During the past few years there has been an important boost in the application of environment valuation techniques in forest ecosystems. In Spain, these studies have been characterized, among other features, by having been carried out in Protected Natural Areas and by not having included the spatial component of the territory. In this paper, it is aimed to make a valuation of the recreation activities for all the forest systems in a specific province (Segovia), integrating the space component by means of the CORINE Land Cover 2000 cartography. For that purpose, the results of 42 research works conducted in Spain have been taken, and, through a meta-analysis exercise, a model has been set up to estimate the willingness to pay for any recreation activity in the above forests. The model has different explanatory variables, including the inhabitants situated at a certain distance from the forest, the provincial income or the forest category associated with the CORINE polygon. The number of visitors has been obtained from the occupation degree of the accommodation in the rural dwellings of this province. Thus, the results obtained can be taken as being a low threshold of the recreation value associated with these ecosystems.

This paper reports an assessment of the economic profitability from the use of grafted stone-pines for afforestations in Valladolid, Central Spain. With this technical change, the plantations begin to yield cones at few years, saving the long unproductive youth stage of traditional stone-pine stands. Some assumptions are made, due to a lack of empirical data, about the expected yield of the grafted plantations in order to obtain their optimal rotation and profitability. As alternative land-use options, the profitability of traditional afforestations and barley crops are calculated. The cases analysed indicate that grafted plantations are competitive under a broad spectrum of essential financial parameter variations, even with the agricultural crop described in this paper. In the basic cases, expected annual return of grafted plantations is about 430-680 euros per hectare, whereas income from barley crop is about 100 euros per hectare.

This paper illustrates how analytical methods like linear programming can be fruitfully applied to forest management problems. This kind of approach is rather ignored in Spain. In fact, since last century Spanish forests have been managed with the help of German methods, which are not supported by any optimisation model. A linear programming model is built and applied to the Spanish forest Navafría. This forest has been chosen for our exercise because it has been deeply studied with the help of classic methods, so that different methodologies can be compared. Four objectives functions have been defined. Two are typically linked to silvicultural goals: maximise the total timber volume and veneer volume, and the other two show economic targets: maximise the net present value and maximise a similar cash flow in each period. Several constraints have been introduced. In all cases except one a feasible solution was found. Besides, a sensitivity analysis have been incorporated in order to check the influence of variations of the discount rate and expected wood price. The management alternatives proposed in this paper show harvest flows longer than the harvest flow indicated in the management project. In short, the results generated in our application by classic (German) methods can be considered a particular case of the results provided by the optimisation models based upon linear programming.

IntroducciónAunque actualmente los sistemas forestales españoles se están orientando hacia un modelo de gestión en el que priman los servicios que prestan los bosques sobre los bienes tangibles obtenidos de estos ecosistemas, la producción de madera sigue teniendo una gran importancia, dada la magnitud y diversidad de productos manufacturados que de ella se derivan y el conjunto de industrias que contribuyen a su generación, lo que se viene a denominar cadena de la madera.Si se quisiera, a través de unos datos básicos, caracterizar estas industrias, cabría decir que según los últimos datos disponibles en el Instituto Nacional de Estadística (INE, 2002), a nivel nacional las tres principales ramas de la cadena de la madera (industria de la madera, industria del papel, industria del mueble) presentaban un valor añadido bruto (VAB) que superaba los 10. ResumenA pesar de la importancia superficial de los ecosistemas forestales en España, esta circunstancia no ha redundado en una estructura empresarial poderosa y bien estructurada. Más bien se ha desarrollado un núcleo empresarial generalmente fragmentado, que no suele estar integrado con otros eslabones de la cadena de valor de los productos forestales, y sobre el que se posee una información generalmente incompleta y poco actual.Este trabajo pretende profundizar en el conocimiento de las empresas que componen la cadena de la madera en España (industrias de la madera, del papel y del mueble), centrándonos en aspectos tanto generales de las empresas (antigüedad, tamaño, forma de sociedad, etc.), como en cuestiones relativas a la producción, la innovación, la gestión ambiental o los sistemas de calidad. Para ello se ha distribuido una encuesta a más de 2.800 empresas, obteniendo un número de cuestionarios válidos igual a 351, lo que supone un porcentaje de respuesta del 12,18%. Los resultados muestran una acusada heterogeneidad entre los tres sectores anteriormente definidos, así como la escasa penetración de algunos requisitos ambientales, como puede ser la certificación forestal. Por último, el análisis estadístico realizado a ciertos resultados de esta encuesta ha mostrado una serie de relaciones funcionales entre ciertas variables estructurales y las características ambientales y de innovación estudiadas.Palabras clave: economía forestal, industria basada en la madera, empresa forestal. AbstractIn spite of the importance of the forest ecosystems in Spain, this circumstance has not redounded in a wood-based industry powerful and well structured. Usually, these industries are not integrated with other components of the value chain of the forest products. Besides, current information about these industries is incomplete and not very present.This article seeks to deepen in the knowledge of the industries included in the value chain of the wood in Spain (wood industry, paper industry and furniture industry) analyzing several aspects of its production structure (age, size, etc.), as questions relative to the innovation, environmental management or quality systems of. I...

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