Abstract:The aim of this research is to identify, quantify and characterize the potential available forest biomass of Pinus radiata D. Don and Eucalyptus globulus Labill. across Biscay province in northern Spain. In order to do this, we have used information from the National Inventories of Spain to quantify the amount of carbon dioxide accumulated in the forests of Biscay by means of stratum-species-based forestry statistics. The total biomass and biomass fractions have been estimated using two different methods: allometric biomass equations (ABE) and biomass expansion factors (BEF). The second objective is to develop a methodology to quantify and produce a cartography of the prospective energy production of residual biomass from the most representative forest species of Biscay. For this purpose, we have used a Geographic Information System (GIS) computer tool. We have found that the stock of carbon accumulated in the main forest species in Biscay in 2014 amounts to 8.2 Tg (ABE) and 6.63 Tg (BEF) equivalent to 30 and 24.3 Tg of CO 2 , respectively. The quantity of forestry biomass residue (FBR) obtained has been estimated as 52,214 Mg·year −1 dry matter. This amount means a prospective energy supply of 947,000 GJ·year −1 .

Abstract:The aim of this work has been the development of a methodology for the evaluation of residual forest biomass in Biscay, a province in northern Spain. The study area is located in the Oka river basin, an area of great ecological value qualified by UNESCO (United Nations Educational Scientific and Cultural Organization) in 1984 as a Biosphere Reserve. The project tries to determine the potential, available and usable as energy resource, residual forests biomass, after the treatments of forest species in the area. Soil erosion was modeled using the USLE (Universal Soil Loss Equation) and MUSLE (Modified USLE) methods by estimating rainfall erosivity factor (R), the soil erodibility factor (K), the topographic factors (L and S), cropping factor (C), and the conservation practice factor (P). By means of these models, it will be possible to determine the current soil erosion rate and its potential evolution due to different forest treatments. Soil erodibility, slope of the terrain and the loss of SOC (Soil Organic Carbon) were the restrictive indicators for the bioenergy use of forest biomass, taking into account principles of sustainability. The amount of residual forestry biomass useable for energy purposes has been estimated at 4858.23 Mg year −1 .

The substitution of energy based on fossil fuel by bioenergy could be an effective solution to reduce external energy dependency, thereby promoting sustainable development. This article details a study of the use of biomass residues produced in the forestry sector as a consequence of field operations of the two predominant forest species (Pinus radiata D. Don and Ecualyptus globulus Labill) of Biscay (Spain). The potential of forest residues is estimated to be 66,600 dry Mg year − 1 . These residues would provide 1307 TJ year − 1 . Energy parameters, ultimate and proximate analyses, and the level of emissions of the forest residues are performed in order to estimate their characteristics as fuel. The research done has shown very similar values in terms of the net calorific value of the residues of P. radiata (19.45 MJ kg − 1 ) and E. globulus (19.48 MJ kg − 1 ). The determined emission factors indicate a reduction in gas emissions: CO (23–25%), CO 2 (22–25%), SO 2 (87–91%) and dust (11–38%) and an increase of 11–37% in NO x compared to hard coal. Estimation of the emission factors of the residual biomass allows the environmental impacts, that are potentially produced by biofuel, to be estimated.

Vegetal residues, cereal straws included, constitute the most abundant biomass of our planet. Some 10 11 metric tons are produced annually in the biosphere with an energy content of 2.425 × 10 18 kJ. The methods for utilizing residues of cereal crops have always been of great interest, but this interest has recently grown in Europe and the USA, due to the potential value of straws as a source of useful energy. The high cost of fossil fuels and technological progress have made possible the appearance of energy development of biomass systems that allow us to obtain energy directly or indirectly by means of combustion, pyrolysis or gasification processes. These development systems are becoming more and more efficient, reliable and clean. Due to this fact, biomass is currently being taken into account as a total or partial alternative to fossil fuels.

Forest management has been considered a subject of interest, because they act as carbon (C) sinks to mitigate CO 2 emissions and also as producers of woody litter (WL) for bio-energy. Overall, a sustainably managed system of forests and forest products contributes to carbon mitigation in a positive, stable way. With increasing demand for sustainable production, the need to effectively utilise site-based resources increases. The utilization of WL for bio-energy can help meet the need for renewable energy production. The objective of the present study was to investigate biomass production

The Kyoto protocol officially recognised the role of forests as carbon sinks in the mitigation of global climate change factors, basically by reducing the atmospheric concentrations of CO2. The utilization of forest biomass residues for bio-energy can help meet the need for renewable energy production. The aim of this research work is the development of a methodology to quantify and yield cartography of the prospective energy production of residual biomass from the most representative forest species of Biscay, province of the Autonomous Community of the Basque Country (ACBC, Spain), using a Geographic Information System (GIS) computer tool. A model of indirect estimation has been used in order to estimate the evolution of forest masses throughout in any area of Biscay. In the study area, residues from forest represent a large biomass potential. The stock of total forest biomass (aboveground and underground) (TB) existing in the forests of the province of Biscay in the year 2016 amounted to 16.380 Tg of dry material, which implies a sequestration of 29.874 Tg of CO2. The results obtained after the statistical analyses of the data showed that the amount of mean forest biomass residue achieved with a 95% confidence interval was 73,216.7 Mg year−1. The estimation of biomass quantities that may generate forest activity will allow us to accomplish its planned exploitation, taking into account both economic and environmental aspects, with the aim of determining which the optimum location for setting up an energy production plant is.

En este artículo se muestra los resultados obtenidos en un proyecto de investigación de la Universidad del País Vasco (NUPV/08) realizado con el objetivo de estimar y cartografiar la biomasa procedente de los residuos generados en los tratamientos selvícolas de las principales especies forestales (BRF) potencialmente aprovechables como recurso energético en Bizkaia utilizando como herramienta informática un SIG (Sistema de Información Geográfica). Se trata de identificar, cuantificar y caracterizar la biomasa forestal residual que se pueda explotar de forma sostenible en Bizkaia. Se ha estimado en 52,214 toneladas la biomasa residual obtenida anualmente tras los tratamientos silvícolas del pinus radiata y eucalyptus globulus, con un potencial energético estimado en 32,011 tep /año.

No abstract