The presence of caviomorph and ctenomid rodents in the Patagonian Andean Forest during the Holocene—beyond their present-day distribution, largely restricted to the steppe and steppe–forest ecotone—raises interpretive challenges. These concerns relate to the palaeoecological implications of the discrepancy between current and past distributions, as well as their potential involvement in human subsistence strategies, given the persistence of forests in this region since the Pleistocene–Holocene transition. Stable isotope analysis is a valuable approach to addressing these issues, as nitrogen isotope values in faunal and human assemblages have been shown to reflect forest resource use in Patagonia. We analysed δ 13 C and δ 15 N values in caviomorph rodent remains from the Población Anticura archaeological site, which is located within the Andean forest, around 40 km from the steppe. The assemblage includes multiple caviomorph taxa distributed across five archaeological units spanning from the Early Holocene to historical times, providing a diachronic perspective on isotopic variability. The specimens yielded mean δ 13 C values of −22.1‰ ± 0.6‰ and δ 15 N values of 2.0‰ ± 0.95‰. These results were then compared with isotopic data from steppe rodents, as well as from cervids ( Hippocamelus bisulcus and Pudu puda ), which serve as ecological references for forest environments. This comparative analysis confirms an association between the Población Anticura rodents and an isotopic signal derived from the forest, highlighting the effectiveness of stable isotopes in assessing the interaction between human groups and different species in forest landscapes in northwestern Patagonia during the Holocene.
The Echigo Plain in central Japan is an actively subsiding sedimentary basin influenced by tectonic subsidence and anthropogenic activity. In this study, late Pleistocene to Holocene sequences were analyzed using high-density borehole data from geological databases and radiocarbon dates obtained in previous studies to estimate spatiotemporal variations in subsurface geological distribution and paleo-water depths, as well as to understand the trend of subsidence. The results showed that paleowater depths were shallow in the early stages of sea-level rise, but continued rise caused the sea to expand inland, deepening the paleowater depths near the mouth of the present river. Paleo-water depths were estimated to be shallower in areas with barriers, lagoons, and delta systems that developed during the transgression and maximum sea-level periods. The relationships between local land subsidence zones identified from leveling surveys and GNSS observations and the spatiotemporal distribution of surface geology were compared. In areas where marine or lagoon deposits are thickly distributed; a temporarily low water table may cause plastic compaction of clay layers adjacent to aquifer layers composed of river and dune deposits. However, even under similar depositional conditions, significant land subsidence areas were identified that cannot be explained by local geology and local tectonics alone; other factors, such as the effects of human activities and deformation of deeper geology, need to be considered. These findings provide important insights for future regional development and groundwater use.
During the Middle-to-Late-Holocene, Deception Island, in the South Shetland Islands (Antarctica), experienced exceptionally intense seismic and volcanic processes, culminating in a caldera collapse event on a scale comparable to some of the largest on Earth over the past several millennia. In this study, we explored new evidence of the relationship between volcanic and seismic activity on Deception Island and the geochemical and sedimentary record in the periglacial Jurasee Lake at King George Island. Our sediment core spans the period 890 +/- 30-4870 +/- 50 calibrated (cal) years (yr) Before Present (BP). We combined different techniques such as X-ray fluorescence (XRF) scanning, X-ray diffraction (XRD), magnetic susceptibility (MS), and sedimentation rates, which allowed us to recognize both the volcanic impact, the seismicity, and the climatic record at the South Shetland Islands. Our sediment core depicted a clear two-phase record, one during the Middle-to-Late-Holocene characterized by rapid/abnormal sedimentation taking place before the collapse of Deception Island's large caldera (around 4600 and 3980 +/- 125 cal yr BP), leading to intense landslides into lakes. The second phase, corresponding to the Late-Holocene period, is when the geochemical record follows the climatic pattern, especially the reconstructed summer air temperatures and possibly run-off processes due to deglaciation. Our study establishes a relationship between cataclysmic volcanic events and the associated sedimentary, and geochemical lacustrine response aiming to better understand the impact of volcanic eruptions at the regional context.
This study focuses on the new archaeobotanical materials recovered from the Tiaotou site dating from the Late Neolithic to the Early Bronze Age to explore changes of agriculture in the Hangjiahu Plain, southeastern China. The stratigraphic succession at Tiaotou spans from the Late Liangzhu Culture (3300-2300 BC) to Western Zhou Dynasty (1046-771 BC), providing a long sequence of macrobotanical evidence. The results show that, compared with the Liangzhu Culture period (3300-2300 BC), the intensity of rice farming at the Tiaotou area likely declined during the Maqiao Culture period (1900-1200 BC). However, during the Late Shang period (1200-1000 BC), coinciding with the introduction of bronze technology, signs of a revival in the rice agricultural economy may have emerged at Tiaotou. Based on the identification and statistical analysis of charred crop remains from the Tiaotou site, along with comparative analysis of previous archaeobotanical findings from nearby sites, this research provides new insights into understanding the developmental trajectory of ancient agricultural societies in the Hangjiahu Plain.
The distribution and abundance of species is a product of the interplay of climatic and environmental factors, both past and present, natural, and anthropogenic. In the most recent stage of the Anthropocene, these changes have been extremely rapid and abrupt. The objective of this work is to discuss some socio-environmental problems of northern Patagonia by comparing micromammal archeological and paleontological sequences attributable to the final Late-Holocene and post-Hispanic period with current samples from the region. Several sites in northern Patagonia, from the Andean forest, the Steppe and Monte regions, and their ecotone, were selected as study cases. The comparison of the species composition from the final Late-Holocene and post-Hispanic assemblages with local small mammal communities indicates species extinctions, considerable reductions in their distributional ranges, and an increase in the abundance of opportunistic taxa. The causes have been attributed to the accelerated deterioration of natural ecosystems due to anthropogenic factors, including habitat destruction caused by the expansion of agriculture and livestock farming, the introduction of exotic plant and animal species, soil compaction, and other factors. Paleoecology, as a historical science of nature, inevitably requires the use of modern analogues in its interpretations, a situation that became increasingly difficult and challenging in the times of the Anthropocene, where current communities are constantly changing due to anthropogenic causes.
