Downscaling of surface moisture flux and precipitation in the Ebro Valley (Spain) using analogues and analogues followed by random forests and multiple linear regression

In this paper, reanalysis fields from the ECMWF have been statistically downscaled to predict from large-scale atmospheric fields, surface moisture flux and daily precipitation at two observatories (Zaragoza and Tortosa, Ebro Valley, Spain) during the 1961-2001 period. Three types of downscaling models have been built: (i) analogues, (ii) analogues followed by random forests and (iii) analogues followed by multiple linear regression. The inputs consist of data (predictor fields) taken from the ERA-40 reanalysis. The predicted fields are precipitation and surface moisture flux as measured at the two observatories. With the aim to reduce the dimensionality of the problem, the ERA-40 fields have been decomposed using empirical orthogonal functions. Available daily data has been divided into two parts: a training period used to find a group of about 300 analogues to build the downscaling model (1961-1996) and a test period (19972001), where models' performance has been assessed using independent data. In the case of surface moisture flux, the models based on analogues followed by random forests do not clearly outperform those built on analogues plus multiple linear regression, while simple averages calculated from the nearest analogues found in the training period, yielded only slightly worse results. In the case of precipitation, the three types of model performed equally. These results suggest that most of the models' downscaling capabilities can be attributed to the analogues-calculation stage.

Competing Ecosystem services: an Assessment of Carbon and timber in the Tropical forests of Central America

4 p.

The Costs of Ecosystem Adaptation: Methodology and Estimates for Indian Forests

34 p.

Competing Ecosystem Services: an Assessment of Carbon and Timber in the Tropical Forests of Central America

29 p.

Photosynthetic responses of trees in high-elevation forests: comparing evergreen species along an elevation gradient in the Central Andes

Plant growth at extremely high elevations is constrained by high daily thermal amplitude, strong solar radiation and water scarcity. These conditions are particularly harsh in the tropics, where the highest elevation treelines occur. In this environment, the maintenance of a positive carbon balance involves protecting the photosynthetic apparatus and taking advantage of any climatically favourable periods. To characterize photoprotective mechanisms at such high elevations, and particularly to address the question of whether these mechanisms are the same as those previously described in woody plants along extratropical treelines, we have studied photosynthetic responses in Polylepis tarapacana Philippi in the central Andes (18 degrees S) along an elevational gradient from 4300 to 4900 m. For comparative purposes, this gradient has been complemented with a lower elevation site (3700 m) where another Polylepis species (P. rugulosa Bitter) occurs. During the daily cycle, two periods of photosynthetic activity were observed: one during the morning when, despite low temperatures, assimilation was high; and the second starting at noon when the stomata closed because of a rise in the vapour pressure deficit and thermal dissipation is prevalent over photosynthesis. From dawn to noon there was a decrease in the content of antenna pigments (chlorophyll b and neoxanthin), together with an increase in the content of xanthophyll cycle carotenoids. These results could be caused by a reduction in the antenna size along with an increase in photoprotection. Additionally, photoprotection was enhanced by a partial overnight retention of de-epoxized xanthophylls. The unique combination of all of these mechanisms made possible the efficient use of the favourable conditions during the morning while still providing enough protection for the rest of the day. This strategy differs completely from that of extratropical mountain trees, which uncouple light-harvesting and energy-use during long periods of unfavourable, winter conditions.

Guided pollards in the Basque Country (Spain) during the Early Modern Ages

Publicado en: "End of Tradition?.Part 1 : History of Commons and Commons Management (Cultural Severance and Commons Past)", edited by Ian D. Rotherham, Mauro Agnoletti and Christine Handley

Las comunidades de montes en Guipúzcoa en el tránsito del Medievo a la Edad Moderna

Ejemplar dedicado a: Élites sociales y poder territorial.

Economic Valuation of Ecosystem Services: Conflicts in Classification

4 p.

Linking Reduced Deforestation and a Global Carbon Market: Impacts on Costs, Financial Flows, and Technological Innovation

25 p.

Classifying Ecosystem Services for Economic Valuation: The case of forest water services

30 p.

Economic Assessment of Forest Ecosystem Services Losses: Cost of Policy Inaction

52 p.

Climate change impacts on the water services in Costa Rica: a production function for the hydroenergy sector

23 p.

Community Turnover of Wood-Inhabiting Fungi across Hierarchical Spatial Scales

For efficient use of conservation resources it is important to determine how species diversity changes across spatial scales. In many poorly known species groups little is known about at which spatial scales the conservation efforts should be focused. Here we examined how the community turnover of wood-inhabiting fungi is realised at three hierarchical levels, and how much of community variation is explained by variation in resource composition and spatial proximity. The hierarchical study design consisted of management type (fixed factor), forest site (random factor, nested within management type) and study plots (randomly placed plots within each study site). To examine how species richness varied across the three hierarchical scales, randomized species accumulation curves and additive partitioning of species richness were applied. To analyse variation in wood-inhabiting species and dead wood composition at each scale, linear and Permanova modelling approaches were used. Wood-inhabiting fungal communities were dominated by rare and infrequent species. The similarity of fungal communities was higher within sites and within management categories than among sites or between the two management categories, and it decreased with increasing distance among the sampling plots and with decreasing similarity of dead wood resources. However, only a small part of community variation could be explained by these factors. The species present in managed forests were in a large extent a subset of those species present in natural forests. Our results suggest that in particular the protection of rare species requires a large total area. As managed forests have only little additional value complementing the diversity of natural forests, the conservation of natural forests is the key to ecologically effective conservation. As the dissimilarity of fungal communities increases with distance, the conserved natural forest sites should be broadly distributed in space, yet the individual conserved areas should be large enough to ensure local persistence.

Paleobotánica del epipaleolítico y mesolítico vascos

Homenaje a Ignacio Barandiarán Maestu / coord. por Javier Fernández Eraso, Juan Santos Yanguas

Disponibilidad de micromamíferos en el área de campeo del cárabo común en los bosques de Burceña (Valle de Mena): Primeros resultados del estudio

[ES] Este trabajo forma parte de un proyecto en el que se estudian dos poblaciones de cárabo común (Strix aluco); una en Durango (Bizkaia) y otra en Burceña (Burgos). Este trabajo se ha llevado a cabo en Burceña y en él se muestran los primeros resultados del uso del espacio de estas rapaces nocturnas y su disponibilidad de alimento en los bosques de esta zona. Para ello hemos obtenido localizaciones de diez cárabos durante un año para conocer los territorios de cada uno y hemos capturado en vivo la dieta principal de esta ave, micromamíferos. Estos resultados los hemos relacionado entre sí para saber si influye el uso del espacio en las capturas de micromamíferos. Estas dos variables también las hemos relacionado con el tipo y la edad de los bosques muestreados. Según los resultados obtenidos podemos afirmar que sí existe una influencia del uso en las capturas, demostrando una relación negativa; es decir, donde se han capturado más micromamíferos es en los bosques que menos frecuentan los cárabos, que a su vez, son los bosques menos accesibles para estas rapaces. ABSTRACT This investigation is part of a work project whereby two Tawny owl (Strix aluco) populations are studied. One of them lives in Durango, Biscay and the other one in Burceña, Burgos. This specific work took place in Burceña and lasted one year. It shows the first results of the study on the use of the space of the Tawny owls and the food availability in their woodland range area. We spotted and traced the home range of ten different tawny owls, and also trapped small mammals which are the staple diet of these owls. We compared both the results obtained in order to know if the use of the area is related to the capture of small mammals. These two variables (space-capture) were also related to the type and age of the sampled forests. The results obtained show that it is true there is an influence of the use of space upon the captures proving to be a negative relation, that is, the largest numbers of micromammals were captured in the woodlands where there are fewer owls, because they are the least accessible forests for these birds of prey.