NW Portugal Research Articles

Ethnobotanical Inventory of Plants Used by Mountainous Rural Communities in NW Portugal.

Mountains matter. Rural subsistence communities living in areas with high biodiversity, such as mountains, are hotspots of ecological knowledge. However, modern lifestyles may threaten this unique cultural heritage. Our study aimed to document and analyze information on plants used to fulfill the everyday needs of the people in three rural communities in NW Portugal. Fieldwork was carried out for a period of one year and information was collected through face-to-face semi-structured interviews. A total of 98 species, belonging to 46 families, were identified, and 142 vernacular names were recorded. Ethnobotanical richness was similar among the studied communities. The five most frequently cited species were: Pterospartum tridentatum, Erica arborea, Ruta graveolens, Zea mays and Chamaemelum nobile. Phanerophytes and hemicryptophytes comprise nearly 81% of the list. The top three uses categories (total 14) were: medicine, fuel and ritual. Digestive, skin and respiratory symptoms were the most often conditions treated with plants. Medicinal plants were used fresh and dried, mostly as infusions. The insights gathered here are important for the preservation of the cultural heritage of the local communities. Moreover, the data are of considerable scientific interest because it provides the fundaments for future studies that aim to validate/invalidate specific uses.

Improved X-ray fluorescence spectroscopic monitoring of potentially toxic elements by multivariate analysis: A case study of soils near abandoned coal mines (NW Portugal)

Reusing soils near abandoned mines requires the assessment of soil quality, which includes determining potentially toxic elements (PTEs), such as As, Cd, Co, Cr, Cu, Fe, Mo, Ni, Pb, Sr, Zn and Zr. Levels of PTEs in soil can be harmful. Hence, the measurement of their concentrations is crucial to assess whether soil properties are reusable or it represents a potential environmental risk. Field techniques such as X-ray fluorescence (XRF) imprinting may be an option for rapid PTEs monitoring. Still, due to low sensitivity and selectivity, the partially obtained results by XRF software can be biased. This study presents an alternative solution for soil PTEs monitoring based on the advantages of multivariate analysis (MVA) principally partial least square (PLS) regression applied to orthogonally signal-corrected (OSC) XRF spectroscopic data. The developed PLS models were applied to soil samples from two regions of adjacent abandoned coal mines, in NW Portugal. High correlation coefficients obtained for As, Fe, Pb, Sr and Zn validation models (R2 = 0.79–0.99) pointed to the improved accuracy of their monitoring (compared to directly obtained XRF results) in this regional soil environment. The other PTEs (Co, Cr, Cu, Ni and Zr) showed good PLS models at local environment (R2 = 0.84–0.98). The test of these models in the contaminated regions reinforces their effectiveness in monitoring contaminated soils toward the reuse of environments near abandoned mines.

Multivariate analysis applied to X-ray fluorescence to assess soil contamination pathways: case studies of mass magnetic susceptibility in soils near abandoned coal and W/Sn mines

Determining the origin and pathways of contaminants in the natural environment is key to informing any mitigation process. The mass magnetic susceptibility of soils allows a rapid method to measure the concentration of magnetic minerals, derived from anthropogenic activities such as mining or industrial processes, i.e., smelting metals (technogenic origin), or from the local bedrock (of geogenic origin). This is especially effective when combined with rapid geochemical analyses of soils. The use of multivariate analysis (MVA) elucidates complex multiple-component relationships between soil geochemistry and magnetic susceptibility. In the case of soil mining sites, X-ray fluorescence (XRF) spectroscopic data of soils contaminated by mine waste shows statistically significant relationships between magnetic susceptibility and some base metal species (e.g., Fe, Pb, Zn, etc.). Here, we show how qualitative and quantitative MVA methodologies can be used to assess soil contamination pathways using mass magnetic susceptibility and XRF spectra of soils near abandoned coal and W/Sn mines (NW Portugal). Principal component analysis (PCA) showed how the first two primary components (PC-1 + PC-2) explained 94% of the sample variability, grouped them according to their geochemistry and magnetic susceptibility in to geogenic and technogenic groups. Regression analyses showed a strong positive correlation (R2 > 0.95) between soil geochemistry and magnetic properties at the local scale. These parameters provided an insight into the multi-element variables that control magnetic susceptibility and indicated the possibility of efficient assessment of potentially contaminated sites through mass-specific soil magnetism.

Assessing the Seasonal and Spatial Dynamics of Zooplankton through DNA Metabarcoding in a Temperate Estuary.

Zooplankton are key components of estuarine trophic networks. However, routine monitoring is hindered by the difficulty of morphology-based identification. DNA-based methods allow us to circumvent some of these hurdles, providing precise species identifications regardless of the taxonomic expertise of the investigator or the developmental stage of the specimens. However, the process is dependent on the completeness of the reference libraries. In this study, we sought to evaluate the potential of DNA metabarcoding to assess the seasonal (summer, autumn, and early spring) and spatial dynamics of zooplankton (four locations spanning ca. 6 km) in the Lima estuary (NW Portugal). Two genetic markers were used: the cytochrome c oxidase subunit I and the V4 hypervariable region of the ribosomal 18S rRNA genes. Overall, 327 species were recovered, and both markers displayed minute overlap (7% were detected with both markers). Species richness, composition, and taxonomic distinctness were majorly influenced by the season, with a declining tendency from summer (highest number of exclusive species, n = 74) to spring. Second to season, the taxa composition was influenced by spatial variation where the most downstream site displayed the highest number of exclusive species, n = 53. A total of 16 non-indigenous species were detected using metabarcoding, but only one (Austrominus modestus) has been documented out in the estuary. In conclusion, both the seasonal and spatial gradients influenced the recovered richness, composition, and taxonomic distinctness, confirming the great aptitude of DNA metabarcoding for providing higher density monitoring and shedding new light on the composition and dynamics of complex zooplankton communities.

New physical and biological evidence of lateral transport affecting dinoflagellate cyst distribution in the benthic nepheloid layer along a land-sea transect off Figueira da Foz (Atlantic Iberian margin)

IntroductionThe production of resting cysts is a key dispersal and survival strategy of many dinoflagellate species. However, little is known about the role of suspended cysts in the benthic nepheloid layer (BNL) in the initiation and decline of planktonic populations.MethodsIn September 2019, sampling of the dinoflagellate cyst community at different water depths in the water column and in the bottom sediments, and studies of spatio-temporal changes in physical properties (temperature, salinity, density and suspended sediment concentration), were carried out along a land-sea transect off Figueira da Foz (NW Portugal) to investigate the dinoflagellate cyst distribution and the factors (physical and biological) affecting it. A clustering analysis was used to compare the BNL and sediment cyst records with the cyst rain recorded by a sediment trap at a fixed station. Furthermore, Lagrangian particle experiments enabled simulating cyst trajectories in the BNL 5 and 10 days before sampling and assessing cross-shore, vertical and alongshore transport within the studied region.ResultsA well-developed BNL was present during the survey, which covered a change from active (14th of September) to relaxed (19th of September) upwelling conditions. Organic-walled dinoflagellate cysts were dominant in all samples, although calcareous dinoflagellate cysts consistently occurred (at low abundances). High proportions of full cysts were observed in the BNL, of which a significant portion was viable as shown by excystment experiments. Moreover, BNL cyst records collected on the 19th of September along the land-sea transect were similar to the sediment trap cyst record but greatly differed from sediment cyst records. The heterotrophic small spiny brown cysts (SBC) and cysts of the autotrophic yessotoxin-producer Protoceratium reticulatum notably increased during the survey, in the BNL and in the water column above.DiscussionThe comparison of the BNL, surface sediment and sediment trap cyst records supported that the main origin of cysts in the BNL was the recent production in the water column. The spatial coincidences in the distribution of cysts and vegetative cells of Protoceratium reticulatum also supported that full cysts in the water column were being produced in surface waters. New data evidenced the presence of a significant reservoir of viable cysts in the BNL that have the potential to seed new planktonic blooms. Furthermore, back-track particle modelling evidenced that alongshore advection was the main physical mechanism controlling cyst dynamics in the BNL during most part of the survey period, being particularly intense in coastal stations (<100 m depth). Consequently, the sediment cyst signal is a mixture of locally and regionally produced cysts. We provide multi-disciplinary data evidencing that cysts recently formed in the photic zone can be laterally advected within the studied region through the BNL, contributing to a better understanding of the role of the BNL in cyst dynamics and tracing the seed sources of the new blooms.

Common lands, landscape management and rural development: a case study in a mountain village in northwest Portugal

Sustainable landscape management is a key aspect for the development of mountain areas, especially where communities historically held common lands. Mountains face depopulation and abandonment, and transition to multifunctional landscapes emerges as an opportunity. We present a village case study (NW Portugal) focusing on people’s perceptions and practices around the common land. Results confirm the common plays a central role in local identity, being perceived as shared heritage with potential to provide multiple benefits. Traditional uses and governance practices are prevalent, revealing inertia in adapting to new users and goals. Public support targeting common land management skills would facilitate these transitions, as well as to overcome lasting effects of former authoritarian regime.

Spatial and temporal patterns of gonadal maturation and spawning in European flounder Platichthys flesus at its southern continental edge

The European flounder (Platichthys flesus) is a marine flatfish with high plasticity in several life-history traits, including spawning sites and habitat use patterns. With the overarching goal of understanding the use of estuaries in connection with maturation and reproduction in adult flounder, this study investigates its reproductive cycle in the Douro Estuary (NW Portugal), at the southern edge of its geographical distribution. Adults were caught by monthly trawling from November 2016 to November 2017. Sex ratio and length-weight relationships were determined. The annual reproductive cycle was described using a combination of gonadosomatic (GSI), hepatosomatic (HSI), and general fish condition (Kn) indices, seasonal gonad development staging (macroscopic and histological), and quantification of plasma sexual steroids. Total sex ratio was 1 M:3 F, and females presented negative allometric growth, while males’ growth was isometric. The various indices consistently indicated that the greatest reproductive activity occurred between January and March, peaking in February. However, some females at advanced reproductive stages (late vitellogenesis), high GSI values and steroid hormone (E2) levels were observed as late as May. Females in spawning condition, i.e., undergoing full oocyte maturation and ovulation, were never found, unlike males who exhibited spermiation within the estuary. Sexual differences in migration patterns were also suggested: males seem to leave earlier and stay longer in offshore spawning grounds, while females return to the estuary shortly after spawning. Overall, there was a good correlation between GSI, seasonal hormone cycling, and sexual maturity of female and male flounder, supporting the use of circulating sex steroids as a less invasive tool to assess maturity status.

Insights from a comparative GIS-MCDA groundwater vulnerability assessment in a granitic and metasedimentary fractured rock media

This work proposes a comprehensive methodology for evaluating fissured hard-rock groundwater resources through an integrative approach based on fieldwork techniques, Geographic Information System (GIS)-based mapping, geospatial analysis and multiple-criteria decision analysis (MCDA). The study sites comprise distinct geological settings and geographic contexts, i.e. granitic rocks (NW Portugal) and metasedimentary rocks (SW Spain). A similar methodological approach was used in both areas to compare and assess the methodological approaches’ effectiveness. The cartographic, field, and laboratory data were analysed through GIS overlay and multi-criteria spatial analysis. This GIS-integrated analysis allowed the calculation of the Infiltration Potential Index (IPI) and groundwater vulnerability indexes: GOD-S, DRASTIC-Fm, SI and DISCO, as well as the development and improvement of the hydrogeological conceptual models. At the Entre-os-Rios site (NW Portugal), the IPI index showed that the most favourable areas for infiltration are the fractured granitic regions, where the slope has the lowest values, combined with forest areas. The recharge values are around 70 to 90 mm/year. Considering hydraulic connection with the borehole data, the DISCO index identified the geostructures with the most important trending to NNE-SSW, NE-SW and WNW-ESE in the area. The highest IPI values were identified in the regional aquifer quartzite unit at Herrera del Duque (SW Spain). The recharge values are around 60 to 80 mm/year. The DISCO index identified zones where discontinuities have a higher hydraulic connection to the borehole, mainly trending NW-SE and NE-SW. The models developed could be helpful for decision-making and sustainable water resources management regarding the planning of hydrogeological investigations, delineating potential contamination areas, and the definition of catchment protection areas.

FEASIBILITY STUDY OF SAND BYPASS AT AVEIRO AND FIGUEIRA DA FOZ INLETS

To mitigate coastal erosion in the sectors Barra-Vagueira and Figueira da Foz-Leirosa (NW of Portugal), Portuguese coastal authority has promoted the discussion on the feasibility of implementing a sand bypassing system to restore natural littoral sediment transport. This study synthesizes the main results of the proposed solutions for Aveiro and Figueira da Foz tidal inlets. The methodology to develop the study compromised tree main phases that included the historical characterization of the study area, the preliminary design of different sand bypassing solutions for each coastal inlet and the discussion of their economic feasibility. The physical performance of the sand bypass solutions demonstrated that several bypassing solutions are technically viable to mitigate coastal erosion. However, it was found that the solution is economically viable only at the coastal sector Figueira da Foz-Leirosa.

Fighting drift sands with pine trees: Reforestation of coastal areas of NW Portugal at the end of eighteenth century

From the late Middle Ages until the end of the nineteenth century, the northwest coast of Portugal was severely affected by drift sands, which led to the disappearance of villages or forced the population to migrate or suffer several losses. Along the northern European Atlantic coast, the most effective response to the drift sands was the reforestation of coastal areas, starting from the end of the eighteenth century and in the nineteenth century. In the northwest coast of Portugal, until the end of the nineteenth century, coastal planning and management was mainly the responsibility of local civil, manorial, and religious institutions. Based on historical sources, monastic institutions' forest management actions will be analyzed, and whether these initiatives successfully made communities in north-western Portugal less vulnerable to drift sands. This study will also allow a comparison of how the coastal landscape in the Portuguese Northwest has been reshaped and managed over two centuries, the profound impacts caused by tourism activities in the second half of the twentieth century, and the implementation of coastal management plans by the Portuguese State from 1993 onwards.

Sea Level Rise Effects on the Sedimentary Dynamics of the Douro Estuary Sandspit (Portugal)

Sandspits are important natural defences against the effects of storm events in estuarine regions, and their temporal and spatial dynamics are related to river flow, wave energy, and wind action. Understanding the impact of extreme wave events on the morphodynamics of these structures for current conditions and future projections is of paramount importance to promote coastal and navigation safety. In this work, a numerical analysis of the impact of a storm on the sandspit of the Douro estuary (NW Portugal) was carried out considering several mean sea level conditions induced by climate change. The selected numerical models were SWAN, for hydrodynamics, and XBeach, for hydrodynamic and morphodynamic assessments. The extreme event selected for this study was based on the meteo-oceanic conditions recorded during Hurricane Christina (January 2014), which caused significant damage on the western Portuguese coast. The analysis focused on the short-term (two days) impact of the storm on the morphodynamics of the sandspit in terms of its erosion and accretion patterns. The obtained results demonstrate that the mean sea level rise will induce some increase in the erosion/accretion volumes on the seaward side of the sandspit. Overtopping of the detached breakwater and the possibility of wave overtopping of the sandspit crest were observed for the highest simulated mean sea levels.

What drives the recruitment of European sardine in Atlanto-Iberian waters (SW Europe)? Insights from a 22-year analysis

The European sardine (Sardina pilchardus) is the most abundant and socio-economically important small pelagic fish species in Western Iberia Upwelling Ecosystem. As a result of a long series of low recruitments, sardine biomass off Western Iberia has greatly reduced since the 2000s. Recruitment of small pelagic fish is mainly dependent on environmental factors. In order to identify the key drivers of sardine recruitment, it is essential to understand its temporal and spatial variability. To achieve this goal, a comprehensive suite of atmospheric, oceanographic, and biological variables spanning 1998–2020 (22 years) were extracted from satellite datasets. These were then related to in situ recruitment estimates obtained from yearly spring acoustic surveys carried out along two different hotspots of sardine recruitment of the southern Iberian sardine stock (NW Portugal and Gulf of Cadiz). Sardine recruitment in Atlanto-Iberian waters appears to be driven by distinct combinations of environmental factors, although sea surface temperature was identified as the main driver in both regions. Physical conditions that favour larval feeding and retention, such as shallower mixed layers and onshore transport, were also seen to play a vital role in modulating sardine recruitment. Furthermore, high sardine recruitment in NW Iberia was associated with optimal conditions in the winter (January–February). In contrast, recruitment strength of sardine off the Gulf of Cadiz were associated with the optimal conditions during late autumn and spring. The results from this work provide valuable insights to further understand the dynamics of sardine off Iberia, with potential to contribute to the sustainable management of sardine stocks in Atlanto-Iberian waters, particularly under climate change.

Geothermal resources research in a granitic basement - the Braga area case study (NW Portugal)

Geothermal resources research in a granitic basement - the Braga area case study (NW Portugal)

Effect of Photo-Selective Nets on Yield, Fruit Quality and Psa Disease Progression in a ‘Hayward’ Kiwifruit Orchard

The influence of the colour of photo-selective nets on Actinidia deliciosa yield, fruit quality and progression of the bacterial kiwifruit canker (Pseudomonas syringae pv. actinidiae, Psa) need to be characterised due to increasing use of these nets, mainly to protect from hail and storms. From May 2019 onwards, pearl (Pn), yellow (Yn) and grey (Gn) nets were installed permanently in a ‘Hayward’ kiwifruit orchard in NW Portugal and uncovered plants were used as the control. Compared to outside conditions for both seasons, the blue:red ratio and the mean air temperature were higher (mean increase of 12.7% and 0.6 °C, respectively) and the photosynthetic active radiation (PAR) was lower (10.8% less between budbreak and bloom) under the Pn. Crop yield, compared to the control, decreased by 40.3% under the three nets in 2020, and by 23.9% under the Yn and Gn in 2021. Yield and fruit grade under the Pn were similar to that of uncovered crops in 2021, and fruit grade was overall higher under the Pn compared to the Yn and Gn. Photo-selective nets did not affect the fruit quality parameters. Psa progression decreased under the Pn compared to the control during two months in both seasons, although this beneficial impact needs further evaluation.

Assessment of bud fruitfulness of three grapevine varieties grown in northwest Portugal

Assessing bud fruitfulness (fertility) before budburst can provide useful information for determining the yield potential for the following growing season and allows the number of buds per vine to be adjusted according to the productive potential of each season. The present study aims to assess bud fruitfulness and the incidence of necrotic buds using different analysis techniques in three spur pruned (cordon) grapevine white varieties planted in the Vinhos Verdes Demarcated Region (VVDR), NW Portugal. The first two dormant buds and cane samples were collected before winter pruning in December 2016 and 2017 from three (Vitis vinifera L.) varieties (Alvarinho, Fernão-Pires and Loureiro) in two different VVDR sub-regions. The fruitfulness and the incidence of bud necrosis were determined using anatomical bud analysis and by forcing bud growth under controlled environmental conditions. Additional analyses were performed to determine the total soluble sugars and starch in cane samples on node and internode regions. There were significant differences in fruitfulness among varieties over the two growing seasons (2016/2017 and 2017/2018). The Fernão-Pires variety showed the highest bud fruitfulness for the two first buds of the three varieties. Total soluble sugars and starch content were influenced by the site, variety and position on the cane. A year-to-year variation was observed, with a decrease in bud necrosis and an increase in the fruitfulness indices and carbohydrates content from 2016/2017 to 2017/2018. To our knowledge, no previous studies combining anatomical and forced bud growth techniques have been carried out on these three white varieties.

DRASTIC Index GIS-Based Vulnerability Map for the Entre-os-Rios Thermal Aquifer

The sulphurous mineral waters of ‘Entre-os-Rios’, which is sited in NW Portugal, are famous for their long history as thermal baths dating back at least to the mid-sixteenth century. Because of the singularity of its water composition, especially the highest sulphur content, the mineral waters of ‘Entre-os-Rios’ are one of the most important sulphurous waters in Portugal. Despite these mineral waters having a protection perimeter buffer zone to avoid water contamination, there are potentially damaging installations (e.g., fuel station) in the closed protection buffer zone that, according to existing law, are not permitted within the protection perimeters, which defeats the purpose of their delineation. A vulnerability map was created using geographic information system (GIS) tools based on multi-criteria analysis, combining thematic maps and parameters of the DRASTIC index, for evaluating the risk of contamination in the protection area. The results showed that within the perimeter, there was a low risk of pollution. The alluvium-covered terrain was vulnerable to moderate contamination, but it was far from the catchment point. Areas of minimal risk corresponded to locations where the granitic massif had not been significantly weathered. The map enables information collection for a better definition of local resource structures and planning, namely, for restricted areas emplacement where some activities should not be allowed (e.g., agriculture and water prospection), given its influence on the confined granitic aquifer.

Effect of alongshore sediment supply gradients on projected shoreline position under sea-level rise (northwestern Portuguese coast)

Shoreline changes are associated with natural and anthropic factors, such as sea-level rise, sediment budget, and beach fills. Shoreline retreat is mainly related to sediment deficit and sea-level rise. Some studies show that by the end of the 21st century some beaches may be lost, with the erosion of sandy beaches becoming predominant across the globe. The main purpose of this work is to model the shoreline evolution for 2050 and 2100 along a sandy coastal stretch in the NW Portugal, considering different scenarios of sea-level rise, to evaluate the influence this parameter and sediment budget have on shoreline displacement, as well as estimate the nourishment volume necessary to hold the shoreline in case of shoreline retreat. For this, we applied the stochastic version of the Random Shoreface Translation Model (RanSTM), in four cross-shore topo-bathymetric profiles, which are representative of alongshore coastal compartments. The overall results indicate that the key drivers in shoreline migration along the coastal stretch are not the same for the different profiles; in areas with a sediment supply deficit, shoreline recession increases, and hence the volume of sand required to hold the shoreline position in those zones is much greater. In contrast, positive sediment budgets can mitigate or reverse the erosion caused by sea-level rise.

Holocene evolution of the Cávado estuary (NW Portugal)

This paper aims to contribute to the understanding of the Holocene evolution of the Cávado estuarine coastal system (Portugal) and the adjacent terrestrial areas, using a multidisciplinary approach, which includes geomorphology, sedimentology, palynology, radiocarbon and history. During the Early Holocene, the Cávado environment was characterized by the dominance of coarse sediments especially in the most westward areas, corresponding to fluvial energetic dynamics. During the Middle Holocene, the presence of wetlands dominated especially in the most sheltered areas. The pollen data reflect the predominance of forests during the initial phases of the introduction of agriculture, with a significant presence of humid forests. Between 4240 and 3980 cal BP, a sudden marine flooding took place over the peat. During the Late Holocene, there was a succession of low, high and again low energy fluvial environments in the eastward sheltered areas, while high energy dominated in the Fão channel entrance, with marine influence on the uppermost units. The pollen content reflects a situation of high human influence, with a poor representation of natural forests and a predominance of agrosystems, related to the rise of the Cávado estuary as a port during the heyday of the city of Braga during the Roman and Suevian periods, as described in historical texts and archaeological research. In connection with this growth, the pollen data show the existence of local Pinus plantations related to shipbuilding and repair in the port. During these times, the estuary was larger and open to the sea at Fão. After the 15th century, with the general silting of coastal areas, the inlet closed and the river mouth was displaced to the North.

Delineating springs safeguard zones with DISCO-URBAN index: a valuable tool for groundwater vulnerability mapping in local-scale urban areas

Assessing groundwater vulnerability to contamination is vital worldwide, particularly in sustainable water resources management. That is mainly a concern in fractured media in urban areas due to a large diversity of contaminant sources and the complexity of recharge pathways. Thus, groundwater vulnerability assessment is essential to delineate groundwater protection zones around springs or wellheads. Furthermore, it considers the groundwater system’s heterogeneity and the surrounding hydrogeological conditions, as well as provides suitable solutions to protect the resource and mitigate potential hazards. DISCO-URBAN index focused on urban areas was applied to evaluate the intrinsic vulnerability in fractured media in the surroundings of Penafiel city (NW Portugal). The analytic hierarchy process (AHP) was used to determine the weight of each evaluation factor. Furthermore, multi-criteria indexes were applied: GOD‐S, DRASTIC‐Fm, SI DISCO and DISCO-URBAN. Low to moderate vulnerability classes dominate in the combined approach of the vulnerability indexes. However, very high vulnerability classes occur in DISCO and DISCO-URBAN, corroborated by the water-enriched nitrates. Therefore, the DISCO-URBAN method highlights a better delineation of groundwater safeguard zones. In fact, the DISCO-URBAN index is reliable in urban areas to be integrated as a tool to develop local site hydrogeological investigations related to springs safeguard zones.

Raccoon (Procyon lotor) in Iberia: Status update and suitable habitats for an invasive carnivore

Raccoons are American carnivores, considered invasive across several countries worldwide, especially in Europe. In the Iberian Peninsula, previous studies on raccoons documented several breeding populations in Spain a decade ago and only two confirmed records from isolated individuals in Portugal. Given the need for updating its Iberian distribution and identifying suitable areas with higher invasion risk, we compiled presence records from established breeding populations and isolated individuals. By using a Maxent approach based on breeding records, we forecasted the suitable habitats in Iberia with higher invasion risk for raccoons and identified the related environmental drivers. Overall, we collected 1039 records of raccoon presence throughout the Iberian Peninsula, including 980 records from established breeding populations. Their origin is probably linked to escapes from captivity. Climatic conditions, linked to both drier and wetter environments, and proximity to water bodies were the main predictors of suitable areas for raccoon’s expansion from the currently established breeding nuclei in Iberia. The forecasted high probability areas showed a wide, but fragmented distribution concentrated on four main areas: central, central-north, central-east, and north-west Iberia. NW Portugal seems to be the area with higher invasion risk in the country, although field surveys showed no evidence of raccoon presence yet. However, there are several records in Spain near the Portuguese border, comprising isolated individuals and breeding populations. Therefore, it is crucial to ensure regular monitoring of areas with high invasion risk, particularly those near facilities with captive raccoons that often act as a source of feral individuals, to assure early detection and effective control for the expansion of this invasive carnivore.