Ecologies, Volume 6, Issue 2 (June 2025) – 12 articles

Intertidal reefs comprised of the eastern oyster (Crassostrea virginica) are an important habitat type within the estuarine landscape and provide many unique ecosystem services. Within West Galveston Bay (WGB), Texas, this type of reef plays an important ecological role; however, the system’s intertidal reef abundance, structure, and habitat provisions are relatively understudied, and the current spatial extent of these reefs has not been recently quantified. The primary objectives of the study were to identify intertidal oyster reefs utilizing GIS models and sample representative reefs for topographical characteristics, oyster demographics, and the associated benthic macrofauna (ABM) community composition in WGB from August 2019 to February 2020. Secondarily, GIS models and oyster population abundance were utilized to estimate the intertidal oyster abundance in WBG. The total area of intertidal oyster reefs in WGB was estimated to be 818,128 m², with 59,931 m² of reefs confirmed through GIS analysis and ground truthing, and the GIS model estimating an additional 758,197 m² of reef. Through ground truthing, reefs were found to be either shell rakes, consisting of piled shell with minimal three-dimensional structure and oysters, or true intertidal reefs with high reef structure and oyster abundance. High oyster abundance was spatially distributed within the northeastern and southwestern areas of WGB and the total intertidal oyster population, coupling the GIS models and reef sampling, was estimated to be 500 million individual oysters. The ABM community was sparse in terms of richness and diversity, further indicating a lack of structural complexity in most of the reefs within this system. This study demonstrates the importance of coupling field results with GIS modeling to estimate system level population sizes and furthers the understanding of the spatial distributions of intertidal oyster reef to promote management, conservation, and restoration efforts. Full article

This study analyzes 1980–2020 landings data from three Mediterranean coastal lagoons—the Logarou and Rodia-Tsoukalio Lagoons (NW Greece) and the Mar Menor Lagoon (SE Spain)—to assess ecosystem changes and fishing pressure dynamics. The findings classify these systems as low-yielding, with productivity ranked as follows: Yield Logarou > Yield Rodia-Tsoukalio = Yield Mar Menor. Mean trophic level analysis (mTrL) revealed significant differences driven by the contribution of detritivorous and mid-level carnivorous species (TrL Mar Menor > TrL Rodia-Tsoukalio > TrL Logarou). The fishing pressure indices suggest reduced fishing intensity in the Greek lagoons, while in Mar Menor, a stable Fisheries in Balance (FiB) trend corresponded with stable yields despite eutrophication. Cluster analysis (CA) and principal component analysis (PCA) linked ecosystem differences to sediment characteristics and changes in habitat structure. These results underscore a transition of Mediterranean coastal lagoons toward new ecological states, highlighting the urgent need for habitat conservation and adaptive management strategies to ensure sustainable fisheries under increasing environmental pressures. These findings may be extrapolated to similar transitional coastal ecosystems facing comparable anthropogenic stressors worldwide, providing a broader framework for understanding and managing lagoon systems under changing environmental conditions. Full article

Beavers (Castor fiber L.) are recognized as keystone ecological engineers who shape freshwater ecosystems by modifying hydrology, sediment dynamics, and biodiversity. Although beaver populations have recovered across Europe, including Romania, understanding the environmental factors driving their dam distribution remains limited. This study aimed to (i) characterize the physical and compositional features of beaver dams in the Râul Negru basin, Romania, (ii) model the environmental variables influencing the dam distribution using MaxEnt, and (iii) evaluate the implications for broader conservation strategies. Over a five-year survey covering 353.7 km of watercourses, 135 beaver families were identified, with an estimated population of 320–512 individuals. The dam dimensions showed strong correlations with the river slope, channel width, and wetness index. Predictive models based on LIDAR data achieved over 90% accuracy, outperforming SRTM-based models. The results reveal that topographic wetness, flow accumulation, and valley morphology are the strongest predictors of dam presence. These findings contribute to proactive beaver management strategies, highlighting areas of potential future expansion and offering data-driven guidance for balancing ecosystem restoration with human land use, contributing to the development of conservation strategies that balance ecosystem engineering by beavers with human land-use needs in Romania and across Europe. Full article

Animal populations, even among common species, often exhibit demographic heterogeneity. This is particularly evident in species with metapopulation structures, where geographically distinct subpopulations experience varying degrees of inbreeding due to limited interbreeding. A phenomenon termed ‘negative ecology’ highlights cases where species, despite suitable habitat availability, display fragmented distributions within small geographic areas (<20 km²). These subpopulations, however, do not conform to classic metapopulation dynamics, as even vagile species such as birds can theoretically move freely between them. Similar patterns emerge at larger scales (>100 km²) in birds and butterflies, suggesting ecological constraints—either abiotic or biotic—underpin these structured distributions. Understanding these constraints is essential, particularly in conservation efforts. The principles of positive (extant) and negative (locally absent/extinct) ecology have profound implications for species re-introductions, as historical occupancy does not guarantee successful re-establishment. Abiotic and biotic factors may hinder the recolonization of previously inhabited or entirely new habitats. This article primarily explores the ecological forces shaping such fragmented distributions in birds and butterflies, two especially well-studied taxa in the UK and mainland Europe, in the hope that such a new perspective may thereby contribute to broader conservation and ecological restoration strategies. Full article

From April 2016 to the end of July 2024, roadkill mammals were recorded using the road sampling method on the 33.4 km-long Zmajevac-Osijek road in Osijek-Baranja County, located in the northeastern part of Croatia. A total of 86 roadkill specimens of wild mammals, classified into eight species and one subspecies, were recorded. The northern white-breasted hedgehog, Erinaceus roumanicus, topped the list with 38 individuals, followed by the European badger, Meles meles, with 23 individuals, and the red fox, Vulpes vulpes, with 13 individuals. The European badger was the most frequent roadkill in February and March. The northern white-breasted hedgehog was the most common roadkill in June and July, while the red fox was most frequent roadkill in October. The average number of roadkill per km on the Zmajevac-Osijek road, divided into nine road sections, ranged from 1.1 to 5.9. Spearman’s correlation coefficient between the length of the section and the number of roadkill mammals showed a moderate correlation. The only strong positive correlation between roadkill wild mammals and traffic (average annual daily traffic or average summer daily traffic) was recorded for State Road D-212. Full article

Citizen science is increasingly utilized for environmental monitoring and educational purposes. For lotic ecosystems, this approach could be used to implement traditional methods and gain more data on local biodiversity, particularly in areas where professional monitoring is limited. This study, conducted in Italy, aimed to complement data on river macroinvertebrates collected by the Regional Environmental Protection Agency (ARPA) with additional data gained by volunteers. Our results revealed taxonomic differences between the macroinvertebrate communities of ARPA and citizen science sites. ARPA sites host 34.4% of the total biodiversity, with 22 exclusive taxa, while citizen science sites, with 6 exclusive taxa, represent 9.4% of the total gamma diversity. Compositional differences are mainly explained by taxa turnover between sites. ARPA sites, located along the main river stretches, are richer in alpha and gamma diversity, while volunteer-monitored sites, mostly in agricultural ditches, show lower richness at the local and regional scales but host some unique taxa, increasing the total biodiversity. This study supports the implementation of volunteer programs to increase the number of monitored rivers, enhancing information on macroinvertebrate diversity and distribution and generating relevant data to support decision-making and develop strategies for river conservation and ecosystem restoration at a local scale. Full article

Foliar endophytic fungi (FEF) live within leaves without causing visible signs of disease. FEF occur in all vascular plants, yet the exact nature of interactions between specific FEF and their hosts is not well understood. Some FEF are associated with enhanced water use efficiency, nutrient acquisition, and defense. However, others may have negative effects under high-stress conditions. We examined a series of gas exchange traits in sweet birch (Betula lenta, Fagaceae) along an elevation gradient in the Pisgah National Forest Asheville, North Carolina, USA. From these leaves, we cultured surface-sterilized samples to examine FEF frequency and diversity. FEF cultures were categorized by morphotype and identified through analysis of internal transcribed spacer (ITS) sequences. FEF colonization frequency was 100% across all sites, and we identified 68 distinct morphotypes. Genetic identification of a subset of cultures suggests highly diverse FEF communities within this study system. Leaf gas exchange traits showed significant correlations with elevation at the site level, supporting the hypothesis that water stress increases with increasing elevation. However, further research is needed to determine associations between FEF communities and elevation. These findings, especially considering the limited sample size and small spatial scale of this study, indicate that the southern Appalachians are a promising region for future studies of FEF in forest systems. Full article

Moroccan vegetation faces significant pressure particularly from human activities and climate change, while most ecosystems lack detailed assessments. Phytoecological studies and species assessments are implemented using vegetation sampling, analysis of climate data, geological substrate maps, and the Digital Elevation Model (DEM). The study area hosts 565 plant species distributed into 74 families, with Asteraceae being the most abundant family, representing 17.7%. In addition, the correspondence analysis test demonstrates that species are grouped into six distinct blocks. Block 1 comprises a set of Quercus ilex forests. Block 2 encompasses Juniperus phoenicea lands and transition zones between Quercus ilex and Juniperus phoenicea. Block 3 represents Pinus halepensis forests and pine occurrences within Quercus ilex and Juniperus phoenicea stands. Block 4 indicates the emergence of xerophytic species alongside the aforementioned species; it forms the upper limits of Blocks 1, 2, and 3. Block 5 corresponds to formations dominated by Juniperus thurifera in association with xerophytes. Block 6 groups together a set of xerophytic species characteristic of high mountain environments. Additionally, Quercus ilex colonizes the subhumid zones and prefers limestone substrates, Juniperus phoenicea and Tetraclinis articulata, and Pinus halepensis occupies the hot part of the semi-arid in limestone, clays, and conglomerates, while the Juniperus thurifera and xerophytes inhabit the cold parts and limestone substrates. The thermo-Mediterranean vegetation level occupies low altitudes, dominated by Tetraclinis articulata, Juniperus phoenicea, and Olea europaea. The meso-Mediterranean level extends to intermediate altitudes, dominated by Quercus ilex and Juniperus phoenicea. While the supra-Mediterranean level is dominated by Quercus ilex, Arbutus unedo, and Cistus creticus. The mountain Mediterranean level, located in the high mountains, is dominated by Juniperus thurifera associated with xerophytes. Finally, the oro-Mediterranean level, found at extreme altitudes, is dominated by xerophytes. Some species within this region are endemic, rare, and threatened. Consequently, the implementation of effective conservation and protection policies is recommended. Full article

Pluchea ovalis (Pers.) DC. is an invasive alien plant species. It has spread widely on the island of Tenerife since it was first introduced, becoming a major threat to the island’s flora. The aims of this study are to analyze its germination capacity under different environmental conditions (e.g., light and temperature) and determine its effects on soil properties and native plant communities. Germination assays were carried out both in a germination chamber and in a greenhouse. Twelve plots were also established in the field to determine its effect on soil properties and plant species composition. Our results reveal that the germination capacity of Pluchea ovalis decreases under high temperature ranges and increases on flooded substrates. In addition, Pluchea ovalis can modify soil physicochemical properties by increasing soil magnesium content. As its invasive potential has been demonstrated, this study contributes with evidence of its effects on environmental conditions and species composition. Moreover, we recommend its inclusion in the Spanish Alien Invasive Species Catalogue and the development of further studies about its potential distribution and effects in the Canary Islands. Full article

Catastrophic wind events play important but poorly documented roles in shaping bottomland hardwood forest structure and composition. The objective of this study was to survey a forested wetland area in Illinois, USA, twenty years following a severe tornado (wind speeds ranging from 333–418 km/h). Part of the damaged area had a subsequent salvage logging operation, and we compared the stand structure and composition of these damaged areas to adjacent reference sites. Stem density, basal area, and diversity differed significantly but slightly among disturbance types (p < 0.05). The density of Quercus spp. decreased in regenerated stands, while the density of Fraxinus pennsylvanica and invasive non-native species cover increased (p < 0.05). Salvage logging further increased the density of key bottomland taxa: Salix spp., Taxodium distichum, and Nyssa aquatica, as well as early successional species such as Liriodendron tulipifera (p < 0.05). Productivity did not differ between wind-impacted areas that were logged and not logged (p > 0.05). Recognizing the need for caution when informing management with case studies, this study highlights the value of delaying the assessment of even extreme wind disturbance impacts in hardwood forest recovery until the contribution of crown regrowth of severely wind-damaged trees, along with post-disturbance origin regeneration, can be ascertained. Full article

The widespread distribution of microplastics (MPs) is causing increasing concern among the scientific community and the public. Marine mammals are considered indicators of the ecological health of marine ecosystems, and many species, suffering from numerous anthropogenic factors, have been granted protected status. Pinnipeds (Pinnipedia) are susceptible to ingestion and bioaccumulation of MPs from their environment, through direct consumption and trophic chain transfer. This literature review describes MP exposure for representatives of the three pinniped families—true seals (Phocidae), eared seals (Otariidae), and walruses (Odobenus)—and is based on 26 studies. Data on MP content was reported in scat in 17 articles, in the gastrointestinal tract (GIT) in 8 articles, and in the blubber in 1 article. Plastic material was detected in 22 studies, with its overall occurrence varying from 0 to 100% of samples. In addition to the quantitative assessment of MP content, one study provides data on the correlation between MP levels in animal organisms and pollution biomarkers such as phthalates and porphyrins. The contemporary experience of studying MP ingestion and MP exposure for pinnipeds (Pinnipedia) is discussed step-by-step, focusing on: (1) collection, (2) extraction, and (3) identification methods. This review provides current and collated information on the methods and results of studies concerning MP exposure for pinnipeds (Pinnipedia), which can serve as a guide for future researchers in this area. Full article

The European Turtle Dove (Streptopelia turtur) has experienced significant population declines across its European breeding range, primarily due to habitat loss. Our study aimed to provide a new reference for the conservation of Turtle Doves in Evros province, a biodiversity hotspot. We used Maximum Entropy (MaxEnt) modeling to assess Turtle Dove breeding habitat suitability and account for the area of suitable habitats that is not protected or have been affected by a recent mega-fire. The best performing model identified tree cover density, the percent cover of permanently irrigated land and heterogenous agricultural areas, proximity to non-irrigated agricultural land, and forest edge length as the most important predictors of habitat suitability, signifying the importance of an interplay between open and forested land. Our results indicate that 39% of the study area provides a suitable breeding habitat, with the majority located in central and southeastern regions. Conversely, irrigated agricultural areas in the northeast are unsuitable. We found that more than 60% of suitable habitats fall within the Natura 2000 network, underscoring the importance of protected areas for conservation. However, wildfires pose a major threat, with almost 25% of suitable habitats being affected by a recent mega-fire, highlighting the need for recovery in these areas. Our study provides a foundation for targeted habitat management and restoration efforts in NE Greece and contributes to the broader understanding of the species’ habitat requirements across its breeding range. Full article