Janine Schweier

Land availability and potential biomass production with poplar and willow short rotation coppices in Germany

Several factors influence land availability for the growth of short rotation coppices (SRC) with fast‐growing tree species, including the nationwide availability of agricultural land, economic efficiency, ecological impacts, political boundaries and environmental protection regulations. In this study, we analysed the growing potential of poplar and willow SRC for bioenergy purposes in Germany without negative ecological impacts or land use conflicts. The potential biomass production using SRC on agricultural land in Germany was assessed taking into account ecological, ethical, political and technical restrictions. Using a geographic information system (GIS), digital site maps, climate data and a digital terrain model, the SRC biomass production potential on cropland and grassland was estimated using water supply and mean temperature during the growing season as parameters. From this analysis, a yield model for SRC was developed based on the analysed growth data and site information of 62 short rotation plantations in Germany and France. To assess the technical, ethical and ecological potential of SRC, restrictions in protected areas, technical constraints and competition with food and feed production were investigated. Our results revealed that approximately 18% (2.12 Mio. ha) of cropland and 54% (2.5 Mio. ha) of grassland in Germany were highly suitable for SRC plantations, providing favourable water supplies and mean temperatures during the growing season. These identified sites produced an average yield of more than 14 tons of dry matter per hectare per year. Due to local climate and soil conditions, the federal states in northern and eastern Germany had the highest theoretical SRC potential for agricultural land. After considering all ecological, ethical, political and technical restrictions, as well as future climate predictions, 5.7% (680 000 ha) of cropland and 33% (1.5 Mio. ha) of grassland in Germany were classified as suitable for biomass production with fast‐growing tree species in SRC.

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

Abstract 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.

Economic, environmental and social impact of alternative forest management in Baden-Württemberg (Germany) and Västerbotten (Sweden)

The forest sector is important for the German Federal State of Baden-Württemberg (BW) and the Västerbotten (VB) County in Sweden. Their forestry wood chains (FWCs) are of similar magnitude and supply forest industries. This study provides a regional comparison of the performance of FWCs from roundwood harvesting, including hauling, to mill gate concerning the factors that impact sustainability and assess different sustainability indicators for alternative supply chains, in particular fully mechanized chains in comparison to motor-manual operations. The harvest volumes are similar but operational conditions differ. Analysis of sustainability indicators demonstrated that the total costs for roundwood to industry are similar. Higher harvesting costs in BW are compensated for by lower transport costs to the mills. Employment per unit is higher in BW because of the high share of labour in felling. Due to smaller machinery and shorter transport distances in BW, energy use and greenhouse gas emissions per unit are lower than in VB. Areas for improvement are the technologies for logging in BW and the logistics of timber transport in VB.

Environmental impacts of bioenergy wood production from poplar short-rotation coppice grown at a marginal agricultural site in Germany

For avoiding competition with food production, marginal land is economically and environmentally highly attractive for biomass production with short‐rotation coppices (SRCs) of fast‐growing tree species such as poplars. Herein, we evaluated the environmental impacts of technological, agronomic, and environmental aspects of bioenergy production from hybrid poplar SRC cultivation on marginal land in southern Germany. For this purpose, different management regimes were considered within a 21‐year lifetime (combining measurements and modeling approaches) by means of a holistic Life Cycle Assessment (LCA). We analyzed two coppicing rotation lengths (7 × 3 and 3 × 7 years) and seven nitrogen fertilization rates and included all processes starting from site preparation, planting and coppicing, wood chipping, and heat production up to final stump removal. The 7‐year rotation cycles clearly resulted in higher biomass yields and reduced environmental impacts such as nitrate (NO3) leaching and soil nitrous oxide (N2O) emissions. Fertilization rates were positively related to enhanced biomass accumulation, but these benefits did not counterbalance the negative impacts on the environment due to increased nitrate leaching and N2O emissions. Greenhouse gas (GHG) emissions associated with the heat production from poplar SRC on marginal land ranged between 8 and 46 kg CO2‐eq. GJ−1 (or 11–57 Mg CO2‐eq. ha−1). However, if the produced wood chips substitute oil heating, up to 123 Mg CO2‐eq. ha−1 can be saved, if produced in a 7‐year rotation without fertilization. Dissecting the entire bioenergy production chain, our study shows that environmental impacts occurred mainly during combustion and storage of wood chips, while technological aspects of establishment, harvesting, and transportation played a negligible role.

Environmental analysis of Eucalyptus timber production from short rotation forestry in Brazil

There was a fast increase in the planted area of forest plantations in Brazil in the period from 1966 until the beginning of the 1980s due to governmental fiscal incentives, when management practices were adopted from agriculture, which raised environmental concerns. Research investigation has been conducted in order to better adapt the management of these plantations. However, in the last decade, new societal demands towards the sustainability of short rotation Eucalyptus plantations have arisen. Therefore, the goal of the study was to assess the carbon and energy balance and the release of nutrifying agents to the environment of timber production from a short rotation Eucalyptus plantation in Brazil. The Life Cycle Assessment methodology was applied and the impact categories global warming potential, eutrophication potential and cumulative energy demand were used. The results showed that for each ton of timber delivered at the mill gate, 42.49 kg CO2-eq. was released to the air, 0.240 kg PO43- eq. was released to water and air and 830 MJ-eq. of fossil energy was consumed. The forest process was responsible for 86.2% and 97.5% of global warming potential and eutrophication potential, respectively, whereas the upstream process was responsible for 58.7% of cumulative energy demand. However, the CO2-eq and energy ratios were 43.15 and 23.13, respectively. Moreover, eutrophication seems to be overestimated when compared to studies that measured nutrient leaching in conditions similar to this study. Therefore, short rotation Eucalyptus plantations proved to be sustainable systems to produce timber for several uses in Brazil.