Search

[EN] A dendrometric and energetic characterisation of Tamarix africana L. was carried out in this study. This is an indigenous plant species in the Mediterranean area, and it can survive in semi-arid areas with saline soils and occasional floods. Owing to these characteristics, this species is a good candidate for its use in the restoration of several environments, such as the marshes. This opens up the possibility of improving the management of biomass, which can be used for obtaining economic benefits from its energetic use. For the stems, biomass volume functions were determined from their diameter and length with r(2) of 0.96. For the whole plant, biomass volume functions were determined from the diameter of the projected area in the soil and the height of the plant with r(2) of 0.95. For energetic characterisation, the density, higher heat value, and the composition of this wood were measured in terms of following elements: carbon, nitrogen, hydrogen, sulphur and chlorine, volatiles and ash. The determination of its composition in C allows us to evaluate the CO2 fixed by the plant during its growth. The average catchment was estimated to be 2.58 kg/plant., This work was financed by Project 20170734 entitled as follows: Development of methods of quantification of riparian vegetation bio-mass for the management of channels of the Comunidad Valenciana. Direccion General de Universidades. Generalitat Valenciana (Spain).

The unique perspective that microalgae biomass presents for bioenergy production is currently being strongly considered. This type of biomass production involves large amounts of nutrients, due to nitrogen and phosphorous fertilizers, which impose production limitations. A viable alternative to fertilizers is wastewater, rich in essential nutrients (carbon, nitrogen, phosphorus, potassium). Therefore, Arthrospira platensis was cultivated in 150 mL photobioreactors with 70% (v/v) with the wastewater from a dairy industry, under a regime of light:dark cycles (12 h:12 h), with an irradiance of 140 &mu, mol m&minus, 2 s&minus, 1 photon. The discontinuous cultures were inoculated with an average concentration of chlorophyll-a of 13.19 &plusmn, 0.19 mg L&minus, 1. High biomass productivity was achieved in the cultures with wastewater from the dairy industry (1.1 &plusmn, 0.02 g L&minus, 1 d&minus, 1). This biomass was subjected to thermal and physical treatments, to be used in co-digestion with cattle manure. Co-digestion was carried out in a mesophilic regime (35 &deg, C) with a C: N ratio of 19:1, reaching a high methane yield of 482.54 &plusmn, 8.27 mL of CH4 g&minus, 1 volatile solids (VS), compared with control (cattle manure). The results demonstrate the effectiveness of the use of cyanobacterial biomass grown in wastewater to obtain bioenergy.

[EN] Vasconcellea stipulata Badillo is a fruit tree native of the temperate areas of the Andes valleys, found between 2000 and 2600 m above sea level. The good organoleptic qualities and few seeds of its fruit, compared with those of other Caricas, give it a high potential in markets. The development of this crop would allow the economic development of small-scale farmers and contribute to the preservation of genetic resources native to the Andean region. However, there are few studies concerning its appropriate cultivation. The aim of this study was to analyze the effect of different pruning techniques under greenhouse conditions. Trees were pruned to one, two, or three axes, or not pruned (control). The experiment was performed in a tunnel greenhouse with polyethylene cover, located 2950 m above sea level in Querochaca (Ecuador),with an annual rainfall of 465mmand an average annual temperature of 12.9 8C. The duration of each stage of development was recorded. The number of flower clusters, number of flowers, production, incidence of diseases, and weight and size of fruit were recorded. Cuttings took over 90 days for getting before being transplanted into the greenhouse. Flowering began 283 days (40 weeks) after transplantation; fruit set began at 30 days after flowering (44 weeks after transplant); and the fruit started to mature 170 days after fruit set (69 weeks after transplant). The plants pruned to three axes had the greatest number of flowers and fruits and the greatest production, with an average 54 fruits per tree. Pruning had no effect on fruit dimensions., The participation of Borja Velazquez Marti in this work was possible by the funding from the Ecuadorian Government through PROMETEO program, leaded by the Secretaria Nacional de Educacion Superior, Ciencia y Tecnologia (SENESCYT).

The development of dendrometric methodologies could allow accurate estimation of variables associated with the crown, such as primary production (fruit and timber) and tree vigor. The aim of this work was to develop a suitable method to estimate woody biomass in plum trees (Prunus domestica L.) in Imbabura, Ecuador by using an adapted dendrometry. Form factors and regression models were defined for branch volume calculation. From this, the distribution of woody biomass in the crown tree was characterized in every stratum. Occupation Factor and regression models were obtained in order to calculate the biomass in the crown tree, which can be used to estimate the CO2 captured in its structure during its development. Regression models for calculation of whole volume of the tree and pruned biomass were directly obtained from crown diameter and crown height with Rajustated 2 of 0.74 and 0.81. The average moisture content of green material was 51%, and the average density of dry material was 0.66 ± 0.07 g cm−3. Proximate analysis of plum wood showed at 79.8 ± 9.2% volatiles and 2.1 ± 0.3% ash. Elemental analysis of the wood pointed to 46.5 ± 1.2% C, 6.1 ± 0.5% H, 46.3 ± 1.2% O, 0.6 ± 0.3% N, 0.06 ± 0.02% S and 0.02 ± 0.01% Cl. Cl, S and N contents are lower than the limits established by the standard EN 14691-part 4.With 46% of C, considering the relation 3.67 (44/12) between CO2 and C content, the CO2 sequestrated in the materials is 1.11 Mg m−3 wood material. Such method represents a tool to manage orchard resources and for assessing other parameters, such as raw materials for cultivation, fruit production, CO2 sink and waste materials (residual wood) used for energy or industry., The authors appreciate the financial support provided by the ECUMASA, Red ecuatoriana para la investigacion del aprovechamiento energetico de la biomasa.

Agricultural residues have gained increasing interest as a source of renewable energy. The development of methods and techniques that allow to inventory residual biomass needs to be explored further. In this study, the residual biomass of olive trees was estimated based on parameters derived from using a Terrestrial Laser Scanning System (TLS). To this end, 32 olive trees in 2 orchards in the municipality of Viver, Central Eastern Spain, were selected and measured using a TLS system. The residual biomass of these trees was pruned and weighed. Several algorithms were applied to the TLS data to compute the main parameters of the trees: total height, crown height, crown diameter and crown volume. Regarding the last parameter, 4 methods were tested: the global convex hull volume, the convex hull by slice volume, the section volume, and the volume measured by voxels. In addition, several statistics were computed from the crown points for each tree. Regression models were calculated to predict residual biomass using 3 sets of potential explicative variables: firstly, the height statistics retrieved from 3D cloud data for each crown tree, secondly, the parameters of the trees derived from TLS data and finally, the combination of both sets of variables. Strong relationships between residual biomass and TLS parameters (crown volume parameters) were found (R2 = 0.86, RMSE = 2.78 kg). The pruning biomass prediction fraction was improved by 6%, in terms of R2, when the variance of the crown-point elevations was selected (R2 = 0.92, RMSE = 2.01 kg). The study offers some important insights into the quantification of residual biomass, which is essential information for the production of biofuel.

[EN] The use of biomass raw material from agricultural areas is a challenge for Ecuatorian government. However there is lack information about surveying systems and processing in its height and weather conditions. The objective of this work was to develop methods to quantify straw residues, easily applicable in corn areas of Guaranda (Ecuador), and model the drying process at different air conditions. Two dendrometric equations were obtained for predicting dry available biomass by stem and cultivated area respectively, from corn mean height and radius of the stem. High coefficients of determination were obtained (0.94 and 0.97 respectively). Straw chips with initial moisture content ranging from 70 to 80% with an average moisture content of 76.7% wet basis were dried until they reached constant moisture content. Traditional models used to describe the drying process of agricultural products were employed to fit the observed data of the drying process of straw corn chips. Among the tested models, the Midili, Page, and sigmoid model were those that best fit the observed data representing the drying process. The effective diffusion (Def) was determined by means of an analytical solution of Fick's second law. Effective moisture diffusivity values obtained at natural outdoor drying conditions were 2.443E-11 and 2.035E-10 m2/s, for the first and second falling periods, respectively., The participation of Dr. Sergio Perez and Dr. Zulay Nino-Ruiz in this work was possible by funding from the Ecuadorian Government by means of PROMETEO program, leaded by the Secretaria Nacional de Educacion Superior, Ciencia y Tecnologia (SENESCYT).

[EN] For the economically depressed communities such as of those in the Canton Guaranda, Ecuador, to generate their own energy, from organic waste is very important because they are sometimes insulated and its gas and electricity supply is very deficient. The aim of this research, was to determine the feasibility of anaerobic co-digestion of wasted cabbage from the town's market in Guaranda, Ecuador, and livestock manure. Two variables were studied: temperature of the process and the percentage of cabbage and livestock manure. Biogas quantity and kinetic parameters were evaluated. Kinetic model were analyzed by minimizing the mean percentage of error between the observed values (measured experimentally) and predicted, using the Runge-Kutta of order 4 for solving the system of differential equations obtained from mass balance. The results showed that a 50-50% ratio cabbage-manure at 30 degrees C temperature gave the highest production of biogas achieved is (389.47cm(3)N/g initial SV) with a composition of 61% methane. The kinetic parameters found were mu(max)=0.1053day(-1); Ks=0.1153mg/l; Y=0.00246g VSS /g COD and K-dec=0.001005day(-1)., This research work has been carried out inside the cooperation framework funded by the ADSIDEO program of the Centro de Cooperacion al Desarrollo (CCD) of Universidad Politecnica de Valencia (Spain), in collaboration with the Centro de Estudios de la Biomasa (CEB), Universidad Estatal de Bolivar, Guaranda, Ecuador. The participation of Dr. Sergio Perez in this work was possible thanks to funding from the Ecuadorian Government by means of the PROMETEO program, led by the Secretaria Nacional de Educacion Superior, Ciencia y Tecnologia (SENESCYT).

[EN] The objective of this work was to perform a complete evaluation of using biomass from pruning residues of ficus trees (Ficus benjamina), widely grown as ornamental plants in cities in Ecuador. Due to their great capacity for propagation and fast growth, these trees need frequent pruning and so generate a large amount of ligneous residues. A dendrometric analysis of the plant was performed to calculate the quantity of residues generated from easily measurable variables, such as crown diameter and plant height. The models obtained gave a coefficient of determination of R2 = 0.75. Pruning residues included mixtures of wood and leaves. The percentages of leaf and woody biomass were measured and a calorific analysis, elemental analysis, proximal analysis and structural analysis of the different mix proportions were carried out. Nitrogen content was acceptable for use as biofuel. Ash content in the wood is 5%, but the inclusion of leaves in the sample increases the ash content up to 11% when the leaf percentage is greater than 50%. About 10 kg of material, on average, was obtained from each tree. The mean calorific value of these residues was 19 MJ kg¿1 and was influenced by the volatile content and lignin., This work has been funded by Universidad Catolica Santiago de Guayaquil through a research program coordinated by the Sistema de Investigacion y Desarrollo (SINDE).

[EN] This study compares the estimations of biophysical parameters of Platanus hispanica urban trees, namely total height, crown height, crown volume, and the amount of residual biomass from pruning, obtained by terrestrial laser scanner (TLS), airborne laser scanner (ALS)of low density (0.7 points · m¿2), and measured by standard field methods. Regression models were calculated to obtain the relationships among parameters retrieved by all techniques, testing all possible combinations (manual-TLS, manual-ALS, TLS-ALS, and vice versa). The most accurate fits were found for vegetation attributes (stem and crown diameter) estimated by TLS and ALS data with R2 between 0.84 and 0.96, respectively. The least accurate models were found when crown height and pruning biomass were estimated from ALS data (R2 ¿ 0.68 and R2 ¿ 0.59, respectively). The methods reported in this research might be of interest for the management of urban forests to study residual biomass calculation, sink CO2, the influence of humidity and of shadow areas whatever the information capture system used, whether it is derived from ALS, TLS, or classical dendrometry measurements.

The amount of residual biomass from pruning operations of urban trees is a potentially abundant, and an underutilized source that could contribute significantly more to regional and national bio-economies than it does at present. Better utilization of woody biomass from urban green space, leisure and industrial areas could offer bio-based fuels for heat and power generation, reduce pressure on forests and reduce the management costs on a local and regional level. The aim of the work was to quantify woody biomass proceeding from pruning operations and verify the potential of using allometric relationships developed for urban forests. Quantitative results of the residual wood biomass obtained from annual pruning operations of Sophora japonica are presented in the paper according to the type of pruning practice applied. Wood formed 59.97% of total weight of all pruned material before the drying process, wood moisture content in wet basis was 44.88% and mean quantity of dry biomass (branches without leaves) obtained per tree was 18.07 kg. Regression models were applied to predict weight of dry biomass obtained per tree. Significant relationship was observed between quantity of biomass and diameter at breast height at R2 = 0.60. The analysis indicates that an abundant amount of residual biomass originating from pruning operations of ornamental species can be used to achieve ecological and energy targets. Moreover, the presented methodology creates a tool for better prediction of income, field work and logistics management for the future.

Several studies have addressed the biomass and volume of trees using Airborne Light Detection and Ranging (LiDAR) data. However, little research has been conducted into shrub vegetation, which covers a high percentage of Mediterranean forest. We used LiDAR data and an airborne image to estimate biomass and volume of shrub vegetation. Field data were collected in 29 square plots of 100 m2. In each plot, the percentage of the surface covered was measured in the field. Shrub vegetation inside 3 stands for each plot was clear cut to calculate the biomass and volume of the 29 plots. To find the best fit between LiDARspectral data and field measurements, stepwise regressions were performed using previously selected variables. The highest accuracy was found when variables derived from LiDAR data and the airborne image were combined (R2 values of 0.78 and 0.84 for biomass and volume, respectively). Biomass and volume were predicted using variables from height metrics of LiDAR data (median and standard deviation); density metrics (percentage of points whose height was between 0.50 m and 0.75 m, 0.75 me1 m, and higher than 1 m); and spectral data (standard deviation of green band, mean of the vegetation index NDVI). These results revealed the potential of LiDAR and spectral data to characterize shrub structure and make it possible to estimate and map the biomass and volume of this vegetation.

This research quantified the available residual biomass obtained from pruning vines stock. The additional biomass quantified could be used as a source of energy or as raw material for the wood industry and would provide additional income for fruit producers and also a more sustainable system. Several factors were analyzed: Variety, aim of the pruning, age of the plants, size of the plantation, crop yield and irrigation. Regression models were also calculated to predict the weight of dry biomass, obtained per tree and tonnes of dry biomass obtained per hectare, according to the significant factors. These equations could implement logistic planning as the Borvemar model, which defines a logistics network for supplying bio-energy systems. The results show that the shape of the structure of plantation has a strong influence on the quantity of biomass produced, and therefore on the quantity of pruning material. In the vineyards cultivated for fresh grape production, the horizontal trellis produces 3.5 kg/tree and 4.2 t/ha, the more dry matter per vine tree than the double of the high trellis, and the triple than the standard trellis. In the vineyards cultivated for wine production, the standard trellis and vase shape do not have significant differences, reaching 0.8 kg dry matter per vine tree. Nevertheless, on the other hand, the standard trellis produces 2.15 t/ha, a 25% more dry biomass per hectare than the vase shape. The presence of irrigation increases biomass in vineyards by 42%. © 2011 Elsevier Ltd.

[EN] This research quantified the available residual biomass obtained from pruning almond trees. The additional biomass quantified could be used as a source of energy or as raw material for the wood industry and would provide additional income for fruit producers and also a more sustainable system. Several factors were analyzed: Variety, aim of the pruning, age of the plants, size of the plantation, crop yield and irrigation. Regression models were also calculated to predict the weight of dry biomass obtained per tree and tonnes of dry biomass obtained per hectare according to the significant factors. These equations could implement logistic planning as the Borvemar model, which defines a logistics network for supplying bioenergy systems. Almond tree varieties were classified into three groups: a first group with high residual biomass productivity (average yield 12.6. kg dry biomass/tree), a second group with low productivity (average yield 4.5. kg dry biomass/tree) and a transition group with a intermediate biomass yield of 7. kg dry biomass/tree. This means that in Mediterranean areas the residual biomass from almond pruning reaches an average 1.34. t/ha annual. © 2010 Elsevier Ltd.

[EN] The importance of replacing fossil fuels with new energy routes such as the use of biomass leads to the improvement of sources such as agricultural and forest systems through adequate management techniques. The selection of the vegetal material and the management practices can influence the properties and quality of the obtained biofuel. The properties of the biomass obtained from pruning almond trees (Prunus dulcis (Mill)) have been analyzed in this study. Two varieties were tested, Marcona and Vayro, with three rootstocks, GF305, GF677 and GN Garnem, under different fertilization systems. The quality of the biofuel was evaluated with respect to the chemical composition and gross calorific value. We observed that the variables that mostly influenced the gross calorific value of the biomass were the variety, the rootstock and, primarily, the variety-rootstock interaction. Marcona presented better biomass properties than Vayro. Trees grafted on GF305 obtained a higher gross calorific value than the ones grafted on GF677 and GN Garnem. The percentage of nitrogen highly depended on the fertilization treatment applied, with saccharides and aminoacid fertilization accumulating a higher level of nitrogen than the humic and fluvic fertilization., This work was funded by Project 20170734. Development of methods of quantification of riparian vegetation biomass for the management of channels of the Comunitat Valenciana. Direccion General de Universidades. Generalitat Valenciana (Spain).

[EN] Pruning is a cultural operation linked to Mediterranean agricultural management and it offers through its wastes the chance to procure biofuels. Currently, these residues are disposed of by burning or shredding, not being exploited because of several technical difficulties in extraction, handling and transport as well as because of the lack of accurate data on the quantity and suitability of these residues. However, recent work has reported methods of supplying new biomass detection models and concentration locations. These make it possible to tackle reliable collection plans as a part of the decision support system in a biomass supply management information system. This paper addresses the biomass collection problem, as an application of the classical vehicle routing problem, where minimum cost routes have to be calculated for a fleet of several agricultural vehicles (chippers, trucks, tipper trailers and tractors). A hybrid approach based on genetic algorithms and local search methods is presented to solve a real case study. Results show a significant improvement in the operational efficiency obtained by applying such methods that come from the industrial engineering domain.

The amount of urban biomass waste derived from pruning operations represents a potential source of bioenergy little studied or considered in local bio-economies. This research focused on direct quantification of lignocellulosic residual biomass yielded during tree pruning, characterization of basic tree parameters and development of indirect biomass prediction models. Sample individuals of 30 Platanus hispanica Munchh. with mean diameter at breast height 23.56 cm, crown diameter 8.44 m, crown base height 3.76 m, and total height 11.57 m were examined. Wood formed 43.34% of pruned biomass before the drying process and wood moisture content in wet basis reached 40.16%. Mean quantity of dry biomass obtained per tree was 23.98 kg and standard deviation was 15.16 kg. Allometric relationships were analyzed. Significant coefficients of determination were observed for dry biomass and diameter at breast height (R-2 = 0.87), as well as for dry biomass and conical and parabolic crown volume (R-2 = 0.78). The best result (R-2 = 0.93) was obtained from a multiple regression model with several explicative variables. Indirect biomass prediction equations and characteristics of yielded residuals derived from this research can be useful for biomass planning and management purposes. These equations can be implemented for urban inventories, and the application of logistic models. The significance of this topic is beyond doubt for urban environment, especially for the possibilities of reducing carbon dioxide emissions and perspectives of biomass utilization as a biofuel. (C) 2013 Elsevier Ltd. All rights reserved.

Pruning urban forests generates significant amounts of lignocellulosic biomass every year. The energy potential of this biomass is unclear. The aim of this research was direct analysis of the gross calorific value (GO!), elemental composition and moisture content of Morus alba L., Platanus hispanica Munchh. and Sophora japonica L by means of laboratory equipment. This analysis allowed for further development of indirect GCV prediction models which are economically attractive and less time consuming to direct analysis. These models presented high coefficients of determination (R-2 0.66-0.96). It has been determined that the species with highest mean GCV is S. japonica L. (19615.68 kJ/kg-dry sample) whereas the one with the lowest is the M. alba L (18192.87 kJ/kg-dry sample). Elemental analysis showed highest carbon (48.22%), hydrogen (6.17%) and nitrogen (1.16%) content in S. japonica L in dry samples. Sulfur was constant at the level 0.05% for all analyzed species. Also percentage of bark and wood density were determined. Mean percentage of bark was highest for P. hispanica Miinchh. (13.05%) while wood density was highest for S. japonica L. (0.86 g cm(-3)). This way the research has proven that the biomass produced by pruning urban forests appears to be an interesting source of renewable energy. (C) 2013 Elsevier Ltd. All rights reserved.

Within the realm of renewable energies, biomass will play a fundamental role in the coming years, especially due to the rise in the prices of fossil fuels, the doubtful safety of nuclear energy, and the need to reduce CO2 emissions. In Almería (SE Spain), a million tonnes of plant wastes are generated per year from greenhouse crops such as Cucurbita pepo L., Cucumis sativus L., Solanum melongena L., Solanum lycopersicum L., Phaseolus vulgaris L., Capsicum annuum L., Citrillus vulgaris Schrad, and Cucumis melo L., which have an energy potential of around a million MWh year-1. The aim of the present work is to conduct structural analyses (lignin, cellulose, hemicellulose, and extractives) together with new HHV prediction models based on these parameters. For the analyses, internationally recognised methods and norms were used. Also, in the 15 univariate and multivariate prediction equations formulated, R2 and adjusted R2 proved higher in all cases (0.748 and 0.717), respectively, with the mean absolute percentage error varying between 0.119 and 0.623. Finally, only 10 equations were validated., This work has been partially financed by Research Project C400860 (University of Almeria).

Highlights? Biomass removed from pruning could be used as source of renewable energy. ? The amount of this residual biomass has been quantified for Platanus hispanica. ? Models for residual biomass estimation were developed from dendrometric parameters obtained by TLS. Large quantity of residual biomass with possible energy and industrial end can be obtained from management operations of urban forests. The profitability of exploiting this resource is conditioned by the amount of existing biomass within urban community ecosystems. Prior research pointed out that residual biomass from Platanus hispanica and other tree species can be calculated from dendrometric parameters. In this study, two approaches have been analyzed: First, applicability of TLS was tested for residual biomass calculation from crown volume. In addition, traditional models for residual biomass prediction were developed from dendrometric parameters (tree height, crown diameter, and diameter at breast height). Next, a comparison between parameters obtained with both methodologies (standard methodologies vs TLS) was carried out. The results indicate a strong relationship (R2=0.906) between crown diameters and between total tree heights (R2=0.868). The crown volumes extracted from the TLS point cloud were calculated by 4 different methods: convex hull; convex hull by slices of 5cm height in the XY plane; triangulation by XY flat sections, and voxel modeling. The highest accuracy was found when the voxel method was used for pruned biomass prediction (R2=0.731). The results revealed the potential of TLS data to determine dendrometric parameters and biomass yielded from pruning quitar of urban forests.

Terrestrial laser scanners (TLSs) are used in forestry and fruit culture applications to perform a threedimensional geometrical characterization of trees and so make it easier to develop management systems based on that information. In addition, this data can improve the accuracy of dendrometric variable estimations, such as crown volume, obtained by standard methods. The main objective of this paper is to compare classical methods for crown volume estimation with the volumes obtained from the processing of point clouds obtained using a terrestrial laser scanner (TLS) on urban Platanus hispanica trees. This will allow faster quantification of residual biomass from pruning and therefore an improved management in future. The methods applied using TLS data were also evaluated in terms of processing speed. A set of 30 specimens were selected and their main dendrometric parameters (such as diameter breast height, crown diameter, total height, and distance from the crown base to the soil) were manually measured using classical methods. From these dendrometric parameters, the apparent crown volumes were calculated using three geometric models: cone, hemisphere, and paraboloid. Simultaneously, these trees were scanned with a Leica ScanStation2. A laser point cloud was registered for each tree and processed to obtain the crown volumes. Four processing methods were analyzed: (a) convex hull (an irregular polyhedral surface formed by triangles that surround the crown) applied to the whole point cloud that forms the crown; (b) convex hull using slices of 10 cm in height from the top to the base of the crown; (c) XY triangulation in horizontal sections; and (d) voxel discretization. All the obtained volumes (derived from classical methods and TLS) were assessed and compared. The regression equations that compare the volumes obtained by dendrometry and those derived from TLS data showed coefficients of determination (R2) greater than 0.78. The highest R2 (0.89) was obtained in the comparison between the volume calculated using a paraboloid and flat sections, which was also the fastest method. These results show the potential of TLS for predicting the crown volumes of urban trees, such as P. hispanica, to help improve their management, especially the quantification of residual biomass., The authors appreciate the financial support provided by the Spanish Ministry of Science and Innovation in the framework of the Project AGL2010-15334 and by the Generalitat Valenciana in the framework of the Project GV/2012/003.

[EN] Large quantity of residual biomass with possible energy and industrial end can be obtained from management operations of urban forests. The profitability of exploiting these resources is conditioned by the amount of existing biomass within urban community ecosystems. This research was focused on direct and indirect quantification of lignocellulosic waste from urban tree pruning of Morus alba, which is widely deployed as ornamental vegetation in Mediterranean countries. The mean quantity of dried pruned biomass obtained in street and park location was 31.67 kg/tree and 77.78 kg/tree with standard deviation 16.88 kg/tree and 29.51 kg/tree, respectively. Mathematical models for predicting the available amount of pruning residues for this species were developed from easily measurable dendrometric parameters, such as diameter at breast height, crown diameter and total tree height. The best functions were obtained when several variables were combined in quadratics models. R2 was 0.96 for topping type of pruning practice and street location, and 0.88 in maintenance pruning applied in park areas. Good results were also found when correlating apparent crown volume with kilograms of yielded residues. These models can be used for urban inventories and the application of logistic models. The analysis indicates that an abundant amount of residual biomass originating from pruning operations of ornamental species can be used to achieve ecological and energy targets

The aim of this work has been to characterize the chemical composition of the eight most emblematic varietal olive oils from the West of the Mediterranean Sea. These were classified into two groups according to the International Olive Council (IOC norms): Sweet oils (Farga, Morruda and Serrana) which were compared with Arbequina as standard of the Spanish sweet oils; and bitter–spicy oils (Alfafara, Blanqueta, and Villalonga) that were compared with Picual, considered as the standard of the bitter–spicy olive oils. For the study, sampled trees were chosen in their geographically separated originating areas. They were cultivated in the traditional conditions. The variety of each sampled tree was previously identified by the International Union for the Protection of new Varieties for Plants (UPOV TG/99/4). We have attempted to find differences between these varieties based on their fatty acid and sterol components. Although our results of only the sterols in olive oils suggested that stigmasterol could allow the segregation of the varieties, our experience indicates that analysis of the main fatty acids (palmitic, oleic and linoleic), together with a PCA applied to all fatty acids and sterols, can be used to validate the varietal determinations with enough precision. In addition, α-tocopherol can be used as differentiator in bitter–spicy oils.

[EN] Following the discovery of fire, biomass became the main source of energy used by mankind. Advanced societies have largely replaced the use of biomass with the use of fossil fuels, but our dependence on these ever scarcer resources, plus the need to reduce CO2 emissions in the face of climate change, is forcing us to make use of renewable sources of energy, including biomass. The exploitation of this resource often requires that its heating value be known. This can be determined either directly (though not cheaply) or by the use of models that predict it using a number of easily and economically determined variables. The present review gathers together the most recent models for predicting the heating value of biomass, assesses their areas of application, and highlights errors that have been made in their formulation, transcription, and in the references made to them. Different models have relied upon elemental, proximal, structural, physical and chemical analyses to determine the values of necessary variables, although those relying on the results of the first two types of analysis have been the most popular. The simplest models and those with the widest range of applications are those most often referred to in the literature. The frequency with which important information has been left unconsidered in some studies, which has led to errors in the expressions presented, as well as errors of transcription and referencing, suggest that future work should be undertaken with greater diligence., This work was partly funded by Proyecto de Investigacion C400860 of the University of Almeria.

Shrub vegetation is a key element of Mediterranean forest areas and it is necessary to develop tools that allow a precise knowledge of this vegetation. This study aims to predict shrub volume and analyze the factors affecting the accuracy of these estimations in small stands using airborne discrete-return LiDAR data. The study was performed over 83 circular stands with 0.5 m radius located in Chiva (Spain) mainly occupied by Quercus coccifera. The vegetation inside each area was clear cut, and the height and the diameter of each plant was measured to compute the volume of shrub vegetation per stand. Volume values were related with maximum height values derived from LiDAR data reaching a coefficient of determination value R2=0.26. Afterwards, factors affecting the quality of volume estimations were analyzed, i.e., vegetation type, LiDAR density, and accuracy of the digital terrain model (DTM). Significant accuracy improvements (R2=0.71) were detected for stands with 0.5 m, LiDAR data density greater than 8 points/m2, vegetation Q. coccifera, and error associated to the DTM less than 0.20 m. These results show the feasibility of using LiDAR data to predict shrub volume under certain conditions, which can contribute to improved forest management and characterization., The authors appreciate the financial support provided by the Spanish Ministerio de Ciencia e Innovacion in the framework of the project CGL2010-19591.

The presence of shrub vegetation is very significant in Mediterranean ecosystems. However, the difficulty involved in shrub management and the lack of information about behavior of this vegetation means that these areas are often left out of spatial planning projects. Airborne LiDAR (Light Detection And Ranging) has been used successfully in forestry to estimate dendrometric and dasometric variables that allow to characterize forest structure. In contrast, little research has focused on shrub vegetation. The objective of this study was to estimate dry biomass of shrub vegetation in 83 stands of radius 0.5 m using variables derived from LiDAR data. Dominant species was Quercus coccifera, one of the most characteristic species of the Mediterranean forests. Density of LiDAR data in the analyzed stands varied from 2 points/m(2) to 16 points/m(2), being the average 8 points/m(2) and the standard deviation 4.5 points/m(2). Under these conditions, predictions of biomass were performed calculating the mean height, the maximum height and the percentile values 80th, 90th, and 95th derived from LiDAR in concentric areas whose radius varied from 0.50 m to 3.5 m from the center of the stand. The maximum R(2) and the minimum RMSE for dry biomass estimations were obtained when the percentile 95th of LiDAR data was calculated in an area of radius 1.5 m, being 0.48 and 1.45 kg, respectively. For this radius, it was found that for the stands (n = 39) where the DTM is calculated with high accuracy (RMSE lower than 0.20 m) and with a high density of LiDAR data (more than 8 points/m(2)) the R(2) value was 0.73. These results show the possibility of estimating shrub biomass in small areas when the density of LiDAR data is high and errors associated to the DTM are low. These results would allow us to improve the knowledge about shrub behavior avoiding the cost of field measurements and clear cutting actions. (C) 2011 Elsevier B.V. All rights reserved.

This research quantified the available residual biomass obtained from pruning olive trees. The additional biomass quantified could be used as a source of energy or as raw material for the wood industry and would provide additional income for fruit producers and also a more sustainable system. Several factors were analyzed: Variety, aim of the pruning, age of the plants, size of the plantation, crop yield and irrigation. Regression models were also calculated to predict the weight of dry biomass obtained per tree and tonnes of dry biomass obtained per hectare according to the significant factors. These equations could implement logistic planning as the Borvemar model, which defines a logistics network for supplying bio-energy systems. Olive tree varieties were classified into two groups for annual pruning: high residual biomass productivity (average yield 10.5 kg dry biomass tree −1 ) and low productivity (average yield 3.5 kg dry biomass tree −1 ). Some varieties are in transition between the two groups. There are no differences in biennial pruning, reaching an average residual biomass of 33 kg tree −1 . This means that in Mediterranean areas the residual biomass from olive pruning reaches an average 1.31 t ha −1 in annual pruning and 3.02 t ha −1 in biennial pruning.

The energy use of biomass in rural areas is starting to interest the farmers in Ecuador. Its use is recognized as environmentally friendly, but knowledge about the raw materials to be used as bioenergy remains meager. The objective of this research was to characterize five species located in the province of Guayas: avocado (Persea americana L.), carob (Prosopis spp.), mango (Mangifera indica L.), neem (Azadirachta indica L.), and bananas (Musa acuminata L.). The elemental composition and higher heating value were analyzed following harmonized standards. These species did not significantly differ in CHN composition, being about 33.012% C, 6.232% H, 0.610% N, and their higher heating value 14.322 MJ kg−1. However, significant differences were found with respect to Cl and S: banana wood had the highest Cl and S content 1.162% and 0.134%, respectively, while avocado had the lowest Cl and S content, 0.032% and 0.063%, respectively. Fifteen mathematical models were formulated to predict the higher heating values from elemental analysis. Three of these were selected to be used under better conditions based primarily on C with an R2 greater than 0.829 and mean percentage absolute error less than 3.38%.

[EN] This study evaluates the technology and work systems used in order to harvest residual biomass from pruning in the specific conditions of Mediterranean fruit orchards (narrow distances between crop-rows). Harvesting has been divided into several types of operations pruning, biomass alignment between crop tracks, biomass concentration in piles, chipping and bundling - which have been analyzed in five Mediterranean cultivations for three years. Altogether, three types of pruning have been analyzed: Manual, previous mechanical followed by manual, and fully mechanical; Two types of alignment: Manual and mechanical; Three concentration systems: Manual, tractor with a rake and a forwarder; Four chipping work organization systems: chipper driven inside orchard and manually fed by operators, mobile chipper driven inside orchard with pick-up header, mobile chipper fed by means of mechanical crane, chipper mounted on a truck fed by means of mechanical crane, which was working in a fixed position in a border of the plot after wood concentration. Also two bundling organization systems were checked: bundler machine working in a fixed position after wood concentration and working inside the plot driven among the crops. Previous concentration of the materials was the best alternative for their chipping or bundling in the studied conditions. Regression models have been calculated to predict the time of work of machinery and labor for each alternative. These equations were used to implement logistic planning as the Borvemar model, which defines a logistics network for supplying bio-energy systems., The research shown in this paper was developed by the project AGL2007-62328 funded by the Ministry of Education and Science of Spain, and FEDER funds of European Union.