Search

In cities across the United States, many more tree species are found in residential yards than in nearby parks or native landscapes outside the city, according to a new analysis. [...]

With rapid global change in the Anthropocene, it is important to understand and predict changes in species distributions that could potentially impact entire ecosystems. Turkey Vulture (Cathartes aura) distribution has been expanding and, as an obligate scavenger, its presence can have an impact on the ecosystems it inhabits. Here we investigated the relative impact of human population density and climate (temperature and precipitation) on Turkey Vulture presence. We used eBird community science data from 2010-2020 to create a species distribution model for Turkey Vultures across their entire range using a Random Forests algorithm. We then projected this distribution for the year 2070 to estimate any changes. Our model predicted an expansion in Turkey Vulture distribution during the breeding season of May-August. This suggests that areas of both North and South America where only seasonal, migratory Turkey Vultures currently exist can expect resident populations of Turkey Vultures in the future. Mild temperature was an important variable for presence during the nonbreeding season, whereas low human density was more important for predicting presence during the breeding season. The distribution of Turkey Vultures is widest during the breeding season, meaning that factors influencing the breeding range could be considered more important when considering range expansion. As such, our findings suggest that warmer boreal winters coupled with the potential presence of domestic carcasses in agricultural areas (i.e., low human density) are facilitating Turkey Vulture range expansion. This expansion has important implications for the scavenging community in northern latitudes where increased Turkey Vulture presence might impact other species relying on carrion. Key words: climate, global change, human density, random forests, range expansion, scavenger. Con el rápido cambio global en el Antropoceno, es importante entender y predecir cambios en distribución de especies que podrían potencialmente tener un impacto en ecosistemas completos. La distribución del zopilote de cabeza roja (Cathartes aura) se ha ido expandiendo y, como carroñero obligado, su presencia puede tener un impacto en los ecosistemas que habita. Aqui investigamos el impacto relativo de la densidad de población humana y del clima (temperatura y precipitación) en la presencia del zopilote de cabeza roja. Utilizamos datos de ciencia ciudadana de eBird del 2010-2020 para crear modelos de distribución de especies de los zopilotes de cabeza roja en su rango completo usando un algoritmo de Random Forests. Luego proyectamos su distribución para el año 2070 para estimar cambios posibles. Nuestro modelo predijo una expansión en la distribución del zopilote de cabeza roja durante la temporada reproductiva de mayo-agosto. Esto sugiere que áreas tanto de Norte como Sudamérica donde los zopilotes de cabeza roja eran solo estacionales migratorios podrían esperar tener poblaciones residentes de este zopilote en el futuro. La variable temperatura templada fue importante para la presencia durante la temporada no-reproductiva, mientras que la baja densidad humana fue un predictor más importante durante la temporada reproductiva. La distribución de los zopilotes de cabeza roja es más amplia durante la temporada reproductiva, lo que significa que los factores que influyen en el rango reproductivo podrían ser considerados más importantes al considerar la expansión de rango. Asi, nuestros hallazgos sugieren que inviernos boreales más cálidos junto con la presencia potencial de restos de animales domésticos en áreas agrícolas (es decir, de baja densidad humana) facilitan el rango de expansión del zopilote de cabeza roja. Esta expansión tiene implicaciones importantes para la comunidad de carroñeros en latitudes norteñas donde la presencia en aumento del zopilote de cabeza roja puede tener un impacto en otras especies dependientes de la carroña. Palabras clave: cambio global, carroñero, clima, densidad humana, expansión de rango., Vultures are declining on a global scale, with 62% of species showing declining populations and 57% threatened with extinction (IUCN 2020). In contrast to vulture populations in Africa and Asia, [...]

It is often assumed that the northern peripheral populations of species' ranges are genetically depauperate due in part to founder effects from postglacial colonization. The majority of federally protected plant species are peripheral in Canada, yet we have little information about their patterns of genetic diversity and structure. In British Columbia, the majority of these protected plant species occur in two threatened habitats: the Garry oak and Okanagan shrub-steppe ecosystems. Using universal noncoding chloroplast DNA markers, we investigated genetic diversity and genetic structure in four rare and common plant species pairs inhabiting these two ecosystems. We found that rare species had lower genetic diversity than their common congeners, and detected contrasting patterns of regional diversity and structure based on ecosystem. Species from the Garry oak ecosystem showed lower genetic diversity in the northern deglaciated region and significant differentiation between regions, likely due to limited dispersal between Vancouver Island and the mainland. Species from the Okanagan shrub-steppe, however, tended to have uniform diversity across their range and lack regional structure. This study provides an important first look at the phylogeographic patterns of four rare plant species in British Columbia. Key words: conservation genetics, British Columbia, rare plants, chloroplast DNA, phylogeography, genetic diversity, Garry oak ecosystem, shrub-steppe ecosystem, Introduction Genetic diversity is critical to the long-term viability of wild plant and animal species (Frankham 1996; Hughes et al. 2008) and is considered a prerequisite for adaptation to changing [...]

Nonnative, invasive plant species have been notoriously problematic for many ecosystems by outcompeting native plant species and disrupting habitat for insects and other animal life. Within the last decade, a nonnative orchid, Epipactis helleborine L. Crantz (Orchidaceae), has become increasingly present in Minnesota and is considered invasive in some eastern states, including Wisconsin. This study provides insights into the presence and habitat preferences of E. helleborine in Winona County, in southeastern Minnesota. A large portion of Winona County lies within the Driftless region, which is characterized by bluff land and unique plant communities that hat e been greatly impacted by invasive species. This study used MaxEnt software to create a habitat suitability model for E. helleborine using six environmental predictors: elevation, slope, aspect, soil type, land cover, and distance to roads. The results were a model with high habitat suitability predictability with elevation and slope being the most important predictors, whereas other variables contributed little to the final model. The final model showed relatively small areas with high suitability, where management efforts should be concentrated. Based on the model, this species does not seem to be a substantial threat to areas of great conservation concern, such as southwestern facing bluff prairies., INTRODUCTION Biological invasion facilitated by human interactions and globalization has become a growing concern in conserving the world's biodiversity (Crall et al., 2013; Kolanowska, 2013). There are many reasons, often [...]

The present work examines the ecological and biological characteristics of primrose plants and the regional characteristics of their distribution on the basis of field observations using the 'releve' method and an examination of herbarium specimens. Point data were derived from field surveys from 2010 through 2020 and herbarium collections. Based on the results, 12 primrose taxa of the genus Primula (eight species and four subspecies) were found in the flora of Transbaikalia, in particular P. nivalis subsp. turkestanica (J. H. Haage & E. Schmidt) Kovt., P. bukukunica Kovt., P. macrocalyx Bunge, P. pallasii Lehm, P. maximowiczu Regel, P. serrata Georgi, P. denticulata Sm, P. nutans Georgi, P. matthioli subsp. altaica (Losinsk.) Kovt., P. matthioli subsp. brotheri (R. Knuth) Kovt., P. longiscapa Ledeb. and P. nivalis Subsp. nivalis Pall. All these species and subspecies are taxonomic elements of the Transbaikalia ecosystem as a model territory of Eastern Siberia. Consequently, the overall results can be extrapolated to the territory of Eastern Siberia, which can be used as additional material for further floristic research in that region. With regard to the number of taxa, the taiga and forest-steppe areas are the most dense natural areas of Transbaikalia with 4-6 species units of primrose in each area. However, further experimental studies are required to investigate the environmental effect on the distribution of primrose in eastern Siberia in order to prevent the extinction of the primrose. Keywords Primroses of Transbaikalia * Biodiversity of primroses * Ecological features of distribution * Flora of eastern Siberia * Eastern Siberia, Introduction One of major processes occurring in terrestrial plant ecosystems and threatening their existence is the destruction and fragmentation of habitats (Aguilar et al., 2019). Once widespread populations, such as [...]

We validated a procedure for the determination of indicator congeners (ICs) of polychlorinated biphenyls (PCBs) (IUPAC nos. 28, 52, 101, 118, 138, 153, and 180) in water at an ultratrace concentration level in the range from 0.02 to 0.90 ng/L. The procedure includes collecting 1-L samples, extraction of PCBs with n-hexane, preconcentration of the extracts (k.sub.conc = 10.sup.4), and the direct analysis of the preconcentrates by gas chromatography-tandem mass spectrometry. The chromatographic separation of the preconcentrates in columns with a carborane stationary phase (HT-8, 30 m), the detection of analytical peaks in the selected reaction monitoring mode, and the use of ICs labeled with .sup.13C as surrogate internal standards ensured the high reliability of peak identification and the accuracy of quantitative determination with a total error (±[delta], P = 0.95) of 35%. The procedure was tested in monitoring PCBs in the aquatic ecosystem of Lake Baikal, and the concentrations of ICs were determined in the upper water layer of the pelagic zone and the lake's tributaries., Author(s): O. V. Kustova [sup.1], A. S. Stepanov [sup.2], A. G. Gorshkov [sup.1] Author Affiliations: (1) grid.425246.3, 0000 0004 0440 2197, Limnological Institute, Siberian Branch, Russian Academy of Sciences, , [...]