Atlantic Forest in southern Brazil has been subject to overexploitation in the past prompting the formulation of a rigorous conservation orientated policy by the government including a strict ban of timber harvesting. In the region, the forestland is mostly owned by farmers. The economic value of the forest is rather limited for those farmers, because of the prohibition of commercial timber harvesting as a source of income. Sustainable forest management systems can offer great potential as new income opportunities for land holders, and further actively support the process of ecosystem rehabilitation and protection of these ecosystems. Yet, successful implementation of such sustainable management systems requires feasible and adapted timber harvesting systems. In order to develop such harvesting systems, a regional comparative case study was conducted at a typical smallholder forestry venture with the objective to analyze and evaluate harvesting methods supporting sustainable management of the Atlantic Forest. This study assessed production rates and associated costs of a common conventional timber harvesting method (CM) and a proposed alternative method (AM). CM was performed by a selected, typical forest landowner who had only basic training in chainsaw operations, but 20 years of experience at the wood yard of his small sawmill. In contrast, AM employed a professional chainsaw operator from the Amazon forest, trained and experienced in reduced impact logging techniques using state of the art equipment, supplemented by a snatch block and a skidding cone for improved extraction. Time study based models identified tree volume, winching distance and skidding distance to landing as the most significant independent variables affecting productivity. Total net productivity ranged from 4.9 m³ PMH 0 -1 for CM to 3.1 m³ PMH 0 -1 for AM. Corresponding gross-productivity ranged from 3.0 m³ SMH -1 to 1.9 m³ SMH -1 with an overall mean utilization rate of 60.8 % and 60.9 %, respectively for CM and AM. Associated harvesting costs ranged from 12.05 € m -3 to 20.94 € m -3 with an estimated annual production of 4000 m³ and 2700 m³, respectively. Although AM showed overall lower productivity and higher costs, it enabled important improvements in terms of occupational 204

Impact Assessment of Timber Harvesting Operations for Enhancing Sustainable Management in a Secondary Atlantic Forest

“…The total size of the case study area was 42 ha. The forest cover consisted of a 35 year old second growth forest, regenerated after the abandonment of plots cultivated under swidden agricultural farming [10,12]. The Institute for the Environment of Santa Catarina (IMA) is one of the partners in this study and provided the exceptional permit for timber harvesting as part of long-term research.…”

“…The effectiveness of such policy is, however, questionable. Various researchers argued that sustainable management of secondary forests providing income opportunities would be more effective in increasing the willingness of land owners to conserve and possibly even expand the forest, favoring local development through income generation [3,5,[8][9][10][11][12].…”

“…Alarcon et al [9] highlighted the importance of research to support alternative management strategies, including potential utilization of native trees from the Atlantic Forest biome through regulated timber harvesting. Despite its relevance, only a few studies on timber harvesting systems and related impacts on forest stands have been done in the Atlantic Forest biome [10,[12][13][14]. According to Spinelli et al [15], physical damage to the residual stand is driven by several factors such as the harvesting system, site and stand characteristics, harvesting intensity, skills of operators, and extraction systems, including the layout of skid trails.…”

“…An appropriate timber harvesting method is fundamental for economically viable and environmentally sound forest management plans [10]. Our goal is, therefore, to contribute to fill the current knowledge gap on harvesting method and forest utilization in secondary forests by evaluating the damage caused during timber harvesting and log extraction.…”

Productivity of a Portable Winch System Used in Salvage Logging of Storm-Damaged Timber

“…This system is usually integrated with a skidding cone, which improves the system performance by reducing ground friction and decreasing the risk of hanging logs on obstacles, which reduces the skidding time and increases productivity (Acar 2016). Also, the use of a skidding cone significantly reduces the damage to residual trees (Britto et al 2017).…”