We reconstructed Holocene water-level and vegetation dynamics based on pollen and plant macrofossils from a coastal lake in Upper Michigan. Our primary objective was to test the hypothesis that major fluctuations in Great Lakes water levels resulted in part from climatic changes. We also used our data to provide temporal constraints to the mid-Holocene dry period in Upper Michigan. From 9600 to 8600 cal yr B.P. a shallow, lacustrine environment characterized the Mud Lake basin. A Sphagnum-dominated wetland occupied the basin during the mid-Holocene dry period (∼8600 to 6600 cal yr B.P.). The basin flooded at 6600 cal yr B.P. as a result of rising water levels associated with the onset of the Nipissing I phase of ancestral Lake Superior. This flooding event occurred contemporaneously with a well-documented regional expansion of Tsuga. Betula pollen increased during the Nipissing II phase (4500 cal yr B.P.). Macrofossil evidence from Mud Lake suggests that Betula alleghaniensis expansion was primarily responsible for the rising Betula pollen percentages. Major regional and local vegetational changes were associated with all the major Holocene highstands of the western Great Lakes (Nipissing I, Nipissing II, and Algoma). Traditional interpretations of Great Lakes water-level history should be revised to include a major role of climate.

Geochemical, mineralogical, and palynological records from a Holocene sediment core 12.7 m long from Lake Silvana, southeastern Brazil, served to identify the source of detrital sediments within catchment soils. The lake basin was first flooded in the early Holocene (9400 14C yr B.P.), when a gibbsite-rich B soil horizon started to accumulate. Four distinct hydrologic phases are consistent with vegetational changes indicated by pollen data. Phases of slope instability (colluviation) and low lake level correspond to pollen-free intervals and point to a severe retreat of the vegetation cover. The rapid sedimentation of slope-wash sediments alternating with alluvial sediments appears to have formed a tributary fan 7.8 m thick that dammed the Lake Silvana Basin 8500 14C yr B.P., probably as a response to a drastic increase in precipitation rates.

Pollen records from perennially frozen sequences provide vegetation and climate reconstruction for the last 48,000 14C years in the central part of Taymyr Peninsula. Open larch forest with Alnus fruticosa and Betula nana grew during the Kargin (Middle Weichselian) Interstade, ca. 48,000–25,000 14C yr B.P. The climate was generally warmer and wetter than today. Open steppe-like communities with Artemisia, Poaceae, Asteraceae, and herb tundralike communities with dwarf Betula and Salix dominated during the Sartan (Late Weichselian) Stade, ca. 24,000–10,300 14C yr B.P. The statistical information method used for climate reconstruction shows that the coldest climate was ca. 20,000–17,000 14C yr B.P. A warming (Allerød Interstade?) with mean July temperature ca. 1.5°C warmer than today occurred ca. 12,000 14C yr B.P. The following cooling with temperatures about 3°–4°C cooler than present and precipitation about 100 mm lower corresponds well with the Younger Dryas Stade. Tundra–steppe vegetation changed to Betula nana–Alnus fruticosa shrub tundra ca. 10,000 14C yr B.P. Larch appeared in the area ca. 9400 14C yr B.P. and disappeared after 2900 14C yr B.P. Cooling events ca. 10,500, 9600, and 8200 14C yr B.P. characterized the first half of the Holocene. A significant warming occurred ca. 8500 14C yr B.P., but the Holocene temperature maximum was at about 6000–4500 14C yr B.P. The vegetation cover approximated modern conditions ca. 2800 14C yr B.P. Late Holocene warming events occurred at ca. 3500, 2000, and 1000 14C yr B.P. A cooling (Little Ice Age?) took place between 500 and 200 14C yr ago.

The paleo-depositional environment of inner Prydz Bay, East Antarctica, has been reconstructed for the past 21,320 14C yr B.P., using diatom assemblages and sediment facies from a short, 352-cm-long gravity core. Between 21,320 and 11,650 14C yr B.P., compact tillite and diamicton are present in the core, and diatom frustules are rare to absent. These data suggest that an ice sheet grounded over the site during the last glacial maximum. Following glacial retreat, siliceous muddy ooze was deposited, from 11,650 to 2600 14C yr B.P., in an open marine setting. During this stage, diatom frustules are abundant and well preserved, and Thalassiosira antarctica resting spores and Fragilariopsis curta dominate the assemblage. This assemblage suggests open marine deposition in an environment where the spatial and temporal distribution of sea ice is less than today. Since 2600 14C yr B.P., sea-ice and ice-edge diatom species have become more abundant, and neoglacial cooling is inferred. The assemblage is similar to that forming currently in Prydz Bay, where sea ice is absent (<10% cover) for 2–3 months of the year and permanent ice edge and/or multiyear sea ice remains in close proximity to the site.

Terrestrial mollusks, easily identified in Quaternary sediments, represent a reliable tool for quantitative estimates of environmental parameters. Our study, comparing the species distribution with meteorological parameters in Europe, shows that mean temperature of the coldest month and annual thermal magnitude are the most important forcing parameters. This survey allows us to adapt the mutual climatic range (MCR) method to terrestrial mollusk assemblages following two main steps. A set of assemblages from different European regions (northern Norway to southern France) is used to apply the method to present-day mollusks. The reconstructed values describe the latitudinal temperature gradient prevailing over Europe. However, the comparison between the reconstructed and the measured values indicates a shift, similar to that observed, with the same method applied to beetle assemblages. Thus, estimates must be calculated after the reconstruction is tuned with the observations. The results from the modern mollusk assemblages indicate that the MCR method can be safely applied to reconstructing temperatures from terrestrial mollusk assemblages in any worldwide Quaternary sequence. A trial application is made on Late Pleistocene assemblages from Achenheim (Alsace, France).