DOI: 10.3897/jbgs.e185535

Authors: Saleh Eddine Zahli

Abstract: Soil erosion and sediment transport represent major environmental challenges in semi-arid Mediterranean watersheds, where high erosion rates do not necessarily translate into high sediment delivery to river systems. This study assesses sediment regulation ecosystem services in the Nfifikh watershed (Morocco) to clarify how landscape connectivity controls sediment export, retention, and internal buffering processes. A spatially explicit connectivity-based modelling approach was implemented using the InVEST Sediment Delivery Ratio (SDR) model, integrating a 30 m digital elevation model, land use and land cover data (2019), soil properties, and rainfall erosivity factors within a GIS environment. The results reveal a marked decoupling between potential soil erosion and effective sediment transfer. Despite high erosion potential in upstream areas, sediment export remains spatially limited due to reduced connectivity, whereas midstream sectors with moderate erosion exhibit higher sediment delivery efficiency. High SDR values are confined to a limited number of well-connected zones, while large portions of the basin function as sediment sinks. Valley-floor deposition locally exceeds 1100 kg yr-1, under-scoring their buffering capacity. Ecosystem service indicators further show spatial differentiation between avoided soil erosion and avoided sediment export, reflecting the role of land-cover configuration in regulating sediment fluxes. Overall, the findings demonstrate that sediment regulation is primarily governed by landscape connectivity and land-cover structure rather than erosion intensity alone, providing transferable insights for ecosystem-based watershed management in semi-arid Mediterranean environments.

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DOI: 10.3897/jbgs.e163188

Authors: Svetoslav Anev, Sonya Damyanova

Abstract: The impact of latitude and altitude on phenological rhythms was studied from 2017 to 2023 at two European beech forest sites in western Bulgaria, Petrohan and Belasitsa. These sites are part of the European Long-Term Ecological Research network. We used products from the Copernicus program’s High-Resolution Vegetation Plant Productivity to extract the main phenological events: start-of-season date, max-of-season date, end-of-season date, and season length. Our findings indicate that the spring phenology of European beech is closely linked to altitude, while autumn events are more significantly affected by latitude. Spring phenological events were delayed by 2.9 days per 100 m at Petrohan and 2.3 days per 100 m at Belasitsa. This relationship weakens in summer and almost disappears in autumn when latitude becomes a leading factor. The average difference in the end-of-season date between Belasitsa and Petrohan is 10.8 days, which means 5.4 days per degree of latitude. Although the end of the season has been occurring later each year, the relationship is still insignificant. The dynamics of individual phenological events in different years, at various altitudes and latitudes, show that European beech has good potential for acclimating to present climate conditions in the western Bulgarian mountains. Further research is needed on the influence of longitude, considering the uneven transition between Mediterranean and temperate-continental climates in the southeastern part of the species’ range.

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DOI: 10.3897/jbgs.e159980

Authors: Aditya Kumar, Pankaj Kumar, Rumi Rongpi, Prabhat Ranjan, Aditi Kumari, Anju Singh

Abstract: Forests are vital to terrestrial ecosystems and they offer essential services for climate regulation and human welfare. However, the increasing trend in forest fires poses a significant threat to these ecosystems. This study aims to map and assess forest fire vulnerability zones within Almora district, Uttarakhand, India, using geospatial technologies and the Artificial Neural Network (ANN) technique. Twelve environmental indicators related to forest fire vulnerability, including elevation, slope, land use/land cover (LULC), Normalized Difference Vegetation Index (NDVI), Vegetation Health Index (VHI), temperature, precipitation, humidity, wind speed, Land Surface Temperature (LST), and distance from settlements and roads, were considered. The study revealed that a strip running from northern to southern Almora, including Someshwar, Dwarahat, and Ranikhet, is highly vulnerable to forest fires. This region is characterized by moderate to high elevation, a moderate to steep slope, and well-connected roads and settlements, particularly in Dwarahat and Ranikhet tehsils. The central and southern parts of Almora also exhibit good road connectivity, dense human settlements, and receive moderate to low precipitation, all of which contribute to a higher fire risk. In contrast, the eastern and western parts of Almora, comprising northern Sult, northern Bhikiyasain, and Banoli tehsils, are significantly less vulnerable to forest fires. These areas have moderate slopes, low to moderate elevation, higher precipitation in the eastern parts, and lower precipitation in the western parts, making them comparatively less prone to fire incidents. Validation through the Receiver Operating Characteristic (ROC) curve confirmed the accuracy of the model, with an 82% area under the curve.

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DOI: 10.3897/jbgs.e159722

Authors: Igor Leščešen, Pavla Pekárová, Zbyněk Bajtek

Abstract: Accurate forecasting of river discharge is critical for the sustainable management of water resources, influencing applications such as irrigation planning, flood and drought mitigation, and infrastructure development. This study investigates the application of the Seasonal Autoregressive Integrated Moving Average (SARIMA) model to forecast minimum monthly discharges of the Danube River, addressing challenges posed by nonlinear and time-dependent hydrological processes. The study utilizes an extensive dataset comprising daily discharge records from ten stations across seven countries, spanning over a century. Monthly minimum discharges were computed and analyzed to identify long-term trends and seasonal patterns. The SARIMA model was selected for its proven ability to capture seasonal variations and optimize forecasting accuracy in da-ta-limited environments. Model performance was evaluated using statistical measures such as mean absolute error and root mean square error with results indicating robust predictive capabilities across the studied stations. The findings reveal significant vari-ability in discharge trends, with notable decreasing trends in minimum flows at several upstream and midstream stations, highlighting potential impacts of climate change and anthropogenic influences. In contrast, downstream stations exhibited relatively stable discharge patterns. These insights underscore the need for adaptive water manage-ment strategies to mitigate the risks associated with decreasing low flows. The study demonstrates the utility of SARIMA models in hydrological forecasting and provides a foundation for future research exploring hybrid modeling approaches incorporating climate variables. The results offer valuable inputs for policymakers and stakeholders in managing water resources under evolving climatic conditions.

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