Search Results (110)

The Southeastern European territory is under severe climatic pressure owing to accelerating dry–thermal trends. The present survey illustrates the spatial and temporal evolution of the climate regime over the natural and agricultural landcover of South-eastern Europe and individual countries (Albania, Bosnia Herzegovina, Bulgaria, Croatia, Greece, N. Macedonia, Montenegro, Romania, Serbia, and Slovenia). For this purpose, a high spatial resolution of the Johansson Continentality index, the Kerner Oceanity index and the Pinna Combinative index was first estimated over two climatic periods (1964–1993; 1994–2023). The Johansson index depicts increasing continentality over the southern and eastern regions, majorly by the spatiotemporal expansion of the Continental climate over the agricultural and natural areas of Bulgaria (respectively, from 49.9% to 73.7% and from 13.3% to 36.8%) followed by Serbia, Romania, and Greece. The Kerner index illustrates increasing continentality over most of the study area owing to the spatiotemporal increase in the Sub-Continental climate type over the agricultural and the natural regions of Bosnia Herzegovina (from 68.6% to 84% and from 41.4% to 63.2%), N. Macedonia, Slovenia and the natural areas of Croatia and Serbia. The extension of the Continental over the agricultural and natural areas of Romania is also shown. The Pinna index exhibits an increasing aridity trend, which is more intense in the central and eastern regions. This trend is demonstrated by the higher distribution of the Semi-Dry in the second period mostly over the agricultural and natural areas of Bulgaria (2.4% to 23.1% and 0.7% to 5.8%), and a remarkable expansion of the Moderate Wet climate over both area types of Romania (from 3.3% to 44.8% and from 5.6% to 15.2%) and Bosnia Herzegovina (from 13.7% to 33.5% and from 3.5% to 13.2%). This study’s results highlight the necessity for intensifying adaptation plans and actions aiming at the feasibility of agricultural practices and the conservation of natural areas. Full article

In recent years, many spruce (Picea abies (L.) H. Karst., Pinaceae) forests have been severely affected by bark beetle (Ips typographus L., Coleoptera: Curculionidae) outbreaks in the Southern Alps, but their ecological impacts remain poorly studied. We analyzed the distribution, ecological, and floristic–vegetational characteristics of forests recently affected by the bark beetle in the upper basin of the Oglio River (Northern Italy) and developed a MaxEnt model to map forests with a bioclimate more prone to severe insect attacks in the coming decades. The results showed that the spruce forests affected by the bark beetle are located exclusively in the submountain and mountain belts (below 1600 m a.s.l.) and that 85% of them are found in areas with high annual solar radiation (>3500 MJ m⁻²). The predictive model for areas susceptible to severe bark beetle attacks proved highly accurate (AUC = 0.91) and was primarily defined by the mean temperature of the dry winter quarter (contribution: 80.1%), with values between −2.5 and 2.5 °C being particularly suitable for the pest. According to the model, more than 58% of the current spruce forests in the study area will exhibit high susceptibility (probability > 0.7) to severe bark beetle attacks by 2080. The floristic–vegetational and ecological analysis of plant communities of 11 bark beetle-affected areas indicated that more thermophilic and significantly different forest communities (in both floristic and physiognomic terms) are expected to develop compared to those of pre-disturbance. Furthermore, the high coverage of spruce snags/standing dead trees appears to accelerate plant succession, enabling the establishment of mature forest communities in a shorter time frame. Full article

This data descriptor presents δ-MedBioclim, a newly developed dataset for the Euro-Mediterranean region. This dataset applies the delta-change method by comparing the values of 25 General Circulation Models (GCMs) for the reference period (1981–2010) with their projections for future periods (2026–2050, 2051–2075, and 2076–2100) under the SSP1-RCP2.6, SSP2-RCP4.5, and SSP5-RCP8.5 scenarios. These anomalies are added to two pre-existing datasets, ERA5-Land and CHELSA, yielding resolutions of 0.1° and 0.01°, respectively. Additionally, this manuscript provides a ranking of GCMs for each major river basin within the study area to guide model selection. δ-MedBioclim includes, for all the aforementioned scenarios, monthly mean temperature, total monthly precipitation, and 23 bioclimatic variables, including 9 (biorm1 to biorm9) from the Worldwide Bioclimatic Classification System (WBCS) that are not available in other databases. It also provides two bioclimatic classifications: Köppen–Geiger and WBCS. This dataset is expected to be a valuable resource for modeling the distribution of Mediterranean species and habitats, which are highly affected by climate change. 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

Bioclimatic classifications provide critical insights into the relationships between climatic variables and the geographic distribution of organisms. Advances in high-resolution climate data, geobotanical integration, and spatial analysis techniques have improved the delineation of bioclimatic units, enabling more precise characterization of terrestrial ecosystems. This study characterizes the bioclimatic conditions of Jalisco, Mexico, through the identification of bioclimatic units and variants using bioclimatic indices and parameters. High-resolution climate data (1980–2018) from the CHELSA database and GIS-based spatial analysis were employed to delineate bioclimatic patterns and their correlation with climatophyllous potential vegetation. The results identified one macrobioclimate and two bioclimates—Tropical pluviseasonal (56.62%) and Tropical xeric (43.38%)—as well as two bioclimatic variants, six thermotypes, and seven ombrotypes. Notably, 49.84% of the territory exhibits bioclimatic variants, and a total of 42 isobioclimates were associated with 14 types of climatophyllous potential vegetation. These findings provide a foundation for understanding vegetation dynamics and support territorial planning and land management. The integration of remote sensing and bioclimatic analysis enhances the identification of spatial heterogeneity in climate–vegetation relationships, facilitating applications in ecological modeling, drought assessment, and conservation planning. This study contributes to ongoing research on terrestrial ecosystem functioning, aligning with current advancements in remote sensing-based environmental analysis. Full article

This article explores the impacts of climate change on the rural and natural landscapes in the region of Eastern Macedonia and Thrace, northeastern Greece. The spatial distributions of the bioclimatic de Martonne Index and the phytoclimatic Emberger Index were calculated at a very high resolution (~500 m) for present conditions (1970–2000), two future time periods (2030–2060; 2070–2100), and two greenhouse gas concentration scenarios (RCP4.5; RCP8.5). The results show significant bioclimatic changes, especially in the Rhodope Mountain range and along almost the whole length of the Greek–Bulgarian border, where forests of high ecosystem value are located, together with the rural areas along the Evros river valley, as well as in the coastal zone of the Aegean Sea. The article describes the processes of bioclimatic changes that can significantly modify the study area’s landscapes. The study area reveals a shift toward xerothermic environments over time, with significant bioclimatic changes projected under the extreme RCP8.5 scenario. By 2100, de Martonne projections indicate that around 40% of agricultural areas in the eastern, southern, and western regions will face Mediterranean and semi-humid conditions, requiring supplemental irrigation for sustainability. The Emberger Index predicts that approximately 42% of natural and agricultural landscapes will experience sub-humid conditions with mild or cool winters. In comparison, 5% will face drier humid/sub-humid, warm winter conditions. These foreseen futures propose initial interpretations for key landscape conservation, natural capital, and ecosystem services management. Full article

A recent review of species distribution modelling (SDM) published in Earth contains much useful information. However, the introductory paragraphs lack basic information about the first SDM package called BIOCLIM, which became available in January 1984. For example, BIOCLIM-related advances underpinned the development of the most used SDM variables and data. The first SDM climate change studies published in 1988 highlighted the importance of ex situ and native distribution data. This brief note highlights the importance of the early SDM work and its continuing relevance. Full article

The sustainability of agriculture is seriously threatened by climate change. In Europe, chestnut ecosystems, which are growing mainly in Mediterranean climate, are facing during summertime increasing of heat and drought stresses. These induce fragilities on trees, leading to a reduction in productivity and predisposing them to pest and disease attacks. The plasticity of chestnut species under contrasting climate is known. Understanding the specific adaptation of cultivars to different climate features is now important to anticipating climate changes. Caucasian Region is considered the origin center of chestnut (Castanea sativa), which is characterized by climatic transition from the Mediterranean to the Euro-Siberian area. Mostly, areas of chestnut are concentrated in the countries around the Mediterranean Basin, thriving in regions with humid and Pré-Atlantic bioclimates. In Portugal, more than 95% of the chestnut area is located in the Center and North side of Portugal. This is an anisohydry species, characterized by good hydroplasticity: 90% reduction in A occurs when Ψ_wstem drops to −1.25 MPa, and a 50% reduction in A occurs at values of −1.7 MPa. The highest fatty acid contents in chestnut chloroplasts are a-linolenic acid (18:3), ranging between 40 and 50% of the total amount and being the unsaturated/saturated 2.27 for Longal. New strategies are being investigated in order to increase tolerance against those abiotic factors in chestnut species. They include the use of innovative irrigation techniques, which can increase production 22–37%. Fertilization with silicone (Si) has been investigated to promote the tolerance of plants against heat and drought stresses. Breeding programs, mostly (in Europe) against ink disease, have been performed since the middle of the XX century to create new genotypes (such the Portuguese ColUTAD^®). ClimCast, a network of orchards, was created in Portugal with the aim of responding to the new challenges facing orchards in the context of climate change. Full article

Previous studies assessing population exposure to heat stress have focused primarily on environmental heat loads without accounting for variations in human thermo–physiological responses to heat. A novel 30-year (1991–2020) human thermal bioclimate dataset, consisting of hourly mPET (modified physiologically equivalent temperature) values for diverse populations, was employed in the present study to assist in addressing this gap. Focusing on the Athens urban area (AUA), Greece, the climatology and long-term trends in acclimatization-based strong heat stress (accliSHS) experienced by average male and female adult and senior individuals during the warm period of the year (April–October) were investigated. Results showed that an average adult (senior) in AUA experienced, on average, approximately 13 (18) additional days with at least 1 h accliSHS in 2020 compared with 1991. The increasing rates per year were particularly pronounced for days with ≥6 h accliSHS, indicating a rise in the daily duration of heat stress in AUA from 1991 to 2020. Combining the variations in climate and demographics in AUA during the examined 30-year period, the long-term trends in ≥1 h accliSHS exposure for the study population types were further examined. This analysis revealed that seniors’ exposure to ≥1 h accliSHS in AUA increased by up to +153,000 person-days $\times$ year⁻¹ from 1991 to 2020. Increasing population aging was the main driver of this outcome, highlighting the urgent need for heat–health action planning in Greece. Full article

This paper presents a comprehensive revision of the dry grasslands, specifically the alliance Chrysopogono grylli-Koelerion splendentis within the order Scorzoneretalia villosae along the eastern Adriatic, aimed at developing a formalized classification of this vegetation type. The revision is based on 490 relevés, including 44 newly sampled from the loci classici of previously identified associations, alongside additional relevés from the phytosociological literature. Both hierarchical and non-hierarchical cluster analysis, as well as NMS ordination, were employed to delineate the main vegetation types. Although numerous associations have been described to date, several were found to be floristically similar and were subsequently merged. Ultimately, 15 associations and one plant community were identified, including the description of a new association, Sideritido purpureae-Asphodeletum ramosi, from Montenegro, along with four new subassociations. The associations of the Chrysopogono grylli-Koelerion splendentis predominantly occur in the sub-Mediterranean variant of the temperate bioclimate. While this study provides a comprehensive framework for the syntaxonomic diversity of this alliance, it also underscores the need for additional phytosociological data from poorly known areas within its distribution range, particularly in the southernmost regions and inland areas (e.g., Albania, Bosnia and Herzegovina). Full article

Climate change is altering the temperature and precipitation patterns in the Iberian Peninsula and on the Balearic Islands, with potential impacts on the distribution of plant communities. This study analyses the evolution of bioclimatic units in this region during the 1953–2022 period. Data from 3668 weather stations distributed throughout the study area were analysed. Two 35-year periods (1953–1987 and 1988–2022) were compared to assess changes in macrobioclimates and bioclimates. The results showed expansion of the Mediterranean macrobioclimate, whose total area increased by 6.93%, mainly at the expense of the Temperate macrobioclimate. For bioclimates, a trend towards more xeric and continental conditions was observed in the Mediterranean region, while temperate areas moved towards homogenisation of climate conditions. Likewise, two new bioclimates were detected, which indicate the emergence of new climate conditions. These results suggest a reorganisation of bioclimatic conditions, with particular implications for biodiversity in mountainous and transitional areas, where endemic species face higher risks of habitat loss. This study provides useful information for developing targeted conservation strategies, establishing a baseline for monitoring future changes and developing early warning systems for vulnerable ecosystems, thus supporting the design of climate-adapted conservation measures in the region studied. Full article

This work establishes the relationship between climate, bioclimate, and forest ecosystems and highlights the need to teach these topics in educational institutions. It was found that such knowledge is not currently taught in universities, leading to scarce or non-existent teacher training in these areas. However, the teaching of bioclimatic aspects over a three-year period as a basis for land use planning, has shown highly positive results. The objective is to propose the teaching of bioclimatology to future managers and teachers in order to obtain a balanced environmental development. The analysis of bioclimatic diagrams makes it possible to stipulate the duration of the water reserve in the soil. This is essential for agricultural and forestry management. The edaphic factor and the bioclimatic ombrotclimatic (Io) and thermoclimatic (It/Itc) indexes condition the types of forests and crops that can exist in a territory, with the particularity that the ombrotype is conditioned by the edaphic factor, which allows a decrease in the ombrothermal index, expressed by the ombroedaphoboxerophilic index (Ioex). The humid ombrotypes condition the presence of Abies pinsapo, Quercus pyrenaica, Q. broteroi, and Q. suber, and the dry ones Q. rotundifolia and Olea sylvestris. Full article

This study deals with the information gap on desertification risk for wetland habitat types in Natura 2000 network sites of Greece. Using the Environmentally Sensitive Areas (ESA) index as a proxy, all Natura 2000 wetland habitat types have been assessed and assigned to desertification risk categories. The assessment was conducted at the national, regional, and local scales in order to provide different outcomes for targeted support on decision and policy making regarding restoration and conservation measures. The main results document that circa 20% of wetland habitat types area are considered under desertification risk, while circa 10% are considered as potentially affected by desertification. It was also shown that there should be prioritization of the habitat types that need attention due to their inclusion in the different desertification risk categories. The study also highlights the administrative regions (NUTS2) and Natura 2000 sites and the need to structure, draft, and implement conservation projects to mitigate wetlands’ risk as well as the use of wetlands as primary nature-based solutions (NbS) in the battle with desertification and climate change. Management implications are also provided from the perspective of habitat restoration as well as for their exploitation as valuable NbS for biodiversity conservation and ecosystem services maintenance. Full article

This study predicted the potential habitats of Monochamus alternatus, a known vector of Bursaphelenchus xylophilus, utilizing its occurrence points and environmental variables—ecoclimatic indices and terrain variables. SSP2-4.5 and SSP5-8.5 scenarios were applied to predict the potential habitat under climate change. We secured the 20,514 occurrence points of Monochamus alternatus among the points with geographic coordinates of PWD-affected trees (2017–2022). The maximum entropy model (MaxEnt) and ensemble model (ensemble) were used to identify and compare the variability of potential habitats in the baseline period, near future, intermediate future, and distant future. At the outset, both the MaxEnt and the ensemble models showed a high model fit, and the ensemble was judged to be relatively superior. Next, both models showed that the habitat will expand northward according to climate change scenarios. Finally, the binary maps were superimposed to examine the differences between individual and multiple models; both models showed similar distributions in the baseline period and near future. Nonetheless, MaxEnt tended to overestimate expansion in the intermediate and far future. In the future, it is expected that the accuracy and reliability of forecasts can be improved by building optimized models to reduce uncertainty by supplementing field data and collaborating with model experts. Full article

It is crucial to have precise and current maps of aboveground biomass (AGB) in boreal forests to accurately track global carbon levels and develop effective plans for addressing climate change. Remote sensing as a cost-effective tool offers the potential to update AGB maps for boreal forests in real time. This study evaluates different machine learning algorithms, namely Light Gradient Boosting Machine (LightGBM), Extreme Gradient Boosting (XGBoost), Random Forest (RF), and Support Vector Regression (SVR), for predicting AGB in boreal forests. Conducted in the Qilian Mountains, northwest China, the study integrated field measurements, space-borne LiDAR, optical remote sensing, and environmental data to develop a training dataset. Among 34 variables, 22 were selected for AGB estimation modeling. Our findings revealed that the LightGBM AGB model had the highest level of accuracy (R² = 0.84, RMSE = 15.32 Mg/ha), outperforming the XGBoost, RF, and SVR AGB models. Notably, the LightGBM AGB model effectively addressed issues of underestimation and overestimation. We also observed that the disparity in accuracy among the models widens with increasing altitude. Remarkably, the LightGBM AGB model consistently demonstrates optimal performance across all elevation gradients, with residuals generally below 25 Mg/ha for low-value overestimation and below −38 Mg/ha for high-value underestimation. The model developed in this study presents a viable and alternative approach for enhancing AGB estimation accuracy in boreal forests based on remote sensing technology. Full article