Harvesting techniques for non-industrial SRF biomass plantations on farmland

<p>The goal of this study was to compare the technical and economic performance of terrain chipping and roadside chipping, applied to short rotation biomass plantations. The null hypothesis was that no significant difference are in the performance of the two work systems, when applied to short rotation coppices. Those systems especially designed for non-industrial SRF plantations, were used for conventional logging operations. The difference on the above mentioned systems consisted especially in the chipping location: chipping was performed directly to the field (containers reach the chipper in the field) or at the field’s edge (roadside chipping). Both systems were tested on two of the most common SRF poplar clones in Italy, namely: AF2 and Monviso. Plots were allocated randomly to the two treatment levels ( roadside or field chipping) than blocked for two main clone types ( AF2 and Monviso ) so that each of the 4 treatments level and clone types has a minimum repetition plot of 6 times (total of 24 replications). The Plot were identified with paint markings at the stump so each plot area could be identified at the ground. Net weight of each charge was obtained by a certified weighbridge, so each plot has its own productivity in terms of weight and time consumption. Results were encouraging: harvesting cost varied from 16.3 to 23.2 tonne-1, and was lower for terrain chipping and for the most productive clone (Monviso). Despite its higher cost, roadside chipping was preferred for its better terrain capability and for the superior storage quality of uncomminuted biomass. Both systems were suboptimal in their current configurations. They could offer a better performance, subject to minor improvements.</p

Trends and Perspectives in Coppice Harvesting

Coppice management is applied to many species, in many countries and in many ways, so that several harvesting techniques have been developed depending on specific local conditions. However, all techniques designed for handling coppice stands must be suitable for coping with small stem size and stump crowding, and often with steep and generally difficult terrain. Traditional harvesting systems are labor intensive because they usually include motor-manual felling and processing into one-meter lengths at the stump site, and manual loading of the short logs onto pack animals or tractors. Thus, in industrialized countries, these systems are no longer viable and they are being replaced with mechanized cut-to-length and whole-tree harvesting, depending on site conditions. Mechanization dramatically improves worker safety, and compensates for the reduced availability of rural labor, with their propensity to perform heavy and low-paying jobs. Much progress has already been made, with the massive introduction of modern harvesters, forwarders and tower yarders in coppice harvesting operations. The presence of multiple stems on the same stump offers a serious challenge to the introduction of mechanized felling to coppice harvesting operations, because stump crowding hinders felling head movements. However, new machines have been designed that can handle coppice stumps. Further research should address the relationship between stump damage and regeneration vigor, in order to define new standards for cut quality. Silvicultural practice may need adapting to the new harvesting technology and to the products required by the modern bio-economy

Tree instance segmentation and traits estimation for forestry environments exploiting LiDAR data collected by mobile robots

Forests play a crucial role in our ecosystems, functioning as carbon sinks, climate stabilizers, biodiversity hubs, and sources of wood. By the very nature of their scale, monitoring and maintaining forests is a challenging task. Robotics in forestry can have the potential for substantial automation toward efficient and sustainable foresting practices. In this paper, we address the problem of automatically producing a forest inventory by exploiting LiDAR data collected by a mobile platform. To construct an inventory, we first extract tree instances from point clouds. Then, we process each instance to extract forestry inventory information. Our approach provides the per-tree geometric trait of “diameter at breast height” together with the individual tree locations in a plot. We validate our results against manual measurements collected by foresters during field trials. Our experiments show strong segmentation and tree trait estimation performance, underlining the potential for automating forestry services. Results furthermore show a superior performance compared to the popular baseline methods used in this domain

Sustainability Assessment of Alternative Strip Clear Cutting Operations for Wood Chip Production in Renaturalization Management of Pine Stands

In Mediterranean regions, afforested areas were planted to ensure the permanence of land cover, and to protect against erosion and to initiate the vegetation processes. For those purposes, pine species were mainly used; however, many of these stands, without silvicultural treatments for over fifty-sixty years, were in a poor state from physical and biological perspective, and therefore, clear-cutting on strips was conducted as silvicultural operation with the aim to eliminate 50% of the pine trees and to favor the affirmation of indigenous broadleaves seedlings. At the same time, the high and increasing demand of the forest based sector for wood biomass related to energy production, needs to be supplied. In a modern and multifunctional forestry, in which society is asking for sustainable forestry and naturalistic forest management, forestry operations should ideally be carried out in a sustainable manner, thus support the concept of sustainable forest management. All these aspects are also related to the innovation in forestry sector for an effective energetic sustainability. Three different forest wood chains were applied in pine plantations, all differing in the extraction system (animal, forestry-fitted farm tractor with winch, and double drum cable yarder). The method of the sustainability impact assessment was used in order to assess potential impacts of these alternative management options, and a set of 12 indicators covering economic, environmental, and social dimensions was analyzed. Further, to support decision makers in taking informed decisions, multi-criteria decision analysis was conducted. Decision makers gave weight towards the indicators natural tree regeneration and soil biological quality to support the achievement of the forest management goal. Results showed that first ranked alternative was case 2, in which extraction was conducted by a tractor with a winch. The main reason for that lies in the fact that this alternative had best performance for 80% of the analyzed criteria

New Holland Forage Harvester's Productivity in Short Rotatation Coppice: Evaluation of Field Studies from a German Perspective

Modified forage harvesters are a common technology used to harvest short rotation coppice (SRC). This paper describes results of time studies from harvest trials with the New Holland forage harvester equipped with the cutting head 130 FB. Seven fields comprising a total of 13.6 ha SRC were harvested, and data from 22h 41 min were collected. In the studies, 0.77 hectares were harvested per productive machine hour (pmh‐1). The share of productive times was 74% of the total work time. The average harvesting productivity was 20.5 odt pmh‐1. Under good conditions, productivities up to 30 odt pmh‐1 were reached. The harvesting costs were 19.70€ odt‐1 on average, excluding the costs for the transport of the chips and of the harvesting machine to the fields. Keywords: Short rotation coppice (SRC), harvest operation, productivity, forage harvester, New Holland, cutting head 130 FB. Received 11 July 2011, Revised 26 April 2012, Accepted 30 April 2012

Comparison of A Cable-Based and a Ground-Based System in Flat and Soil-Sensitive Area: A Case Study from Southern Baden in Germany

The results of this study showed that the application of cable-based systems in flat terrain must not necessarily be more cost intensive than its application in other terrains. In recent years, criteria other than purely economic ones have been taken into account in forest management decisions, with the aim of avoiding ecosystem damage and promoting better ecosystem services. Since precipitation in winter is becoming more intensive and weeks with frozen soils are becoming rare, one option might be the use of cable-based instead of ground-based extraction systems. Both vary in terms of economy and flexibility. Thus, it is important to make reliable estimates of potential costs and benefits before an operation is conducted. The aim of this study was to analyze a cable-based and a ground-based extraction system that could be applied to a forest stand in a flat and soil-sensitive area. The study, based on a cable-based operation, was conducted in a mixed forest stand that was vulnerable to traffic. Furthermore, we modeled an alternative operation focusing on a ground-based system, addressing the soil vulnerability by considering manual felling, processing, and use of a combi-forwarder for extraction. In the cable-based system, yarding productivity was high (20.3 m3ub/PMH15) due to several reasons, such as a high share of larger dimension timber, the fact that heavy timber was partially de-limbed and processed motor-manually in the stand, the fact that a mini forestry crawler was used for pre-winching the material and finally due to the experience of the operators. Resulting costs for harvesting and extraction were on average &euro;27.8/m3ub. In the ground-based system, costs were on a comparable level (&euro;28.30/m3ub). In our case, the application of a cable yarder in flat terrain was a good alternative and should be considered in future forest management to support environmentally friendly operations and allow independent planning of the operation

Productivity, Costs, and Selected Environmental Impacts of Remote-Controlled Mini Forestry Crawlers

An effective way to reduce off-road traffic in forests is to implement greater distances between skid trails. However, this implies that trees beyond the boom reach of the harvester need to be felled motor manually before being winched to the skid trail, for example using a remote-controlled mini forestry crawler (MFC). They are only a few local studies which have evaluated the performance of such MFCs. The use of MFCs for wood extraction operations in mixed soft- and hardwood stands is presented in this study conducted in Southwestern Germany. The aim of this study was to analyze the productivity, costs, and selected environmental impacts of mini forestry crawlers during winching operations through a time study. Using statistical regression, time consumption was analyzed in order to determine significant explanatory variables. Environmental impacts were evaluated using the life cycle assessment (LCA) methodology with Umberto software. The mean net cycle time was 4.82 min and the net productivity rate was 7.77 m(3) by productive machine hour (PMH0). Explanatory variables which significantly affected the net cycle time were the winched volume, the number of trees per load, and winching distance. Environmental analysis showed that inputs of fossil energy were mostly due to diesel and lubricant consumption. Raw materials for machine manufacture and maintenance showed the highest impact in human toxicity potential category. The MFCs showed good environmental performances, but the harvesting system should become more productive in order to be more cost effective

How Climate Change Will Affect Forest Composition and Forest Operations in Baden-Württemberg—A GIS-Based Case Study Approach

In order to accommodate foreseen climate change in European forests, the following are recommended: (i) to increase the number of tree species and the structural diversity; (ii) to replace unsuitable species by native broadleaved tree species, and (iii) to apply close-to-nature silviculture. The state forest department of Baden-Württemberg (BW) currently follows the concept of Forest Development Types (FDTs). However, future climatic conditions will have an impact on these types of forest as well as timber harvesting operations. This Geographic Information System (GIS)-based analysis identified appropriate locations for main FDTs and timber harvesting and extraction methods through the use of species suitability maps, topography, and soil sensitivity data. Based on our findings, the most common FDT in the state forest of BW is expected to be coniferous-beech mixed forests with 29.0% of the total forest area, followed by beech-coniferous (20.5%) and beech-broadleaved (15.4%) mixed forests. Where access for fully mechanized systems is not possible, the main harvesting and extraction methods would be motor manual felling and cable yarding (29.1%). High proportions of large dimensioned trees will require timber extraction using forestry tractors, and these will need to be operated from tractor roads on sensitive soils (23.0%), and from skid trails on insensitive soils (18.4%)