Classification and Interpretation of Disturbed Bedding Types in Jackfork Flysch Rocks (Upper Mississippian), Ouachita Mountains, Arkansas

Author(s):  
Robert C. Morris
2019 ◽  
Author(s):  
David M. Hough ◽  
◽  
Thomas A. Colby ◽  
Corbin G. Cannon ◽  
Michael T. DeAngelis

Zootaxa ◽  
2018 ◽  
Vol 4375 (3) ◽  
pp. 409
Author(s):  
PAUL E. MAREK ◽  
JACKSON C. MEANS ◽  
DEREK A. HENNEN

Millipedes of the genus Apheloria Chamberlin, 1921 occur in temperate broadleaf forests throughout eastern North America and west of the Mississippi River in the Ozark and Ouachita Mountains. Chemically defended with toxins made up of cyanide and benzaldehyde, the genus is part of a community of xystodesmid millipedes that compose several Müllerian mimicry rings in the Appalachian Mountains. We describe a model species of these mimicry rings, Apheloria polychroma n. sp., one of the most variable in coloration of all species of Diplopoda with more than six color morphs, each associated with a separate mimicry ring.


2017 ◽  
Vol 24 (1-2) ◽  
Author(s):  
Jan Lenart

Although relatively extensive extraction of the pelocarbonate iron ore in the Podbeskydská pahorkatina Upland and the Moravskoslezské Beskydy Mts. have terminated until the end of the 19th century, the remnants are rarely preserved in the recent relief as collapsed shafts, mining pits, dumps or their combinations. The adits are occurring infrequently, because the majority of them are completely collapsed or at least the entrance is filled up with rocks. Similarly, the shafts formerly many meters deep, are recently reflected only as shallow concave hollows. Distinct post-mining landforms are still preserved e.g. in Chlebovice, Libotín near Štramberk, Čeladná or Kozlovice villages. The causes of wrong preservation of these forms, which stood at the beginning of the Ostrava industrial agglomeration, are as: (i) mining in the incoherent fine flysch rocks, (ii) primitive mining methods without wooden setts, and (iii) intensive anthropogenic activities after the mining termination in the landscape. Some of the localities with preserved free underground spaces are remnants after the mining of the other or the related materials, or even crevice type caves. Because of the historical importance of the iron ore mining in the wider area, I would recommend consideration of at least some basic protection of preserved landforms. Otherwise, at the present rate of the landscape changes intensity, they would shortly vanish. 


PLoS ONE ◽  
2021 ◽  
Vol 16 (3) ◽  
pp. e0247586
Author(s):  
Christine E. Edwards ◽  
Brooke C. Tessier ◽  
Joel F. Swift ◽  
Burgund Bassüner ◽  
Alexander G. Linan ◽  
...  

Understanding genetic diversity and structure in a rare species is critical for prioritizing both in situ and ex situ conservation efforts. One such rare species is Physaria filiformis (Brassicaceae), a threatened, winter annual plant species. The species has a naturally fragmented distribution, occupying three different soil types spread across four disjunct geographical locations in Missouri and Arkansas. The goals of this study were to understand: (1) whether factors associated with fragmentation and small population size (i.e., inbreeding, genetic drift or genetic bottlenecks) have reduced levels of genetic diversity, (2) how genetic variation is structured and which factors have influenced genetic structure, and (3) how much extant genetic variation of P. filiformis is currently publicly protected and the implications for the development of conservation strategies to protect its genetic diversity. Using 16 microsatellite markers, we genotyped individuals from 20 populations of P. filiformis from across its geographical range and one population of Physaria gracilis for comparison and analyzed genetic diversity and structure. Populations of P. filiformis showed comparable levels of genetic diversity to its congener, except a single population in northwest Arkansas showed evidence of a genetic bottleneck and two populations in the Ouachita Mountains of Arkansas showed lower genetic variation, consistent with genetic drift. Populations showed isolation by distance, indicating that migration is geographically limited, and analyses of genetic structure grouped individuals into seven geographically structured genetic clusters, with geographic location/spatial separation showing a strong influence on genetic structure. At least one population is protected for all genetic clusters except one in north-central Arkansas, which should therefore be prioritized for protection. Populations in the Ouachita Mountains were genetically divergent from the rest of P. filiformis; future morphological analyses are needed to identify whether it merits recognition as a new, extremely rare species.


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