Search Results (3)

This study analyses land use changes in the Sado Estuary (West-Central Portugal) based on a multi-temporal analysis of 19th century cartographic data and 21st century remote sensing land use maps, updated by fieldwork. A GIS plot of land use evolution is summarized in a quantitative table. The comparison shows the changes in land use, with increasing occupation by human economic activities, including extensive agriculture and forestry, as well as localized urbanization and industrialization. The main elements of the landscape impacted by anthropogenic uses were (i) hydrography—river dams affected the flow dynamics and sedimentary processes in the estuary; (ii) vegetation—increasing agriculture and forestry reduced the area of native vegetation, which is now mostly occupied by vineyards, pine forests and cork oaks; (iii) wetlands—tidal and alluvial plains are being occupied by rice cultivation, aquaculture, industries, and ports; (iv) coastal dunes—new developments are occupying large areas of Holocene coastal dunes; and (v) natural environment—mining and dredging have affected some habitats and biodiversity. This analysis is intended to help the territorial organization of present and future economic activities, as well as to reduce environmental and social problems, thus promoting the long-term sustainability of this rapidly evolving region. Full article

Studying regeneration processes in oak-dominated forests requires a multi-faceted approach that considers local factors, disturbances, management actions, and tree responses. Our aims were to quantify the carbon and water-use responses of saplings and evaluate ecological consequences at the early tree regeneration phase of a pedunculate oak-hornbeam forest. We measured plant eco-physiological parameters using an open-chamber IRGA equipment in large experimental canopy gaps (instantaneous field data) and greenhouse (climate-controlled reference data) conditions. We used the non-parametric Kruskal–Wallis ANOVA test to analyze differences and similarities in the gas-exchange response. Functional fingerprints indicated shared resource use and efficiency functions at species-specific performance levels with temporal variations. Medium-level and seasonally balanced carbon uptake and water-use functions characterized pedunculate oak (Quercus robur L.) and European hornbeam (Carpinus betulus L.). In contrast, the response patterns in wild cherry (Prunus avium (L.) L.) and green ash (Fraxinus pennsylvanica Marshall) were dominated by water use. Goat willow (Salix caprea L.) had consistently elevated gas-exchange levels with the largest seasonal variation among the study species. We found that trees could be ranked on a relative isohydric-to-anisohydric scale regarding their species–environment interaction. According to the carbon-gain response pattern coupling with a non-structural carbohydrate exchange scheme, we were able to classify tree species as having medium- and long-term carbon resource management. In conclusion, spatially heterogeneous and temporally balanced canopy gaps facilitate tree species’ development and mixed-stand regeneration by providing a functionally diversifying recruiting environment. Full article

At a global level, different land use change processes (changes in use, presence of invasive alien species, public use activities, intensification in agricultural and livestock activities, loss of compatible and low-intensity traditional uses, climate change, etc.) and phytosanitary problems (black alder disease) are currently threatening factors that generate, with different degrees of intensity, the deterioration and fragmentation of the habitats of river corridors, both in the upper and middle basin, as well as in the estuarine sections. LIFE FLUVIAL (LIFE16 NAT/ES/000771) develops a transnational strategy of sustainable management of river corridor habitats in several Atlantic river basins of the Iberian Peninsula (Spain and Portugal), so the overall objective is the improvement in the conservation status of Atlantic Natura 2000 river corridors and associated wetlands, mainly targeting the 91E0* priority habitat (alluvial forests with Alnus glutinosa and Fraxinus excelsior). Another target habitat is considered in the project, the habitat type 9230 Galician-Portuguese oak woods with Quercus robur and Quercus pyrenaica, which represents continuity with the 91E0* habitat type. To achieve the overall objective, a series of specific objectives are considered, which are designed to combat threats that contribute to habitat degradation: (1) implementation of a transnational model for sustainable management of river corridors for the improvement in their conservation status, through the restoration of the composition, structure and functionality of their types of habitats, as well as improving the connectivity and reduction in fragmentation; (2) control of exotic invasive alien plants; (3) improvement in the plant health of river corridors by the partial removal of dead trees; (4) promoting the dissemination and awareness of the natural values, socio-economic benefits and ecosystem services of river corridors; (5) improvement in training and technical capacity for stakeholders in the management and conservation of river corridors. To achieve these objectives, the project proposes a set of specific conservation actions that constitute a compendium of best practices in relation to the design and execution of viable and effective action measures to improve the conservation status of river corridors and contribute to halting the loss of biodiversity. Full article