Fate and preservation of the late pleistocene cave bears from Niedzwiedzia Cave in Poland, through taphonomy, pathology, and geochemistry.

This comprehensive study examines fossil remains from Niedzwiedzia Cave in the Eastern Sudetes, offering detailed insights into the palaeobiology and adversities encountered by the Pleistocene cave bear Ursus spelaeus ingressus. Emphasising habitual cave use for hibernation and a primarily herbivorous diet, the findings attribute mortality to resource scarcity during hibernation and habitat fragmentation amid climate shifts. Taphonomic analysis indicates that the cave was extensively used by successive generations of bears, virtually unexposed to the impact of predators. The study also reveals that alkaline conditions developed in the cave during the post-depositional taphonomic processes. Mortality patterns, notably among juveniles, imply dwindling resources, indicative of environmental instability. Skeletal examination reveals a high incidence of forelimb fractures, indicating risks during activities like digging or confrontations. Palaeopathological evidence unveils vulnerabilities to tuberculosis, abscesses, rickets, and injuries, elucidating mobility challenges. The cave's silts exhibit a high zinc concentration, potentially derived from successive bear generations consuming zinc-rich plants. This study illuminates the lives of late cave bears, elucidating unique environmental hurdles faced near their species' end.

Subfossil markers of climate change during the Roman Warm Period of the late Holocene.

Abundant bog oak trunks occur in alluvial deposits of the Raba River in the village of Targowisko (southern Poland). Several of them contain galleries of the great capricorn beetle (Cerambyx cerdo L.). A well-preserved subfossil larva and pupa, as well as adults of this species, are concealed in some of the galleries. These galleries co-occur with boring galleries of other insects such as ship-timber beetles (Lymexylidae) and metallic wood borers (Buprestidae). A dry larva of a stag beetle (Lucanidae) and a mite (Acari) have been found in the C. cerdo galleries. Selected samples of the trunks and a sample of the C. cerdo larva were dated, using radiocarbon and dendrochronological methods, to the period from 45 BC to AD 554; one sample was dated to the period from 799 to 700 BC. Accumulation of the channel alluvia containing the bog oak trunks is synchronous with the Roman Warm Period (late antiquity/Early Mediaeval times). The most recent part of this period correlates with massive accumulations of fallen oak trunks noted from various river valleys in the Carpathian region and dated to AD 450-570. The results indicate that C. cerdo was more abundant within the study area during the Roman Warm Period than it is today.

Snezna jama (Slovenia): Interdisciplinary dating of cave sediments and implication for landscape evolution.

Caves are important markers of surface evolution, since they are, as a general rule, linked with ancient valley bottoms by their springs. However, caves can only be dated indirectly by means of the sediments they contain. If the sediment is older than common dating methods, one has to use multiple dating approaches in order to get meaningful results. U/Th dating, palaeomagnetic analysis of flowstone and sediment profiles, cosmogenic dating of quartz pebbles, and mammalian dating allowed a robust estimate of speleogenesis, sediment deposition, climatic change at the surface, and uplift history on the Periadriatic fault line during the Plio-Pleistocene. Our dates indicate that Snezna jama was formed in the (Upper) Miocene, received its sedimentary deposits during the Pliocene in a rather low-lying, hilly landscape, and became inactive due to uplift along the Periadriatic and Sava faults and climatic changes at the beginning of the Quaternary. Although it is only a single cave, the information contained within it makes it an important site of the Southern Alps.

Is acid rain impacting the Sudetic lakes?

The diatoms and Cladocera (Crustacea) remains from two lakes in the Sudets Mountains were analyzed to indicate an influence of acidification induced by anthropogenic factors during the last 150 years. The border area of the Czech Republic, Germany and Poland, the so-called "Black Triangle", has been strongly impacted by developed industry for several decades. The most visible effect of this process is the destruction of mountain forests in the region by acid rains. The diatom communities of Maly Staw and Wielki Staw show that acid rain has strongly affected water biota. Diatom-inferred pH reconstruction suggests major acidification during the last two decades. This process was controlled mainly by anthropogenic factors. Cladoceran records also presented changes of dominant taxa in this period and point to significant changes in living conditions. The discovery of a pH decrease during the last decade is contradictory to emissions data that suggest decrease in industrial pollution.