Contributions of throughfall, forest and soil characteristics to near-surface soil water-content variability at the plot scale in a mountainous Mediterranean area.

Soil water-content (SWC) variability in forest ecosystems is affected by complex interactions between climate, topography, forest structure and soil factors. However, detailed studies taking into account the combined effects of these factors are scarce. This study's main aims were to examine the control that throughfall exerts on local spatial variation of near-surface soil water-content and to combine this information with forest structure and soil characteristics, in order to analyze all their effects together. Two stands located in the Vallcebre Research Catchments (NE Spain) were studied: one dominated by Quercus pubescens and the other by Pinus sylvestris. Throughfall and the related shallow SWC were monitored in each plot in 20 selected locations. The main characteristics of the nearest tree and soil parameters were also measured. The results indicated that mean SWC increment at the rainfall event scale showed a strong linear relationship with mean throughfall amount in both forest plots. The % of locations with SWC increments increased in a similar way to throughfall amount in both forest plots. The analyses considering all the effects together indicated again that throughfall had a significant positive effect in both forest plots, while soil litter depth showed a significant negative effect for the oak plot but lower statistical significance for the pine plot, showing a comparable -although more erratic- influence of the organic forest floor for this plot. These results, together with lower responses of SWC to throughfall than expected in rainfall events characterized by low preceding soil water-condition and high rainfall intensity, suggest that litter layer is playing an important role in controlling the soil water-content dynamics. The biometric characteristics of the nearest trees showed significant but very weak relationships with soil water-content increment, suggesting that stemflow and throughfall may act at lower distances from tree trunk than those presented in our study.

Land use change impacts on floods at the catchment scale: Challenges and opportunities for future research.

Research gaps in understanding flood changes at the catchment scale caused by changes in forest management, agricultural practices, artificial drainage, and terracing are identified. Potential strategies in addressing these gaps are proposed, such as complex systems approaches to link processes across time scales, long-term experiments on physical-chemical-biological process interactions, and a focus on connectivity and patterns across spatial scales. It is suggested that these strategies will stimulate new research that coherently addresses the issues across hydrology, soil and agricultural sciences, forest engineering, forest ecology, and geomorphology.

Validating alternative methodologies to estimate the regime of temporary rivers when flow data are unavailable.

Hydrological data for assessing the regime of temporary rivers are often non-existent or scarce. The scarcity of flow data makes impossible to characterize the hydrological regime of temporary streams and, in consequence, to select the correct periods and methods to determine their ecological status. This is why the TREHS software is being developed, in the framework of the LIFE Trivers project. It will help managers to implement adequately the European Water Framework Directive in this kind of water body. TREHS, using the methodology described in Gallart et al. (2012), defines six transient 'aquatic states', based on hydrological conditions representing different mesohabitats, for a given reach at a particular moment. Because of its qualitative nature, this approach allows using alternative methodologies to assess the regime of temporary rivers when there are no observed flow data. These methods, based on interviews and high-resolution aerial photographs, were tested for estimating the aquatic regime of temporary rivers. All the gauging stations (13) belonging to the Catalan Internal Catchments (NE Spain) with recurrent zero-flow periods were selected to validate this methodology. On the one hand, non-structured interviews were conducted with inhabitants of villages near the gauging stations. On the other hand, the historical series of available orthophotographs were examined. Flow records measured at the gauging stations were used to validate the alternative methods. Flow permanence in the reaches was estimated reasonably by the interviews and adequately by aerial photographs, when compared with the values estimated using daily flows. The degree of seasonality was assessed only roughly by the interviews. The recurrence of disconnected pools was not detected by flow records but was estimated with some divergences by the two methods. The combination of the two alternative methods allows substituting or complementing flow records, to be updated in the future through monitoring by professionals and citizens.

[Primary peritonitis. Study of four cases (author's transl)]. / Peritonitis primaria: a propósito de cuatro casos.

Four cases of primary peritonitis in the adult, with favourable evolution, are presented. This is a rare condition which still involves a not unappreaciable mortality rate. The treatment was surgical in three cases, in one case a paracentesis was performed and antibiotics were administered. The treatment included an exploratory laparotomy, smear with Gram stain and culture of the pus, washing of the peritoneal cavity with isotonic saline solution, appendectomy, closing of the abdominal cavity without drainage and parenteral antibiotic therapy. Exclusive medical treatment carries a greater risk of complications and should be reserved for those patients in very precarious general condition.