Available proxy records from the Florida peninsula give a varying view on hydrological changes during the late Holocene. Here we evaluate the consistency and sensitivity of local wetland records in relation to hydrological changes over the past ~ 5 ka based on pollen and diatom proxies from peat cores in Highlands Hammock State Park, central Florida. Around 5 cal ka BP, a dynamic floodplain environment is present. Subsequently, a wetland forest establishes, followed by a change to persistent wet conditions between ~ 2.5 and 2.0 ka. Long hydroperiods remain despite gradual succession and basin infilling with maximum wet conditions between ~ 1.3 and 1.0 ka. The wet phase and subsequent strong drying over the last millennium, as indicated by shifts in both pollen and diatom assemblages, can be linked to the early Medieval Warm Period and Little Ice Age, respectively, driven by regionally higher sea-surface temperatures and a temporary northward migration of the Intertropical Convergence Zone. Changes during the 20th century are the result of constructions intended to protect the Highlands Hammock State Park from wildfires. The multiple cores and proxies allow distinguishing local and regional hydrological changes. The peat records reflect relatively subtle climatic changes that are not evident from regional pollen records from lakes.

The use of rodent middens from northern Chile as paleoecological archives has at times been questioned due to concerns about their biogenic origin and the degree to which their record represents vegetation composition rather than rodent habits. To address such concerns, we carried out a modern calibration study to assess the representation of vegetation by pollen records from rodent middens. We compared vegetation censuses with soil-surface and midden (matrix and feces) pollen samples from sites between 21° and 28°S. The results show that (1) the pollen signal from the midden matrix provides a more realistic reflection of local vegetation than soil-surface samples due to the pollen-deposition processes that occur in middens; and (2) in contrast to feces pollen assemblages, which feature some biases, rodent dietary habits do not seem to influence midden matrix pollen assemblages, probably because midden agents are dietary generalists. Our finding that modern pollen data from rodent middens reflect vegetation patterns confirms the reliability of midden pollen records as paleoecological archives in northern Chile.

Siberian peatlands provide records of past changes in the continental climate of Eurasia. We analyzed a core from Mukhrino mire in western Siberia to reconstruct environmental change in this region over the last 1300 years. The pollen analysis revealed little variation of local pine-birch forests. A testate amoebae transfer function was used to generate a quantitative water-table reconstruction; pollen, plant macrofossils, and charcoal were analyzed to reconstruct changes in vegetation and fire activity. The study revealed that Mukhrino mire was wet until the Little Ice Age (LIA), when drought was recorded. Dry conditions during the LIA are consistent with other studies from central and eastern Europe, and with the pattern of carbon accumulation across the Northern Hemisphere. A significant increase in fire activity between ca. AD 1975 and 1990 may be associated with the development of the nearby city of Khanty-Mansiysk, as well as with the prevailing positive Arctic Oscillation.

The large prehistoric city of Liangzhu and its associated earthen dike emerged on the Yangtze delta-coast after two millennia of occupation in this area by scattered communities. Details of its development have been widely discussed in the literature. Our results reveal that the city was selectively built at the head of an embayment backed by hills, with close access to food, freshwater and timber, and with protection from coastal hazards. Radiocarbon and optically stimulated luminescence (OSL) dating shows that it was built around 4.8–4.5 ka, and the earthen dike was constructed a little later at ~ 4.1 ka. During this time, saltwater wetlands were changing to freshwater in response to rapid coastal progradation as the postglacial sea-level rise stabilized. This facilitated rice farming and furthered the development of the city with elaborate city planning. The younger large-scale earthen dike and artificial ponds possibly suggest increasing demand for flood mitigation and irrigation.

Stratigraphy, geochemistry and radiocarbon dating of a succession of sediment in the Santiaguillo Basin (central-northern Mexico) help reconstruct the millennial-scale dynamics of hydrological variability that occurred in the southern part of western subtropical North America since the late last glacial. Runoff was generally above average during the late last glacial from ~ 27 to 18 ka. Following this interval, runoff decreased and deposition of authigenic carbonate and aeolian transported sediment increased until ~ 4 ka. Heinrich 1 and 2, and Younger Dryas were intervals of reduced runoff and increased aeolian activity. The wetter climate of central-northern Mexico and arid conditions in north–northwestern Mexico during the late last glacial were probably related to formation of tropical cyclones in the eastern North Pacific during the autumn with restricted rainfall swaths and an absent/weaker North American Monsoon. Enhanced North American Monsoon and tropical cyclones with expanded rainfall swaths brought more summer and autumn precipitation to a broader region extending from the central-northern Mexico to the continental interiors of southwestern US during the early Holocene.

The Cascade Range of southwestern Oregon contains some of North America's most diverse forests, but the ecological history of this area is poorly understood. A 7900-yr-long pollen and charcoal record was examined to better understand past changes in vegetation and fire activity in relation to large-scale climate variability. From 7900 to 3500 cal yr BP, the dominance of xerophytic species and the frequent fires are consistent with a climate that was warmer and drier than at present. The period from 3500 cal yr BP to present experienced an abundance of mesophytic taxa and reduced fire frequency, suggesting cooler and wetter conditions. The regional history of Abies indicates that it was most widespread during the late-glacial period; its range contracted during the early Holocene thermal maximum, and it steadily expanded during the middle and late Holocene. In contrast, Pseudotsuga was restricted in range during the glacial period, became abundant at low-elevation sites in the Coast and northern Cascade ranges during the early Holocene, and was more prevalent in southern mid-elevation sites as the climate became cooler and wetter in the late Holocene. The sensitivity of these species to past climate change suggests that biogeographic responses to future conditions will be highly variable in this region.

Thirteen intact cynipine galls (Cynipidae) are identified from the significant late Pleistocene locality of Rancho La Brea, mostly within the range of approximately 30,000 to 48,000 14C yr BP. Late Cenozoic cynipids have a poor fossil record; it is thus of great interest that the provisional dates for this fossil gall collection establish that these insects and their hosts were an important part of the late Pleistocene ecosystem in and around Rancho La Brea. Cynipine host specificity both verifies, as well as augments, the proportionally low record of plants recovered at Rancho La Brea in comparison to records of mammals, birds, and other fauna. Because galler and hosts represent extant species, their climate and habitat restrictions offer a good basis for making paleoecological inferences. In particular, they imply that many of the diverse habitats found in California today, or, at least plant associations with similar environmental restrictions, some presently a distance from the Rancho La Brea Tar Pits, existed in the vicinity of this locality during the late Pleistocene. This material also includes previously undescribed species, several of which are morphologically similar to extant comparative material that exhibits a “jumping” behavior, previously believed to be unique to Neuroterus saltatorius Edwards.

The effect of changing environment on the evolution of Homo sapiens is heavily debated, but few data are available from equatorial Africa prior to the last glacial maximum. The Karungu deposits on the northeast coast of Lake Victoria are ideal for paleoenvironmental reconstructions and are best studied at the Kisaaka site near Karunga in Kenya (94 to > 33 ka) where paleosols, fluvial deposits, tufa, and volcaniclastic deposits (tuffs) are exposed over a ~ 2 km transect. Three well-exposed and laterally continuous paleosols with intercalated tuffs allow for reconstruction of a succession of paleocatenas. The oldest paleosol is a smectitic paleo-Vertisol with saline and sodic properties. Higher in the section, the paleosols are tuffaceous paleo-Inceptisols with Alfisol-like soil characteristics (illuviated clay). Mean annual precipitation (MAP) proxies indicate little change through time, with an average of 764 ± 108 mm yr− 1 for Vertisols (CALMAG) and 813 ± 182 to 963 ± 182 mm yr− 1 for all paleosols (CIA-K). Field observations and MAP proxies suggest that Karungu was significantly drier than today, consistent with the associated faunal assemblage, and likely resulted in a significantly smaller Lake Victoria during the late Pleistocene. Rainfall reduction and associated grassland expansion may have facilitated human and faunal dispersals across equatorial East Africa.

We describe the first complete sediment core to bedrock in southwestern Michigan of a radiocarbon defined sequence of Michigan Subepisode (Marine Oxygen Isotope Stage [MIS] 2) glacial sediments, Athens Subepisode (MIS 3) non-glacial sediments, and two older tills using sedimentological, lithological, and radiocarbon analyses. Organics from Athens Subepisode lacustrine and palustrine sediments yield radiocarbon ages of 41,920–42,950 and 43,630–45,340, and > 43,500 14C yr BP. We propose the name Port Sheldon Formation for these organic-bearing sediments. We interpret the underlying diamictons as two basal tills separated by glaciolacustrine fines. The youngest till (Hemlock Crossing till) lying below the Port Sheldon Formation is a dark gray, gravel-poor clay loam to loam with a mean kaolinite–illite ratio of 0.98 ± 0.04. The oldest till (Glenn Shores till) is a dark grayish brown, gravel-rich, clay loam to sandy loam with mean kaolinite–illite ratio of 1.22 ± 0.08. About 130 water-well records demonstrate that organic sediments and underlying diamictons are common in the subsurface of Ottawa County. These tills are likely Illinois Episode (MIS 6) or older, but an Ontario Subepisode (MIS 4) age cannot be ruled out. Deep bedrock basins in Lower Michigan provide an untapped archive of pre-Michigan Subepisode history.

The drainage area of the Iberian Ranges (NE Spain) houses one of the most extensive Quaternary fluvial tufaceous records in Europe. In this study, tufa deposits in the Añamaza, Mesa, Piedra and Ebrón river valleys were mapped, stratigraphically described and chronologically referenced from U/Th disequilibrium series, amino acid racemization and radiocarbon methods. Tufa deposits accumulated in cascades, barrage-cascades and related damming areas developed in stepped fluvial systems. The maximum frequency of tufa deposition was identified at 120 ka (Marine Oxygen Isotope Stage [MIS] 5e), 102 ka (MIS 5c), 85 ka (~ MIS 5a) and 7 ka (MIS 1), probably under warmer and wetter conditions than today. Additional phases of tufa deposition appear at ~ 353 ka (~ end of MIS 11), 258–180 ka (MIS 7) and 171–154 ka (MIS 6). Although most tufa deposition episodes are clearly correlated with interstadial periods, the occurrence of tufa deposits during the penultimate glaciation (MIS 6) is remarkable, indicating that the onset of this stage was climatically favourable in the Iberian Peninsula. Biostatic conditions and the dynamics of karstic systems regulating tufa deposition seem to be sensitive to the precipitation regime, controlled by shifts in the position of North Atlantic atmospheric belts, and summer insolation, regulated by orbital forcing.

Stable carbon isotope (δ13C) values of organic matter in lacustrine sediments are commonly used to trace past changes in terrestrial and aquatic carbon cycles. Here we use a high-resolution, well-dated δ13C record from Lake Tengchongqinghai (TCQH) in southwestern China, together with other proxy indices, to reconstruct the paleolimnological history over the past 18.5 ka. Organic matter in the sediments of Lake TCQH is derived predominately from aquatic macrophytes. The lacustrine primary productivity is closely linked with lake-level changes affected by variations in the strength of the Asian summer monsoon and modified by evapotranspiration. Similar to lake sediments world-wide, a ca. − 3‰ shift occurred in the δ13C values of Lake TCQH in response to the significant increase in atmospheric CO2 concentration during the last deglaciation. In the Holocene, the availability of dissolved CO2 in the lake water of Lake TCQH was determined by variations in hydraulic energy: low water turbulence creates a thick, stagnant boundary layer around aquatic plants, which will restrict the rate of CO2 diffusion and result in more positive δ13C values of aquatic plants. In contrast, significant water turbulence dramatically reduces the boundary layer thickness leading to more negative δ13C values of aquatic plants.

The Waco Mammoth Site (WMS) in central Texas contains the remains of the largest mammoth herd (Mammuthus columbi) in North America that died in a single catastrophic event. Most mammoths at the site died on a gravel bar of the ancient Bosque River adjacent to a collapsing tributary wall. However, the timing and cause of death of the 26 mammoths documented to date are controversial. The objectives of this research are to: describe and interpret the alluvial stratigraphy and infer the cause of death, employ optically stimulated luminescence (OSL) dating to determine the timing of death, and analyze stable C isotopes of pedogenic carbonate to infer local plant communities, dietary habits, and summer temperatures. Dating of quartz from seven sediment samples by OSL places the death event to a weighted mean of 66.8 ± 5.0 ka. The site is coeval with Marine Oxygen Isotope Stage 4, consistent with our reconstructed mean July temperatures ~ 4°C cooler than today based on a buried soil isotopic transfer function. Our buried soil isotopic interpretation of a dominance of C3 plants is contrary to previous studies of mammoth tooth enamel at the site suggesting a dietary preference for warm season grasses (C4).

At the Drmno open-pit coal mine near Kostolac in Serbia, a nearly complete skeleton of Mammuthus trogontherii (nicknamed Vika) was discovered in a fluvial deposit overlain by a loess–paleosol sequence where a second paleontological level named Nosak with remains of M. trogontherii was found. We studied the magnetostratigraphy of the Kostolac sedimentary sequence and found that the Vika layer dates to ~ 0.8 Ma, shortly before the Brunhes–Matuyama boundary. In addition, according to our age model and previously reported optically stimulated luminescence and electron spin resonance dates, the Nosak fossils have an estimated age of 0.19 Ma and lived during the earliest part of Marine Isotope Stage 6. It appears therefore that at Kostolac, M. trogontherii is preserved both at its earliest occurrence at ~ 0.8 Ma and close to its latest occurrence at 0.19 Ma, and may well have been present in between, albeit not yet found. We speculate that megaherbivores such as M. trogontherii entered Europe along a conjunct Danube–Po River migration conduit connecting western Asia-Levant with central-southern Europe where vast and exploitable ecosystems, particularly suited for steppe- or savanna-adapted megaherbivores from Asia and Africa, developed during the late early Pleistocene climate revolution at around 0.8 Ma.

Pollen analysis was done on lacustrine sedimentary sequences dated by micromammals as late Pliocene–early Pleistocene that outcrop in two Neogene graben basins from SW Turkey. This study shows vegetation changes from steppe-like to more forested environments, very similar to the cyclic oscillations related to late Pleistocene glacial–interglacial climate changes. Artemisia was abundant during cold–arid periods, indicating that this species was already widespread in this area during the latest Pliocene and the beginning of the Pleistocene. A review of pollen records from Anatolia agrees with this study, suggesting that the spreading of this arid species occurred during a major climatic change: the beginning of the first glaciations and probably a change in seasonality towards summer aridity. Artemisia temporarily disappeared from the region during warm–wet periods and thus we suggest that glacial–interglacial-type oscillations already occurred in the area during the late Pliocene–early Pleistocene.

Deciphering the climatic evolution of the Tibetan Plateau region during the Plio-Pleistocene is hampered by the lack of continuous archives and proxy datasets indicative of moisture availability. Here we assess the suitability of magnetic susceptibility (χ) measured on lacustrine sediments as a paleohydrological proxy based on material from drill core SG-1 (2.69–0.08 Ma) from the western Qaidam Basin. Our assessment is based on directly comparing χ with the Artemisia/Chenopodiaceae (A/C) pollen ratio, which represents a sensitive, well-established proxy for moisture changes in arid environments. We find that higher and lower χ values represent drier and less dry conditions, respectively, for the Late Plio-Pleistocene. Less dry phases were likely caused by transiently increased influence of the westerlies and/or decreased influence of the Asian winter monsoon on glacial–interglacial time scales. An exception from this relationship is the interval between ~ 1.9 and 1.3 Ma, when the SG-1 χ record exhibits a 54 ka cyclicity, which may indicate summer monsoon influence on the Qaidam Basin during that time. After ~ 1.3 Ma, the summer monsoon influence may have ceased due to global cooling, with the consequence that the Asian winter monsoon and the westerlies exerted a stronger control on the hydrology of the Qaidam Basin.

Using the record of shallow-marine ostracode fauna and sediment grain size data from an 865-cm-long piston core obtained from Mutsu Bay, northeast Japan, paleoceanographic changes of the bay were determined at high resolution for the early to middle Holocene. Changes in the relative frequencies of several species showed periodicities of 1300–1800 years similar to Bond cycles. At around 10,300 cal yr BP and again, at 9500–9300 cal yr BP, cold water strongly influenced the bay owing to cooling events. Since at least 10,200 cal yr BP the Tsugaru Warm Current influenced the surface waters, and since ca. 7400 cal yr BP, also the bottom waters of the bay. Since ca. 8400 cal yr BP the water depth rapidly increased and peaked at 7000–5900 cal yr BP due to global sea-level rise. Subsequently, a drop of water temperature and sea level in the bay at 5900 and around 4000 cal yr BP influenced the composition of the ostracode assemblages. These millennial-scale oscillations in relative sea level and bay temperature during the Holocene can be correlated to paleoclimate records elsewhere.