Forest Woody Biomass Research Articles

Modern Animal Traction to Enhance the Supply Chain of Residual Biomass

Throughout history, the use of animals for agricultural and forestry work has been closely associated with human societies, with multiple references to animal power being utilized for various tasks since the Neolithic period. However, the advent of industrialization has fundamentally transformed the reality of society, leading to a significant shift towards the mechanization of processes. Despite this, animal traction continues to play an important role as a workforce in many developing countries and developed nations, where there is a renewed interest in the use of animal traction, particularly for tasks intended to have a reduced environmental impact and a smaller carbon footprint. The present study conducted a SWOT analysis to examine the potential of animal traction as an alternative for the recovery processes of forest residual woody biomass, particularly when the use of mechanical equipment is not feasible. This can contribute to the creation of value chains for residual products, which can be harnessed for energy recovery. The utilization of modern animal traction can promote the sustainable development of projects at the local and regional level, with efficient utilization of endogenous resources and the creation of value for residual forest woody biomass. This approach can thus facilitate the optimization of supply chains, from biomass to energy.

Air quality impact of slash pile burns: Simulated geo-spatial impact assessment for Washington State

In the Western U.S., the prescribed burning of woody biomass in forests, mainly harvest slash, is the prevailing practice for in-woods fuel reduction and wildfire mitigation. Though these prescribed burns play an essential role in mitigating the wildfire risks, the resultant emission is a major air pollutants source that adversely affects air quality, negatively impacting human health. With an increased need for fire hazard reduction thinning, coupled with shrinking regional demand for lower quality biomass (pulpwood, hog-fuel, etc.), the volumes of unused biomass left on the forest floor as ‘waste’ will continue to grow. Reducing prescribed burns by utilizing this ‘waste’ biomass for alternate bio-based solutions (like bio-energy or bio-char) will enhance the economic feasibility of much-needed thinning operations and reduce uncontrolled emissions and related environmental and local health impacts.In this study, we simulate the increase in air pollutants due to additional prescribed fires in the Southwestern part of Washington State. Using the ‘BlueSky smoke modeling system,’ the study estimated the emissions associated with burning additional 726,000 dry t of residual biomass, which corresponds to a 30% increment from 2011. The burn was simulated over 29 days of the fall quarter and subsequently incorporated into the AIRPACT pollution transportation modeling system using the 2011 air quality and meteorological data as the baseline. The results showed that the ambient PM2.5 concentrations, due to the simulated pile burns, exceeded EPA's air quality standards on multiple days and in various locations across the Western part of the state, with two days reaching “very unhealthy” levels and one day reaching “hazardous” levels. By layering the census data on top of the pollution concentration data, the model estimated that, over the 29-day burn period, approximately 440,000 additional human days would be affected by higher than the EPA air-quality standards for ambient PM2.5 levels.

Modeling Forest Woody Biomass Availability for Energy Use Based on Short-Term Forecasting Scenarios

Bioenergy in Mexico offers a great potential as a transition strategy for introducing new energy supply chains. However, studies which focus on wood supply chains for bioenergy generation at a national level are scarce. Hence, this paper presents a model for predicting short-term availability of woody biomass for energetic use according to two scenarios. Scenario A exhibits business as usual conditions. In scenario B, the availability of forest woody biomass is improved by an increment in the areas of sustainably managed forest. The theoretical, technical and economic potentials of forest woody biomass availability for energetic use were assessed using (a) numerical modeling, (b) Holt-Winters exponential smoothing and (c) regression analyses Sustainability constraints and challenges such as soil degradation, terrain slope and mechanization level were considered. A regional case study was carried out, focusing on three species with the highest utilization rates (Pinus, Quercus and Abies). Setting the base at the year 2013, a forecast analysis for the year 2023 was performed. Under scenario B, for year 2023 a technical potential of 60.22 PJ was calculated, meaning an achievement of the goals set by the National Forestry Council regarding hectares under sustainable utilization. Furthermore, a net future value analysis was carried out to account the economic output during the forecasted period. Where comprehensive data was not available, the developed model was especially useful for predicting potentially available woody biomass for energy use.

Теоретико-методологічні основи оцінювання енергетичного потенціалу деревної біомаси лісів на засадах сталого лісоуправління

Опрацьовано термінологічно-поняттєвий інструментарій та теоретико-методологічний базис для розроблення методики оцінювання енергетичного потенціалу деревної біомаси лісів, що відповідає концептуальним засадам сталого розвитку.
 Розраховано показники енергоємності основних компонентів деревної біомаси. Для їх встановлення використано якісні характеристики компонентів біомаси та кількісні параметри енергоємності однієї тонни вуглецю, депонованого у фітомасі дерев.
 Встановлено, що найвищою енергоємністю характеризується деревина граба звичайного. Найнижчу енергоємність виявлено у компонентів біомаси хвойних деревних видів, які дещо поступаються перед м’яколистяними.
 У ході опрацювання методологічних основ оцінювання енергетичного потенціалу деревної біомаси лісів її диференційовано на три основні складові частини: дров’яна стовбурова деревина, лісові деревні відходи та лісопромислові деревні відходи. Для цих складників запропоновано математичні залежності для оцінювання їх загального енергетичного потенціалу.
 Для забезпечення оцінювання енергетичного потенціалу деревної біомаси на засадах сталого лісоуправління, запропоновано виокремити п’ять його типів: теоретично можливий, технічно доступний, екологічно безпечний, економічно доцільний та соціально зумовлений. Це дасть змогу гармонійно поєднувати питання екологічної безпеки та економічного розвитку регіонів, а також враховувати соціальні особливості життя місцевих громад.

Bioenergy Potential and Utilization Costs for the Supply of Forest Woody Biomass for Energetic Use at a Regional Scale in Mexico

While considering constraints in regard to sustainability, this paper reviews the development of a methodology to assess the introduction of bioenergy supply chains in Mexico based on forest woody biomass. Three research modules include analyses of forest biomass utilization residues that originated from: (1) harvesting activities, (2) non-extracted stands and (3) sawmills. A regional case study focusing on tree species of commercial importance (pine, oak and fir) in the 10 provinces with the highest timber production located in the north and central-south part of the country, is analyzed. After applying the methodology, the theoretical potential of available woody biomass for energetic use amounts to 6,357,482 m3. When applying the sustainability constraints, the technically feasible supply of forest woody biomass for energetic use sums up to 5,798,722 m3, which relate to a technical energy potential of 45.96 PJ for 2013. Moreover, a biomass energy flow chart showing energy values for each analyzed source and species is presented. Monte Carlo simulations were carried out for each cost involved in utilizing the resulting available woody biomass for energetic use. In the absence of national studies which include forest operations and bioenergy transformation to calculate the sustainable energy potential, the developed methodology adds innovation for assessing woody biomass availability.

Tourists’ perception of deadwood in mountain forests

In the traditional forest management the non-living woody biomass in forests was perceived negatively. Generally, deadwood was removed during the silvicultural treatments to protect forests against fire, pests and insects attacks. In the last decades, the perception of forest managers regarding forest deadwood is changing. However, people’s opinions about the presence of deadwood in the forests have been few investigated. In view of this gap, the aim of the paper is to understand the tourists’ perception and opinions towards the deadwood in mountain forests. The survey was carried out in two study areas: the first one in Italy and the second one in Bosnia-Herzegovina. A structured questionnaire was administered to a random sample of visitors ( n =156 in Italy; n =115 in Bosnia-Herzegovina). The tourists’ preferences were evaluated through a set of images characterized by a different amount of standing dead trees and lying deadwood. The collected data were statistically analyzed to highlight the preferred type of forests related to different forms of management of deadwood (unmanaged forests, close-to-nature forests, extensive managed forests and intensive managed forests). The results show that both components of deadwood are not perceived negatively by tourists. More than 60% of respondents prefer unmanaged forests and close-to-nature managed forests, 40% of respondents prefer intensive managed forests in which deadwood is removed during the silvicultural treatments.

Estimating daily forest carbon fluxes using a combination of ground and remotely sensed data

AbstractSeveral studies have demonstrated that Monteith's approach can efficiently predict forest gross primary production (GPP), while the modeling of net ecosystem production (NEP) is more critical, requiring the additional simulation of forest respirations. The NEP of different forest ecosystems in Italy was currently simulated by the use of a remote sensing driven parametric model (modified C‐Fix) and a biogeochemical model (BIOME‐BGC). The outputs of the two models, which simulate forests in quasi‐equilibrium conditions, are combined to estimate the carbon fluxes of actual conditions using information regarding the existing woody biomass. The estimates derived from the methodology have been tested against daily reference GPP and NEP data collected through the eddy correlation technique at five study sites in Italy. The first test concerned the theoretical validity of the simulation approach at both annual and daily time scales and was performed using optimal model drivers (i.e., collected or calibrated over the site measurements). Next, the test was repeated to assess the operational applicability of the methodology, which was driven by spatially extended data sets (i.e., data derived from existing wall‐to‐wall digital maps). A good estimation accuracy was generally obtained for GPP and NEP when using optimal model drivers. The use of spatially extended data sets worsens the accuracy to a varying degree, which is properly characterized. The model drivers with the most influence on the flux modeling strategy are, in increasing order of importance, forest type, soil features, meteorology, and forest woody biomass (growing stock volume).

Potentials for forest woody biomass production in Serbia

The paper presents the analysis of possible potentials for the production of forest biomass in Serbia taking into consideration the condition of forests, present organizational and technical capacities as well as the needs and situation on the firewood market. Starting point for the estimation of production potentials for forest biomass is the condition of forests which is analyzed based on the available planning documents on all levels. Potentials for biomass production and use refer to initial periods in the production and use of forest biomass in Serbia.

Lianas in gaps reduce carbon accumulation in a tropical forest

Treefall gaps are the “engines of regeneration” in tropical forests and are loci of high tree recruitment, growth, and carbon accumulation. Gaps, however, are also sites of intense competition between lianas and trees, whereby lianas can dramatically reduce tree carbon uptake and accumulation. Because lianas have relatively low biomass, they may displace far more biomass than they contribute, a hypothesis that has never been tested with the appropriate experiments. We tested this hypothesis with an 8‐yr liana removal experiment in central Panama. After 8 years, mean tree biomass accumulation was 180% greater in liana‐free treefall gaps compared to control gaps. Lianas themselves contributed only 24% of the tree biomass accumulation they displaced. Scaling to the forest level revealed that lianas in gaps reduced net forest woody biomass accumulation by 8.9% to nearly 18%. Consequently, lianas reduce whole‐forest carbon uptake despite their relatively low biomass. This is the first study to demonstrate experimentally that plant–plant competition can result in ecosystem‐wide losses in forest carbon, and it has critical implications for recently observed increases in liana density and biomass on tropical forest carbon dynamics.

Balancing wood market demand and common property rights: a case study of a community in the Italian Alps

Common property rights have a long tradition in the Italian Alps, dating back to the Middle Ages, when alpine village communities managed common forests. On these properties, in accordance with rules aimed at regulating the collective use of resources, shareholders have the right of common use of the land. As many mountainous areas still rely on firewood for the heating of homes, the right to gather firewood from common forests is the most important common property right. In the last few decades, renewable bio-energy production based on forest woody biomass has undergone significant development. In Italy, in communities where the right to gather wood still has economic, social, and cultural relevance, decision makers and community members have a different vision about the use of firewood. This paper focuses on this issue by presenting a case study located in the Italian Eastern Alps, characterised by a historical tradition of common property management. In order to define the optimal strategy to manage the common forests, taking into consideration the local community's needs, a semi-structured questionnaire was submitted to the administrators of the common forests and to the shareholders. Different scenarios of wood use were developed to support managers and decision makers in identifying on-going trends in firewood demand. The results show that the economic scenario for the development of the bio-energy supply chain cannot be reconciled with the historical tradition and social needs.

Estimating aboveground woody biomass of forests in Poland for FAO/ECE and UNFCCC reporting

Abstract The United Nations Framework Convention on Climate Change and the Kyoto Protocol have committed member states to reduce greenhouse gas emissions by, among others, promoting the increase of carbon sequestration by carbon sinks (including woody biomass in forests). In order to achieve these objectives, an international reporting system was designed. The stock of woody biomass depends on several environmental and managerial factors, which determine species composition and age structure of a forest as well as characteristics of individual trees. Estimating aboveground woody biomass, especially on a nation-wide level, is generally based on the application of conversion factors to known characteristics such as the volume of the growing stock. The application of default conversion factors, as proposed by international guidelines, however, is questionable, since inventory systems for and definitions of growing stock differ from country to country. In this paper, the methods used in Poland to estimate woody biomass for the FAO and the UNFCC reporting, were presented and analysed. We also analysed the influence of some stand and tree characteristics, such as tree species composition and content of bark and its density, on the stock of woody biomass. We conclude that issues not addressed in the IPCC guidelines, such as big differences in wood and bark density, especially for pine, need to be taken into consideration when making estimations. Moreover, the results of this paper show that biomass conversion and expansion factors (BCEF) proposed by IPCC are not adequate for Polish conditions.

竹とスギ炭化物の混合試料によるバイオコークスの成形特性

The utilization of unused biomass such as logging residues and broadleaf trees has come to attract attention to protect forests and satoyamas (a Japanese term for undeveloped woodlands near populated areas) in Japan. In this study, the modification of bio-coke fuels as an alternative to coal coke is investigated by using bamboo and Japanese cedar, which are the typical domestic woody biomass in forests and satoyamas. To improve the compressive strength under high temperature environment and the heating value of bio-coke, carbonized Japanese cedar is mixed with bamboo. The effect of the carbide mixture on the forming characteristics of bio-coke such as density, compressive strength, and heating value are experimentally clarified. The results obtained in the present study are as follows: (1) the density of bio-coke increases with increase in forming temperature and forming pressure, but is reduced by the addition of carbide as the thermoplastic polymer is reduced (2) the increase in carbide reduces the compressive strength under normal temperature environment and improves the compressive strength under high temperature environment. When the carbide content was 30%, the compressive strength under high temperature environment was 3.26MPa. (3) The addition of carbide is an effective way to improve the compressive strength under high temperature environment and to enhance the heating value of bio-coke.

Use of ETM+ images to extend stem volume estimates obtained from LiDAR data

Airborne LiDAR techniques can provide accurate measurements of tree height, from which estimates of stem volume and forest woody biomass can be obtained. These techniques, however, are still expensive to apply repeatedly over large areas. The current paper presents a methodology which first transforms mean stand heights obtained from LiDAR over small strips into relevant stem volume estimates. These are then extended over an entire forest by applying two estimation methods ( k-NN and locally calibrated regression) to Landsat ETM+ images. The methodology is tested over a coastal area covered by pine forest in the Regional Park of San Rossore (Central Italy). The results are evaluated by comparison with the ground stem volumes of a recent forest inventory, taking into consideration the effect of stand size. In general, the accuracies of two estimation methods are dependent on the size of the forest stands and are satisfactory only when considering stands larger than 5–10 ha. The outputs of the parametric regression procedure are slightly more stable than those of k-NN and more faithfully reproduce the spatial patterns of the ground data.

Remote sensing estimates of boreal and temperate forest woody biomass: carbon pools, sources, and sinks

The relation between satellite measurements of the normalized difference vegetation index (NDVI), cumulated over the growing season, and inventory estimates of forest woody biomass carbon is estimated statistically with data from 167 provinces and states in six countries (Canada, Finland, Norway, Russia and the USA for a single time period and Sweden for two periods). Statistical tests indicate that the regression model can be used to represent the relation between forest biomass and NDVI across spatial, temporal and ecological scales for relatively long time scales. For the 1.42 billion ha of boreal and temperate forests in the Northern Hemisphere, the woody biomass carbon pools and sinks are estimated at a relatively high spatial resolution (8×8 km). We estimate the carbon pool to be 61±20 gigatons (10 9) carbon (Gt C) during the late 1990s and the biomass sink to be 0.68±0.34 Gt C/year between the 1982 and 1999. The geographic detail of carbon sinks provided here can contribute to a potential monitoring program for greenhouse gas emission reduction commitments under the Kyoto Protocol.

Forest woody biomass classification with satellite-based radar coherence over 900 000 km 2 in Central Siberia

In the current context of global deforestation and global warming, a wide range of organisations, with local to international remits, need estimates of forest biomass to assess the state of the World’s forests and their rate of change. The task would be impossible without space-based Earth observation, which allows the rapid generation of extensive data sets describing land surface properties. It is the task of remote sensing scientists to interpret these data into a meaningful source of forest information. Here, a fast and easily automated method for classifying boreal forests in terms of growing stock volume is presented. The work was conducted as part of the SIBERIA project, which has resulted in the recent publication of a map of forest growing stock volume covering 900 000 km 2 in Central Siberia. The paper describes the use of satellite-based radar coherence to differentiate categories of forest growing stock volume, the application of this method to classify and map Central Siberian forests, and the characterisation of the forest classes to help in the interpretation. A list of acronyms and abbreviations used in the text is provided in Appendix A.

Modelling the dynamics of ERS-1/2 coherence with increasing woody biomass over boreal forests

In this study, changes in the temporal and volume contributions (| n | temporal, | n | volume ) to the observed ERS-1/2 coherence are modelled in response to an increase of forest woody biomass in Central Siberia. It is demonstrated that the distance between neighbouring trees and the vertical structure of boreal forest canopies must be accounted for to model | n | volume . Results confirm that | n | temporal is the main decorrelation factor although | n | volume contributes significantly to the overall loss of coherence observed over mature forests.

The effect of topography on radar scattering from vegetated areas

The ways in which radar scattering from vegetated areas is affected by the topography of the surface underneath the vegetation are discussed. It is shown, using a discrete scatterer model, that the dominant scattering mechanism may change drastically when the ground surface is tilted relative to the horizontal. For a horizontal ground surface, for example, the total scattering may be dominated by scattering off the tree trunks, followed by a reflection off the ground surface. For a relatively small tilt in the ground surface, the ground-trunk interaction term may be replaced by scattering from the branches alone as the dominant scattering mechanism. The effect of the topography is more pronounced for scattering by longer wavelengths, and the implications on algorithms designed to infer forest woody biomass and soil and vegetation moisture using polarimetric SAR data are discussed. The effect of the topography on the scattering behavior from forested areas is illustrated with images acquired by the NASA/JPL three-frequency polarimetric SAR over the Black Forest in Germany. >