The present study evaluates the applicability performance of the Soil and Water Assessment Tool (SWAT) in small forested watersheds (less than 1000 km2). This open-source software is widely used in investigations focused on water availability and quality. Overall, SWAT model performance ranges between satisfactory to good. Normally, underestimates daily peak discharges. The limitations of the model are related to the accuracy of climate data used and to the time period used for validation. Watershed area, forest cover and streamflow spatial distribution have an important influence on modeling processes. Overall, from the analyzed studies, we observed for discharge a decreasing tendency, more pronounced towards the end of the 21st century (up to -54%). For surface runoff, was noticed the same decreasing tendency up to 41%. Regarding sediment yield, the results vary within very wide limits. These findings vary according to watershed location, scenarios adopted, and the eligible period of time.

Silver fir (Abies alba Mill.) is one of the most valuable and productive tree species across European mountains, that accomplish multiple economic, protective and ecologic functions. Alongside spruce (Picea abies (L.) Karst) and beech (Fagus sylvatica L.), silver fir is a characteristic species for the Romanian Carpathians. Although silver fir tree is recommended for the diversification of forests in order to increase the resistance to climate change, it is very sensitive to climatic excesses, especially those that proceed rapidly. Therefore, the aim of this study is to investigate both the environmental conditions and stand characteristics of fir from five mountain ranges of the Romanian Carpathians. The study is based on data recorded over a period of 10 years (1990–2000). As such, a total of 77,251 stands that occupy 211,954 hectares have been investigated in regard to silver fir behaviour. MATLAB scripts were used for analysing consistent data volumes as well as the impact of eight factors on the silver fir productivity (altitude, field aspect, field slope, soil type, participation percentage, road distance, structure and consistency). Our analysis has revealed that higher silver fir productivity is found at altitudes of up to 1200 m, on mid and upper slopes, on NW field aspects, on eutric cambisols and dystric cambisols, with a 10–20% participation in stand composition and in relatively-even aged stands with a full consistency. This study offers valuable insights for forest managers that require comprehensive information in adopting effective strategies to enhance forest resilience under climate change.

The present review summarizes the existing knowledge regarding the afforestation of sand dunes. Our main focus was on the role of trees in stabilizing and rehabilitating these complex ecosystems. We analyzed 937 publications through a systematic bibliometric review and then proceeded to select 422 articles that met our criteria. This methodological approach—combining a comprehensive bibliometric analysis with an in-depth traditional literature review—represents a novel contribution to the field and allows for both quantitative trends and qualitative insights to be captured. This was then complemented by an in-depth literature review. Our results sustain the global importance of this subject, as they include studies from more than 80 countries, with a focus on the USA, China, Australia, and Japan. We have also identified a series of main tree species that are usually used in the afforestation of sand dunes (Pinus, Acacia, Juniperus) and then proceeded to analyze their ecologic and socio-economic impact. As such, we have analyzed case studies from all continents, showcasing a variety of strategies that were successful and adapted to local conditions. This did not exclude challenges, mainly invasive species, low survival rates, and effects on biodiversity and stabilization. The main factors that impact the success of afforestation are represented by topography, soil structure, water dynamics, and climate. Unlike previous reviews, this study offers a global synthesis of both the scientific output and the applied outcomes of sand dune afforestation, bridging the gap between research and practice. As such, afforestation has a positive impact on soil fertility and carbon sequestration but can also present a major risk to native ecosystems. In this context, the present review highlights the need to adopt strategies that are unique for that site, and that must integrate all aspects (ecological, social, economic) to ensure good results. Our ISI-indexed literature review helped us to address the link between the current knowledge, research trends, and future topics that must be addressed.

This study aims to build and test the adaptability and reliability of the Soil and Water Assessment Tool hydrological model in a small mountain forested watershed. This ungauged watershed covers 184 km² and supplies 90% of blue water for the Brașov metropolitan area, the second largest metropolitan area of Romania. After building a custom database at the forest management compartment level, the SWAT model was run. Further, using the SWAT-CUP software under the SUFI2 algorithm, we identified the most sensitive parameters required in the calibration and validation stage. Moreover, the sensitivity analysis revealed that the surface runoff is mainly influenced by soil, groundwater and vegetation condition parameters. The calibration was carried out for 2001–2010, while the 1996–1999 period was used for model validation. Both procedures have indicated satisfactory performance and a lower uncertainty of model results in replicating river discharge compared with observed discharge. This research demonstrates that the SWAT model can be applied in small ungauged watersheds after an appropriate parameterisation of its databases. Furthermore, this tool is appropriate to support decision-makers in conceiving sustainable watershed management. It also guides prioritising the most suitable measures to increase the river basin resilience and ensure the water demand under climate change.

Mountain areas are prone to the occurrence of extreme events, especially torrential floods, amplified by climatic and environmental changes. In this context, it is mandatory to increase resilience and guide decision-makers toward more effective measures. Life cycle assessment (LCA) is considered as a decision support tool that can provide the qualitative and quantitative criteria required by the Do No Significant Harm, thus contributing to a more accurate assessment of environmental impacts of the torrent control structures. This study aimed to investigate the current state of the LCA applications in the torrent control to provide practitioners perspectives for new research and a pathway for optimized LCA analysis. Our analysis reveals that in the torrent control area, these studies are still limited. Most of the papers considered Ecoinvent as the main database source and cradle to grave as the main system boundary. This study suggests that restoring the functional capacity of dams and other torrent control structures instead of demolition or decommissioning from the end-of-life stage will ensure an orientation towards more sustainable and circular strategies. Although strong partnerships and consistent efforts are needed, general findings reveal that LCA is a useful tool for moving towards more sustainable construction practices.

The interest to assess the relationship between forest gap characteristics and topography features has been growing in the last decades. However, such an approach has not been studied in undisturbed mixed sessile oak–beech old-growth forests. Therefore, the present study carried out in one of the best-preserved sessile oak–beech old-growth forests in Europe, aims to assess the influence of topographic features (slope, altitude and aspect) on (i) some characteristics of canopies and expanded gaps (surface, diameter and perimeter) and (ii) the proportion of beech and sessile oak as bordering trees, gap fillers and gap makers. Through a complete gap survey on an area of 32 ha, 321 gaps were identified and mapped. The largest gaps and also the highest gap frequency (140) was found in the slope class (15.1–20°), while the gap frequency increased with altitude, with 99 gaps being recorded at 601–650 m a.s.l. The size and perimeter of the canopy and expanded gaps, as well as the number of gap makers, were negatively related to the slope and altitude. The expanded gap to canopy gap size ratio decreased with the slope and was positively related to the altitude, while a significant negative decrease in gap filler density with altitude was encountered. The sessile oak participation ratio as bordering trees forming the gap increased not only with the altitude but also with the slope. The topography plays an important role in the formation of gaps as well as in the characteristics of the future stand. This study provides valuable insights into the relationship between canopy gap characteristics and topography, which is useful information for forest owners that pursue the design of forest management toward nature-based solutions.