Western North America Research Papers (original) (raw)

2025, Zootaxa

We present the systematics and ecology of a new species of arboreal oribatid mite in the family Peloppiidae (Acari: Oribatida), Dendrozetes jordani n. sp., a dominant arthropod on branch tips and arboreal lichens associated with western hemlock (Tsuga heterophylla (Pinaceae)) and Pacific silver fir (Abies amabilis (Pinaceae)) in the coniferous temperate and montane forests of the Pacific Northwest of North America. Dendrozetes jordani represents the first record of the genus Dendrozetes in North America. The species is described on the basis of morphology of all active instars plus molecular sequence data for the mitochondrial cytochrome oxidase I (COI) gene. Dendrozetes jordani is compared with type specimens of D. caudatus Aoki from Japan, and a revised diagnosis of the genus Dendrozetes is given. Dendrozetes jordani has a stable, overlapping population structure through the year, and its association with trees in Pinaceae is an ecological characteristic shared with D. caudatus from Japan.

2025, Zootaxa

The oribatid mite family Tegoribatidae has been represented in continental North America by the genera Tegoribates and Tectoribates. Herein, I describe a new genus of Tegoribatidae from North America, Protectoribates, and two new species: Protectoribates occidentalis sp. nov., from forest habitats in western North American, and Tegoribates walteri sp. nov., from forest habitats in California, based on adults and immatures. The descriptions of adults of the type species of Tegoribates, T. subniger Ewing, and other North American species, T. americanus Hammer and T. bryophilus Woolley, are expanded and immatures of T. americanus are described for the first time. Immatures of Protectoribates are apheredermous whereas those of Tegoribates are eupheredermous, though retaining centrodorsal setae. Scutozetes Hammer 1952 is transferred from Tegoribatidae to Ceratozetidae after re-examination of type material. I provide a revised diagnosis for Tegoribates and a key to tegoribatid genera and species for North America. Finally, I provide a revised diagnosis for Tegoribatidae based on world genera.

2025

RESUMEN -Una nueva especie de Proarna Stål se describe en el sur de Brasil. Proarna gianucai sp. nov. se distingue por su coloración y genitalias. La especie habita en ambientes de dunas costeras y se asocia con la hierba perenne Panicum racemosum (P. Beauv.) Spreng. Los adultos son activos desde Diciembre a Marzo. Los primeros registros de Carineta durantoni Boulard, Carineta gemella Boulard, Carineta pilifera Walker, Fidicina christinae Boulard & Martinelli, Fidicina torresi Boulard & Martinellli, Fidicinoides determinata (Walker), Fidicinoides distanti (Goding), Fidicinoides glauca (Goding), Majeorona truncata Goding, y Zammara columbia Distant, en el Brasil son descritos en este estudio. Contando la nueva especie y los nuevos registros presentados aqui, la diversidad de la cigarras alcanza un total de 146 especies en el Brasil.

2025, Earth-Science Reviews

2025, Geophysical Research Letters

We estimate the averaged 1‐D shear‐wave velocity of the upper mantle beneath western North America and the Kaapvaal region in southern Africa by inverting dispersion measurements of fundamental and higher Rayleigh modes recorded by ∼2000 km aperture broadband arrays. The overtones at periods exceeding 25 s constrain the averaged 1‐D shear‐wave velocity to 650 km depth across the regional arrays. Our overtone analysis confirms the shear‐wave velocity differences observed in global tomographic models with similar horizontal resolution: the western North American mantle features a prominent low velocity zone at depths 50–200 km, while the shear velocity in the upper 180–200 km of the mantle beneath southern Africa is at least 6% higher than in western North America which we interpret as the expression of a cratonic keel. There is no resolvable difference in shear‐wave velocity between southern Africa and western North America below a depth of about 300 km.

2025, The European Zoological Journal

Understanding why some small populations succeed while others fail to establish in novel environments has major implications in applied fields such as in situ species conservation and reintroductions. Species introductions outside their native range provide excellent opportunities to address such topic, since invasions usually start with small populations. We studied the life-history strategy of a population of the fire-bellied toad (Bombina bombina) introduced in France, outside the natural range of the species, to estimate its population demographic potential. The introduced population showed a fast life history strategy, with early sexual maturation at 2 years of age, a relatively short lifespan (3.1 years in females and 2.3 in males, with a maximum age of 5 years), and survival rates similar to those of populations from its native range. The population presents the characteristics for becoming invasive and might pose a threat to the native yellow-bellied toad (B. variegata) populations nearby through hybridization, competition and as potential vector of pathogens and parasites. Its spread should be closely monitored and additional introductions avoided to limit its potential negative impact.

2025, Recherche

Notice. Imprimer la notice. The cordilleran miogeosyncline in north america: geologic evolution and tectonic nature. Auteur : LYATSKY Henry V. Prix indicatif 137,10 Ajouter au panier le livre de LYATSKY Henry V. Date de parution :... more

2025

A b s t r a c t An isolated humerus, attributed to a dicynodont therapsid and identified as aff. Dinodontosaurus, from the Lower Keuper (Middle Ladinian, Middle Triassic) of southwestern Germany is redescribed. An additional but smaller humerus that is similar in morphology might pertain to the same taxon. Several morphological features preclude an identification of the material as either aff. Dinodontosaurus, a dicynodont, or even a synapsid. The deltopectoral crest shows a number of tubercles, probably for muscle attachment. The supinator process is strongly developed and clearly offset from the rest of the bone. The distal articulation facet is very narrow transversely. There is no foramen entepicondyloideum. The ectepicondyle has a deeply concave distal surface, at least in the large and presumably adult specimen. An alternative identification for the two humeri proves difficult, as they do not agree with any other known tetrapod from the Lower Keuper. They bear close resemblanc...

2025, Geological Quarterly

Two road side lo cal i ties on the north ern fringes of Moab, Grand County, Utah yield pre vi ously un-de scribed Up per Tri as sic ver te brate tracks from the Chinle Group (Rock Point For ma tion). The first lo cal ity, des ig nated the high way 191 site, yields doz ens of small theropod di no saur tracks (Grallator) pre served on a sin gle, fallen slab. The tracks form a monospecific as sem blage pre served as nat u ral casts. The as sem blage is rep re sen ta tive of what has been re ferred to as Rha etic as sem blage II which is dom i nated by small Grallator tracks. In situ Grallator tracks are also de scribed from a nearby lo cal ity, re ferred to as the Mat ri mony Spring site, where they are found in as so ci a tion with the ichnogenus Brachychirotherium. Many other sites with sim i lar, of ten more-di verse, Late Tri as sic ichnofaunas are known from the re gion.

2025

Anomoepus, a purported ornithischian footprint, is a significant component of several diverse ichnofaunas from the Early Jurassic Glen Canyon Group in the western USA. The first authentic occurrence was reported from the Wingate-Kayenta transition zone at Lisbon Valley Oilfield in eastern Utah. Anomoepus also occurs quite abundantly in the Kayenta-Navajo transition zone in the Lake Powell region of south-central Utah. A reevaluation of Hopiichnus shingi from the Glen Canyon Group of northern Arizona suggests that it is a junior synonym of Anomoepus, and so is referred to A. shingi comb. nov. Likewise, Trisauropodiscus moabensis is reinterpreted as A. moabensis. Thus, Anomoepus is currently known to occur at about 20 sites in the region and is distributed sporadically throughout much of the Lower Jurassic part of the Glen Canyon Group (top Wingate through Kayenta and Navajo formations), where it co-occurs with Otozoum, Batrachopus, Grallator and Eubrontes. These occurrences give insight into variation in size, pedal morphology, distribution, and diversity of Early Jurassic ornithischian tracks (Anomoepus and Moyenisauropus). These occurrences also help to demonstrate that Haubold's Lower Jurassic Anomoepus-Grallator (Eubrontes) palichnostratigraphic zone (sensu lato) can be recognized in the middle to upper part of the Glen Canyon Group of the western United States. However, the zone is not clearly distinguishable from his Rhaetic Grallator-Batrachopus zone at least in the western USA. Thus, we agree with Lucas (in press) that tetrapod track assemblages in the Lower Jurassic are equally well accommodated in a single zone (or biochron). Correlation of Lower Jurassic track assemblages from the western United States with palichnostratigraphic zones based on the eastern United States, southern Africa and Europe suggests a Hettangian-Sinemurian age for Anomoepus sites in Utah and Arizona, and suggests that the larger, related ichnogenus Moyenisauropus is also present locally, possibly in younger (i.e., Pliensbachian) deposits. In addition to Anomoepus, the Lisbon Valley site also reveals a varied suite of vertebrate (Grallator) and invertebrate tracks and traces, including large enigmatic traces of unknown origin. This ichno-assemblage, like those from younger beds at Lake Powell, is one of the most diverse and unusual reported from the Glen Canyon Group, and so provides insight into paleoecology. Evidence is accumulating that many tracksites in the Glen Canyon Group are associated with "transition zones" or boundaries between lithosomes or formations.

2025

Numerous tracksites have been reported from the three formations (Wingate, Kayenta and Navajo) that comprise the Glen Canyon Group in eastern Utah (Lockley and Hunt, 1995; Lockley et al., 1998; Lockley and Gierlinski, 2006). These yield typical Lower Jurassic ichnofaunas in which the most common ichnogenera are Grallator, Eubrontes, Anomoepus and Otozoum. This typical assemblage was labeled the Early Jurassic footprint biochron by Lucas (2007). As noted elsewhere in this volume, tracksites appear to be particularly abundant in the upper part of the Kayenta Formation or in the Kayenta-Navajo transition zone. Here we report a newly-discovered tracksite at this level, which appears to be dominated almost exclusively by Otozoum.

2025, Geology

During middle Miocene time, western North America was subject to flood-basalt volcanism, dike-swarm injection, and broad-scale fracturing and folding of the crust. We propose a simple model to account for these events and for a regional pattern of geologic and geophysical features. Aeromagnetic maps reveal some of the most important elements of this pattern, which are several narrow, arcuate anomalies, here referred to as the Northern Nevada rifts. These rifts extend hundreds of kilometers across Nevada and are likely caused by highly magnetic, middle Miocene mafic dikes. With the aid of filtering techniques, the anomalies can be traced into Oregon. Together with other geologic features, such as fold axes, dike swarms, and faults, they produce a spoke-like pattern fanning over 220؇ of arc that converges toward a point near the Oregon-Idaho border (lat ϳ44؇N). A possible cause for this pattern is a point source of stress at the base of the crust related to the formation of the Yellowstone hotspot. The spoke-like pattern, however, does not persist at large distances from the emerging hotspot; several hundred kilometers to the south, the Northern Nevada rifts deviate significantly (Ͼ30؇) from a radial trend. We show that a simple model-imposing a point source of stress at the base of the crust and a regional stress field aligned with the presumed middle Miocene stress direction-fits the observed fracture pattern. It thus accounts for both the radial pattern present near the nascent hotspot and the far-field pattern due to regional stresses.

2025, Mycologia

The life cycles of the conidiating species of Neurospora are adapted to respond to fire, which is reflected in their natural history. Neurospora is found commonly on burned vegetation from the tropic and subtropical regions around the world and through the temperate regions of western North America. In temperate Europe it was unknown whether Neurospora would be as common as it is in North America because it has been reported only occasionally. In 2003 and 2004 a multinational effort surveyed wildfire sites in southern Europe. Neurospora was found commonly from southern Portugal and Spain (37uN) to Switzerland (46uN). Species collected included N. crassa, N. discreta, N. sitophila and N. tetrasperma. The species distribution and spatial dynamics of Neurospora populations showed both similarities and differences when compared between temperate Europe and western North America, both regions of similar latitude, climate and vegetation. For example the predominant species in western North America, N. discreta phylogenetic species 4B, is common but not predominant in Europe, whereas species rare in western North America, N. crassa NcB and N. sitophila, are much more common in Europe. The meiotic drive element Spore killer was also common in European populations of N. sitophila and at a higher proportion than anywhere else in the world. The methods by which organisms spread and adapt to new environments are fundamental ecosystem properties, yet they are little understood. The differences in regional diversity, reported here, can form the basis of testable hypotheses. Questions of phylogeography and adaptations can be addressed specifically by studying Neurospora in nature.

2025, Ecological Modeling

Seedling recruitment is an important reproductive process for sustaining riparian tree populations in arid and semi-arid environments. Riparian tree species such as cottonwoods and willows are highly adapted to the dynamic riparian environment; their seed dispersal and germination patterns are tied with climatic signals that also drive hydrology. The magnitude and timing of seasonal hydrologic components determine environmental conditions that either promote or limit seedling establishment processes. This article presents the development and testing of a potential niche model for riparian seedling recruitment. The presented Riparian Seedling Recruitment Model (RSRM) identifies spatially explicit locations of suitable habitat for seedling recruitment driven by relevant hydrophysical processes. This model extends previous seedling recruitment algorithms by accounting for seedling mortality due to scour by sediment mobilization, the reduction of potential germination sites due to existing forest canopy shade, and the incorporation of engineered channel and substrate modifications. The model is integrated into the open-source river analysis software River Architect. Potential future applications for the model include assessing seedling recruitment patterns for existing conditions, under alternative flow regimes, or for designs with topographic modifications. A canonical test channel and five scenarios with relevant hydrographic features are used to perform an implementation verification. Predictable recruitment patterns for the canonical test channel demonstrate model functionality and establish a dataset for future benchmarking. Finally, results from a site on the lower Yuba River, California are presented to illustrate the usefulness of a simplified test site given the complexity of results from real-world data.

2025

A splitplot experimental design, with three blocks, four treatments, and 44 plots, was established in the summer of 1985. Twenty plots (4 x 4 m) were trenched approximately one meter in depth, and 24 non-trenched plots were used to assess the effects of root competition of overstory trees on understory plants. Trees were commercially thinned in the winter and spring 1986 from a density of 345 to 148 trees/ha -1 to increase light levels to the understory. Thinning significantly increased light, decreased midday relative humidity and increased midday air temperatures and soil temperatures. Xylem potential of the dominant graminoid, Carex qeyeri, soil water potential, mineralizable nitrogen, and pH were significantly increased within the trenched treatment in comparison to the nontrenched plots. Micro and macro nutrients in C. qeyeri and Symphoricarpos albus, the dominant shrub, significantly increased in both treatments. Controlling root competition for soil water and nutrients did significantly increase understory aboveground biomass, whereas increasing light had no effect. A supplemental experiment during the third year of this study indicated that water and nitrogen had a synergistic effect in improving production. Species composition, cover and density, however, were significantly effected by light, water, and nutrients. Vavra for his financial support throughout the duration of this project and in particular his generosity in providing a roof over my head in Burns during the winter and spring of 1989. Dr. Rick Miller, my major professor, mentor, and now a good friend, patiently guided me through the perils of my graduate program. Rick, without your assistance, emotional support, and warmth of your family, this dissertation would not have been possible. Thanks Rick! I thank my committee members Drs. Bill Emmingham, Bill Krueger, and Dave Perry for their help and constructive criticism throughout my program. You all contributed your expertise to make this dissertation substantially better. Thanks to all of you! Appreciation is extended to Dr. Krueger, my on-campus advisor, who made sure I always got my moneys worth! Appreciation is extended to my graduate representatives, Drs. Don Horton, program meetings; Michael Burke, preliminary exam, and Tim Righetti, final exam. Thanks Tim for your thoughtful discussion and assistance in interpretation of the nutrient analysis from the trenching experiment and subsequent design of the fertilization experiment. Chuck Ballard and the crew at EOARC-Union were instrumental in their support, advice, and living accommodations. I wish to thank my summer technicians

2025, Prehistory and Early History of the Malpai Borderlands: Archaeological Synthesis and Recommendations

Prehispanic and early historic archaeological information for the Malpai Borderlands of southwest New Mexico and southeast Arizona is reviewed using data derived from field reconnaissance, discussion with relevant scholars, archival resources from varied agencies and institutions, and published literature. Previous regional research has focused on late prehistory (A.D. 1200 to 1450), shaping the scope of cultural historical overview and providing an opportunity to examine relationships with Casas Grandes (Paquime) to the south. A second important objective of current study is the exploration of prehispanic and early historic human impacts to Borderlands ecosystems, particularly in relation fire ecology. A recommended sequence of future research is intended to address significant questions surrounding both culture history and anthropogenic environments in the Malpai Borderlands.

2025, PhytoKeys

The border area between south-eastern Yunnan, China and northern Vietnam is one of the regions with richest biological diversity including that of the fern genus Angiopteris (Marattiaceae). Based on the analysis of morphology and DNA sequences of multiple chloroplast regions (atpB, rbcL, rps4-trnS spacer and trnL-F spacer), we revised Angiopteris tonkinensis (Hayata) J.M.Camus and proposed a new combination Angiopteris tamdaoensis (Hayata) J.Y.Xiang & T.Wang, comb. nov., which was previously regarded as a synonym of A. tonkinensis. We found support for a monophyletic Angiopteris including Protomarattia. This discovery adds two new distribution sites of A. tonkinensis, one in China (Malipo, Yunnan) and one in Vietnam (Quan Ba, Ha Giang). We suggest A. tonkinensis should be categorised as Critically Endangered (CR) species according to the criteria of IUCN.

2025, IEEE Transactions on Power Systems

3. A simplified procedure was developed for computing the new u.e.p. after generation-shedding is imple¬ mented. 4. An efficient method was introduced for estimating the required amount of generation-shedding. Results obtained with a reduced model of the B.C. Hydro system model, show good agreement with results obtained by time solution using classical models. Discusser: A. Rahimi Run stability (bese case) Store results of P0l, <t _L Col culote reduced admittance! matrices Calculate oost-fault stable eau ti ter I um, toe.p. end energy moram UV> Calculate .,, w( at

2025, CATENA

In a semi-arid, upland setting on the Colorado Plateau that is underlain by nutrient-poor Paleozoic eolian sandstone, alternating episodes of dune activity and soil formation during the late Pleistocene and Holocene have produced dominantly sandy deposits that support grass and shrub communities. These deposits also contain eolian dust, especially in paleosols. Eolian dust in these deposits is indicated by several mineralogic and chemical disparities with local bedrock, but it is most readily shown by the abundance of titaniferous magnetite in the sandy deposits that is absent in local bedrock. Magnetite and some potential plant nutrients (especially, P, K, Na, Mn, and Zn) covary positively with depth (3 -4 m) in dune-crest and dune-swale settings. Magnetite abundance also correlates strongly and positively with abundances of other elements (e.g., Ti, Li, As, Th, La, and Sc) that are geochemically stable in these environments. Soil-property variations with depth can be ascribed to three primary factors: (1) shifts in local geomorphic setting; (2) accumulation of relatively high amounts of atmospheric mineral dust inputs during periods of land-surface stability; and (3) variations in dust flux and composition that are likely related to changes in dust-source regions. Shifts in geomorphic setting are revealed by large variations in soil texture and are also expressed by changes in soil chemical and magnetic properties. Variable dust inputs are indicated by both changes in dust flux and changes in relations among magnetic, chemical, and textural properties. The largest of these changes is found in sediment that spans late Pleistocene to early Holocene time. Increased dust inputs to the central Colorado Plateau during this period may have been related to desiccation and shrinkage of large lakes from about 12 to 8 ka in western North America that exposed vast surfaces capable of emitting dust. Soil properties that result from variable dust accumulation and redistribution in these surficial deposits during the late Quaternary are important to modern ecosystem dynamics because some plants today utilize nutrients deposited as long ago as about 12 -15 ky and because variations in fine-grained (silt) sediment, including eolian dust, influence soil-moisture capacity.

2025, Applied Vegetation Science

Questions: What is the floristic composition of the plant communities that inhabit the beaches and dunes of the Pacific coast of North America? What are their ecological relationships in the zonal and successional gradients typical of coastal dune systems? Does climate affect the latitudinal distribution of the azonal vegetation? What other environmental factors influence their distribution on the regional or local scale?Location: Pacific coast of North America, from Baja California (23°02′ N) to Cook Inlet, Alaska (61°30′ N).Methods: A total of 1730 phytosociological relevés were obtained by sampling 279 coastal localities. In all localities, zonation was interpreted by considering transects from the shoreline inland. Through traditional phytosociological tabular classification and average linkage clustering, relevés were syntaxonomically classified. Syntaxa, supported by fidelity calculations, are described and interpreted according to their phytogeographical distribution, their r...

2025, Nature communications

Chromosomal inversions have been implicated in a remarkable range of natural phenomena, but it remains unclear how much they contribute to standing genetic variation. Here, we evaluate 64 inversions that segregate within a single natural population of the yellow monkeyflower (Mimulus guttatus). Nucleotide diversity patterns confirm low internal variation for the derived orientation (predicted by recent origin), elevated diversity between orientations (predicted by natural selection), and localized fluctuations (predicted by gene flux). Sequence divergence between orientations varies idiosyncratically by position, not following the suspension bridge pattern predicted if the breakpoints are the targets of selection. Genetic variation in gene expression is not inflated close to inversion breakpoints but is clearly partitioned between orientations. Like sequence variation, the pattern of expression variation suggests that the capture of coadapted alleles is more important than the breakpoints for the fitness effects of inversions. This work confirms several evolutionary predictions for inversion polymorphisms, but clarity emerges only by synthesizing estimates across many loci.

2025

The endemic Australian stiletto fly genus Laxotela Winterton & Irwin is revised with four new species described: L. citriterminalis sp. n., L. genalis sp. n., L. kimseyorum sp. n. and L. malleensis sp. n. Laxotela malleensis sp. n. was initially discovered based on images posted on the social platform iNaturalist, resulting in this collaboration to describe it formally. Additionally, L. atmis (Winterton, 2009) comb. n. is transferred from Neodialineura Mann, 1928. All of the previously described species are diagnosed in light of the morphological diversity found in the genus and a revised key to all 13 species of Laxotela is presented.

2025, PaleoBios

Commercial phosphate excavation in the Maastrichtian of Morocco has yielded several new specimens of the bizarre mosasaurid Xenodens calminechari, a rare species previously known from a single maxilla. Here, we describe a partial skull consisting of the maxillae, frontal, parietal, postorbitofrontal, and temporal elements, as well as an unassociated dentary and isolated teeth found within the same horizon. The newly discovered frontal is approximately rectangular in shape, with parallel preorbital margins, constriction between the orbits, and expansion at the posterior alae. Alae are acute and posterolaterally oriented. The parietal foramen is ovate and without contribution from the frontal. The postorbitofrontals buttress the frontal posteriorly and the parietal laterally. The squamosal processes of the postorbitofrontals diverge, producing an expanded temporal region. Consistent across all specimens is the remarkable dental adaptation of squaliform-like cutting teeth. Tooth crowns are close-packed to two tooth crowns per alveolar crypt and sit elevated from the dental parapet by fused tooth roots collectively forming a continuous ridge of bone. These elevated “tooth pedicles” suggest a potentially unique implantation and dental replacement strategy. Isolated teeth are typically found in pairs as adjacent crowns are shed with a section of the tooth pedicle. Preliminary analysis of the new material suggests a close relationship with durophagous mosasaurids in the tribe Globidensini. CT imaging of mandibular elements is forthcoming to better understand tooth attachment, development, and replacement.

2025, AGUFM

The sensitivity of remote alpine ecosystems to global change has been documented by 20th century changes in climate, glacial recession, and terrestrial and aquatic ecosystems. Here we present sedimentary records of biogeochemical responses in two alpine lake ecosystems to multiple environmental drivers over the last ∼500 years in Banff and Jasper National Parks (Alberta, Canada). We combine paleoecological measures of primary production and diatom community structure with geochemical proxies of reactive N (Nr) deposition to describe the nature and rate of recent ecosystem changes. Curator Lake in Jasper shows a strong diatom response to the limnological effects of climate warming (e.g., thermal stratification), but little evidence of changes in Nr cycling over the last ∼500 years. The response of McConnell Lake in Banff to climate change is strongly mediated by glacial activity within the catchment and changing inputs of Nr. Our findings highlight the range of limnological responses that may be expressed by similar ecosystems subjected to comparable abiotic stressors, while further documenting the magnitude of the ecological footprint associated with recent environmental change in mountain park environments. Résumé : La sensibilité des écosystèmes alpins éloignés au changement global a été démontrée par les modifications produites au cours du 20 e siècle dans le climat, dans le retrait des glaciers et dans les écosystèmes terrestres et aquatiques. Nous présentons ici des enregistrements sédimentaires de réponses biogéochimiques de deux écosystèmes lacustres alpins aux multiples facteurs de changement du milieu au cours des derniers ∼500 ans dans les parcs nationaux de Banff et de Jasper (Alberta, Canada). Nous combinons des mesures paléoécologiques de la production primaire et des analyses de structure des communautés de diatomées à des variables géochimiques de remplacement du dépôt de N réactif (Nr) afin de décrire la nature et le taux des changements récents à l'écosystème. Le lac Curator à Jasper montre une forte réponse des diatomées aux effets limnologiques du réchauffement du climat (par ex., la stratification thermique), mais peu d'indications de changements dans le recyclage de Nr au cours des derniers ∼500 ans. La réponse du lac McConnell à Banff au changement climatique est fortement influencée par l'activité glaciaire au sein du bassin versant et par les apports changeants de Nr. Nos résultats soulignent l'étendue des réponses limnologiques qui peuvent être exprimées par des écosystèmes semblables soumis à des facteurs abiotiques de stress comparables; ils apportent des informations additionnelles sur l'importance de l'empreinte écologique associée au changement récent dans les environnements montagneux des parcs. [Traduit par la Rédaction]

2025, Doklady Earth Sciences

In the locality of Oblazowa Cave (Polish Carpathians), in addition to the remains of ancient man, mammals, birds, and mollusks, the remains of cold-blooded terrestrial vertebrates have been found. The absolute age of the remains is approximately 33000 years. This corresponds to the absolute dating of layer VIII of the cave accumulations. We have identified the following species of amphibians and reptiles:

2025, Transactions of the Royal Society of South Australia

Discovered within the sequence of Neoproterozoic metasediments upon a wavecut platform at Ochre Point, south of Adelaide, in South Australia, is an abundance of circular structures, primarily shallow cylindrical fossils with rounded to hemispherical bases and, less commonly, discoidal fossils of Aspidella. Emanating from the cores of some Aspidella are elongate attachments and on a sandstone surface encountered upon the adjacent clifftop is an impression of a partial frond. These features all occur within the finer-grained interbedded components of cyclical shales/siltstones with capping sandstones/quartzites that constitute the entire cliff and wavecut platform exposures between the beaches of Moana and Maslins. A similar abundance of circular/cylindrical structures is known only from the Moorillah Formation amid the Neoproterozoic Brachina sequence within the central Flinders Ranges, suggesting that this Ochre Point occurrence is its stratigraphic correlative. Together these fossils/trace fossils add to the growing list of organic features that pre-date, by possibly as much as 50 million years, the famed Ediacara macrofossils of the White Sea/Flinders Ranges Assemblage found elsewhere within the Ediacara and Nilpena members of the Rawnsley Quartzite in South Australia. KEY POINT (1) Neoproterozoic outcrops at Ochre Point, south of Adelaide, comprise the early Ediacaran Moorillah Formation of the Brachina sequence. (2) The Moorillah Formation includes several cycles of shale and siltstone of shallow subtidal, lower deltaic slope origin capped by storm-generated sandstones and quartzites. (3) Preserved within the interbedded shales and siltstones are numerous cylindrical to cup-shaped fossils of possible actinian affinity, as well as less common Aspidella with attached stalks and a possible partial frond.

2025, Transactions of the Royal Society of South Australia

2025

The Sonsela Member of the Petrified Forest Formation (Upper Triassic) is widely exposed in northeastern Arizona and northwestern New Mexico. Fossil wood is common in the fluvial Sonsela, but the high energy depositional conditions appear to have destroyed all fossil bone except for small fragments. The first identifiable vertebrate fossil from channel-facies of this unit is an incomplete phytosaur skull preserved on a fallen block of sandstone on a cliff in the Rainbow Forest area of Petrified Forest National Park, Arizona. This cliff is "Flattops Sandstone I," which we consider to represent the upper part of the Sonsela Member. The left side of the skull, lacking the anterior half of the rostrum, is preserved in lateral view. The specimen is uncollectable, but casts are preserved at Mesalands Dinosaur Museum, Petrified Forest National Park, and the New Mexico Museum of Natural History and Science. The two most important morphological features of this specimen are: (1) the external nares are at approximately the same level as the skull deck; and (2) the posterior squamosal process in lateral view is narrow and not pendulous. This combination of features is diagnostic of the genus Nicrosaurus. The only other published account of Nicrosaurus in North America is Nicrosaurus buceros from the Chama basin of north-central New Mexico. The common Nicrosaurus kapffi and the rare N. meyeri occur in the Norian Stubensandstein of southwestern Germany. This specimen is biochronologically sig:p.ificant as it demonstrates that the Sonsela is indeed Norian in age, as has been suggested previously. Paleobiogeographically, it is one of an increasing number of Late Triassic tetrapod taxa that were previously thought to be exclusively European in distribution (e.g., Erpetosuchus, Aetosaurus, Stagonolepis) that have now been identified in North America.

2025, Minerals

The post-impact fauna of the Dalby Limestone of Tvären Bay has been extensively examined, with the exception of the Palaeostomate bryozoan taxa present. Here, we report three palaeostomate bryozoans found in limestone boulders recovered from glacial deposits on Ringsö Island derived from Tvären Bay, Sweden. The bryozoan fauna includes Pachydictya bifurcata, Hallopora sp., and Trematoporid sp. indet. Pachydictya bifurcata has bifoliate zoaria with two layers of zooecia oriented in opposite directions along the mesotheca. Hallopora sp. is characterized by the presence of mesozooecia, tubular autozooecia with rounded apertures, thin walls, and possessing diaphragms. The zoaria of Trematoporid sp. indet are loosely arranged and slightly ambiguous, but lack further identifying features. The report of Pachydictya bifurcata herein represents an extension of its stratigraphic range within the late Ordovician. These findings enhance our understanding of the bryozoan diversity in the region, providing the first detailed report of the presence of these taxa in this geological context.

2025, International Journal of Plant Sciences

Section Ovales is the most species-rich section of the sedge genus Carex in the New World. Phylogenetic analyses of molecular data recover a predominantly New World clade as sister to a solitary east Asian species, C. maackii. Nuclear ribosomal DNA are congruent in the placement of all taxa within the section, with a solitary exception: incongruence between ITS and ETS data in the placement of C. bonplandii and C. roraimensis suggests a hybrid origin for this lineage. Biogeography correlates strongly with phylogeny in the section, but there have been at least two instances of long-range dispersal, one from an eastern North American clade to western North America and one from the New World to Eurasia. Morphological characters studied are all homoplastic. Developing a comprehensive infrasectional classification with a phylogenetic basis would be complicated by the fact that most of the novel morphological characters in the section have evolved within relatively small, independent clades.

2025, Journal of The Lepidopterists Society

The first report of Oecophora bractella (L.) from North America is given, based on collection records from Washington and British Columbia. This species is found throughout Europe, but is generally rare to uncommon through most of its range. Larvae occur on rotting wood in association with certain fungi and are not expected to reach pest status. Adults were captured at nine locations, with the first record from Seattle, WA in 1998. This first record and some of the subsequent records are from sites immediately adjacent to or associated with international shipping routes. Other sites with O. bractella are from residential areas, two of which have established breeding populations. The introduction of this moth is surprising, particularly given the low interception rate at United States ports and its specialized feeding niche. A diagnosis and photographs of adults are provided to enable North American researchers to identify this species and to monitor its spread. Additional key words:...

2025, The American Naturalist

In western North America, hummingbirds can be observed systematically visiting flowers that lack the typical reddish color, tubular morphology, and dilute nectar of "hummingbird flowers." Curious about this behavior, we asked whether these atypical flowers are energetically profitable for hummingbirds. Our field measurements of nectar content and hummingbird foraging speeds, taken over four decades at multiple localities, show that atypical flowers can be as profitable as typical ones and suggest that the profit can support 24-h metabolic requirements of the birds. Thus, atypical flowers may contribute to successful migration of hummingbirds, enhance their population densities, and allow them to occupy areas seemingly depauperate in suitable resources. These results illustrate what can be gained by attending to the unexpected.

2025

Northeast Asia as defined in this study includes the Russian Far East, Northeast China, the northern part of the Korean Peninsula, and Hokkaido Island (Japan). We determined the species richness of Northeast Asia at various spatial scales, analyzed the floristic relationships among geographic regions within Northeast Asia, and compared the flora of Northeast Asia with surrounding floras. The flora of Northeast Asia consists of 971 genera and 4953 species of native vascular plants. Based on their worldwide distributions, the 971 gen- era were grouped into fourteen phytogeographic elements. Over 900 species of vascular plants are endemic to Northeast Asia. Northeast Asia shares 39% of its species with eastern Siberia-Mongolia, 24% with Europe, 16.2% with western North America, and 12.4% with eastern North America. Species richness and floristic relationships among different regions within Northeast Asia were discussed. The northernmost (Arctic) region shares 64% of its genera and 9% o...

2025, Climatic Change

Recent changes in global climate have dramatically altered worldwide temperatures and the corresponding timing of seasonal climate conditions. Recognizing the degree to which species respond to changing climates is therefore an area of increasing conservation concern as species that are unable to respond face increased risk of extinction. Here we examine spatial and temporal heterogeneity in the rate of climate change across western North America and discuss the potential for conditions to arise that may limit the ability of western migratory birds to adapt to changing climates. Based on 52 years of climate data, we show that changes in temperature and precipitation differ significantly between spring migration habitats in the desert southwest and breeding habitats throughout western North America. Such differences may ultimately increase costs to individual birds and thereby threaten the long-term population viability of many species.

2024, CATENA

Soil aggregate stability is widely recognized as a key indicator of soil quality and rangeland health. However, few standard methods exist for quantifying soil stability in the field. A stability kit is described which can be inexpensively and easily assembled with minimal tools. It permits up to 18 samples to be evaluated in less than 10 min and eliminates the need for transportation, minimizing damage to soil structure. The kit consists of two 21 = 10.5 = 3.5 cm plastic boxes divided into eighteen 3.5 = 3.5 cm sections, eighteen 2.5-cm diameter sieves with 1.5-mm distance openings and a small spatula used for soil sampling. Soil samples are rated on a scale from one to six based on a combination of ocular observations of slaking during the first 5 min following immersion in distilled water, and the percent remaining on a 1.5-mm sieve after five dipping cycles at the end of the 5-min period. A laboratory comparison yielded a correlation between the stability class and percent aggregate stability based on oven dry weight remaining after treatment using a mechanical sieve. We have applied the method in a wide variety of agricultural and natural ecosystems throughout western North America, including northern Mexico, and have found that it is highly sensitive to differences in management and plant community composition. Although the field kit cannot replace the careful laboratory-based measurements of soil aggregate stability, it can clearly provide valuable information when these more intensive procedures are not possible.

2024, Journal of South American Earth Sciences

Volcanic successions underlying clastic and carbonate marine rocks of the Oxfordian-Kimmeridgian Zuloaga Group in northeastern Mexico have been attributed to magmatic arcs of Permo-Triassic and Early Jurassic ages. This work provides stratigraphic, petrographic geochronological, and geochemical data to characterize pre-Oxfordian volcanic rocks outcropping in seven localities in northeastern Mexico. Field observations show that the volcanic units overlie Paleozoic metamorphic rocks (Granjeno schist) or Triassic marine strata (Zacatecas Formation) and intrude Triassic redbeds or are partly interbedded with Lower Jurassic redbeds (Huizachal Group). The volcanic rocks include rhyolitic and rhyodacitic domes and dikes, basaltic to andesitic lava flows and breccias, and andesitic to rhyolitic pyroclastic rocks, including breccias, lapilli, and ashflow tuffs that range from welded to unwelded. Lower-Middle Jurassic ages (U/ Pb in zircon) have been reported from only two studied localities (Huizachal Valley, Sierra de Catorce), and other reported ages (Ar/ Ar and K-Ar in whole-rock or feldspar) are often reset. This work reports a new U/Pb age in zircon that confirms a Lower Jurassic (193 Ma) age for volcanic rocks exposed in the Aramberri area. The major and trace element contents of samples from the seven localities are typical of calc-alkaline, subduction-related rocks. The new geochronological and geochemical data, coupled with the lithological features and stratigraphic positions, indicate volcanic rocks are part of a continental arc, similar to that represented by the Lower-Middle Jurassic Nazas Formation of Durango and northern Zacatecas. On that basis, the studied volcanic sequences are assigned to the Early Jurassic volcanic arc of western North America.

2024, Lucr. Şt

The research conducted during March-June 2010, on the Ezăreni farm, under the condition of Moldavian forest steppe, analyzed in the first year of alfalfa crop, at the first cut, the influence of seed inoculation with symbiotic bacteria... more

2024, Phytotaxa

Two Gymnopilus species are described and illustrated from northern parts of Khyber Pakhtunkhwa province, Pakistan. Gymnopilus swaticus is described as new to science based on morphological characters and data from nITS and nLSU.... more

2024

BENTHIC INVERTEBRATE RESPONSE TO HABITAT COMPLEXITY IN SOUTH BAY SALT PONDS by Jessica L. Murphey Wetlands are unique ecosystems that support specific flora, fauna, hydrology, and geology. These ecosystems increase groundwater availability, improve water quality, decrease flood water impacts, and help decrease shoreline erosion. In the south San Francisco Bay, the South Bay Salt Pond Restoration Project is restoring over 6,000 hectares of former salt ponds to tidal marshes and managed pond habitats. These habitats will support endangered species as well as migratory birds, diving ducks, invertebrates, and algal species. Benthic invertebrates are a vital piece of the South Bay food web as they provide the sustenance for other invertebrates, fish, shorebirds, and waterfowl. Improving the health of benthic communities in existing ponds is expected to attract more birds to those ponds and improve the overall health of the South Bay. This study assessed the relationship between invertebr...

2024

1. All eight USFS (7) and BLM (1) projects scored poorly (primarily D or F) and failed to successfully meet the key ecological criteria employed in this evaluation. Project will result in habitat loss and/or degradation for ESA-listed species? Degree to which use of prescribed fire is incorporated into project planning and implementation USFS Northern Region Gold Butterfly 5,281 Yes No Yes Yes Low-Moderate Hungry Ridge 7,164 Yes No Yes Yes Moderate Bitterroot Front 27,477 Yes No Yes Yes High USFS Rocky Mtn Region Lower North-South 94,575 Unknown No Yes Likely Moderate USFS Pacific Southwest Region North Yuba 91,025 Yes Partial; >24 to 40" dbh depending on land use allocation Yes Yes Low-Moderate USFS Pacific Northwest Region Grasshopper 3,858 Yes No (partial in Riparian Reserves; 24-30" dbh) Yes Yes Low Oregon BLM Last Chance 8.240 Yes Partial; >36 to 40" dbh depending on land allocation No Yes Low-Moderate USFS Eastern Region Early Successional Habitat Creation Project (Green Mountain NF) 12,000 Up to 160year-old stands but does not meet Eastern Region OG definition No Yes Yes (state listed in VT) N/A Relationship of Findings to Forest Service Proposed National Old Growth Amendment (NOGA) Absent significant improvements, the Forest Service's proposed NOGA policy will not address or rectify the many ecologically inappropriate management actions that are currently being planned and implemented on the national forests, as described in the project reviews included in this report. This is primarily because the agency's preferred alternative would allow and encourage "proactive stewardship" in old-growth stands and in forests with large/old treesdefined in the agency's draft environmental analysis as management actions that "promote the composition, structure, pattern, or ecological processes necessary for old-growth forests to be resilient and adaptable to stressors and likely future environments." Under this broad definition, the agency can propose almost any type of vegetation management as "proactive stewardship"including commercial logging of mature and old-growth treeseven if these actions will clearly degrade old forest attributes and values. As currently written, the NOGA preferred alternative would reinforce the status quo, which we demonstrate is resulting in the continued, unnecessary loss of mature and old-growth trees and the many irreplaceable values they provide. All of the NOGA's four alternatives would allow local Forest Service personnel to subjectively decide what constitutes "proactive stewardship," without any clear guidance to ensure that large/old trees and other important old forest attributes will be retained. In fact, the draft environmental analysis explicitly acknowledges that field personnel can eliminate old growthboth stands and treesin the process of implementing proactive stewardship. For example, under the proposed draft plan, the agency's proactive stewardship policy could be used to log old-growth stands "down to the minimum" for various structural attributes (e.g., large trees, canopy cover, etc.) that are included in existing old-growth forest definitions. This is a troubling practice that is already occurring on some national forests, including the Gold Butterfly project in Montana's Bitterroot National Forest (page 25). Without clear, transparent standards to ensure the retention of large/old trees, it is highly likely that agency projects will continue to use ecological justifications to further reduce and degrade remaining old-growth forests across federal lands. Examples of old-growth (L) and mature (R, unmarked to right of figure) Douglas-fir trees planned for logging in the Gold Butterfly project, Bitterroot National Forest. Photo credits: Mac Donofrio