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24 pages, 7997 KiB  
Article
Comparative Analysis of Habitat Expansion Mechanisms for Four Invasive Amaranthaceae Plants Under Current and Future Climates Using MaxEnt
by Mao Lin, Xingzhuang Ye, Zixin Zhao, Shipin Chen and Bao Liu
Plants 2025, 14(15), 2363; https://doi.org/10.3390/plants14152363 - 1 Aug 2025
Viewed by 247
Abstract
As China’s first systematic assessment of high-risk Amaranthaceae invaders, this study addresses a critical knowledge gap identified in the National Invasive Species Inventory, in which four invasive Amaranthaceae species (Dysphania ambrosioides, Celosia argentea, Amaranthus palmeri, and Amaranthus spinosus) [...] Read more.
As China’s first systematic assessment of high-risk Amaranthaceae invaders, this study addresses a critical knowledge gap identified in the National Invasive Species Inventory, in which four invasive Amaranthaceae species (Dysphania ambrosioides, Celosia argentea, Amaranthus palmeri, and Amaranthus spinosus) are prioritized due to CNY 2.6 billion annual ecosystem damages in China. By coupling multi-species comparative analysis with a parameter-optimized Maximum Entropy (MaxEnt) model integrating climate, soil, and topographical variables in China under Shared Socioeconomic Pathways (SSP) 126/245/585 scenarios, we reveal divergent expansion mechanisms (e.g., 247 km faster northward shift in A. palmeri than D. ambrosioides) that redefine invasion corridors in the North China Plain. Under current conditions, the suitable habitats of these species span from 92° E to 129° E and 18° N to 49° N, with high-risk zones concentrated in central and southern China, including the Yunnan–Guizhou–Sichuan region and the North China Plain. Temperature variables (Bio: Bioclimatic Variables; Bio6, Bio11) were the primary contributors based on permutation importance (e.g., Bio11 explained 56.4% for C. argentea), while altitude (e.g., 27.3% for A. palmeri) and UV-B (e.g., 16.2% for A. palmeri) exerted lower influence. Model validation confirmed high accuracy (mean area under the curve (AUC) > 0.86 and true skill statistic (TSS) > 0.6). By the 2090s, all species showed net habitat expansion overall, although D. ambrosioides exhibited net total contractions during mid-century under the SSP126/245 scenarios, C. argentea experienced reduced total suitability during the 2050s–2070s despite high-suitability growth, and A. palmeri and A. spinosus expanded significantly in both total and highly suitable habitat. All species shifted their distribution centroids northward, aligning with warming trends. Overall, these findings highlight the critical role of temperature in driving range dynamics and underscore the need for latitude-specific monitoring strategies to mitigate invasion risks, providing a scientific basis for adaptive management under global climate change. Full article
(This article belongs to the Section Plant Ecology)
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24 pages, 3832 KiB  
Article
Temperature and Precipitation Extremes Under SSP Emission Scenarios with GISS-E2.1 Model
by Larissa S. Nazarenko, Nickolai L. Tausnev and Maxwell T. Elling
Atmosphere 2025, 16(8), 920; https://doi.org/10.3390/atmos16080920 - 30 Jul 2025
Viewed by 255
Abstract
Atmospheric warming results in increase in temperatures for the mean, the coldest, and the hottest day of the year, season, or month. Global warming leads to a large increase in the atmospheric water vapor content and to changes in the hydrological cycle, which [...] Read more.
Atmospheric warming results in increase in temperatures for the mean, the coldest, and the hottest day of the year, season, or month. Global warming leads to a large increase in the atmospheric water vapor content and to changes in the hydrological cycle, which include an intensification of precipitation extremes. Using the GISS-E2.1 climate model, we present the future changes in the coldest and hottest daily temperatures as well as in extreme precipitation indices (under four main Shared Socioeconomic Pathways (SSPs)). The increase in the wet-day precipitation ranges between 6% and 15% per 1 °C global surface temperature warming. Scaling of the 95th percentile versus the total precipitation showed that the sensitivity for the extreme precipitation to the warming is about 10 times stronger than that for the mean total precipitation. For six precipitation extreme indices (Total Precipitation, R95p, RX5day, R10mm, SDII, and CDD), the histograms of probability density functions become flatter, with reduced peaks and increased spread for the global mean compared to the historical period of 1850–2014. The mean values shift to the right end (toward larger precipitation and intensity). The higher the GHG emission of the SSP scenario, the more significant the increase in the index change. We found an intensification of precipitation over the globe but large uncertainties remained regionally and at different scales, especially for extremes. Over land, there is a strong increase in precipitation for the wettest day in all seasons over the mid and high latitudes of the Northern Hemisphere. There is an enlargement of the drying patterns in the subtropics including over large regions around Mediterranean, southern Africa, and western Eurasia. For the continental averages, the reduction in total precipitation was found for South America, Europe, Africa, and Australia, and there is an increase in total precipitation over North America, Asia, and the continental Russian Arctic. Over the continental Russian Arctic, there is an increase in all precipitation extremes and a consistent decrease in CDD for all SSP scenarios, with the maximum increase of more than 90% for R95p and R10 mm observed under SSP5–8.5. Full article
(This article belongs to the Section Meteorology)
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17 pages, 3919 KiB  
Article
On the Links Between Tropical Sea Level and Surface Air Temperature in Middle and High Latitudes
by Sergei Soldatenko, Genrikh Alekseev and Yaromir Angudovich
Atmosphere 2025, 16(8), 913; https://doi.org/10.3390/atmos16080913 - 28 Jul 2025
Viewed by 189
Abstract
Change in sea level (SL) is an important indicator of global warming, since it reflects alterations in several components of the climate system at once. The main factors behind this phenomenon are the melting of glaciers and thermal expansion of ocean water, with [...] Read more.
Change in sea level (SL) is an important indicator of global warming, since it reflects alterations in several components of the climate system at once. The main factors behind this phenomenon are the melting of glaciers and thermal expansion of ocean water, with the latter contributing about 40% to the overall rise in SL. Rising SL indirectly indicates an increase in ocean heat content and, consequently, its surface temperature. Previous studies have found that tropical sea surface temperature (SST) is critical to regulating the Earth’s climate and weather patterns in high and mid-latitudes. For this reason, SST and SL in the tropics can be considered as precursors of both global climate change and the emergence of climate anomalies in extratropical latitudes. Although SST has been used in this capacity in a number of studies, similar research regarding SL had not been conducted until recently. In this paper, we examine the links between SL in the tropical North Atlantic and North Pacific Oceans and surface air temperature (SAT) at mid- and high latitudes, with the aim of assessing the potential of SL as a predictor in forecasting SAT anomalies. To identify similarities between the variability of tropical SL and SST and that of SAT in high- and mid-latitude regions, as well as to estimate possible time lags, we applied factor analysis, clustering, cross-correlation and cross-spectral analyses. The results reveal a structural similarity in the internal variability of tropical SL and extratropical SAT, along with a significant lagged relationship between them, with a time lag of several years. Full article
(This article belongs to the Section Climatology)
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16 pages, 5628 KiB  
Article
Contrasting Impacts of North Pacific and North Atlantic SST Anomalies on Summer Persistent Extreme Heat Events in Eastern China
by Jiajun Yao, Lulin Cen, Minyu Zheng, Mingming Sun and Jingnan Yin
Atmosphere 2025, 16(8), 901; https://doi.org/10.3390/atmos16080901 - 24 Jul 2025
Viewed by 279
Abstract
Under global warming, persistent extreme heat events (PHEs) in China have increased significantly in both frequency and intensity, posing severe threats to agriculture and socioeconomic development. Combining observational analysis (1961–2019) and numerical simulations, this study investigates the distinct impacts of Northwest Pacific (NWP) [...] Read more.
Under global warming, persistent extreme heat events (PHEs) in China have increased significantly in both frequency and intensity, posing severe threats to agriculture and socioeconomic development. Combining observational analysis (1961–2019) and numerical simulations, this study investigates the distinct impacts of Northwest Pacific (NWP) and North Atlantic (NA) sea surface temperature (SST) anomalies on PHEs over China. Key findings include the following: (1) PHEs exhibit heterogeneous spatial distribution, with the Yangtze-Huai River Valley as the hotspot showing the highest frequency and intensity. A regime shift occurred post-2000, marked by a threefold increase in extreme indices (+3σ to +4σ). (2) Observational analyses reveal significant but independent correlations between PHEs and SST anomalies in the tropical NWP and mid-high latitude NA. (3) Numerical experiments demonstrate that NWP warming triggers a meridional dipole response (warming in southern China vs. cooling in the north) via the Pacific–Japan teleconnection pattern, characterized by an eastward-retreated and southward-shifted sub-tropical high (WPSH) coupled with an intensified South Asian High (SAH). In contrast, NA warming induces uniform warming across eastern China through a Eurasian Rossby wave train that modulates the WPSH northward. (4) Thermodynamically, NWP forcing dominates via asymmetric vertical motion and advection processes, while NA forcing primarily enhances large-scale subsidence and shortwave radiation. This study elucidates region-specific oceanic drivers of extreme heat, advancing mechanistic understanding for improved heatwave predictability. Full article
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21 pages, 5333 KiB  
Article
Climate Extremes, Vegetation, and Lightning: Regional Fire Drivers Across Eurasia and North America
by Flavio Justino, David H. Bromwich, Jackson Rodrigues, Carlos Gurjão and Sheng-Hung Wang
Fire 2025, 8(7), 282; https://doi.org/10.3390/fire8070282 - 16 Jul 2025
Viewed by 709
Abstract
This study examines the complex interactions among soil moisture, evaporation, extreme weather events, and lightning, and their influence on fire activity across the extratropical and Pan-Arctic regions. Leveraging reanalysis and remote-sensing datasets from 2000 to 2020, we applied cross-correlation analysis, a modified Mann–Kendall [...] Read more.
This study examines the complex interactions among soil moisture, evaporation, extreme weather events, and lightning, and their influence on fire activity across the extratropical and Pan-Arctic regions. Leveraging reanalysis and remote-sensing datasets from 2000 to 2020, we applied cross-correlation analysis, a modified Mann–Kendall trend test, and assessments of interannual variability to key variables including soil moisture, fire frequency and risk, evaporation, and lightning. Results indicate a significant increase in dry days (up to 40%) and heatwave events across Central Eurasia and Siberia (up to 50%) and Alaska (25%), when compared to the 1980–2000 baseline. Upward trends have been detected in evaporation across most of North America, consistent with soil moisture trends, while much of Eurasia exhibits declining soil moisture. Fire danger shows a strong positive correlation with evaporation north of 60° N (r ≈ 0.7, p ≤ 0.005), but a negative correlation in regions south of this latitude. These findings suggest that in mid-latitude ecosystems, fire activity is not solely driven by water stress or atmospheric dryness, highlighting the importance of region-specific surface–atmosphere interactions in shaping fire regimes. In North America, most fires occur in temperate grasslands, savannas, and shrublands (47%), whereas in Eurasia, approximately 55% of fires are concentrated in forests/taiga and temperate open biomes. The analysis also highlights that lightning-related fires are more prevalent in Eastern Europe and Southeastern Asia. In contrast, Western North America exhibits high fire incidence in temperate conifer forests despite relatively low lightning activity, indicating a dominant role of anthropogenic ignition. These findings underscore the importance of understanding land–atmosphere interactions in assessing fire risk. Integrating surface conditions, climate extremes, and ignition sources into fire prediction models is crucial for developing more effective wildfire prevention and management strategies. Full article
(This article belongs to the Section Fire Science Models, Remote Sensing, and Data)
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12 pages, 5143 KiB  
Article
Ochrolechia raynori, a New Lichen Species from the Southern Rocky Mountains (Colorado, USA) and Key to Asexually Reproducing Ochrolechia in Western North America
by Erin A. Manzitto-Tripp and Jacob L. Watts
Wild 2025, 2(3), 28; https://doi.org/10.3390/wild2030028 - 14 Jul 2025
Viewed by 229
Abstract
Ochrolechia is a diverse and charismatic lineage of both sexually and asexually reproducing lichens, with centers of species richness in northern temperate areas of the world, including North America. As part of recent work to comprehensively inventory the lichens of the Indian Peaks [...] Read more.
Ochrolechia is a diverse and charismatic lineage of both sexually and asexually reproducing lichens, with centers of species richness in northern temperate areas of the world, including North America. As part of recent work to comprehensively inventory the lichens of the Indian Peaks Wilderness (Arapaho–Roosevelt National Forest, Front Range Mountains, Colorado), we discovered material of a sorediate member of the genus to which no existing names could be applied. This material was collected in very remote, extremely difficult-to-access mid-montane forests of the west slope of the Indian Peaks Wilderness, in a steep and jagged off-trail drainage (Hell Canyon). Subsequent study of this material along with review of pre-existing collections at the COLO Herbarium revealed it to represent a new scientific species. We here formally describe Ochrolechia raynori, in honor of Seth Raynor who led the Indian Peaks Wilderness lichen inventory. We additionally document the occurrence of Dactylospora parasitica on this new lichen species. Ochrolechia raynori is distinctive for its continuous, smooth, shiny thallus that bears discrete soralia and coarse soredia, its occurrence on mosses and other lichens that overgrow rocks, and its chemistry. We generated a molecular phylogeny of this and other members of Ochrolechia using the nrITS locus and show O. raynori to be sister to the widespread, sexually reproducing species O. upsaliensis. This occurrence of an asexual species that is sister to a sexual species is consistent with the “species pair” hypothesis in lichenology, which suggests an intimate role of reproductive mode divergence in the process of speciation. Examination of the phylogeny yielded evidence of four additional pairs in Ochrolechia, for a total of five species pairs, which indicates that this phenomenon may be a common occurrence in this lineage. IUCN Conservation Assessment of Ochrolechia raynori revealed the species to be best considered as Critically Endangered. However, we expect that continued efforts to inventory the lichens of the southern Rocky Mountains, especially in some of its wildest, most remote regions in similar habitats, will likely result in the discovery of additional populations of this remarkable new species. Full article
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57 pages, 42873 KiB  
Article
The Mazenod–Sue–Dianne IOCG District of the Great Bear Magmatic Zone Northwest Territories, Canada
by A. Hamid Mumin and Mark Hamilton
Minerals 2025, 15(7), 726; https://doi.org/10.3390/min15070726 - 11 Jul 2025
Viewed by 192
Abstract
The Mazenod Lake region of the southern Great Bear Magmatic Zone (GBMZ) of the Northwest Territories, Canada, comprises the north-central portion of the Faber volcano-plutonic belt. Widespread and abundant surface exposure of several coalescing hydrothermal systems enables this paper to document, without ambiguity, [...] Read more.
The Mazenod Lake region of the southern Great Bear Magmatic Zone (GBMZ) of the Northwest Territories, Canada, comprises the north-central portion of the Faber volcano-plutonic belt. Widespread and abundant surface exposure of several coalescing hydrothermal systems enables this paper to document, without ambiguity, the relationships between geology, structure, alteration, and mineralization in this well exposed iron-oxide–copper–gold (IOCG) mineral system. Mazenod geology comprises rhyodacite to basaltic-andesite ignimbrite sheets with interlayered volcaniclastic sedimentary rocks dominated by fine-grained laminated tuff sequences. Much of the intermediate to mafic nature of volcanic rocks is masked by low-intensity but pervasive metasomatism. The region is affected by a series of coalescing magmatic–hydrothermal systems that host the Sue–Dianne magnetite–hematite IOCG deposit and several related showings including magnetite, skarn, and iron oxide apatite (IOA) styles of alteration ± mineralization. The mid to upper levels of these systems are exposed at surface, with underlying batholith, pluton and stocks exposed along the periphery, as well as locally within volcanic rocks associated with more intense alteration and mineralization. Widespread alteration includes potassic and sodic metasomatism, and silicification with structurally controlled giant quartz complexes. Localized tourmaline, skarn, magnetite–actinolite, and iron-oxide alteration occur within structural breccias, and where most intense formed the Sue–Dianne Cu-Ag-Au diatreme-like breccia deposit. Magmatism, volcanism, hydrothermal alteration, and mineralization formed during a negative tectonic inversion within the Wopmay Orogen. This generated a series of oblique offset rifted basins with continental style arc magmatism and extensional structures unique to GBMZ rifting. All significant hydrothermal centers in the Mazenod region occur along and at the intersections of crustal faults either unique to or put under tension during the GBMZ inversion. Full article
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18 pages, 3402 KiB  
Article
Synergistic Detrital Zircon U-Pb and REE Analysis for Provenance Discrimination of the Beach-Bar System in the Oligocene Dongying Formation, HHK Depression, Bohai Bay Basin, China
by Jing Wang, Youbin He, Hua Li, Tao Guo, Dayong Guan, Xiaobo Huang, Bin Feng, Zhongxiang Zhao and Qinghua Chen
J. Mar. Sci. Eng. 2025, 13(7), 1331; https://doi.org/10.3390/jmse13071331 - 11 Jul 2025
Viewed by 310
Abstract
The Oligocene Dongying Formation beach-bar system, widely distributed in the HHK Depression of the Bohai Bay Basin, constitutes a key target for mid-deep hydrocarbon exploration, though its provenance remains controversial due to complex peripheral source terrains. To address this, we developed an integrated [...] Read more.
The Oligocene Dongying Formation beach-bar system, widely distributed in the HHK Depression of the Bohai Bay Basin, constitutes a key target for mid-deep hydrocarbon exploration, though its provenance remains controversial due to complex peripheral source terrains. To address this, we developed an integrated methodology combining LA-ICP-MS zircon U-Pb dating with whole-rock rare earth element (REE) analysis, facilitating provenance studies in areas with limited drilling and heavy mineral data. Analysis of 849 high-concordance zircons (concordance >90%) from 12 samples across 5 wells revealed that Geochemical homogeneity is evidenced by strongly consistent moving-average trendlines of detrital zircon U-Pb ages among the southern/northern provenances and the central uplift zone, complemented by uniform REE patterns characterized by HREE (Gd-Lu) enrichment and LREE depletion; geochemical disparities manifest as dual dominant age peaks (500–1000 Ma and 1800–3100 Ma) in the southern provenance and central uplift samples, contrasting with three distinct peaks (65–135 Ma, 500–1000 Ma, and 1800–3100 Ma) in the northern provenance; spatial quantification via multidimensional scaling (MDS) demonstrates closer affinity between the southern provenance and central uplift (dij = 4.472) than to the northern provenance (dij = 6.708). Collectively, these results confirm a dual (north–south) provenance system for the central uplift beach-bar deposits, with the southern provenance dominant and the northern acting as a subsidiary source. This work establishes a dual-provenance beach-bar model, providing a universal theoretical and technical framework for provenance analysis in hydrocarbon exploration within analogous settings. Full article
(This article belongs to the Section Geological Oceanography)
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16 pages, 8021 KiB  
Article
From First Frost to Last Snow: Tracking the Microclimate Evolution of Greenhouses Across North China’s Winter Spectrum
by Hongrun Liu, He Zhao, Yanan Tian, Song Liu, Wei Li, Yanfang Wang, Dan Sun, Tianqun Wang, Ning Zhu, Yuan Tao and Xihong Lei
Agronomy 2025, 15(7), 1663; https://doi.org/10.3390/agronomy15071663 - 9 Jul 2025
Viewed by 472
Abstract
Global climate change has intensified the challenges of low-temperature, low-light, and high-humidity microclimates in North China’s greenhouses during winter, exposing the limitations of traditional controlled-environment agriculture (CEA) facilities. This study monitored air temperature, relative humidity, and light intensity in three greenhouse types—an externally [...] Read more.
Global climate change has intensified the challenges of low-temperature, low-light, and high-humidity microclimates in North China’s greenhouses during winter, exposing the limitations of traditional controlled-environment agriculture (CEA) facilities. This study monitored air temperature, relative humidity, and light intensity in three greenhouse types—an externally insulated plastic greenhouse, soft-shell solar greenhouse, and brick-walled solar greenhouse—across three overwintering periods (pre-, mid-, post-) using high-precision sensors (monitoring period is from 1 October 2024 to 31 March 2025). A Comprehensive Evaluation Index (CEI) based on the entropy method was developed, integrating seven indicators (daily average temperature, temperature range, hours below 5 °C, average humidity, hours above 80% humidity, average light intensity, and light utilization efficiency) to systematically evaluate greenhouse microclimate regulation performance. Results showed that the brick-walled solar greenhouse exhibited superior thermal insulation, with nearly zero hours below 5 °C during mid-overwintering, while the soft-shell solar greenhouse achieved the highest light utilization efficiency (75.1–79.6%). The externally insulated plastic greenhouse exhibited the highest relative humidity (>80% for 13–19 h/day) but a poor thermal insulation performance. The CEI ranked the brick-walled solar greenhouse (0.86) and the soft-shell solar greenhouse (0.84) significantly higher than the externally insulated plastic greenhouse (0.39), with the relative humidity significantly negatively correlated with light indicators (P < 0.05), and the temperature and light indicators strongly correlated with the CEI (P < 0.01). Structural design and material innovation are critical for climate adaptation. Brick-walled and soft-shell solar greenhouses balance thermal and light performance, while the externally insulated plastic greenhouse faces structural limitations. The findings provide a scientific basis for greenhouse optimization and regional layout planning. Full article
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60 pages, 1066 KiB  
Review
Dwarf Mistletoes (Arceuthobium, Viscaceae) of North America: Classification Systems, Phylogenetic Relationships, and Taxonomic Characteristics
by Shawn C. Kenaley and Robert L. Mathiasen
Plants 2025, 14(13), 2051; https://doi.org/10.3390/plants14132051 - 4 Jul 2025
Viewed by 481
Abstract
Arceuthobium—the dwarf mistletoes—is a clearly defined genus of hemi-parasitic plants in the family Viscaceae. The genus occurs throughout much of the Northern Hemisphere; however, the greatest concentration of species and subspecies occurs within coniferous forests of western North America, where considerable research [...] Read more.
Arceuthobium—the dwarf mistletoes—is a clearly defined genus of hemi-parasitic plants in the family Viscaceae. The genus occurs throughout much of the Northern Hemisphere; however, the greatest concentration of species and subspecies occurs within coniferous forests of western North America, where considerable research was executed in the mid-to-late 20th century to determine their geographic distributions, host specializations, and taxonomic boundaries. However, the last monograph of Arceuthobium presenting morphological, phenological, phylogenetic, and physiological information for N. American dwarf mistletoes was published in 1996, and since that time, no subsequent publications have presented taxonomic information for the present classification of N. American Arceuthobium. Thus, herein, we provide updated phylogenetic and taxonomic data for 44 taxa of Arceuthobium indigenous to N. America while simultaneously addressing knowledge gaps and suggesting future research to improve our understanding of these ecologically and economically important forest tree parasites. The present classification systems for and recent treatments of N. American Arceuthobium are also discussed. Full article
(This article belongs to the Special Issue Taxonomy, Phylogeny and Distribution of Vascular Plants)
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18 pages, 7356 KiB  
Review
Applied Chemical Ecology of Spruce Beetle in Western North America
by Christopher J. Fettig, Jackson P. Audley and Allen Steven Munson
Forests 2025, 16(7), 1103; https://doi.org/10.3390/f16071103 - 3 Jul 2025
Viewed by 287
Abstract
Spruce beetle (Dendroctonus rufipennis (Kirby)) is a major cause of spruce (Picea spp.) mortality in western North America. We synthesized the literature on the chemical ecology of spruce beetle, focusing on efforts to reduce host tree losses. This literature dates back [...] Read more.
Spruce beetle (Dendroctonus rufipennis (Kirby)) is a major cause of spruce (Picea spp.) mortality in western North America. We synthesized the literature on the chemical ecology of spruce beetle, focusing on efforts to reduce host tree losses. This literature dates back to the mid-20th century and focuses on spruce beetle populations in Alaska, U.S., western Canada, and the central and southern Rocky Mountains, U.S. Spruce beetle aggregation pheromone components include frontalin (1,5-dimethyl-6,8-dioxabicyclo[3.2.1]octane), seudenol (3-methyl-2-cyclohexen-1-ol), MCOL (1-methyl-2-cyclohexen-1-ol), and verbenene (4-methylene-6,6-dimethylbicyclo[3.1.1]hept-2-ene). The attraction of spruce beetle to one aggregation pheromone component is enhanced by the co-release of other aggregation pheromones and host compounds (e.g., α-pinene). Several baits that attract spruce beetles are commercially available and are used for survey and detection, population suppression, snag creation, and experimental purposes. The antiaggregation pheromone is MCH (3-methyl-2-cyclohexen-1-one), which has been evaluated for reducing colonization of felled spruce since the 1970s. Beginning in the early 2000s, MCH has been evaluated for protecting live, standing spruce from colonization by and mortality attributed to spruce beetle. With a few exceptions, significant reductions in levels of spruce beetle colonization and/or spruce mortality were reported. More recent efforts have combined MCH with other repellents (e.g., nonhost compounds) in hope of increasing levels of tree protection. Today, several formulations of MCH are registered for tree protection purposes in the U.S. and Canada. Full article
(This article belongs to the Section Forest Health)
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24 pages, 15859 KiB  
Article
The Analysis of the Extreme Cold in North America Linked to the Western Hemisphere Circulation Pattern
by Mohan Shen and Xin Tan
Atmosphere 2025, 16(7), 781; https://doi.org/10.3390/atmos16070781 - 26 Jun 2025
Viewed by 276
Abstract
The Western Hemisphere (WH) circulation pattern was discovered in recent years through Self-Organizing Maps (SOMs) clustering of the Northern Hemisphere 500 hPa geopotential height during winter. For example, the extremely cold wave that occurred in North America during 2013–14 is associated with WH [...] Read more.
The Western Hemisphere (WH) circulation pattern was discovered in recent years through Self-Organizing Maps (SOMs) clustering of the Northern Hemisphere 500 hPa geopotential height during winter. For example, the extremely cold wave that occurred in North America during 2013–14 is associated with WH circulation anomalies. We discussed the extremely cold weather conditions within the WH pattern during the winter season from 1979 to 2023. The variations of cold air in North America during the WH pattern have been demonstrated using the NCEP/NCAR reanalysis datasets. By defining WH events and North American extremely cold events, we have identified a connection between the two. In extremely cold events, linear winds are the key factor driving the temperature drop, as determined by calculating temperature advection. The ridge in the Gulf of Alaska serves as an early signal for this cold weather. The WH circulation anomaly triggers an anomalous ridge in the Gulf of Alaska region, leading to trough anomalies downstream over North America. This results in the southward movement of cold air from the polar regions, causing cooling in the mid-to-northern parts of North America. With the maintenance of the stationary wave in the North Pacific (NP), the anomalous trough over North America can be deepened, driving cold air into the continent. Influenced by the low pressure over Greenland and the storm track, the cold anomalies are concentrated in the central and northern parts of North America. This cold air situation persists for approximately two weeks. The high-level patterns of the WH pattern in both the 500 hPa height and the troposphere level have been identified using SOM. This cold weather is primarily a tropospheric phenomenon with limited correlation to stratospheric activities. Full article
(This article belongs to the Section Climatology)
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17 pages, 3762 KiB  
Article
Spatiotemporal Dynamics of Nitrogen and Phosphorus in the Water and Sediment from the Source Reservoir of the Mid-Route of China’s South-to-North Water Diversion Project
by Yuanyuan Zhang, Donghua Zhang, Yue Li, Xueqing Han, Xinyu Wang, Ji’ao Zhang, Kaidi Gu, Shuaijie Sun, Qigen Liu and Jun Lv
Water 2025, 17(12), 1824; https://doi.org/10.3390/w17121824 - 18 Jun 2025
Viewed by 447
Abstract
To investigate the spatiotemporal distribution characteristics of nitrogen and phosphorus in the water and sediment of the Danjiangkou Reservoir, the source of the Middle Route of China’s South-to-North Water Diversion Project, we designed a year-long monitoring program. The water and sediment samples were [...] Read more.
To investigate the spatiotemporal distribution characteristics of nitrogen and phosphorus in the water and sediment of the Danjiangkou Reservoir, the source of the Middle Route of China’s South-to-North Water Diversion Project, we designed a year-long monitoring program. The water and sediment samples were collected from 13 sampling points in the upstream and downstream areas over the year. The results revealed significant spatial heterogeneity in N and P concentrations, with higher levels of total nitrogen, nitrate nitrogen, and nitrite nitrogen in the upstream area compared to the downstream area (p < 0.01). Total phosphorus was also significantly higher in the upstream area (p < 0.05). Seasonal variations were observed, with TN and TP levels peaking in February and August, respectively. The TN:TP ratio indicated a severe P-limited state in most periods, transitioning to a co-limited state of N and P during summer. Sediment analysis showed that TN and TP concentrations were higher in the upstream area, with no significant differences between upstream and downstream on an annual basis, exhibiting strong stoichiometric internal stability. However, seasonal differences were noted, particularly in February and November. This study highlights the complex interactions between water and sediment, emphasizing the role of sediment resuspension, water flow, and seasonal changes in nutrient dynamics. These findings provide a scientific basis for the management and protection of water quality in the Danjiangkou Reservoir, ensuring its role as a critical water source for the South-to-North Water Diversion Project. Full article
(This article belongs to the Section Water Quality and Contamination)
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15 pages, 4123 KiB  
Article
Characterizing Risks for Wildfires and Prescribed Fires in the Great Plains
by Zifei Liu, Izuchukwu Oscar Okafor and Mayowa Boluwatife George
Fire 2025, 8(6), 235; https://doi.org/10.3390/fire8060235 - 18 Jun 2025
Viewed by 476
Abstract
Increasing wildfire activities across the Great Plains has raised concerns about the effectiveness and safety of prescribed fire as a land management tool. This study analyzes wildfire records from 1992 to 2020 to assess spatiotemporal patterns in wildfire risk and evaluate the role [...] Read more.
Increasing wildfire activities across the Great Plains has raised concerns about the effectiveness and safety of prescribed fire as a land management tool. This study analyzes wildfire records from 1992 to 2020 to assess spatiotemporal patterns in wildfire risk and evaluate the role of prescribed fires through the combined analysis of wildfire and prescribed fire data. Results show a threefold increase in both wildfire frequency and area burned, with fire size increasing from east to west and frequency rising from north to south. Wildfire seasons are gradually occurring earlier due to climate change. Negative correlation between prescribed fires in spring and wildfires in summer indicated the effectiveness of prescribed fire in mitigating wildfire risk. Drought severity accounted for 51% of the interannual variability in area burned, while grass curing accounted for 60% of monthly variability of wildfires in grasslands. The ratio of wildfire area burned to total area burned (dominated by prescribed fires) declined from over 20% in early March to below 1% by early April. The results will lay a foundation for the development of a localized fire risk assessment tool that integrates various long-term, mid-term, and short-term risk factors, and support more effective fire management in this region. Full article
(This article belongs to the Special Issue Firefighting Approaches and Extreme Wildfires)
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22 pages, 10685 KiB  
Article
The Co-Evolution of Paleoclimate, Paleoceanography, and Sedimentation in the Yanshan Basin, North China: Records from the Yangzhuang Formation of the Jixian Section
by Yan Zhang, Yaoqi Zhou, Mengchun Cao, Hui Tian and Xingcheng Yin
Minerals 2025, 15(6), 633; https://doi.org/10.3390/min15060633 - 11 Jun 2025
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Abstract
The Yangzhuang Formation of the Mesoproterozoic Jixian System exhibits a well-developed carbonate sedimentary sequence. However, the carbonate cycles within the Yangzhuang Formation and their co-evolution with paleoclimate and paleoceanographic environment changes remain insufficiently studied. This study conducts a systematic investigation of the rhythmic [...] Read more.
The Yangzhuang Formation of the Mesoproterozoic Jixian System exhibits a well-developed carbonate sedimentary sequence. However, the carbonate cycles within the Yangzhuang Formation and their co-evolution with paleoclimate and paleoceanographic environment changes remain insufficiently studied. This study conducts a systematic investigation of the rhythmic layers of the Yangzhuang Formation within the Yanshan Basin, North China, through major and trace element analysis, rare earth element analysis, inorganic carbon isotope analysis, granulometric analysis, and time series analysis. The results show that the low content of terrigenous clastics (11.2%~32.6%), slow sedimentation rate (2.2–2.5 cm/ka), Mg/Ca molar ratio close to 1 (1.05–1.53), and small fluctuation of δ13Ccarb (−0.37‰~−0.05‰) in Member 3 of the Yangzhuang Formation constitutes the processes of co-evolution, along with a mid-phase fluctuation. It indicates the stable evolution of the sedimentary environment and slow ocean expansion speed. However, there is a fluctuating characteristic affected by the breakup of the Colombian supercontinent. The chemical and granulometric analysis of the red and gray layers shows that the terrigenous materials are mainly derived from the eolian sediments, with differences in the wind carrying materials. The time series analysis of the dense samples displays the coupling between the rhythm of the red and gray layers, the inorganic carbon isotope cycle, and the 15 ka precessional cycle in the Mesoproterozoic. We conclude that the rhythm of layers is mainly affected by the monsoon change driven by low-latitude solar radiation at that time, and the age of the Yangzhuang Formation is limited to 1550~1520 ± 2 Ma. The study of the Mesoproterozoic sequence using geochemical data from carbonate deposits reveals the underlying mechanism of global co-evolution during this period, providing a basis for understanding the evolution of the Mesoproterozoic Earth system. Full article
(This article belongs to the Section Environmental Mineralogy and Biogeochemistry)
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