Western North American Naturalist最新文献

{"title":"Late Pleistocene Herpetofauna from Two High-Elevation Caves in the Upper Gunnison Basin, Colorado","authors":"Jim I. Mead, S. Emslie, D. Meltzer","doi":"10.3398/064.083.0310","DOIUrl":"https://doi.org/10.3398/064.083.0310","url":null,"abstract":"Abstract. Cement Creek and Haystack caves in Colorado have produced a diverse record of high-elevation late Quaternary mammals. Intermixed with the abundant mammalian remains were rare occurrences of amphibian and reptile fossils reported here. Cement Creek Cave (2860 m elevation) contained the fossils of only a few anurans and a limited number of snakes, whereas Haystack Cave, at a substantially lower elevation (2450 m), contained the fossils of a salamander, a larger number of snakes, and an extensive number of lizard remains, yet no anurans. The 2 faunas are overall distinct in composition, and, although not diverse or abundant in terms of species or number of faunal remains, they provide a rare and exceptional record of a late Pleistocene high-elevation herpetofauna from the Intermountain West. Resumen. Las cuevas Cement Creek y Haystack en Colorado han producido un diverso registro de mamíferos de gran altitud del Cuaternario tardío. Entre los abundantes restos de mamíferos, se registraron raros casos de anfibios y reptiles, los cuales reportamos a continuación. En la cueva Cement Creek (2860 m de elevación) se encontraron solo unos pocos anuros y un número limitado de serpientes. Mientras que, en la cueva Haystack, a una elevación sustancialmente más baja (2450 m de elevación), se encontraron una salamandra, una mayor cantidad de serpientes y una gran cantidad de restos de lagartos, pero no anuros. Las dos faunas son distintas en su composición en general y, aunque no son diversas ni abundantes en términos de especies o número de restos de fauna, proporcionan un registro único y excepcional de una herpetofauna de alta elevación del Pleistoceno tardío del oeste intermontañoso.","PeriodicalId":49364,"journal":{"name":"Western North American Naturalist","volume":null,"pages":null},"PeriodicalIF":0.6,"publicationDate":"2023-10-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139320378","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Potentially Adaptive Significance of Genome Size Diversity across Ecological Gradients and Seed Size in Ivesia (Rosaceae)","authors":"I. Borokini, Shaun R. Broderick, Zhi Gao, Joshua M. Hallas, James A. Birchler, Mary M. Peacock","doi":"10.3398/064.083.0301","DOIUrl":"https://doi.org/10.3398/064.083.0301","url":null,"abstract":"Abstract. Variation in genome size across taxa has been explained using neutral and nonadaptive theories; however, genome size variation among taxonomic groups can also be shaped by natural selection if it correlates with functional traits. This study investigated the potential adaptive significance of genome size in Ivesia, a radiating genus distributed in the western North American desert ecosystems. We estimated the genome size of 34 taxa (including 31 Ivesia taxa, 2 Potentilla taxa, and 1 Horkelia taxon) using flow cytometric methods. For each taxon, leaf samples were collected from 6 individuals in 1 location each; intraspecific genome size variation was investigated using samples collected from 11 Ivesia webberi populations. The results showed an 8.1-fold variance in genome size, ranging from 0.73 pg/2C in I. baileyi var. beneolens to 5.91 pg/2C in I. lycopodioides var. megalopetala. Only 6 taxa, with a genome size >1.5 pg/2C, significantly differed from the remaining taxa. Genome size in Ivesia is relatively small, which is typical of plants living in stressful environments. Also, genome size was significantly correlated with seed size and actual evapotranspiration both within I. webberi and among Ivesia taxa, thus supporting the predictions of the nucleotype theory and suggesting an adaptive significance of genome size in the genus. Genome size in I. webberi is mostly statistically nonsignificant; however, populations near the center of the species' known range have significantly larger genomes, which decrease in size toward the marginal populations. This intraspecific genome size gradient from range center toward range margins could be attributed to patterns of gene flow and geographic isolation. Resumen. La variación en el tamaño del genoma entre los taxones se ha explicado utilizando teorías neutrales y no adaptativas. Sin embargo, la variación del tamaño del genoma entre grupos taxonómicos también puede estar determinada por selección natural si se correlaciona con rasgos funcionales. Este estudio investigó la posible importancia adaptativa del tamaño del genoma en Ivesia, un género radiante distribuido en los ecosistemas desérticos del oeste de Norteamérica. Estimamos el tamaño del genoma de 34 taxones, incluidos 31 taxones de Ivesia y dos taxones adicionales de Potentilla y un taxón de Horkelia, utilizando métodos de citometría de flujo. Para cada taxón, recolectamos muestras de hojas de seis individuos en una localización cada uno. Mientras, investigamos la variación del tamaño del genoma intraespecífico utilizando muestras recolectadas de 11 poblaciones de Ivesia webberi. Los resultados mostraron una variación de 8.1 veces en el tamaño del genoma, que va desde 0.73 pg/2C en I. baileyi var. beneolens hasta 5.91 pg/2C en I. lycopodioides var. megalopetala. Solo seis taxones, con un tamaño de genoma >1.5 pg/2C, fueron significativamente diferentes al resto de los taxones. El tamaño del genoma en Ivesia es relativamente pequeño, lo cu","PeriodicalId":49364,"journal":{"name":"Western North American Naturalist","volume":null,"pages":null},"PeriodicalIF":0.6,"publicationDate":"2023-10-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139321259","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Floral Constancies of Flies and Native Bees Visiting Ceanothus perplexans (Rhamnaceae) Flowers in Western Arizona","authors":"W. Wiesenborn","doi":"10.3398/064.083.0311","DOIUrl":"https://doi.org/10.3398/064.083.0311","url":null,"abstract":"Abstract. Ceanothus perplexans (Rhamnaceae) is a chaparral and montane shrub found mostly in southern California and northern Baja California, Mexico, and infrequently in western Arizona. The plant produces inflorescences of small, perfect, white or cream flowers during winter to early spring. I examined the pollination of C. perplexans in the Cerbat Mountains in western Arizona during March and April 2022 by collecting flies and native bees on flowers and estimating floral constancies from the proportions of conspecific pollen in pollen loads. Flowers are protandrous with the pistil elongating and the stigmas separating after the anthers lose pollen. Pollen from C. perplexans flowers is tricolporate and interhexagonal in polar view and suboblate in shape with a polar axis length of 17 µm and an equatorial diameter of 19 µm. Flowers were visited by 2 genera of bees (Hymenoptera: Apoidea) in Andrenidae and 9 genera of flies (Diptera) in Syrphidae, Calliphoridae, Anthomyiidae, Muscidae, Tachinidae, and Bombyliidae. Bees were most abundant on flowers, and bee visitors were composed primarily of a Panurginus species followed in abundance by Andrena mackieae. Mean proportions of conspecific pollen in pollen loads were high (>0.80) in all of the species examined, slightly higher in bees (0.99) compared with flies (0.95), and lowest in Syrphidae (0.92). Ceanothus perplexans in western Arizona appears to be pollinated primarily by bees in Panurginus and Andrena and less frequently by various flies. Early flowering by C. perplexans likely reduces competition with other species of plants for pollinators. Resumen. El Ceanothus perplexans (Rhamnaceae) es un arbusto chaparral de las montañas que se encuentra principalmente en el sur de California y el norte de Baja California, México, y ocasionalmente en el oeste de Arizona. La planta produce inflorescencias de flores pequeñas, perfectas, de color blanco o crema durante el invierno hasta principios de la primavera. Examiné la polinización de C. perplexans en las montañas Cerbat en el oeste de Arizona, durante marzo y abril de 2022, recolectando moscas y abejas nativas en las flores y estimando la constancia floral a partir de las proporciones de polen conespecífico en las cargas de polen. Las flores son protándricas con el pistilo alargado y los estigmas separados, después de que las anteras sueltan el polen. El polen de las flores C. perplexans es tricolporado e interhexagonal en vista polar y de forma suboblada con una longitud del eje polar de 17 µm y un diámetro ecuatorial de 19 µm. Las flores fueron visitadas por dos géneros de abejas (Hymenoptera: Apoidea) en Andrenidae y nueve géneros de moscas (Diptera) en Syrphidae, Calliphoridae, Anthomyiidae, Muscidae, Tachinidae y Bombyliidae. Las abejas fueron las más abundantes en las flores, componiéndose principalmente de una especie de Panurginus seguida de Andrena mackieae. Las proporciones medias de polen conespecífico en las cargas de polen fueron altas (>","PeriodicalId":49364,"journal":{"name":"Western North American Naturalist","volume":null,"pages":null},"PeriodicalIF":0.6,"publicationDate":"2023-09-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139335255","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Spatial and Temporal Distribution of Phalaropes (Phalaropus spp.) and Adult Brine Flies (Ephydra spp.) are Linked on Great Salt Lake, Utah","authors":"Maureen G. Frank, Michael R. Conover","doi":"10.3398/064.083.0309","DOIUrl":"https://doi.org/10.3398/064.083.0309","url":null,"abstract":"Abstract. Great Salt Lake (GSL), Utah, is home to some of the world's largest concentrations of Wilson's Phalaropes (Phalaropus tricolor), Red-necked Phalaropes (Phalaropus lobatus), American Avocets (Recurvirostra americana), and Black-necked Stilts (Himantopus mexicanus). These birds spend several weeks on GSL feeding on larvae, pupae, and adult brine flies (Ephydra spp.) before migrating to their wintering grounds in Central and South America. Unfortunately, GSL is shrinking in size and becoming more saline due to water diversions and climate change. Assessing how a smaller and more saline GSL will affect adult brine flies is difficult without knowing their temporal and spatial distribution on GSL. During 2014 and 2015, we measured adult brine fly abundance across different GSL bays during July through September, when phalaropes are staging on the lake. Abundance of adult brine flies showed a bimodal pattern, peaking during weeks 27–29 and then again during week 33. Wilson's Phalaropes were abundant during the first peak in fly numbers but not during the second peak; Red-necked Phalaropes exhibited the opposite pattern. Time of day and weather had little impact on adult fly numbers, with the exception that abundance was positively correlated with air temperature. During this study, a deep brine layer (which is toxic to brine fly larva) existed at water depths >6 m, and adult brine fly abundance was low over these areas. Adult brine fly abundance did not differ with distance from shore or time of day but was positively correlated with salinity. Substrate impacted their abundance, with adult brine flies being 5 times more abundant over microbialites—which are rocky, reef-like structures—than over sand or mud. Phalarope numbers were also highest over microbialites. Thus, most brine fly eggs are laid over microbialites, which is the preferred habitat for brine fly larvae and pupae. Information about the temporal and spatial distribution of adult brine flies is critical for wildlife managers who are tasked with ensuring that GSL will continue to support the large avian populations that depend on GSL's adult brine flies for their existence. Resumen. El lago Great Salt Lake (GSL), en Utah, alberga algunas de las concentraciones más grandes del mundo de falaropo tricolor o falaropo de Wilson (Phalaropus tricolor), falaropo picofino o de cuello rojo (Phalaropus lobatus), avoceta americana (Recurvirostra americana) y cigüeñuela de cuello negro (Himantopus mexicanus). Estas aves pasan varias semanas en GSL alimentándose de larvas, pupas y moscas de salmuera adultas (Ephydra spp.) antes de migrar a sus áreas de invernada en Centro y Sudamérica. Desafortunadamente, el lago GSL se está reduciendo en tamaño y se está volviendo más salino debido a las desviaciones de agua y el cambio climático. Es difícil evaluar cómo estos cambios en el lago afectarán a la mosca de salmuera adulta sin conocer su distribución temporal y espacial. Durante 2014 y 2015, medimos ","PeriodicalId":49364,"journal":{"name":"Western North American Naturalist","volume":null,"pages":null},"PeriodicalIF":0.6,"publicationDate":"2023-09-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139339757","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Reproductively Viable Population of American Black Bears (Ursus americanus) in Lowland Chihuahuan Desert Habitat of Trans-Pecos Texas","authors":"F. Yancey, Stephen Kasper","doi":"10.3398/064.083.0305","DOIUrl":"https://doi.org/10.3398/064.083.0305","url":null,"abstract":"Abstract. During a 6.5-year camera-trap study in Big Bend Ranch State Park (situated in the Trans-Pecos region of West Texas), we documented a persistent breeding population of American black bears (Ursus americanus) in the Solitario region of the park. The habitat in the Solitario, which is an isolated, eroded remnant of volcanic activity, is low-elevation Chihuahuan Desert scrub but includes significant and complex localized topography and prolonged water sources in the form of tinajas. From January 2016 to May 2022, camera traps captured 367,301 photographs. Of these, 868 contained one or more black bears, resulting in 1010 black bear images. Based on age class, size, color, body markings, facial patterns, presence of cubs, and dates of images, we determined that these images represent a minimum of 17 distinct individuals. Adult and subadult bears were identified during each year, yearlings were detected during 4 years, and cubs were noted during 3 years of the study. Based on these data, the Solitario black bears can be considered the westernmost reproductively viable population of American black bears in Trans-Pecos, Texas, and the only one that is situated exclusively in lowland desert habitat. Dietary resources of black bears from other Chihuahuan Desert localities in Texas and northern Mexico are also found in the current study area. This American black bear population is in an area spatially separated from other black bear populations in the region, and we discuss its relevance to the sky island metapopulation hypothesis of recolonization previously proposed for the species in northern Mexico and Trans-Pecos Texas. Resumen. Como resultado de un estudio de seis años y medio de duración en Big Bend Ranch State Park (localizado en la región Trans-Pecos del oeste de Texas) documentamos una población viable de oso negro americano (Ursus americanus) en la región “Solitario” del parque, la cual se encuentra en un remanente volcanico erosionado. La vegetación es desierto Chihuahuense de baja elevación, con topografía local compleja y presencia de cuerpos de agua conocidos como “tinajas”. De enero de 2016 a mayo de 2022 se capturaron 367,301 fotografías con trampas cámara. De ellas, 868 contuvieron uno o más osos negros, para un total de 1010 imágenes con osos negros. Con base en su edad relativa, tamaño, color, marcas corporales, patrones faciales, presencia de oseznos y fechas de las imágenes, determinamos un mínimo de 17 individuos. Se identificaron osos adultos y subadultos cada año, por cuatro años se detectaron juveniles del año, y se registraron oseznos del año durante tres años del estudio. Con base en estos datos, los osos de Solitario pueden considerarse como la población reproductivamente viable más occidental de oso negro americano en Trans-Pecos, Texas, y la única que ocurre exclusivamente en matorral desértico de baja elevación. Los recursos vegetales usados por los osos negros en otras localidades del Desierto Chihuahuense de Texas","PeriodicalId":49364,"journal":{"name":"Western North American Naturalist","volume":null,"pages":null},"PeriodicalIF":0.6,"publicationDate":"2023-09-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139341592","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"First Documentation of Least Chub in the Snake River Drainage in Idaho","authors":"E. Billman, Dallin Stokes, Isaac Calderwood, Cody Diehl","doi":"10.3398/064.083.0306","DOIUrl":"https://doi.org/10.3398/064.083.0306","url":null,"abstract":"Abstract. The Least Chub (Iotichthys phlegethontis) is a small minnow endemic to the Bonneville Basin in Utah, where the current distribution of extant populations is limited to a few small spring complexes. We report on the first documentation of Least Chub in the upper Snake River drainage in Idaho. In June 2021, October 2021, and June 2022, we surveyed for small-bodied fishes in off-channel habitat of lower Henrys Fork in Cartier Slough Wildlife Management Area west of Rexburg, Idaho. Small-bodied fishes were sampled at 17 sites in off-channel habitat; 5 baited minnow traps (galvanized steel) were set for approximately 24 h at each site. We captured Least Chub in side-channel habitats during all sampling occasions; we captured 214 Least Chub in June 2021, 34 Least Chub in October 2021, and 41 Least Chub in June 2022. Least Chub were captured at 13 of the 17 sites: 6 sites in June 2021, 6 sites in October 2021, and 12 sites in June 2022. Least Chub ranged in size from 35 mm to 56 mm total length. In both June sampling occasions, female and male Least Chub were mature; females were expressing eggs and males had red/orange breeding coloration laterally. The habitat at sites where Least Chub were captured consisted of muddy or sandy substrate, slow-moving or stagnant water, submerged and emergent macrophytes, and filamentous algae. Additional surveys should be completed to determine the extent of the distribution of Least Chub in Henrys Fork and Snake River. Genetic analyses should also be completed to determine the relationship of this population of Least Chub to populations of Least Chub in the Bonneville Basin. Resumen. El pequeño pez Iotichthys phlegethontis es endémico de la cuenca de Bonneville en Utah, la distribución actual de sus poblaciones se limita a unos cuantos pequeños complejos de manantiales. En este trabajo reportamos el primer registro de peces I. phlegethontis en la corriente superior del río Snake en Idaho. Durante junio y octubre de 2021 y en junio de 2022, muestreamos peces de pequeño tamaño en el hábitat fuera del canal de la parte inferior de Henrys Fork en el Área de Manejo de Vida Silvestre de Cartier Slough al oeste de Rexburg. Se capturaron de peces pequeños en 17 sitios en un hábitat fuera del canal; se colocaron cinco trampas de acero galvanizado con cebo durante aproximadamente 24 horas en cada sitio. Capturamos peces I. phlegethontis dentro de los hábitats del canal en todas las ocasiones de muestreo: 214 I. phlegethontis en junio de 2021, 34 en octubre de 2021 y 41 en junio de 2022. Los peces I. phlegethontis fueron capturados en 13 de los 17 sitios: seis sitios en junio de 2021, seis sitios en octubre de 2021 y en doce sitios en junio de 2022. El tamaño de los peces I. phlegethontis varió entre 35 y 56 mm de longitud total. En ambas ocasiones durante los muestreos de junio, las hembras y los machos de I. phlegethontis fueron adultos; las hembras se encontraban en época de desové y los machos tenían coloración rep","PeriodicalId":49364,"journal":{"name":"Western North American Naturalist","volume":null,"pages":null},"PeriodicalIF":0.6,"publicationDate":"2023-08-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139347202","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Soil Seed Bank Composition and Spatial Distribution in a Cheatgrass (Bromus tectorum L.)–Dominated Rangeland in Colorado, USA","authors":"Ryan W. R. Schroeder, J. Jonas, M. N. Grant-Hoffman, M. Paschke","doi":"10.3398/064.083.0205","DOIUrl":"https://doi.org/10.3398/064.083.0205","url":null,"abstract":"Abstract. Invasion by nonnative annual plants that form prolific seed banks, including Bromus tectorum L. (cheatgrass), throughout western North America is a major natural resource concern. Even with known economic and ecological implications, soil seed banks and their potential to impact ecological restoration in arid and semiarid ecosystems are poorly understood. Quantifying the regenerative potential of the soil seed bank—the living seeds in the soil profile and on the soil surface—can help natural resource managers make decisions to increase the likelihood of restoration success. We analyzed the germinable soil seed bank composition and distribution of a rangeland site in western Colorado that experienced a wildfire in 1994 and is dominated by cheatgrass. We collected soil seed bank samples from 118 points in a 100 × 110 m grid to a depth of 5 cm. Each sample was split by depth from 0 to 2 cm and from 2 to 5 cm, and the seed bank was quantified using greenhouse emergence methods. We found that seeds of native species were more dense and evenly distributed (3391 seeds ∙ m–2) than seeds of nonnative species were (1880 seeds ∙ m–2) in the 0–5 cm seed bank across the site. We also found that seeds of both native and nonnative species were concentrated in the 0–2 cm layer of the seed bank but that native and nonnative seeds were present in substantive densities in the 2–5 cm layer. These findings suggest that the soil seed bank of the site is resilient, and a targeted approach to specifically deplete the seed bank of nonnative annuals could facilitate restoration by the in situ native seed bank. Resumen. La invasión de plantas anuales no autóctonas que forman prolíficos bancos de semillas, entre ellas Bromus tectorum L. (pasto espiguilla), en todo el oeste de Norteamérica es una preocupación muy importante de recursos naturales. A pesar de sus conocidas implicaciones económicas y ecológicas, los bancos de semillas del suelo y su potencial para influir en la restauración ecológica de los ecosistemas áridos y semiáridos son poco conocidos. Cuantificar el potencial regenerativo del banco de semillas del suelo—las semillas vivas en el perfil y la superficie del suelo—puede ayudar a los gestores de recursos naturales a tomar decisiones para aumentar las probabilidades de éxito de la restauración. Analizamos la composición y distribución del banco de semillas germinables del suelo de un pastizal del oeste de Colorado que sufrió un incendio forestal en 1994 y en el que predomina el pasto espiguilla. Recogimos muestras del banco de semillas del suelo en 118 puntos de una cuadrícula de 100 × 110 metros a una profundidad de 5 cm. Cada muestra se dividió por profundidad de 0–2 cm y 2–5 cm y el banco de semillas se cuantificó utilizando métodos de emergencia en invernadero. Encontramos que las semillas de especies nativas fueron más densas y estaban distribuidas uniformemente (3391 semillas ∙ m–2) que las semillas de especies no nativas (1880 semillas ∙ m–2) ","PeriodicalId":49364,"journal":{"name":"Western North American Naturalist","volume":null,"pages":null},"PeriodicalIF":0.6,"publicationDate":"2023-08-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139350203","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effects of Annual Weather Variation on Peak Herbaceous Yield Date in Sagebrush Steppe","authors":"J. Bates, Dustin Johnson, Kirk W. Davies, Tony Svejcar, Stuart Hardegree","doi":"10.3398/064.083.0207","DOIUrl":"https://doi.org/10.3398/064.083.0207","url":null,"abstract":"Abstract. Interannual climate variability impacts forage yield in semiarid rangelands, but it also affects the timing of peak yields. Knowledge of peak standing crop or yield dates would be useful when planning fieldwork for various research or management activities and for developing more accurate models linking herbage production to climatic variables. In this study, herbaceous yield was measured every 2 weeks (April–August) over an 8-year period in a Wyoming big sagebrush (Artemisia tridentata ssp. wyomingensis) community in southeastern Oregon. Date of peak yield (Julian day) was calculated for morphological groups (tall perennial bunchgrasses, perennial forbs, annual forbs), Sandberg bluegrass (Poa secunda J. Pressl), and total herbaceous yield. Linear and multiple regression analyses were used to correlate date of peak yield of herbaceous morphological groups with spring precipitation, reference evapotranspiration (RET), and air temperature. Peak yield dates for the herbaceous response variables were strongly correlated to annual climatic variation, commonly a combination of early growing season precipitation (March to 16 May) and March through May RET. Depending on morphological group, peak yield date varied by 3 to 7 weeks during the growing season. The best regression coefficients for peak yield date of perennial bunchgrasses, perennial forbs, Sandberg bluegrass, annual forbs, and total herbaceous vegetation alone or with various combinations of precipitation, temperature, and RET were 0.97, 0.82, 0.86, 0.90, and 0.98, respectively. For planning fieldwork, estimates of peak yield date can be used to accurately sample for yields of herbaceous morphological groups and community production potentials. Resumen. La variabilidad climática interanual influye en el rendimiento del forraje de los pastizales semiáridos, pero también afecta al momento en que alcanzan su rendimiento máximo. El conocimiento de las fechas de máxima cosecha o rendimiento podría ser útil en el momento de planificar el trabajo de campo para diversas actividades de investigación o gestión y para desarrollar modelos más precisos que relacionen la producción de hierba con las variables climáticas. En este estudio, se midió el rendimiento herbáceo cada dos semanas (abril-agosto), durante un periodo de ocho años, en una comunidad de artemisa de Wyoming (Artemisia tridentata ssp. wyomingensis) en el sureste de Oregón. Se calculó la fecha de máximo rendimiento (en días julianos) para cada grupo morfológico (hierbas altas o pasrtos perennes, hierbas perennes, hierbas anuales), el pasto azul de Sandberg (Poa secunda J. Pressl) y el rendimiento herbáceo total. Se utilizaron análisis de regresión lineal y múltiple para correlacionar la fecha de máximo rendimiento de los grupos morfológicos herbáceos con la precipitación primaveral, la evapotranspiración de referencia (RET) y la temperatura del aire. Las fechas de máximo rendimiento para las variables de respuesta herbáceas se corre","PeriodicalId":49364,"journal":{"name":"Western North American Naturalist","volume":null,"pages":null},"PeriodicalIF":0.6,"publicationDate":"2023-08-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139350260","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Aquatic Insect Communities Remain Impaired Following Large-Scale River Restoration","authors":"Jared Meek, Jackson Birrell, Teagan Mulford, Dennis K. Shiozawa, C. R. Nelson","doi":"10.3398/064.083.0206","DOIUrl":"https://doi.org/10.3398/064.083.0206","url":null,"abstract":"Abstract. River manipulation and degradation can cause detrimental impacts on aquatic insect communities. River restoration projects seek to mitigate these human disturbances. Assessing the efficacy of river restoration remains an important goal for river managers and conservation biologists so that improved restoration methods can be used in the future. From 1999 to 2008, the Utah Reclamation Mitigation and Conservation Commission restored a 15-km channelized portion of the Provo River (Wasatch County, Utah, USA). Before (1999) and during (2002) the restoration project, macroinvertebrate samples were collected using modified kick nets from 3 sites within the restored area and 1 site outside the restored area. In 2017, we collected macroinvertebrates from these same sites using identical sampling methods to assess the long-term outcomes of the Provo River Restoration Project through a comparison of macroinvertebrate species richness, Shannon diversity, %EPT (Ephemeroptera, Plecoptera, Trichoptera), functional feeding groups, and habit groups. We show that macroinvertebrate richness and diversity have significantly decreased in the restored reaches of the river, despite the restoration project being completed in 2008. Additionally, we found that EPT taxa declined in the restored reaches and that the community remains dominated by collectors. Our results help quantify the efficacy of the Provo River Restoration Project and highlight the need for additional remediation techniques. Significant reductions in richness, Shannon diversity, and functional feeding group diversity at the reference site suggest that factors unaddressed by the restoration such as river damming, lack of riparian vegetation, maintenance of nonnative fish, nutrient pollution, and climate change may be preventing the full rehabilitation of the river. We discuss potential factors that may be contributing to river degradation in this system and advocate for revised and more holistic river restoration approaches, along with the importance of regular monitoring programs for completed restoration projects. Resumen. La manipulación y degradación de los ríos puede tener efectos perjudiciales en las comunidades de insectos acuáticos. Los proyectos de restauración de ríos tratan de mitigar estas perturbaciones humanas. Evaluar la eficacia de la restauración de los ríos sigue siendo un objetivo importante para los gestores de ríos y los biólogos conservacionistas, de modo que en el futuro puedan utilizarse mejores métodos de restauración. Entre 1999 y 2008, la Utah Reclamation Mitigation and Conservation Commission restauró una porción canalizada de 15 km del río Provo (condado de Wasatch, Utah, EE.UU.). Antes (1999) y durante (2002) el proyecto de restauración, se recogieron muestras de macroinvertebrados utilizando redes modificadas en tres sitios dentro del área restaurada y un sitio fuera del área restaurada. En 2017, recogimos macroinvertebrados de estos mismos sitios utilizando métod","PeriodicalId":49364,"journal":{"name":"Western North American Naturalist","volume":null,"pages":null},"PeriodicalIF":0.6,"publicationDate":"2023-08-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139351089","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Insights on the Distribution of Struthanthus palmeri Kuijt (Loranthaceae), the Northernmost Species of the Genus","authors":"Mónica I. MIGUEL-VÁZQUEZ, Yasser S. López de Olmos-Reyes, Maria Guadalupe Maldonado-Borja, R. Cerros-Tlatilpa","doi":"10.3398/064.083.0215","DOIUrl":"https://doi.org/10.3398/064.083.0215","url":null,"abstract":"Abstract. Struthanthus (Loranthaceae) is native to the Americas, and several species occur in Mexico, some of which are endemic, such as S. palmeri. Within the genus, S. palmeri has the northernmost distribution, inhabiting the arid environments of northwestern Mexico near the border with the United States. In this study, the known distribution of the species was updated. The elevation, hosts, and vegetation types where S. palmeri occurs were compiled to infer its potential distribution, using ecological niche modeling. Based on the results, the endemic status of S. palmeri is reinforced. This taxon occurs in several types of vegetation, from near sea level to 1300 m, and it parasitizes taxa of 12 families. There are records of the species for 1 of the 21 federal Protected Natural Areas that are included in the “M area” employed in the analysis. The potential distribution of S. palmeri shows high probabilities of presence mainly in the North American Terrestrial Ecoregions that include the coastal areas of Sonora and Sinaloa. This study expands our knowledge of mistletoes from arid regions of America as well as our knowledge of Mexican endemic species, providing additional habitat and host information for the management and conservation of this group. Resumen. Struthanthus (Loranthaceae) es nativo de América y varias de sus especies se encuentran en México, algunas de las cuales son endémicas, por ejemplo S. palmeri. Dentro del género, S. palmeri tiene la distribución más septentrional, habitando en los ambientes áridos del noroeste de México, cerca de la frontera con Estados Unidos. En este estudio, se actualizó la distribución conocida de la especie. Se compiló la elevación, hospederos y tipos de vegetación donde S. palmeri se encuentra, para inferir su distribución potencial, usando modelado de nicho ecológico. Con base en los resultados, se reforzó el estatus de endemismo de S. palmeri. Este taxón se presenta en varios tipos de vegetación, desde cerca del nivel del mar hasta los 1300 m y parasitando taxa de 12 familias. Hay registros de la especie para una de las 21 Áreas Naturales Protegidas federales incluidas en el área M empleada en el análisis. Su distribución potencial muestra probabilidades altas de presencia, principalmente en las Ecorregiones Terrestres de Norteamérica que incluyen las áreas costeras de Sonora y Sinaloa. Este estudio expande el conocimiento de muérdagos de regiones áridas de América y de las especies endémicas de México, proporcionando información adicional sobre hábitat y hospederos, para el manejo y conservación de este grupo.","PeriodicalId":49364,"journal":{"name":"Western North American Naturalist","volume":null,"pages":null},"PeriodicalIF":0.6,"publicationDate":"2023-08-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139351276","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}