Tomislav Poršinsky

Forestry and Life Cycle Assessment

Life cycle assessment is an approach in assessing how technologies and industrial systems used in forestry affect the environment. It is a so called “cradle-to-grave” approach because it begins from the use of raw materials and ends with recycling of the materials so that all environmental effects of a product through its entire life cycle: production, use, recycling, and final disposal are gathered. ISO/EN 14040 standard defines LCA as a tool for assessing the potential impacts of a product through: 1) goal and scope definition ; 2) inventory compilation of system’s relevant inputs and outputs ; 3) evaluation of environmental impacts of system’s inputs and outputs ; 4) result interpretation. LCA can be used for comparing environmental aspects of specific products because it enables ecological comparison of products made of different raw materials, but used for the same purpose and accordingly, ecological comparison of products made of same raw materials but used for different purpose is also possible. Goal of LCA, according to ISO standards, is to improve product manufacturing (or service guarantees), product development, strategic planning, decision-making support and marketing in environmental aspects of a product through its life cycle. It is recommended that processing machines, manpower, buildings and land-use are not included in gathering inventory data for LCA because analyses can become very complex. Major reasons for introducing LCA in forestry is to obtain sound information on environmental impact of products, to improve system production and recycling, enable comparison between products and to determine which information in product’s life cycle are missing. COST action E9 defined certain problems for the use of LCA in forestry: 1) forestry uses considerable areas of land ; 2) forest products have relatively long production period and use chains which start with wood production in the forest and end with disposal or burning for energy. The steps in between can be processing, trading, secondary processing, usage (including maintenance) and recycling ; 2) life cycle of forest product can range from relatively short (e.g. paper) to very long (e.g. structural timber) and 4) relations between products, by-products and waste in forestry in not always clearly defined. Classical LCA corresponds to a static approach where temporal and spatial dimensions are not being considered. On the other hand forestry is a dynamic model where temporal dimension is fundamental because predictions are based on time dimension of growing stock (rotation period) and spatial component is crucial, as forests, according to FAO, cover 4 billion hectares or 31 % of the total land area and therefore have a huge effect on the environment. LCA is considered especially challenging for forestry because: 1) forests are a part of the environment and therefore should be considered as an impact category of their own ; 2) because forests are a substantial part of the global ecosystem they are negatively influenced not only by forestry itself (wrong decision-making in management, technology use etc.), but also by an overall man influence on the planet Earth (manifestation of air pollution, acid rain etc.). Another challenge for LCA in forestry is a “thin line” between definitions of waste and products in forestry industry. Even though general definitions of waste and products are provided within ISO 14000 family of standards, because of that general meaning they do not apply well into forestry sector and wood industry. For example sawdust is generally a waste in sawmills, but can be used as a product (for energy purpose or in construction) and then it should be reclassified as a by-product or a co-product. Data bases availability are also crucial in performing LCA and while data on operations such as “transport” (for example statistical data of transported tones or cubic meters of timber per kilometer) and “harvesting” (statistical data of cut timber in m3/ha etc.) can be found, other such as “use of pesticides”, “stand establishment”, “forest road design, construction and maintenance” (environmental loadings caused by road construction and maintenance) etc. are difficult to find. Different ways of data collection can provide considerable differences in results. Basically there are two ways of gathering data in forestry: 1) statistical data of actual cut or transported wood and 2) work studies of productivity and production efficiency. Latter can be collected according to origin: 1) measurements, 2) measurements and constants, 3) local averages and 4) general averages. Because of daily increasing ecological awareness it is also possible to acquire manufacturer’s data on different machines used in forestry. For example environmental impact throughout different life cycle phases of harvester and forwarder can be found in so called environmental declarations. These declarations provide production rate, maintenance and repair rate, rate of machine manufacturing, use and post-use phase and their share in the total environmental impact along with recyclability rate of the machine and its parts. Even though timber is a primal forest product, there are many secondary forest products such as: resin, mushrooms, berries, cork and even game animals etc. which should also be included in LCA because forests also supply these (and many other) products. LCA is a useful tool in determining an environmental impact of each product (and production processes in which product is produced), especially today when environmentally friendly technologies and renewable energy sources are globally recognized. Maybe the greatest use of LCA in forestry is in comparing different logging systems for selecting environmentally friendly versions and machines. Due to the lack of quality data sources, and conversion of a static character of life cycle assessment into a dynamic, further research of this very complex tool should be done.

Ecoefficient Timber Forwarding on Lowland Soft Soils

Environmental acceptability is one of the criteria for assessing work efficiency of sustainable forest management. Environmentally acceptable timber harvesting is determined by procedures involving different machines and tools and adequate ways of timber processing, after which the damage to habitat (soil, water) and stand (standing trees, seedlings) are as low as possible. Due to an increasing influence of the public opinion on the current forest environment, the aesthetic appearance of the ongoing forest work site should also be taken into account as well as its appearance after the works have been completed.

Forest Transportation Systems as a Key Factor in Quality Management of Forest Ecosystems

The planned values of primary road density in 2010 and 2020 on the level of various relief categories of the Republic of Croatia, besides being the guidelines for strategic planning in the Republic of Croatia, may also be used as landmarks in primary forest road planning on a strategic level in countries of similar orographic, site and stand conditions, as well as the ways of forest management. The existing primary road density should certainly be taken into consideration, and in accordance with the financial, professional and infrastructural resources of a certain country and its forestry, the deadlines for achieving the planned values of primary road density, annual intensity and construction priorities should be defined. The more developed countries and countries with a long forestry tradition, which could have invested significant financial means permanently and systematically into the primary openness of their forests during the last few decades, are expected to have a better primary road density than the Republic of Croatia (which could have started with a more systematic and more intensive forest opening only after being proclaimed independent in the 1990s), and therefore, less need for primary classical openness in the future (with the purpose of achieving planned primary road density) and probably less differences in the existing primary road density of equal or similar (comparable) forest areas, that is, they have a uniform existing primary road density of the same relief categories. A multiple use of truck forest roads, by first of all users outside forestry (e.g. tourism), contributes to greater density and better quality of truck forest roads. Operative planning, as the lowest and the most accurate level of forest road planning, requires a purposeful analysis of the terrain, connecting the possibility of applying potential and suitable timber harvesting systems with terrain factor analysis. At this planning level, timber harvesting systems have a significant influence on the shape and density of the truck forest roads, but even more on the on the shape and density (and existence, in general) of the secondary forest road network. The application of certain timber harvesting systems is, besides the terrain factors, conditioned by the degree of technological growth (technological awareness), resulting in utilization (the possibility of using) the most up-to-date means of timber extraction, and connected with that, the procedures and methods of timber processing. The selection of a timber extraction system is often under the influence of traditional forestry values of a certain country. This paper describes and applies the methodology, but it can serve as a starting point for making a case study in any European and non-European country. Individual differences (specific qualities) of a certain country should be recognized and integrated into the modified methodology in a proper way to make the research results achieve an expected high level. The data about the primary road density does not say much about the quality of spatial distribution of primary forest transportation system components. For better understanding of the real value of primary road density, it is always necessary to present primary classical openness coupled with the average timber extraction distance, or the mean distance of access to the endangered forest area, in the case of forest fire-prevention roads in the karst area. A clear insight into the real, quantitative (amount of primary forest roads) and qualitative (spatial coverage with primary forest roads) parameters of primary forest transportation system may only be achieved by a parallel consideration of primary road density and mean timber extraction distance.

DTM models to enhance planning of timber harvesting

This paper studies the applicability of DTM with the resolution of 4 × 4 m for the analysis of macro-topographic factors (terrain slope, aspect, terrain ruggedness index) and one part of micro-topographic factors (occasional and constant streams) as features important for vehicle mobility during timber skidding. The analysis of directions of timber extraction in relation to the spatial position of primary forest traffic infrastructure of the study area was conducted in order to determine from which forest areas timber will be extracted up or down the slope (moving of loaded vehicle). Determination of water bodies (streams) and the surrounding sensitive areas was carried out using GIS tool TauDEM. Unevenness of the terrain was determined based on the Terrain Ruggedness Index (TRI) which showed moderately to very rugged terrain on 60.1% of the research area where vehicle mobility could be difficult (if not impossible) i.e. the necessity of a secondary forest road network is clear. DTM analysis of study area regarding vehicle (skidder) mobility and possible planning of timber extraction indicated different availability and quality of data. Digital terrain models present a good basis for the analysis of key constraints for forestry vehicles mobility or terrain trafficability (slope and direction of timber extraction). Using DTM of higher resolution (e.g. LiDAR images), will increase the accuracy of the results and the quality of the analysis.