Efficiency analysis of Policies against desertification by applying DEA: a case study in the river Guadalentin catchment (Almeria, Spain)

This paper deals about an attempt to evaluate the different policies against desertification carried out during a twenty five year period (1978-2003) in the eight municipalities which compound the river Guadalentín catchment (Murcia, Spain). The approach is based on DEA and the European Environmental Agency indicator studies, the former to measure the efficiency and the second to select the best environmental indicators. The analysis has been reiterated with three different sets of outputs related to the different levels and aspects of the desertification process- from the merely soil losses to the overall desertification process in which population losses are considered. As a result a set of efficiency indexes has been obtained for each municipality, which show clearly the contribution of each action against desertification. These results are very valuable to establish future long term desertification policies in similar territories

Metodología de trabajo para la ordenación de las zonas humedas

The management of the wetlands takes place, basically, through five stage. The first one consist of making different inventories in order to have a generic knowledge of the wetland and its environment. Then, the goals are fixed and next the different procedures oriented to achieve the proposed aims are defined. Lastly, the mentioned procedures are performed followed by a programme of control and contamination so as to know how the system develops. In the above process, it is important to emphasize that the work should be carried out taking into consideration all and every one of the different functions the wetlands perform

Estudio geográfico estadístico de las relaciones entre las vegetaciones y los climas de la España Peninsular y Balear

En el artículo se analizan las relaciones geográficas existentes entre los tipos de vegetación cartografiados por Ceballos(1966) para la península Ibérica y Baleares. También se estudian las relaciones existentes entre las vegetaciones y los fitoclimas descritos por Allue(1966). El análisis parte de la codificación de la cartografía forestal y fitoclimática, en 47.764 píxeles de información, a escala 1;1.000.000. El análisis de asociación se efectúa mediante el test Chi2 de Pearson. Finalmente se obtienen las relaciones existentes entre las distintas vegetaciones y entre estas y los fitoclimas. Los resultados obtenidos muestran estadísticamente algunos efectos de la intervención antropógena sobre el medio natural

LANDREC, A Set of Interactive Microcomputer Programs Used as a Help on Land Reclamation Projects

This paper deals with LANDREC software which was built for helping in land reclamation and landscape restoration. This program is compound by three modules: EVALUATION, INTMOREINF and INTEGRATION. The first module provides a optimal solutions for lands to be rehabilitated by considering scenic, topographic and economical aspects, the approach is based on linear programing transport algorithm. The second module allow to enter information from nearby areas in order to quantify the influence of the rehabilitation. The third module, called INTEGRATION, test all model to find the best. The paper includes a case-study located in the valley of Jarama (Madrid, Spain) where gravel extraction for construction has produced a deep deterioration in fluvial landscapes

Los recursos de las masas forestales acercamiento a su evaluación global en la Península e Islas Baleares

La tesis versa sobre la evaluación de los recursos forestales. Intenta cuantificar a escala nacional (1: 1.000.000) las producciones de los principales recursos forestales. Parte de una caracterización por elementos macroecológicos del territorio peninsular y balear. Estudia los recursos forestales mercantiles y cuasimercantiles en dos vertientes: estudios de evolución histórica de las variables de mercado y análisis provincial de datos. Finalmente se obtiene un vector para cada tesela del territorio de las características territoriales macrofiológicas y económicas en su faceta productiv

Taxonomic differences between Pinus sylvestris and P. uncinata revealed in the stomata and cuticle characters for use in the study of fossil material

Taxonomic differences in the needle epidermis characteristics of Pinus sylvestris L. and Pinus uncinata Ramond ex DC. from two Iberian populations were sought; such information could help identify these species when pollen analysis and the inspection of wood anatomy fails. The features of the cuticle are commonly well preserved in the fossil record. Although the epidermal patterns of the examined taxa were similar, qualitative differences were seen in the subsidiary and guard cells. P. sylvestris showed small subsidiary cells homogenously arranged around the opening of the epistomatal chamber, while P. uncinata showed small, lateral subsidiary cells and non-differentiated subsidiary cells in the polar position. The aperture of the epistomatic chamber of P. uncinata was also larger in diameter (15.1 ± 1.8 µm P. sylvestris; 21.1 ± 2.8 µm P. uncinata). Principal components analysis and discriminant analysis was performed on the features of the guard cells characterising the size and shape of the cuticular thickenings — all the variables analysed can be measured in disperse stomata in microscope preparations for pollen analysis. Significant differences were found in the upper woody lamellae width and the coefficient associated with the shape of the medial lamellae borders (discriminant analysis weighting 0.739 and 0.826 respectively). Other significant parameters included the coefficient associated with the relative size of the medial lamellae border width of the guard cells with respect to the distance between the external limits of the medial lamellae borders, and the length of the upper woody lamella. Different light regimens appeared not to significantly affect the variability of the studied features

Análisis de la eficiencia de las políticas contra la desertificación llevada a cabo en la cuenca del río Guadalentin mediante Análisis Envolvente de Datos (DEA)

Mediante análisis envolvente de datos (DEA) CCR-input-orientado y DEA con ponderación cruzada se ha analizado la eficiencia de las diversas actuaciones aplicadas en ocho municipios de la cuenca del río Guadalentín, en búsqueda de la mejor política aplicada entre los años 1978 y 2003. Con el análisis CCR-input-orientado se han detectado los municipios claramente ineficientes y las causas de ineficiencia. Mediante el segundo análisis se ha obtenido una valoración de la eficiencia global de cada municipio y se ha podido estudiar la contribución unitaria de cada recurso en cada término municipal

Will climate change influence fish population dynamics in temperature rivers?

The influence of key climate-driven environmental parameters on the population dynamics of three cyprinid fish species; chub (Leuciscus cephalus (L.)), dace (Leuciscus leuciscus (L.)) and roach (Rutilus rutilus (L.)) were modelled. Monthly variability in temperature (cumulative degree days and cumulative degree days increment), flow (cumulative discharge days and Q values) and climate (NWGS) over a 15-year period were investigated to determine their effect on length at age 1, Annual Growth Increment (AGI) and Year Class Strength (YCS). In order to produce a robust and statistically valid model, data sets from four English rivers (Avon, Lee, Great O use and Don) were combined. All models were statistically significant and adjusted r2 values ranged between 0.161 and 0.752. Monthly values for NWGS and cumulative degree day increments had the greatest influence on population dynamics, highlighting the vulnerability of UK cyprinid fish populations to a changing climate, especially increase or decrease in temperature

The impact of reafforestation on the production of natural ecosystems - A study carried out in Santander, Asturias and Vizcaya

In this paper the outcomes of intensive afforestation, carried out in Spain from 1940 to 1985, are presented. An attempt is made to analyse the extent to which these results are consistent with the principles defined in 1939 by Joaquin Ximenez de Embun and Luis Ceballos, who inspired the afforestation. Details of three specific cases in the development of Pinus radiata and Eucaliptus sp. and their effects on the expansion of autochtonous forest are studied

Análisis de la estructura espacial de las masas de Pinus pinaster Aiton de la Comunidad de Madrid mediante imágenes de alta resolución espacial

En este trabajo se aborda el análisis de la estructura espacial de las masas de Pinus pinaster Aiton de la Comunidad de Madrid mediante imágenes de alta resolución espacial, así como la asociación existente entre algunos índices de textura derivados del variograma, y ciertas características dasométricas obtenidas a partir de parcelas de campo. Para ello se utilizaron, ortofotografías y una imagen de satélite IKONOS, correspondientes a puntos en los que se localizan parcelas de muestreo del Inventario Forestal Nacional (IFN). El análisis de las imágenes se fundamenta en la geoestadística y más concretamente en el uso del variograma. Se calculan variogramas experimentales a partir de las distintas imágenes, para a continuación, calcular el correspondiente variograma ideal y realizar la extracción de los parámetros del variograma, con los que se trata de caracterizar la estructura de las masas estudiadas para diferentes resoluciones espaciales. Como resultado del estudio se han encontrado algunas asociaciones significativas entre parámetros de los variogramas y variables dasométricas, pero de escaso poder predictivo, lo que indica la elevada dificultad en la aplicación de este tipo de técnicas en topografías complejas y masas espacialmente heterogéneas, como las propias de los bosques mediterráneos. Palabras clave: fotografía aérea, IKONOS, geoestadística, variograma, inventario forestal