Lake sediments spanning the Last Glacial-Interglacial Transition (LGIT: ca. 14.7 to 8 ka BP) from Muir Park Reservoir (MPR) in west-central Scotland were analysed for chironomids. The site lies just outside the southern limit of a former glacier that advanced into the Loch Lomond Basin during the Loch Lomond (Younger Dryas) Stadial. Chironomid-inferred mean July temperatures were derived using a modern Norwegian calibration dataset. Three tephra layers constrain the sequence chronologically. Inferred temperatures decline from a high value early in the Interstadial, punctuated by two cold oscillations, probably equivalent to GI-1d and GI-1b in the Greenland ice-core record, and a warm oscillation (equivalent to GI-1a) immediately before the severe cooling at the start of the Loch Lomond Stadial (GS-1), when summer temperatures fell by about 5˚C below the Interstadial average. Summer temperatures fell by about 3˚C below the Interstadial average during GI-1d, which is less severe than inferred from other chironomid records from eastern Scotland, and may reflect the influence of an oceanic-continental gradient. Cooling during GI-1b was particularly strong at MPR when minimum temperatures were about the same as those reached during GI-1d, unlike other sites investigated where GI-1d is usually between 1 and 2˚C cooler than GI-1b.

This paper provides an overview of stable isotope analysis (H, C, N, O, Si) of the macroand microscopic remains from aquatic organisms found in lake sediment records and their application in (palaeo)environmental science. Aquatic organisms, including diatoms, macrophytes, invertebrates, and fish, can produce sufficiently robust remains that preserve well as fossils and can be identified in lake sediment records. Stable isotope analyses of these remains can then provide valuable insights into habitat-specific biogeochemistry, feeding ecology, but also on climatic and hydrological changes in and around lakes. Since these analyses focus on the remains of known and identified organisms, they can provide more specific and detailed information on past ecosystem, food web and environmental changes affecting different compartments of lake ecosystems than analyses on bulk sedimentary organic matter or carbonate samples. We review applications of these types of analyses in palaeoclimatology, palaeohydrology, and palaeoecology. Interpretation of the environmental 'signal' provided by taxon-specific stable isotope analysis requires a thorough understanding of the ecology and phenology of the organism groups involved. Growth, metabolism, diet, feeding strategy, migration, taphonomy and several other processes can lead to isotope fractionation or otherwise influence the stable isotope signatures of the remains from aquatic organisms. This paper includes a review of the (modern) calibration, culturing and modeling studies used to quantify the extent to which these factors influence stable isotope values and provides an outlook for future research and methodological developments for the different examined fossil groups.

Palaeoenvironmental records from the now-submerged Bering Land Bridge (BLB) covering the Last Glacial Maximum (LGM) to the present are needed to document changing environments and connections with the dispersal of humans into North America. Moreover, terrestrially based records of environmental changes are needed in close proximity to the re-establishment of circulation between Pacific and Atlantic Oceans following the end of the last glaciation to test palaeo-climate models for the high latitudes. We present the first terrestrial temperature and hydrologic reconstructions from the LGM to the present from the BLB's south-central margin. We find that the timing of the earliest unequivocal human dispersals into Alaska, based on archaeological evidence, corresponds with a shift to warmer/wetter conditions on the BLB between 14 700 and 13 500 years ago associated with the early Bølling/Allerød interstadial (BA). These environmental changes could have provided the impetus for eastward human dispersal at that time, from Western or central Beringia after a protracted human population standstill. Our data indicate substantial climate-induced environmental changes on the BLB since the LGM, which would potentially have had significant influences on megafaunal and human biogeography in the region.

Direct evidence of ancient human occupation is typically established through archaeological excavation. Excavations are costly and destructive, and practically impossible in some lake and wetland environments. We present here an alternative approach, providing direct evidence from lake sediments using DNA metabarcoding, steroid lipid biomarkers (bile acids) and from traditional environmental analyses. Applied to an early Medieval Celtic settlement in Ireland (a crannog) this approach provides a site chronology and direct evidence of human occupation, crops, animal farming and on-site slaughtering. This is the first independently-dated, continuous molecular archive of human activity from an archeological site, demonstrating a link between animal husbandry, food resources, island use. These sites are under threat but are impossible to preserve in-situ so this approach can be used, with or without excavation, to produce a robust and full site chronology and provide direct evidence of occupation, the use of plants and animals, and activities such as butchery.