During the second half of the 20th century, European countries experienced an increase in their forest area due to the global change. Consequently, there has been an increase in large forest fires, mainly in the Mediterranean basin, and this has forced the development of several types of prevention programs. One of them is the control of the understory by livestock. In this sense, browsing with a combination of donkeys and goats could be a good option, as both animals usually feed on forest species. However, little is known about their preferences for the key species of the Mediterranean forest. Using a cafeteria test, the preferences and consumption of both animals have been determined for five typical species of the Mediterranean forest, such as Quercus ilex, Pinus halepensis, Phillyrea latifolia, Rubus ulmifolius, and Brachypodium retusum. Results showed that donkeys and goats could act complementarily in the reduction of the fuel biomass of forests. Donkeys appear to act more on fine fuel, such as B. retusum, and goats on the more pyrophyte species, in this case P. halepensis. In addition, given that donkeys are at severe risk of extinction in Europe, this role of providing ecosystem services could contribute to their conservation. Despite this study only showing that goats and donkeys would consume all five presented plant species and that there are some differences in consumption during a short-term test, it constitutes a useful first step for conservation and fire prevention in the Mediterranean forests.

Grasslands are one of the major sinks of terrestrial soil organic carbon (SOC). Understanding how environmental and management factors drive SOC is challenging because they are scale-dependent, with large-scale drivers affecting SOC both directly and through drivers working at small scales. Here we addressed how regional, landscape and grazing management, soil properties and nutrients, and herbage quality factors affect 20 cm depth SOC stocks in mountain grasslands in the Pyrenees. Taking advantage of the high variety of environmental heterogeneity in the Pyrenees, we built a dataset (n=128) that comprises a wide range of environmental and management conditions. This was used to understand the relationship between SOC stocks and their drivers considering multiple environments. We found that temperature seasonality (difference between mean summer temperature and mean annual temperature; TSIS) was the most important geophysical driver of SOC in our study, depending on topography and management. TSIS effects on SOC increased in exposed hillsides, slopy areas, and relatively intensively grazed grasslands. Increased TSIS probably favours plant biomass production, particularly at high altitudes, but landscape and grazing management factors regulate the accumulation of this biomass into SOC. Concerning biochemical SOC drivers, we found unexpected interactive effects between grazer type, soil nutrients and herbage quality. Soil N was a crucial SOC driver as expected but modulated by livestock species and neutral detergent fibre contenting plant biomass; herbage recalcitrance effects varied depending on grazer species. These results highlight the gaps in knowledge about SOC drivers in grasslands under different environmental and management conditions. They may also serve to generate testable hypotheses in later/future studies directed to climate change mitigation policies.

Prescribed fire is one of the most widely-used management tools to recover encroached rangelands. Fire has been reported to cause changes in the soil physical and chemical properties. However, the legacy effects of former plant species on soil responses to fire remains unknown. The legacy effect of the former extant plant species on soil carbon (C) and nitrogen (N) fractionation distribution after prescribed burning in topsoil (0–5 cm and 5–10 cm) was investigated in Mediterranean shrublands in Montseny. We sampled soils under five vegetation patch types: Cytisus scoparius L., Calluna vulgaris L., Erica arborea L., Pteridium aquilinum L., and Cladonia biocrusts, pre- and post-burning. Multivariate analysis on soil C and N fractions showed that soils under the legume Cytisus and the biocrust were the most differentiated. Vegetation patch types tended to respond differently to burning, soils under Cytisus, Cladonia and Calluna showing the strongest response. Total C and N, and C and N in sand decreased after burning in the 0–5 cm soil layer. Conversely, C in silt, as well as N in clay and silt, increased with soil depth after burning. This study will be helpful for understanding ecological legacy effects and their possible consequences when planning prescribed burning.

Prescribed burning and pyric herbivory play pivotal roles in mitigating wildfire risks, underscoring the imperative of consistent biomass monitoring for assessing fuel load reductions. Drone-derived surface models promise uninterrupted biomass surveillance but require complex photogrammetric processing. In a Mediterranean mountain shrubland burning experiment, we refined a Structure from Motion (SfM) and Multi-View Stereopsis (MVS) workflow to diminish biases in 3D modeling and RGB drone imagery-based surface reconstructions. Given the multitude of SfM-MVS processing alternatives, stringent quality oversight becomes paramount. We executed the following steps: (i) calculated Root Mean Square Error (RMSE) between Global Navigation Satellite System (GNSS) checkpoints to assess SfM sparse cloud optimization during georeferencing; (ii) evaluated elevation accuracy by comparing the Mean Absolute Error (MAE) of six surface and thirty terrain clouds against GNSS readings and known box dimensions; and (iii) complemented a dense cloud quality assessment with density metrics. Balancing overall accuracy and density, we selected surface and terrain cloud versions for high-resolution (2 cm pixel size) and accurate (DSM, MAE = 57 mm; DTM, MAE = 48 mm) Digital Elevation Model (DEM) generation. These DEMs, along with exceptional height and volume models (height, MAE = 12 mm; volume, MAE = 909.20 cm³) segmented by reference box true surface area, substantially contribute to burn impact assessment and vegetation monitoring in fire management systems.

Legume-based livestock forage systems are widespread and socially relevant agroecosystems that are essential for delivering high-quality forage. Therefore, it is critical to determine how climate change and management might affect the functioning of forage agroecosystems. The objective of this study was to explore the potential of sainfoin swards under different management regimes by combining results from an experiment on species diversity effects on yield developed under extreme climatic conditions and a survey of sainfoin (Onobrychis viciifolia Scop.) swards and nutritive value in mountain regions in Catalonia, Western Mediterranean. Our results show that 12–59% of the variability in forage nutritive value parameters was accounted for by management. Young cattle-grazed swards showed higher nutrition quality that decreased faster than sheep-grazed or only mown swards. Mixing sainfoin with orchardgrass increased fiber content (e.g., +22% neutral detergent fiber) and decreased protein (−26%) and lignin (−11%) compared to sainfoin monocultures. However, under the extreme climatic conditions of the last three years, the only diversity effect found on yield was the identity of the species present. We propose that a combination of different sainfoin management regimes might be beneficial regionally for both quality forage production and overall biodiversity conservation, whereas traditional systems may be vulnerable to changing climatic conditions.