More Like this

1. ‘They came from the ends of the earth’: long-distance exchange of obsidian in the High Arctic during the Early Holocene

   https://doi.org/10.15184/aqy.2019.2  

   Pitulko, Vladimir V.; Kuzmin, Yaroslav V.; Glascock, Michael D.; Pavlova, Elena Yu.; Grebennikov, Andrei V. (February 2019, Antiquity)

   Zhokhov Island in the Siberian High Arctic has yielded evidence for some of the most remote prehistoric human occupation in the world, as well as the oldest-known dog-sled technology. Obsidian artefacts found on Zhokhov have been provenanced using XRF analysis to allow comparison with known sources of obsidian from north-eastern Siberia. The results indicate that the obsidian was sourced from Lake Krasnoe—approximately 1500km distant—and arrived on Zhokhov Island c . 8000 BP. The archaeological data from Zhokhov therefore indicate a super-long-distance Mesolithic exchange network. 

   more » « less
2. Studies in Lichens and Lichenicolous Fungi - No. 23: Notes on Appalachian taxa including newly reported disjunctions and multiple species new to North America

   https://doi.org/10.5962/p.388460  

   Lendemer, James C (January 2023, Opuscula philolichenum)

   Arthonia ligniariella is reported for the first time from eastern North America based on a collection growing on lignum in North Carolina, U.S.A. Biatora appalachensis, an Appalachian endemic, is shown to be widespread throughout the Appalachian Mountains, primarily at high elevations. The only report of Fellhanera parvula from North America (Tennessee, U.S.A.) is considered to be F. bouteillei. Fellhanera subtilis, previously reported in North America from the Pacific Northwest, is reported for the first time from eastern North America (southern Appalachian Mountains). Gyalideopsis mexicana, previously reported in North America from the Yukon, Canada and New Mexico, U.S.A. is newly reported from eastern North America (southern Appalachian Mountains, North Carolina, U.S.A.). Lepra ouahensis, a sorediate species with lichexanthone and stictic acid, is reported from disjunct areas of the southern Appalachian Mountains and the Southeastern Coastal Plain. Its distribution is compared to the lichexanthone producing chemotypes of L. trachythallina and Varicellaria velata. Rockefellera crossophylla, a rare species considered extinct in Pennsylvania, U.S.A. is reported to be extant in that state. Psoronactis dilleniana is newly reported from North America from high elevations of the central and southern Appalachian Mountains (North Carolina and Virginia U.S.A.). Xenonectriella streimannii is newly reported for North America based on a collection found growing on Anaptychia palmulata in Georgia, U.S.A. 

   more » « less
3. Between a rock and a hard place: Chrysothrix susquehannensis is more widespread in eastern North America than previously thought

   Lendemer, James C.; Clark, Peter W. (November 2021, Opuscula philolichenum)

   Chrysothrix susquehannensis was originally described from vertical rocks faces at a single locality in southeastern Pennsylvania, U.S.A. Here we document new occurrences discovered as result of fieldwork and the revision of herbarium specimens. We show that C. susquehannensis, although rare, is widespread in the Appalachian Mountains of eastern North America, with a disjunction in New Mexico in southwestern North America. 

   more » « less
4. Population genetics and geographic origins of mallards harvested in northwestern Ohio

   https://doi.org/10.1371/journal.pone.0282874  

   Schummer, Michael L.; Simpson, John; Shirkey, Brendan; Kucia, Samuel R.; Lavretsky, Philip; Tozer, Douglas C. (March 2023, PLOS ONE)

   Chiang, Tzen-Yuh (Ed.)

   The genetic composition of mallards in eastern North America has been changed by release of domestically-raised, game-farm mallards to supplement wild populations for hunting. We sampled 296 hatch-year mallards harvested in northwestern Ohio, October–December 2019. The aim was to determine their genetic ancestry and geographic origin to understand the geographic extent of game-farm mallard introgression into wild populations in more westward regions of North America. We used molecular analysis to detect that 35% of samples were pure wild mallard, 12% were early generation hybrids between wild and game-farm mallards (i.e., F1–F3), and the remaining 53% of samples were assigned as part of a hybrid swarm. Percentage of individuals in our study with some form of hybridization with game-farm mallard (65%) was greater than previously detected farther south in the mid-continent (~4%), but less than the Atlantic coast of North America (~ 92%). Stable isotope analysis using δ 2 H f suggested that pure wild mallards originated from areas farther north and west than hybrid mallards. More specifically, 17% of all Ohio samples had δ 2 H f consistent with more western origins in the prairies, parkland, or boreal regions of the mid-continent of North America, with 55%, 35%, and 10% of these being genetically wild, hybrid swarm, and F3, respectively. We conclude that continued game-farm introgression into wild mallards is not isolated to the eastern population of mallards in North America, and may be increasing and more widespread than previously detected. Mallards in our study had greater incidence of game-farm hybridization than other locales in the mid-continent but less than eastern North American regions suggesting further need to understand game-farm mallard genetic variation and movement across the continent. 

   more » « less
5. North American Winter Dipole: Observed and Simulated Changes in Circulations

   https://doi.org/10.3390/atmos10120793  

   Chien, Yu-Tang; Wang, S.-Y. Simon; Chikamoto, Yoshimitsu; Voelker, Steve L.; Meyer, Jonathan D.; Yoon, Jin-Ho (December 2019, Atmosphere)

   In recent years, a pair of large-scale circulation patterns consisting of an anomalous ridge over northwestern North America and trough over northeastern North America was found to accompany extreme winter weather events such as the 2013–2015 California drought and eastern U.S. cold outbreaks. Referred to as the North American winter dipole (NAWD), previous studies have found both a marked natural variability and a warming-induced amplification trend in the NAWD. In this study, we utilized multiple global reanalysis datasets and existing climate model simulations to examine the variability of the winter planetary wave patterns over North America and to better understand how it is likely to change in the future. We compared between pre- and post-1980 periods to identify changes to the circulation variations based on empirical analysis. It was found that the leading pattern of the winter planetary waves has changed, from the Pacific–North America (PNA) mode to a spatially shifted mode such as NAWD. Further, the potential influence of global warming on NAWD was examined using multiple climate model simulations. 

   more » « less