36 research outputs found
Analysis of Productivity and Cost of Forwarding Bundles of Eucalyptus Logging Residues on Steep Terrain
The objective of this study was to evaluate the productivity and costs of two Spanish forwarders, models Dingo AD-8468 and AD-2452, in the hauling of bundles of residues after Eucalyptus globulus clear cuts on steep terrain in Northern Spain. In addition, various models to predict time consumption for the main work elements and productivity were fitted including several independent variables previously selected using stepwise regression. Finally, the models explain between 83% and 97% of variability. Since the equations are based on simple variables (depending on each individual equation this was either velocity empty and loaded, slope loading, distance empty/loading/loaded or load per cycle), they will be a helpful and easy to use tool to assist in forest management planning. Productivity was 6.75 odt/PMH for the Dingo AD-8468 forwarder and 11.56 odt/PMH for the Dingo AD-2452. Cost per tonne for the Dingo AD-8468 was 6.77 €/odt compared to 3.94 €/odt for the Dingo AD-2452
Large scale semi-automatic detection of forest roads from low density LiDAR data on steep terrain in Northern Spain
[EN] While forest roads are important to forest managers in terms of facilitating the exploitation of wood and timber, their role is far more multifunctional. They permit access to emergency services in the case of forest fires as well as acting as fire breaks, enhance biodiversity, and provide access to the public to enjoy recreational activities. Detailed maps of forest roads are an essential tool for better and more timely forest management and automatic/semi-auto-matic tools allow not only the creation of forest road databases, but also enable these to be updated. In Spain, LiDAR data for the entire national territory is freely available, and the capture of higher density data is planned in the next few years. As such, the development of a forest road detection methodology based on LiDAR data would allow maps of all forest roads to be developed and regularly updated. The general objective of this work was to establish a low density LiDAR data-based methodology for the semi-automatic detection of the centerline of forest roads on steep terrain with various types of canopy cover. Intensity and slope images were generated using the currently available LiDAR data of the study area (0.5 points m-2). Two image classification approaches were evaluated: pixel-based and object-oriented classification (OBIA). The LiDAR-derived centerlines obtained with the two approaches were compared with the real centerlines which had previously been digitized in the field. The road width, type of surface and type of vegetation cover were also recorded. The effectiveness of the two approaches was evaluated through three quality indicators: correctness, completeness and quality. In addition, the accuracy of the LiDAR-derived centerlines was also evaluated by combining GIS analysis and statistical methods. The pixel-based approach obtained higher values than OBIA for two of the three quality measures (correctness: 93% compared to 90%; and quality: 60% compared to 56%) as well as in terms of positional accuracy (± 5.5 m vs. ± 6.8 for OBIA). The results obtained in this study demonstrate that producing road maps is among the most valuable and easily attainable products of LiDAR data analysis.SIThis study was funded by the SCALyFOR project (R&D Projects “Research Challenges”, Spanish Ministry of Economy and Competitivenes
Above-ground biomass equations for Pinus radiata D. Don in Asturias
Aim of the study: The aim of this study was to develop a model for above-ground biomass estimation for Pinus radiata D. Don in Asturias.
Area of study: Asturias (NE of Spain).
Material and methods: Different models were fitted for the different above-ground components and weighted regression was used to correct heteroscedasticity. Finally, all the models were refitted simultaneously by use of Nonlinear Seemingly Unrelated Regressions (NSUR) to ensure the additivity of biomass equations.
Research highlights: A system of four biomass equations (wood, bark, crown and total biomass) was develop, such that the sum of the estimations of the three biomass components is equal to the estimate of total biomass. Total and stem biomass equations explained more than 92% of observed variability, while crown and bark biomass equations explained 77% and 89% respectively.This study was funded by the Asturian Energy Foundation (FAEN) and the Regional Ministry of Rural Environment and Fisheries (Government of the Principality of Asturias) through the project CN-06-007 "Production of biomass in several forestry species in Asturias"S
Management tools for Castanea sativa coppice stands in northwestern Spain = Herramientas de gestión para masas de monte bajo de Castanea sativa en el noroeste de España
Carbon sequestration for different management alternatives in sweet chestnut coppice in northern Spain
This paper provides an innovative approach to assessing carbon sequestration in sweet chestnut coppice
taking into account the importance of carbon fluxes in the whole forest-industry value chain in the
mitigation of climate change. The goals of this study were: to evaluate the baseline carbon capture of
sweet chestnut forest in the north of Spain; to assess the effect of thinning and extending the rotation
period on carbon storage; and to evaluate the substitution effect of using sweet chestnut products as an
alternative to other materials. The CO2FIX model was used to estimate carbon content in different forest
components: aboveground and belowground biomass, soil and wood products, under five different
thinning and rotation scenarios. Model parameterization as a function of stand age was carried out using
growth data, climate data, litterfall rates, sawmill processing data, and data on the lifespan of products
and their final end. Sawmill efficiency was measured in situ using the Lumber Recovery Factor.
The scenarios in which only one thinning was made resulted in more total carbon accumulating than
the baseline, especially when the 40 years rotation was increased by 20 years. In contrast, scenarios
involving two thinning did not even reach the baseline value of total carbon. Additionally, a positive
impact on GHG emissions was found for using wood to substitute other materials, i.e. cement and fossil
fuel. Taken together, these results highlight the sustainability of thinning and rotation treatments in
terms of carbon storage in sweet chestnut coppice, and quantifiably supports the environmental benefits
of the substitution effect of sweet chestnut wood products. As such, it provides valuable information for
forest managers and policy makers who wish to address climate change mitigation in forest management
planning.Instituto Universitario de Gestión Forestal Sostenibl
Detección automática de pistas forestales y evaluación de la precisión a partir de datos LiDAR de baja densidad en Asturias
[ES] Las pistas forestales son infraestructuras esenciales para la gestión sostenible de montes puesto que posibilitan el acceso a las masas forestales para su aprovechamiento o ejecución de tratamientos selvícolas, conectan distintas áreas, sirven de acceso para actividades recreativas y para la lucha contra incendios. Por ello, es imprescindible disponer de una cartografía actualizada de pistas, que permita conocer al menos su localización y longitud. El objetivo general de este estudio fue establecer una metodología para la detección automática del eje de las pistas forestales en un monte de Asturias, con rodales de pino marítimo, pino insigne, roble, castaño y otras frondosas. Para ello, se generaron distintas capas de información partiendo de los datos lidar de la zona de estudio (PNOA). A partir de ellas se evaluaron dos metodologías de clasificación de imágenes: la clasificación basada en píxeles y la orientada a objetos. Los resultados obtenidos se compararon con la cartografía real de las pistas del monte mediante indicadores de Corrección, Integridad y Calidad. Además también se evaluó la precisión del eje de las pistas combinando análisis GIS y métodos estadísticos. La clasificación basada en píxeles obtuvo valores más altos en los tres indicadores evaluados así como en la precisión posiciona
Women’s reactions upon reading a leaflet on Breast Cancer Screening Program
[ES] FUNDAMENTOS // El folleto del Programa de Detección Precoz del Cáncer de Mama (PDPCM) es una importante herramienta de
difusión de ese programa. Conocer la percepción de las mujeres sobre ese material informativo es relevante para entender mejor su
actitud hacia el PDPCM. El objetivo del estudio fue explorar las reacciones de las mujeres respecto al folleto del PDPCM.
MÉTODOS // Se realizó un estudio cualitativo descriptivo en mujeres de entre cuarenta y sesenta años en Asturias (España). Se
realizaron veintiséis entrevistas semiestructuradas a mujeres de diferentes perfiles socioeconómicos en 2018. Se realizó un análisis
de contenido para identificar inductivamente las categorías emergentes.
RESULTADOS // La lectura del folleto despertó emociones positivas como tranquilidad, bienestar o gratitud, pero también miedo o
inquietud. Las mujeres expresaron diversas creencias sobre el CM (enfermedad muy prevalente y de elevada supervivencia), sobre
el PDPCM (programa dirigido a la prevención y que suponía una actividad normalizada en su entorno) y sobre el relevante papel de
los servicios de salud y los medios de comunicación. Se detectaron actitudes ambivalentes hacia el PDPCM y estas actitudes estaban
relacionadas con las emociones.
CONCLUSIONES // La respuesta emocional al leer el folleto es ambivalente, aunque la mayoría de las mujeres expresan emociones
positivas. Las mujeres comparan la información con sus creencias previas, especialmente respecto al CM y al PDPCM. Es importante
entender cómo ciertas emociones (especialmente las negativas) están estrechamente relacionadas con la actitud hacia este programa.[EN] BACKGROUND // Breast cancer screening (BCS) leaflets are important for outreach and dissemination of BCS programs. Knowing
how women perceive these leaflets is relevant to better understand their attitude towards BCS. The objective of this paper was to
explore women’s reactions regarding BCS leaflet.
METHODS // A simple descriptive qualitative design was performed involving women aged between forty and sixty years of age in
Asturias (Spain). Twenty-six semi-structured interviews were conducted with women of different socioeconomic profiles in 2018. Thematic
analysis was carried out.
RESULTS // Reading the leaflet elicited positive emotions such as peace of mind, well-being or gratitude, in addition to fear or anxiety.
The women expressed various beliefs about breast cancer (highly prevalent and high survival rates), about BCS (a program aimed
at prevention, a normative activity among their peers) and about the relevant role of health services and the media. Ambivalent
attitudes towards BCS were detected, related to emotions.
CONCLUSIONS // The emotional response after reading the brochure is ambivalent, although most of the women express positive
emotions. Women compare the information with previous beliefs, especially regarding breast cancer (BC) and BCS. It is important to understand how certain emotions (especially negative ones) are closely related to the attitude towards BCS.S
Meat Intake, Cooking Methods, Doneness Preferences and Risk of Gastric Adenocarcinoma in the MCC-Spain Study
Background: The association of meat intake with gastric adenocarcinoma is controversial. We examined the relation between white, red, and processed meat intake and gastric adenocarcinoma, considering doneness preference and cooking methods, by histological subtype and anatomical subsite. Methods: MCC-Spain is a multicase-control study that included 286 incident gastric adenocarcinoma cases and 2993 controls who answered a food-frequency questionnaire. The association of gastric adenocarcinoma with meat intake, doneness preference and cooking methods was assessed using binary multivariate logistic regression mixed models and a possible interaction with sex was considered. Multinomial logistic regression models were used to estimate risk by tumor subsite (cardia vs. non-cardia) and subtype (intestinal vs. diffuse). Sensitivity analyses were conducted comparing models with and without data on Helicobacter pylori infection. Results: The intake of red and processed meat increased gastric adenocarcinoma risk (OR for one serving/week increase (95% CI) = 1.11 (1.02;1.20) and 1.04 (1.00;1.08), respectively), specifically among men and for non-cardia and intestinal gastric adenocarcinoma. Those who consume well done white or red meat showed higher risk of non-cardia (white: RRR = 1.57 (1.14;2.16); red: RRR = 1.42 (1.00;2.02)) and intestinal tumors (white: RRR = 1.69 (1.10;2.59); red: RRR = 1.61 (1.02;2.53)) than those with a preference for rare/medium doneness. Stewing and griddling/barbequing red and white meat, and oven baking white meat, seemed to be the cooking methods with the greatest effect over gastric adenocarcinoma. The reported associations remained similar after considering Helicobacter pylori seropositivity. Conclusions: Reducing red and processed meat intake could decrease gastric adenocarcinoma risk, especially for intestinal and non-cardia tumors. Meat cooking practices could modify the risk of some gastric cancer subtypes