Microstructure and geochemical properties of modern and buried soils and hosting permafrost sediments of the Batagay retrogressive thaw slump

The paleopedology of the world's largest retrogressive thaw slump, Batagay, is understudied. Micromorphological and geochemical analysis reveal the properties of th host sediments and major pedogenic features. Epigenetic soil profiles of Marine Oxygen Isotope Stage (MIS) 7 (or older) and 5e are clearly distinguished and well developed due to favorable bioclimatic conditions for pedogenesis, probably similar to modern ones. The oldest unit contains a paleosol similar to a Histic Reductaquic Cryosol, indicating a peat-covered, boggy environment. The MIS 5e unit contains organic-rich Histic Spodic Cryosol with well-developed structure, formed during the interglacial optimum, which was relatively warm and presumably resembled modern bioclimatic conditions. MIS 4-3 deposits contains soil-like bodies enriched in coarse organogenic material resembling incipient Histic Reductaquic Cryosols. Interglacial/interstadial units contain micromorphological evidence of aggregate and pore formation, Fe-oxide and organic matter redistribution and clay accumulation. Stadial deposits show weakly expressed soil structure with uneven aggregates, cryogenic disintegration of plant detritus and rare evidence of accumulation of humic substances. Major elemental ratios indicate intensification of biochemical weathering in paleosols and soil-like bodies. Pedogenically reworked material of stadial sedimentary units with sporadic and incipient soil-like bodies provide a significant source for paleoenvironmental reconstruction of harsh Late Pleistocene environments.</p

Modeling and Mapping the Probability of Occurrence of Invasive Wild Pigs across the Contiguous United States

Wild pigs (Sus scrofa), also known as wild swine, feral pigs, or feral hogs, are one of the most widespread and successful invasive species around the world. Wild pigs have been linked to extensive and costly agricultural damage and present a serious threat to plant and animal communities due to their rooting behavior and omnivorous diet. We modeled the current distribution of wild pigs in the United States to better understand the physiological and ecological factors that may determine their invasive potential and to guide future study and eradication efforts. Using national-scale wild pig occurrence data reported between 1982 and 2012 by wildlife management professionals, we estimated the probability of wild pig occurrence across the United States using a logistic discrimination function and environmental covariates hypothesized to influence the distribution of the species. Our results suggest the distribution of wild pigs in the U.S. was most strongly limited by cold temperatures and availability of water, and that they were most likely to occur where potential home ranges had higher habitat heterogeneity, providing access to multiple key resources including water, forage, and cover. High probability of occurrence was also associated with frequent high temperatures, up to a high threshold. However, this pattern is driven by pigs’ historic distribution in warm climates of the southern U.S. Further study of pigs’ ability to persist in cold northern climates is needed to better understand whether low temperatures actually limit their distribution. Our model highlights areas at risk of invasion as those with habitat conditions similar to those found in pigs’ current range that are also near current populations. This study provides a macro-scale approach to generalist species distribution modeling that is applicable to other generalist and invasive species