scholarly journals Tracking late-Quaternary extinctions in interior Alaska using megaherbivore bone remains and dung fungal spores

2020 ◽  
Vol 97 ◽  
pp. 99-110
Author(s):  
Keziah J. Conroy ◽  
Ambroise G. Baker ◽  
Vivienne J. Jones ◽  
Maarten van Hardenbroek ◽  
Emma J. Hopla ◽  
...  
Keyword(s):  
Late Quaternary ◽  
Sediment Cores ◽  
Fungal Spores ◽  
Fungal Spore ◽  
The Holocene ◽  
Interior Alaska ◽  
Before And After ◽  
Last Stage ◽  
Quaternary Extinctions ◽  
Bone Remains

AbstractOne major challenge in the study of late-Quaternary extinctions (LQEs) is providing better estimates of past megafauna abundance. To show how megaherbivore population size varied before and after the last extinctions in interior Alaska, we use both a database of radiocarbon-dated bone remains (spanning 25–0 ka) and spores of the obligate dung fungus, Sporormiella, recovered from radiocarbon-dated lake-sediment cores (spanning 17–0 ka). Bone fossils show that the last stage of LQEs in the region occurred at about 13 ka ago, but the number of megaherbivore bones remains high into the Holocene. Sporormiella abundance also remains high into the Holocene and does not decrease with major vegetation changes recorded by arboreal pollen percentages. At two sites, the interpretation of Sporormiella was enhanced by additional dung fungal spore types (e.g., Sordaria). In contrast to many sites where the last stage of LQEs is marked by a sharp decline in Sporormiella abundance, in interior Alaska our results indicate the continuance of megaherbivore abundance, albeit with a major taxonomic turnover (including Mammuthus and Equus extinction) from predominantly grazing to browsing dietary guilds. This new and robust evidence implies that regional LQEs were not systematically associated with crashes of overall megaherbivore abundance.

Coprophilous fungal spores: NPPs for the study of past megaherbivores

2020 ◽  
pp. SP511-2020-41
Author(s):  
Eline N. van Asperen ◽  
Angelina Perrotti ◽  
Ambroise Baker
Keyword(s):  
Late Quaternary ◽  
Fungal Spores ◽  
Fungal Spore ◽  
Large Herbivore ◽  
Coprophilous Fungi ◽  
Content Type ◽  
Factors Influencing ◽  
Wide Range ◽  
Supplementary Material ◽  
Quantitative Reconstructions

AbstractSpores from coprophilous fungi are some of the most widely used non-pollen palynomorphs. Over the last decades, these spores have become increasingly important as a proxy to study the Pleistocene and Holocene megafauna. Although the number of types used in palaeoecology is relatively small, there is a wide range of coprophilous fungal taxa whose utility in palaeoenvironmental reconstruction remains under-researched. However, environmental and taphonomic factors influencing preservation and recovery of these spores are still poorly understood. Furthermore, our understanding of whether and how spores are transported across the landscape is limited.Dung fungal spore presence appears to correlate well with megaherbivore presence. However, depending on the site, some limitations can remain to quantitative reconstructions of megaherbivore abundance from dung fungal spore records. The presence of dung fungal spores is often more significant than their absence and variation in in abundance with time should be interpreted with caution. Correlation with other proxies may provide a promising way forward.The majority of studies using dung fungal spores as an indicator for large herbivore abundance are of records of Late Pleistocene and Holocene age, with a focus on Late Quaternary megafaunal extinction. However, more research could potentially extend records further back in time.Supplementary material at https://doi.org/10.6084/m9.figshare.c.5240664

An Assessment of Environmental Changes in Three Lakes from King's County (Nova Scotia, Canada) Using Diatom-Based Paleolimnological Techniques

2008 ◽  
Vol 43 (2-3) ◽  
pp. 85-98 ◽  
Author(s):  
Joshua R. Thienpont ◽  
Brian K. Ginn ◽  
Brian F. Cumming ◽  
John P. Smol
Keyword(s):  
Nova Scotia ◽  
Environmental Changes ◽  
Sediment Cores ◽  
Lake Management ◽  
River System ◽  
210Pb Dating ◽  
Hydroelectric Power ◽  
Diatom Assemblages ◽  
Shoreline Development ◽  
Before And After

Abstract Paleolimnological approaches using sedimentary diatom assemblages were used to assess water quality changes over the last approximately 200 years in three lakes from King's County, Nova Scotia. In particular, the role of recent shoreline development in accelerating eutrophication in these systems was assessed. Sediment cores collected from each lake were analyzed for their diatom assemblages at approximately 5-year intervals, as determined by 210Pb dating. Analyses showed that each system has changed, but tracked different ecosystem changes. Tupper and George lakes recorded shifts, which are likely primarily related to climatic warming, with diatom assemblages changing from a preindustrial dominance by Aulacoseira spp. to present-day dominance by Cyclotella stelligera. In addition to the recent climatic-related changes, further diatom changes in the Tupper Lake core between approximately 1820 and 1970 were coincident with watershed disturbances (farming, forestry, and construction of hydroelectric power infrastructure). Black River Lake has recorded an increase in diatom-inferred total phosphorus since about 1950, likely due to impoundment of the Black River system for hydroelectric generation and subsequent changes in land runoff. Before-and-after (i.e., top-bottom) sediment analyses of six other lakes from King's County provided further evidence that the region is being influenced by climatic change (decreases in Aulacoseira spp., increases in planktonic diatom taxa), as well as showing other environmental stressors (e.g., acidification). However, we recorded no marked increase in diatom-inferred nutrient levels coincident with shoreline cottage development in any of the nine study lakes. Paleolimnological studies such as these allow lake managers to place the current limnological conditions into a long-term context, and thereby provide important background data for effective lake management.

The sensitivity of Neotoma to climate change and biodiversity loss over the late Quaternary

2021 ◽  
pp. 1-15
Author(s):  
Catalina P. Tomé ◽  
S. Kathleen Lyons ◽  
Seth D. Newsome ◽  
Felisa A. Smith
Keyword(s):  
Body Size ◽  
Late Quaternary ◽  
Climatic Variability ◽  
Isotope Analysis ◽  
Biodiversity Loss ◽  
Bone Collagen ◽  
Cam Plants ◽  
The Holocene ◽  
Carbon And Nitrogen ◽  
Terminal Pleistocene

Abstract The late Quaternary in North America was marked by highly variable climate and considerable biodiversity loss including a megafaunal extinction event at the terminal Pleistocene. Here, we focus on changes in body size and diet in Neotoma (woodrats) in response to these ecological perturbations using the fossil record from the Edwards Plateau (Texas) across the past 20,000 years. Body mass was estimated using measurements of fossil teeth and diet was quantified using stable isotope analysis of carbon and nitrogen from fossil bone collagen. Prior to ca. 7000 cal yr BP, maximum mass was positively correlated to precipitation and negatively correlated to temperature. Independently, mass was negatively correlated to community composition, becoming more similar to modern over time. Neotoma diet in the Pleistocene was primarily sourced from C3 plants, but became progressively more reliant on C4 (and potentially CAM) plants through the Holocene. Decreasing population mass and higher C4/CAM consumption was associated with a transition from a mesic to xeric landscape. Our results suggest that Neotoma responded to climatic variability during the terminal Pleistocene through changes in body size, while changes in resource availability during the Holocene likely led to shifts in the relative abundance of different Neotoma species in the community.

scholarly journals Diversity, Concentration and Dynamics of Culturable Fungal Bioaerosols at Doha, Qatar

2020 ◽  
Vol 18 (1) ◽  
pp. 182
Author(s):  
Raghdaa K. Fayad ◽  
Roda F. Al-Thani ◽  
Fatima A. Al-Naemi ◽  
Mohammed H. Abu-Dieyeh
Keyword(s):  
Species Richness ◽  
Fungal Spores ◽  
Gravimetric Method ◽  
Fungal Spore ◽  
Industrial Area ◽  
Airborne Fungi ◽  
Culture Collection ◽  
Colony Count ◽  
Study Sites ◽  
Future Work

This research was conducted to investigate the dynamics of airborne fungi using viable culture collection and in respect to different abiotic variables, including seasonal and intra-diurnal variations. A gravimetric method was used to sample airborne fungal deposition on potato dextrose agar plates on alternate days, for a year between April 2015 to March 2016. From 176 settle plate exposures, a total of 1197 mould and 283 yeast colony-forming units (CFU), 21 genera and 62 species were retrieved. The highest fungal spore count was recorded in February 2016, whereas the lowest count occurred in August 2015. The main constituents of the fungal airspora were attributed to Cladosporium (60.2%), Aspergillus (10.4%), Fusarium (9.4%), Alternaria (8.5%), and Ganoderma spp. (2.3%). Temperature was negatively correlated with total colony count (r = −0.231, p ≤ 0.05) or species richness (r = −0.267, p ≤ 0.001), while wind speed was positively correlated with total colony count (r = 0.484, p ≤ 0.001) or species richness (r = 0.257, p ≤ −0.001). The highest dispersal of fungal spores was obtained at 18:00, whereas the lowest fungal spores release was recorded at 00:00 (midnight). There were no significant differences in species composition and richness of the airborne fungal population between two study sites, the Industrial area and Qatar University Campus. The count of Alternaria spp. and Fusarium spp. were significantly higher at the Industrial area site, which corresponds to a higher CO2 level than the Qatar University site. This study lays the foundation for future work to assess the implications of such aeromycological data on public health.

scholarly journals MONITORING OF PARTICLE ENVIRONMENTAL POLLUTION AND FUNGAL ISOLATIONS DURING HOSPITAL BUILDING-WORK ACTIVITIES IN A HEMATOLOGY WARD.

2019 ◽  
Vol 11 (1) ◽  
pp. e2019062 ◽  
Author(s):  
Fabio Pattavina ◽  
Daniele Ignazio La Milia ◽  
Sara Vincenti ◽  
Barbara Fiori ◽  
Riccardo Torelli ◽  
...  
Keyword(s):  
Invasive Aspergillosis ◽  
Fungal Spores ◽  
Antigen Test ◽  
Building Site ◽  
Work Activities ◽  
Significant Difference ◽  
Before And After ◽  
Containment Measures ◽  
Clinical Surveillance ◽  
Galactomannan Antigen

Building-work activities could cause dust contamination and dissemination of fungal spores. Significant relationship was found between building-work activities and the incidence of invasive aspergillosis, in highly immunocompromised patients. Renovation-works activities were carried out by four building sites of the hematology ward in a Teaching Hospital without the interruption of clinical activities. These sites were monitored by environmental sampling to determine the particles and fungi count. Clinical surveillance were made using galactomannan antigen test as a proxy for invasive aspergillosis diagnosis. The galactomannan antigen test showed no significant difference between presence (3,85%) or absence (5,76%)  of renovation work activities (p=0,497). The particle counts showed higher values of small and big-diameter particles before the renovation works if compared to the end of the activities. It was probably due to the containment measures implemented during and immediately after the final phases of the building site. The Fungi counts showed no particular differences between the phase before and after of the renovation activities. Our finding show that is possible to perform renovation work, during clinical activities, by increasing the clinical and the environmental surveillance.

scholarly journals Late Quaternary paleoenvironment of the Ross Sea continental shelf, Antarctica

1998 ◽  
Vol 27 ◽  
pp. 275-280 ◽  
Author(s):  
Akira Nishimura ◽  
Toru Nakasone ◽  
Chikara Hiramatsu ◽  
Manabu Tanahashi
Keyword(s):  
Organic Carbon ◽  
Marine Environment ◽  
Environmental Changes ◽  
Ross Sea ◽  
Late Quaternary ◽  
Sedimentary Environment ◽  
Sediment Cores ◽  
Ice Sheet ◽  
Ice Shelf ◽  
Accelerator Mass Spectrometer

Based on sedimenlological and micropaleontological work on three sediment cores collected at about 167° Ε in the western Ross Sea, Antarctica, and accelerator mass spectrometer l4C ages of organic carbon, we have reconstructed environmental changes in the area during the late Quaternary. Since 38 ka BP at latest, this area was a marine environment with low productivity. A grounded ice sheet advanced and loaded the sediments before about 30-25 ka BP. After 25 ka BP, the southernmost site (76°46'S) was covered by floating ice (shelf ice), preventing deposition of coarse terrigenous materials and maintaining a supply of diatom tests and organic carbon until 20 ka BP. The northernmost site (74°33'S) was in a marine environment with a moderate productivity influenced by shelf ice/ice sheet after about 20 ka BP. Since about 10 ka BP, a sedimentary environment similar to the present-day one has prevailed over this area.

scholarly journals Characterisation of biofluorescent aerosol emissions over winter and summer periods in the United Kingdom

2018 ◽  
Author(s):  
Elizabeth Forde ◽  
Martin Gallagher ◽  
Virginia Foot ◽  
Roland Sarda-Esteve ◽  
Ian Crawford ◽  
...  
Keyword(s):  
United Kingdom ◽  
Relative Humidity ◽  
Aerosol Particles ◽  
Fungal Spores ◽  
Ultra Violet ◽  
Fungal Spore ◽  
Complete Analysis ◽  
Hierarchical Agglomerative Cluster ◽  
The United Kingdom ◽  
Fluorescent Particles

Abstract. Primary biological aerosol particles (PBAP) are an abundant subset of atmospheric aerosol particles which comprise viruses, bacteria, fungal spores, pollen, and fragments such as plant and animal debris. The abundance and diversity of these particles remain poorly constrained, causing significant uncertainties for modelling scenarios and for understanding the potential implications of these particles in different environments. PBAP concentrations were studied at four different sites in the United Kingdom (Weybourne, Davidstow, Capel Dewi, and Chilbolton) using an ultra-violet light induced fluorescence (UV-LIF) instrument, the Wideband Integrated Bioaerosol Spectrometer (WIBS), versions 3 and 4. Using hierarchical agglomerative cluster (HAC) analysis, particles were statistically discriminated between. Fluorescent particles and clusters were then analysed by assessing their diurnal variation and their relationship to the meteorological variables, temperature and relative humidity, and wind speed and direction. Using local land cover types, sources of the suspected fluorescent particles and clusters were then identified. Most sites exhibited a wet discharged fungal spore dominance, with the exception of one site, Davidstow, which had higher concentrations of bacteria, suggested to result from the presence of a local dairy factory. Differences were identified as to the sources of wet discharged fungal spores, with particles originating from arable and horticultural land at Chilbolton, and improved grassland areas at Weybourne. Total fluorescent particles at Capel Dewi were inferred to comprise two sources, with bacteria originating from the broadleaf and coniferous woodland and wet discharged fungal spores from nearby improved grassland areas, similar to Weybourne. The use of HAC and a higher fluorescence threshold (9SD) produced clusters which were considered to be biological following the complete analysis. More knowledge of the reaction of speciated biological particles to differences in meteorology, such as relative humidity and temperature would aid characterisation studies such as this.

scholarly journals Cryostratigraphy, sedimentology, and the late Quaternary evolution of the Zackenberg River delta, northeast Greenland

2017 ◽  
Vol 11 (3) ◽  
pp. 1265-1282 ◽  
Author(s):  
Graham L. Gilbert ◽  
Stefanie Cable ◽  
Christine Thiel ◽  
Hanne H. Christiansen ◽  
Bo Elberling
Keyword(s):  
Late Quaternary ◽  
Sediment Cores ◽  
River Delta ◽  
Optically Stimulated Luminescence ◽  
Delta Plain ◽  
Valley Fill ◽  
Subaerial Exposure ◽  
Facies Associations ◽  
Delta Progradation ◽  
Ice Content

Abstract. The Zackenberg River delta is located in northeast Greenland (74°30′ N, 20°30′ E) at the outlet of the Zackenberg fjord valley. The fjord-valley fill consists of a series of terraced deltaic deposits (ca. 2 km2) formed during relative sea-level (RSL) fall. We investigated the deposits using sedimentological and cryostratigraphic techniques together with optically stimulated luminescence (OSL) dating. We identify four facies associations in sections (4 to 22 m in height) exposed along the modern Zackenberg River and coast. Facies associations relate to (I) overriding glaciers, (II) retreating glaciers and quiescent glaciomarine conditions, (III) delta progradation in a fjord valley, and (IV) fluvial activity and niveo-aeolian processes. Pore, layered, and suspended cryofacies are identified in two 20 m deep ice-bonded sediment cores. The cryofacies distribution, together with low overall ground-ice content, indicates that permafrost is predominately epigenetic in these deposits. Fourteen OSL ages constrain the deposition of the cored deposits to between approximately 13 and 11 ka, immediately following deglaciation. The timing of permafrost aggradation was closely related to delta progradation and began following the subaerial exposure of the delta plain (ca. 11 ka). Our results reveal information concerning the interplay between deglaciation, RSL change, sedimentation, permafrost aggradation, and the timing of these events. These findings have implications for the timing and mode of permafrost aggradation in other fjord valleys in northeast Greenland.

scholarly journals Dental microwear and mesovear of Microtus voles before and after experimental feeding of owls

2019 ◽  
Vol 486 (5) ◽  
pp. 638-642
Author(s):  
Yu. E. Kropacheva ◽  
S. V. Zykov ◽  
N. G. Smirnov ◽  
R. M. Salimov
Keyword(s):  
Small Mammals ◽  
Digestive System ◽  
Tooth Enamel ◽  
Dental Microwear ◽  
Before And After ◽  
Eagle Owl ◽  
Feed Analysis ◽  
Experimental Feeding ◽  
Bone Remains

Form of expressions of dental microwear and mesovear of small mammals depends on abrasiveness, hardness and a number of other characteristics of the feed. Analysis of micro- and mesorelief is used on paleontological materials for the reconstruction of some parameters of the animals diet. Small mammals move a hard way from objects of biocenoses to fossils. Bone remains are modified in the process of accumulation and fossilization. In particular, bone remains from ornithogenous deposits were influenced to the substances of the digestive system of birds. In this work, an experimental estimation was made of the degree of changes in a number of characteristics of narrow-headed vole molars (Microtus gregalis) from the pellets of two species of owls. On the same samples before and after exposure to substances of the digestive system of a Polar Owl (Nyctea scandiaca) and Eagle Owl (Bubo bubo), it was shown that the microrelief of the tooth enamel undergoes serious changes and haven't information about the in vivo diet of the voles. A different degree of preservation of the mesoreliefs characteristic was shown. An assessment of their applicability for paleoreconstructions depending on this was given.

Penguin occupation in the Vestfold Hills

2008 ◽  
Vol 21 (2) ◽  
pp. 131-134 ◽  
Author(s):  
Tao Huang ◽  
Liguang Sun ◽  
Yuhong Wang ◽  
Renbin Zhu
Keyword(s):  
Sediment Core ◽  
Environmental Changes ◽  
Sediment Cores ◽  
East Antarctica ◽  
Before Present ◽  
The Holocene ◽  
History Of ◽  
Vestfold Hills ◽  
Free Area ◽  
Ornithogenic Sediment

AbstractDuring CHINARE-22 (December 2005–March 2006), we investigated six penguin colonies in the Vestfold Hills, East Antarctica, and collected several penguin ornithogenic sediment cores, samples of fresh guano and modern penguin bone and feather. We selected seven penguin bones and feathers and six sediments from the longest sediment core and performed AMS14C dating. The results indicate that penguins occupied the Vestfold Hills as early as 8500 calibrated years before present (cal. yrbp), following local deglaciation and the formation of the ice free area. This is the first report on the Holocene history of penguins in the Vestfold Hills. As in other areas of Antarctica, penguins occupied this area as soon as local ice retreated and the ice free area formed, and they are very sensitive to climatic and environmental changes. This work provides the foundation for understanding the history of penguins occupation in Vestfold Hills, East Antarctica.

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