Seasonal evolution of soil respiration in a mixed forestry plantation of walnuts (Juglans × intermedia Carr.) and alders (Alnus cordata (Loisel.) Duby) in Domaine de Restinclières (France)

The ecological intensification of crops is proposed as a solution to the growing demand of agricultural and forest resources, in opposition to intensive monocultures. The introduction of mixed cultures as mixtures between nitrogen fixing species and non nitrogen fixing species intended to increase crop yield as a result of an improvement of the available nitrogen and phosphorus in soil. Relationship between crops have received little attention despite the wide range of advantages that confers species diversity to these systems, such as increased productivity, resilience to disruption and ecological sustainability. Forests and forestry plantations can develop an important role in storing carbon in their tissues, especially in wood which become into durable product. A simplifying parameter to analyze the amount allocated carbon by plantation is the TBCA (total belowground carbon allocation), whereby, for short periods and mature plantations, is admitted as the subtraction between soil carbon efflux and litterfall. Soil respiration depends on a wide range of factors, such as soil temperature and soil water content, soil fertility, presence and type of vegetation, among others. The studied orchard is a mixed forestry plantation of hybrid walnuts(Juglans × intermedia Carr.) for wood and alders (Alnus cordata (Loisel.) Duby.), a nitrogen fixing specie through the actinomycete Frankia alni ((Woronin, 1866) Von Tubeuf 1895). The study area is sited at Restinclières, a green area near Montpellier (South of France). In the present work, soil respiration varied greatly throughout the year, mainly influenced by soil temperature. Soil water content did not significantly influence the response of soil respiration as it was constant during the measurement period and under no water stress conditions. Distance between nearest walnut and measurement was also a highly influential factor in soil respiration. Generally there was a decreasing trend in soil respiration when the distance to the nearest tree increased. It was also analyzed the response of soil respiration according to alder presence and fertilizer management (50 kg N·ha-1·año-1 from 1999 to 2010). None of these treatments significantly influenced soil respiration, although previous studies noticed an inhibition in rates of soil respiration under fertilized conditions and high rates of available nitrogen. However, treatments without fertilization and without alder presence obtained higher respiration rates in those cases with significant differences. The lack of significant differences between treatments may be due to the high coefficient of variation experienced by soil respiration measurements. Finally an asynchronous fluctuation was observed between soil respiration and litterfall during senescence period. This is possibly due to the slowdown in the emission of exudates by roots during senescence period, which are largely related to microbial activity.

Teaching Planning of Forestry Engineering in Spain : origins and evolution

This paper addresses the historical evolution of, from its inception, to the present day, within the changing context of EHEA and linked to professional competences. The research methodology, although it is mainly a historical document review, expert opinions on university educational planning of university education of forestry engineering in Spain are also included. The results show the evolution of centralized planning, based on technical knowledge transmission to an approach based on competences (technical, contextual and behavioral) focusing on learning for improving employability.

The role of visualizations in urban forestry. Conclusions from managers’ perspectives

La presente tesis examina el uso potencial y actual de las técnicas de simulación visual aplicadas al campo de la gestión y la planificación del arbolado urbano. El estudio incluye las aplicaciones potenciales de las visualizaciones por ordenador, así como los beneficios que esto acarrearía. También se analizan las posibles barreras que surgirían de la implementación de esta nueva herramienta y se ofrece una lista de recomendaciones para superarlas. La investigación tiene un carácter exploratorio que utiliza una combinación de técnicas de investigación cuantitativas y cualitativas, dónde se emplean cuestionarios y entrevistas personales semi-estructuradas para estudiar y analizar las opiniones y reacciones de los gestores de arbolado urbano de los distritos de la ciudad de Londres (Reino Unido), denominados Tree Officers (LTOs). Para el desarrollo de la tesis se recopilaron y analizaron las respuestas al cuestionario del 41 por ciento de los LTOs pertenecientes al 88 por ciento de los distritos de Londres y se realizaron un total de 17 entrevistas personales. Los resultados del análisis estadístico de las respuestas del cuestionario y los análisis cruzados de las distintas variables se complementaron con las conclusiones obtenidas del análisis temático de los datos cualitativos recopilados durante las entrevistas. Los usos potenciales de las técnicas de simulación visual aplicadas a la gestión y planificación del arbolado urbano sugeridos fueron obtenidos combinado las conclusiones de, primero, la comparación de las cuestiones que los LTOs consideraron que más tiempo y recursos necesitaban y que actualmente no era posible resolverlas satisfactoriamente con las herramientas y los procesos disponibles, con la información acerca de cómo se habían empleado las visualizaciones en situaciones similares en otros campos tales como planificación urbano, el paisajismo o la gestión forestal. Segundo, se analizaron las reacciones y opiniones de los LTOs ante un conjunto de visualizaciones presentadas durante las entrevistas, desarrolladas ad hoc para mostrar un abanico representativo de ejemplos de utilización de las técnicas de simulación visual, que, a su vez se complementaron con los usos adicionales que los propios LTOs sugirieron tras ver las visualizaciones presentadas. Los resultados muestran que el uso actual de simulaciones visuales por parte de los LTOs es muy limitado pero si que reciben un gran número de visualizaciones de otros departamentos y como parte de la documentación presentada en las solicitudes de permisos para edificación o desarrollo urbanístico. Los resultados indican que las visualizaciones que son presentadas a los LTOs no son objetivas ni precisas por lo que se argumenta que esta situación es un factor importante que impide una toma de decisiones adecuada y una correcta transmisión de infracción al público y al resto de partes implicadas. Se sugiere la creación de un código que regule el uso de visualizaciones en el campo de la gestión y planificación del arbolado urbano. ABSTRACT This thesis examined the use of computer visualizations in urban forestry management and planning. Potential roles of visualizations were determined the benefits that its use would provide. Additionally, the possible barriers in the implementation of visualizations in urban forestry management and planning were also studied and recommendations on how to overcome them were provided The research conducted was an exploratory study using survey research methods and personal semi-structured interviews. The perspectives and reactions of London (UK) boroughs’ tree officers (LTOs) were analysed combining quantitative and qualitative research methods. The study surveyed 41 percent of all Tree Officers in London, obtaining responses from 88 percent of the boroughs and performed 17 personal interviews. Statistical analysis of the data and cross-variables analysis provided rich information that was then complemented with the conclusions from thematic analysis of the qualitative data from the interviews. Potential roles of visualizations were determined first by understanding the challenges that LTOs are facing today and comparing them with how visualizations have helped in similar situations in urban forestry and other related fields like landscape architecture, urban planning and forestry; second, the reactions of LTOs to a set of examples of proposed uses of visualizations were also complemented with the additional uses proposed by LTOs after seeing the visualizations. The visualizations were created ad hoc to show a variety of representative examples of the sue of visualization in urban forestry management and planning and were presented during the interviews to LTOS. Results show that the current production of visualizations is very reduced among tree officers but that they are frequent receptors of visualizations coming from other departments and as part of the documentation of planning applications. Findings show that the current visualizations that get to Tree Officers are biased and inaccurate and therefore it is argued the the current use of visualizations is a threat to legitimate informed decision making and public information. The development of a code for the use of visualizations in urban forestry management and planning is suggested.