Search Results (355)

Pines (genus Pinus) are a diverse group of conifers widely distributed across the Northern Hemisphere, comprising more than 110 species worldwide. In Europe, pines are a defining component of forests, occupying environments that range from dry Mediterranean lowlands to high-elevation alpine zones. They support a wide spectrum of ecosystem services, from timber and non-wood products to protection, biodiversity, and cultural values. In this review, we bring together ecological traits, silvicultural practices, and management considerations for ten European pine species. This review examines ten major European pine species, including Scots pine (Pinus sylvestris), maritime pine (P. pinaster), stone pine (P. pinea), Aleppo pine (P. halepensis), black pine (P. nigra), mountain pine (P. mugo), Swiss stone pine (P. cembra), Turkish pine (P. brutia), Bosnian pine (P. heldreichii), and Macedonian pine (P. peuce). Together, these species span a wide range of European environments, with Pinus sylvestris showing the broadest distribution. Despite the extensive literature on pine species, information on their ecological, silvicultural, and management attributes remains fragmented across disciplines. To bridge this gap, this review draws on an expert-curated core of scientific and technical literature complemented by a structured literature search adapted from the PRISMA framework, compiling within a single framework their main ecological and silvicultural characteristics, altitudinal range, growth patterns, stand diversity, and management practices and the principal goods and ecosystem services they provide. The comparative analysis highlighted distinct functional groups among European pines, illustrating contrasting adaptive strategies across environmental gradients, with altitudinal distributions ranging from sea level to 2400 m. Mediterranean species, such as P. halepensis, P. pinaster, and P. brutia, generally showed higher drought and fire adaptation, whereas mountain taxa such as P. cembra, P. mugo, and P. heldreichii displayed greater cold tolerance but increased vulnerability due to restricted climatic niches and slow regeneration. Broadly distributed species, such as P. sylvestris and P. nigra, exhibited intermediate ecological strategies, with responses strongly influenced by regional climatic conditions. By integrating evidence on distribution patterns, functional traits, growth patterns, and management practices, this review provides a comparative framework to support adaptive forest management and informed species selection, helping to safeguard forest functions and their associated benefits under ongoing climate change. Full article

High-altitude Andean páramo ecosystems are critical socio-ecological assets that provide key regulating and supporting services, yet they remain highly vulnerable to climate change and anthropogenic pressures. Understanding these services requires frameworks that integrate biophysical capacity with social valuation and demographic accessibility. In this study, we mapped and assessed belowground and aboveground carbon storage and species habitat provision across the altitudinal gradient (3160–4400 m.a.s.l.) of Cajas National Park (PNC), Ecuador, using a spatially explicit socio-ecological approach. Carbon stocks were modeled following The Intergovernmental Panel on Climate Change (IPCC) 2019 Refined Guidelines, combining reference soil organic carbon (SOC) stocks with aboveground biomass coefficients. Habitat provision was modeled through a multi-factor suitability index integrating Normalized Difference Vegetation Index (NDVI), elevation, water bodies, and interpolated climate surfaces. Biophysical supplies were weighted via a Delphi-based expert consultation and integrated with demographic census data (173,672 inhabitants in four adjacent parishes) to estimate actual service capture and effective benefits. Total carbon stocks in PNC were estimated at 1.49 million Mg C, with volcanic Andisols acting as the primary reservoir (97.5% of the total stock). Habitat suitability was highly heterogeneous, with critical refuge patches clustered around the park’s lacustric network and stable microclimatic zones. Socio-ecological mapping revealed that the eastern boundary of the park represents the highest hotspot of effective benefit capture, directly supplying vital water regulation and cultural services to the peri-urban populations of Sayausí and Baños. These results demonstrate the utility of integrating standard IPCC guidelines with the ECOSER protocol, offering a repeatable and transparent framework to guide spatial conservation planning and sustainable land-use zoning in vulnerable high-altitude protected areas. Full article

Seasonal freeze–thaw processes are important disturbances regulating soil carbon cycling in mid- to high-latitude mountain ecosystems, yet the mechanisms underlying carbon-fraction transformation and greenhouse gas emissions across vegetation types remain unclear. Here, we investigated five typical vegetation types along a 400–1500 m elevational gradient on the southern slope of the Altai Mountains. We measured topsoil organic carbon fractions, including particulate organic carbon (POC), mineral-associated organic carbon (MAOC), and dissolved organic carbon (DOC), extracellular enzyme activities, and CO₂ and CH₄ fluxes during the defrosting and melting periods to characterize vegetation-specific patterns of freeze–thaw-driven carbon stability. The results showed the following: (1) During the melting period, POC loss was significant in the low-elevation desert zone, riparian arbor forest, and floodplain meadow, with losses exceeding 90% in the latter two vegetation types. MAOC in the high-elevation mixed coniferous–broadleaf forest increased during the melting period. (2) The activities of carbon-acquiring enzymes, including CBH and AG, and the nitrogen-acquiring enzyme LAP generally decreased during the melting period, whereas the activity of the phosphorus-acquiring enzyme ALP increased in some vegetation types. This enzymatic shift may have partly constrained CO₂ release per unit of mineralized organic carbon, but it did not reverse the overall increase in carbon emissions during the melting period. (3) Carbon dynamics during the defrosting period were mainly characterized by the temporary retention of mineralization-derived carbon in dissolved forms within the DOC pool under low-temperature conditions, followed by a shift during the melting period toward carbon emissions jointly regulated by hydrothermal conditions and extracellular enzyme activities. This study showed pronounced differences in carbon responses among typical vegetation habitats during freeze–thaw processes. These differences may be jointly influenced by vegetation composition, elevation, hydrothermal conditions, and soil properties, revealing an elevational pattern of carbon loss at low elevations and carbon-fraction reorganization at high elevations. These findings suggest that carbon-balance assessments in arid mountain regions should incorporate stratified identification and classified evaluation based on the distribution of dominant vegetation types. Full article

Bamboo shoots, as the most nutritionally valuable food source for giant pandas during key reproductive seasons, are critical for conservation because their availability and timing directly influence panda foraging and habitat use. However, the molecular mechanisms through which altitudinal temperature variation governs rhizome shooting in staple food bamboos remain largely unknown. Here, we performed integrated metabolomic and transcriptomic analyses of Fargesia rufa rhizomes collected along an elevational gradient (1000 m, 1500 m, and 2000 m), with a critical paired comparison at 2000 m between a non-shooting cold gully-edge site (16.4 °C) and a shooting warm gully-center site (21.1 °C), where soil temperature is elevated by approximately 4 °C due to prolonged solar exposure. Our results demonstrate that soil temperature, rather than elevation per se, acts as the primary driver of rhizome shooting, with an apparent threshold near 20 °C. A core shooting metabolome (CSM) comprising 843 metabolites was consistently accumulated across all shooting conditions, which featured gibberellin/auxin precursors, TCA cycle intermediates, and phenylpropanoid compounds. Correspondingly, a core shooting transcriptome (Rh_shooting) of 10,970 genes was identified, which resolved into three functionally distinct temporal clusters: “shooting-on” (activated upon threshold crossing, enriched in hormone signaling and cell wall metabolism), “temperature-dose” (progressively upregulated with rising temperature, enriched in energy metabolism and defense), and “microenvironment-enhanced” (specifically upregulated in the high-elevation warm gully, enriched in photosynthesis and antioxidant pathways). Integrative network analysis further revealed zeatin riboside and multiple hub genes as central coordinators linking hormone signaling, energy metabolism, and cell wall remodeling. Collectively, these findings establish a molecular framework linking altitudinal temperature variation to bamboo rhizome regeneration—a process that directly determines the spatiotemporal availability of bamboo shoots for giant pandas. This work provides mechanistic insights into giant panda foraging ecology and has direct implications for predicting habitat quality under climate change and informing evidence-based conservation strategies for this flagship species and its critical food resource. Full article

Opuntia ficus-indica (L.) Mill. is a crassulacean acid metabolism (CAM) xerophyte whose intraspecific morphological diversity remains poorly documented in Andean agroecosystems. This study characterized the phenotypic diversity of 55 accessions collected along an altitudinal gradient in the dry inter-Andean valleys of northern Ecuador. Twenty morphological descriptors were used to analyse the data. Quantitative descriptors showed moderate to high variability, with reproductive and defensive characters exhibiting greater variation than vegetative descriptors. MCA revealed substantial chromatic diversity, with fruit peel and pulp color emerging as the strongest qualitative discriminators among morphotypes. Cluster analysis identified three statistically distinct groups: a small-fruited, highly spinescent morphotype restricted to the most arid sites; an intermediate and phenotypically diverse morphotype distributed across all provinces; and a large-fruited, low-spinescence morphotype with the highest seed numbers, consistent with a more advanced domestication trajectory. The primary differentiation axis reflected a trade-off between spine investment and reproductive output. Five discriminant descriptors—fruit weight, spine length, seed number, peel color, and pulp color—provide a robust baseline for germplasm characterization and support conservation, breeding, and nutraceutical valorization in Andean drylands. The findings of this research contribute to filling a critical knowledge gap regarding Andean cactus pear germplasm, providing a scientific basis for conservation, sustainable management, and future breeding and agro-industrial initiatives. Full article

Tropical rocky outcrops are considered biological islands with high endemism and challenging environmental conditions. Ant gardens (AGs) represent a sophisticated ant–plant mutualism that may facilitate plant establishment in these restrictive habitats. This study conducted a comprehensive floristic inventory of Morro de Calzada (MdC), a tropical rocky outcrop in the Peruvian Andean–Amazonian piedmont, and evaluated the relationship between plant composition and the presence of AGs across six sampling units (912–1413 m a.s.l.). A total of 310 vascular plant species (77 families, 180 genera) were recorded. Melastomataceae (37 spp.), Moraceae (18 spp.), and Rubiaceae (18 spp.) were the most diverse families. Species richness decreased with elevation, with sampling unit 2 (951–1050 m a.s.l.) showing the highest richness (170 spp.) and sampling unit 6 the lowest (52 spp.). AGs were concentrated in the sampling unit SU4, which hosted the highest phorophyte richness (12 spp.) and number of gardens (22); this diversity was possibly driven by canopy and host-tree structure. The ant Azteca trailii tococae was the primary builder, showing strong associations with Meriania aff. microflora and Ficus citrifolia. Epiphyte composition was dominated by Anthurium gracile, with Epiphyllum phyllanthus as a notable xerophytic element. AG dimensions correlated positively with host-tree DBH and height. High floristic turnover among sampling units (Jaccard dissimilarity 0.78–0.94) contrasted with structural homogeneity of gardens, indicating ecological plasticity of Azteca trailii. The study highlights the role of AGs as ecosystem engineers in rocky outcrops and emphasizes the conservation value of MdC, which harbors endemic and threatened species. Sampling unit SU4 emerges as a functional hotspot for ant–plant mutualisms. Full article

Norway spruce (Picea abies [L.] Karst.) is a paleoecologically relevant species in the Northern Hemisphere since the early Holocene. P. abies populations are sensitive to climate fluctuations; Asian treeline species are under nature protection. The thick wax and cuticle layers of spruce needles enhance their durability, making them frequent in glacial lake and peat bog cores. Their phytoliths are easily recognizable in sedimentary material and can be studied in subfossil tissues. The aim of this study is to assess the applicability of characteristic phytoliths from Norway spruce needles in paleoclimate research. We examined phytolith presence as a function of altitude in plant samples from three Carpathian Mountain ranges. Temperature data loggers were deployed at sampling sites to better characterize the thermal background of phytolith formation. Our results show a decreasing trend in phytolith presence with increasing elevation. The phytoliths formed by the transfusion tissue represent a sensitive type, indicating that spruce needle phytolith production responds to microclimatic variation. These findings are worth further investigation and validation. The study also provides a basis for refining the calculation method, contributing to the development of a potential “phytolith thermometer” for paleoclimatic reconstruction. Full article

Introduction: Survival at high altitudes requires efficient energy management. Although hypobaric hypoxia alters thermodynamic efficiency, the independent impact of altitude versus demographic factors on basal and exertional caloric costs remains uncertain. We evaluated these variables in chronic residents across four Peruvian altitudes. Methodology: A cross-sectional study was conducted involving 141 healthy adults (aged 18–38 years) residing in Lima (154 m), Arequipa (2335 m), Puno (3827 m), and La Rinconada (5100 m). Resting energy expenditure (REE) and physical activity energy expenditure (PAEE) were estimated using continuous photoplethysmography; PAEE was assessed following the 6-min walk test (6MWT). Hemodynamic parameters, oxygen saturation (SpO₂), and hemoglobin (Hb) levels were evaluated. An analysis of covariance (ANCOVA) was employed to adjust metabolic variations for age, sex, and body mass index (BMI). Results: Unadjusted data demonstrated a progressive increase in REE and PAEE proportional to altitude. However, the ANCOVA revealed that the independent effect of the city of residence was no longer statistically significant after adjusting for anthropometric and demographic covariates. Physiologically, the SpO₂ deficit imposed a high metabolic demand (an increase of approximately 1.29 kcal in REE for every 1% drop in SpO₂). Hb concentrations above 18 g/dL were associated with an exponential increase in caloric cost driven by blood hyperviscosity. A positive correlation was identified between Hb levels and energy expenditure (EE), which proved to be statistically stronger in the female cohort. Under extreme hypoxia conditions (5100 m), men exhibited a significantly higher PAEE (50.60 ± 10.17 kcal vs. 40.78 ± 5.21 kcal). Despite the increased biological effort, mechanical performance in the 6MWT remained constant across cities. Conclusions: There is no independent relationship between REE and the altitude of residence. The initial unadjusted relationship between altitude and EE was negated by covariates, particularly body mass index (BMI). The preservation of functional capacity at the expense of the energy economy underscores the profound physiological burden of Andean acclimatization. Full article

Reconstructing long-term continuous precipitation series is essential for characterising rainfall variability, detecting hydroclimatic trends, and supporting water resource management in semi-arid Mediterranean regions. This study analyses rainfall variability in the Sebou watershed (northern Morocco, ~40,000 km²) over 1980–2024, using eleven stations spanning an altitudinal gradient from 5 m (Kénitra) to 1478 m (Aït Khebbach). To reconstruct continuous monthly series over 44 hydrological years, ERA5 reanalyses were bias-corrected using seasonal Quantile Mapping (QM) versus station data, available only until 2001. Raw ERA5 data show a generalised positive bias increasing with altitude (from +8.9% at Kénitra to +112.9% at Pont du Mdez), with severe NSE degradation in complex relief areas (NSE = −3.834 at Pont du Sker). After QM correction, the mean bias drops to −0.1% and mean NSE improves from −0.32 to +0.68. Cross-validation (100 random-splitting iterations) confirms correction robustness, yielding a mean NSE of 0.594 ± 0.076. The stationarity hypothesis at the 2001/2002 boundary is validated for all eleven stations through the Pettitt test applied directly to the ERA5–OBS bias series (p = 1.000). Mann–Kendall trend analysis reveals no significant trend for most stations, reflecting strong natural decadal variability of the semi-arid Mediterranean regime, which may limit trend detection over the study period. SPI-12 analysis identifies four major drought episodes (1981–1985, 1991–1995, 1999–2002, 2018–2022) and notable wet surpluses (1995–1996, 2008–2010). Aïn Timédrine (650 m) shows notable chronic drought vulnerability (9 years with SPI-12 < −1.0). This study provides the first continuous 44-year monthly precipitation series for the Sebou basin, quantifies the ERA5 elevation mismatch (Δz) as the dominant bias predictor (r = −0.828, p = 0.002), and delivers a multi-scale drought characterisation (SPI-3, SPI-6, SPI-12), constituting a valuable dataset for long-term hydrological modelling. Full article

Climate change is increasingly altering forest ecosystems worldwide, reshaping species phenology, productivity, and resilience. In this study, we evaluate the phenoclimatic responses of European beech (Fagus sylvatica L.) forests across Europe by assessing their phenological responses to climate change across climatic zones and altitudinal gradients using remote-sensing data. We used 24 years of satellite-derived land-surface phenology and climate data to quantify phenological trends at 356 beech-dominant locations from the EUFGIS database, of which 274 remained after land-cover homogeneity and data-quality filtering. To reduce land-cover mixing at the MODIS resolution, we applied a land-cover homogeneity filter based on ESA WorldCover. The analysis was structured across the seven climatic zones in Europe. Phenological responses to climate change were assessed through climate–phenology sensitivity analyses and a composite phenoclimatic departure index integrating climatic trends, phenological shifts, and interannual variability. Phenological sensitivity varied across climatic zones and phenological phases. Temperature-related sensitivity was most evident in spring in several continental zones, whereas precipitation sensitivity was more apparent for growing-season length and autumn timing in some regions. The composite phenoclimatic departure analysis showed that regional profiles were not uniform across the European beech range. Although warming was widespread, precipitation trends, phenological shifts, and interannual variability differed strongly among zones. These findings demonstrate heterogeneous and location-specific phenoclimatic responses across Europe, but the departure index should not be interpreted as a direct measure of ecological vulnerability or risk. Full article

Unraveling rhizosphere microbial assembly and plant–microbe co-adaptation is essential for understanding how fragile mountain ecosystems respond to environmental stress. This study investigated the rhizosphere bacterial communities of Carex enervis C. A. Mey, a dominant species in arid and semi-arid alpine meadows, along an altitudinal gradient from 1160 to 1860 m. By integrating high-throughput sequencing, iCAMP-based community assembly analysis, niche differentiation assessment, and partial least squares path modeling, we examined associations among macro-environmental gradients, rhizosphere soil conditions, bacterial community assembly, and ammonium nitrogen availability. The results revealed a dual-track assembly pattern. Macro-environmental heterogeneity, particularly in elevation and precipitation, was associated with rare microbial diversity primarily through heterogeneous selection. In contrast, abundance-weighted patterns suggested homogeneous selection of core dominant microbial groups in the rhizosphere. Within several dominant genera, closely related taxa showed divergent covariation patterns rather than uniform responses along the environmental gradient, suggesting potential fine-scale differentiation in environmental responses. Path analysis further indicated that enzyme-based rhizosphere activity proxies were associated with the relative abundance of microbial response groups and with the availability of ammonium nitrogen. These findings suggest that the rhizosphere conditions of Carex enervis are associated with bacterial assembly patterns, fine-scale taxon differentiation, and nutrient-related soil variables along the elevational gradient. This study provides new insight into plant–microbe co-adaptation in arid and semi-arid mountain ecosystems. Full article

Despite the economic and medicinal value of the tree species Litsea mollis in southern China’s mountain forests, its wild populations remain understudied in terms of their adaptation to altitudinal gradients. This study examined L. mollis populations spanning altitudes of 760–1550 m in Nanshan Park, Hunan Province, to evaluate variation in leaf traits and fruit quality with elevation changes as well as associations with soil chemical properties. Results revealed that increasing altitude corresponded with higher leaf mass, chlorophyll content, soluble compound levels, enzyme activity, and various fruit quality traits (e.g., longitudinal and transverse diameters, weight, and fat, protein, carbohydrate, vitamin A, essential oil, and citral levels). Conversely, leaf area, specific leaf area, petiole length, fruit shape index, fruit stalk length, and ash content declined as altitude rose. Redundancy analysis indicated that specific leaf area, peroxidase activity, and Malondialdehyde content are the primary leaf characteristics influencing fruit quality, and soil pH and total nitrogen, alkaline nitrogen, and available potassium levels were key chemical factors shaping ecological adaptation and fruit quality of L. mollis along the altitudinal gradient. Overall, L. mollis augments light capture and nutrient acquisition by modifying morphological traits, such as leaf area (26.17%) and specific leaf area (44.32%), facilitating adaptation to low-light and nutrient-poor conditions at lower elevations. At higher elevations, plants preferentially allocate resources to increase leaf mass (33.33%) and chlorophyll content (19.02%), improving photosynthetic efficiency, osmotic regulation, and metabolic enzyme activity. This resource allocation promotes nutrient and secondary metabolite accumulation in fruit, enhancing plant stress resistance and fruit quality. This synergistic relationship represents an adaptive adjustment by L. mollis in allocating growth and reproductive resources across different altitude environments. These findings provide a theoretical framework for understanding altitudinal adaptation in L. mollis and offer practical guidance for its introduction, cultivation, and fruit quality improvement in high-elevation regions. Full article

This study investigates the spatiotemporal evolution of ecological environment quality and its driving mechanisms in the Sichuan section of the Yellow River Basin using Landsat imagery from 2000 to 2023. The Remote Sensing Ecological Index (RSEI) was constructed on the Google Earth Engine platform, and a comprehensive evaluation model was developed using principal component analysis. Sen’s slope, the Mann–Kendall test, and the Hurst exponent were applied to assess temporal trends and future persistence, while the optimal parameter-based Geodetector model was used to identify the driving factors of spatial differentiation. Results show that: (1) ecological environment quality exhibits a fluctuating but overall increasing trend, with a multi-year mean RSEI of 0.58, indicating a transition from “moderate” to “good–excellent” conditions; (2) spatially, ecological quality demonstrates significant heterogeneity and clear altitudinal gradients, with better conditions in the northwest than in the southeast, where low- and mid-altitude areas show higher ecological quality and stronger improvement, whereas high-altitude areas remain relatively poor due to strong natural constraints; (3) the spatial differentiation is jointly driven by multiple factors, among which precipitation and temperature are dominant, elevation exerts a fundamental constraint, and human activity plays a relatively minor role, while the interaction between climate and topographic factors shows the strongest explanatory power. These findings provide insights into the evolution and drivers of ecological environment quality in high-altitude regions and support ecological protection and regional management in the upper Yellow River Basin. Full article

The Azorean livestock system depends strongly on pasture-based feeding, making regional agriculture sensitive to global warming. This study assessed the effects of experimental warming on forage productivity, forage quality, and soil fertility in three pastures along an altitudinal gradient over two years (2020–2021). Open-top chambers were used to create warmer conditions, and soil and forage samples were analysed for chemical and mineral composition. Warming increased net forage productivity by 30% and 70% in the lower-altitude pasture in 2020 and 2021, respectively, and by 56% in the intermediate-altitude pasture in 2021. Responses at the highest altitude were weak or not significant. Effects on forage quality were seasonal. In winter and early spring, warming increased crude protein by 14–45% and ash by 4–13% in the lower- and intermediate-altitude pastures. Later in the season, warming was associated with higher fibre fractions, especially in the intermediate-altitude pasture, indicating faster plant maturation. Soil factors significantly structured forage quality, with phosphorus as the main driver. This study contributes to understanding how climate change may affect the sustainability of pasture-based livestock systems in island environments, supporting the development of adaptive management strategies to safeguard productivity, soil fertility, and ecosystem resilience. Full article

Forest conversion from natural forests to secondary forests and plantations has significantly altered wildlife habitats in subtropical regions. However, the drivers of disparities in bird and mammal multidimensional diversity between these forest types remain poorly understood. We analyzed a four-year camera-trapping dataset to compare the taxonomic, functional, and phylogenetic diversity and community structure of birds and mammals. Our results indicated that forest conversion impacts biodiversity differently across taxa. Birds exhibited higher taxonomic and phylogenetic diversity in secondary forests than in plantations. A similar pattern was also evident for birds among different stand types. However, mammals exhibited considerable taxonomic diversity but showed higher phylogenetic diversity and structure in secondary forests. A similar pattern was also evident for mammals among different stand types. Beta diversity revealed significant differences in bird taxonomic composition and mammal phylogenetic composition between secondary and plantation forests. Furthermore, elevation primarily influenced bird taxonomic diversity, phylogenetic diversity and structure in secondary forests, whereas mammal functional diversity, phylogenetic diversity and structure were more sensitive to elevational changes in both secondary and plantation forests. These findings reveal that birds and mammals respond distinctively to forest conversion. We emphasize that management strategies must be group-specific. For birds, we recommend prioritizing the preservation of secondary forests as biodiversity refugia and transforming structurally simplified plantations into complex habitats by retaining legacy trees and native understory vegetation. For mammals, conservation should prioritize landscape-scale connectivity by protecting continuous forest corridors along altitudinal gradients. Practically, this requires restricting further fragmentation of high-altitude habitats and restoring native vegetation in degraded corridors to facilitate dispersal and maintain the phylogenetic integrity of mammal communities. Full article