Abstract The thawing and subsidence of frozen peat mounds (palsas) in permafrost landscapes results the formation organic‐rich thermokarst lakes. We examined effects palsa degradation on CH 4 CO 2 emissions by comparing lakes at two peatland locations subarctic Québec, Canada: northern discontinuous region, southern sporadic where palsas are more rapidly degrading. were shallow (< 3 m) but stratified both sites, most had anoxic bottom waters. surface waters sites supersaturated , to a...

Abstract Macrofossil evidence indicates that the mid-Holocene hemlock [ Tsuga canadensis L. (Carr.)] decline occurred over a wide area in eastern North America was associated with phytophagous insect activity. In situ macrofossils and remains found paludified dunefield at northern limit of testify two defoliation events 4910 ± 90 4200 100 yr B.P., respectively. The sharp coincidence from needles chewing damage typical looper feeding, head capsules ( Lambdina fiscellaria ) spruce budworm...

The Great Whale River region on the eastern shore of Hudson Bay, Canada, encompasses villages Whapmagoostui (Cree First Nation) and Kuujjuarapik (Inuit) surrounding areas. principal field station Centre d'études nordiques (CEN: for Northern Studies) has operated at Whapmagoostui-Kuujjuarapik (W-K; 55° 15′ N, 77° 45′ W) since 1970s, with diverse research projects past present environments. climate W-K is strongly influenced by proximity recent pronounced loss sea ice in this sector northern...

The lichen woodland is one of the most important forest ecosystems in North America, dominating central part boreal forest. southernmost paradoxically heart southern This distribution prompted this study aiming to identify factors responsible for inception and development at its range limit eastern Canada. We tested hypothesis that lichen-spruce a regressive, post-fire type spruce-moss studied adjacent stands growing under similar soil conditions. reconstructed recent history transformation...

The lichen woodland is one of the most important forest ecosystems in North America, dominating central part boreal forest. southernmost paradoxically heart southern This distribution prompted this study aiming to identify factors responsible for inception and development at its range limit eastern Canada. We tested hypothesis that lichen-spruce a regressive, post-fire type spruce-moss studied adjacent stands growing under similar soil conditions. reconstructed recent history transformation...

This project combines the analysis of parasites and pollen remains from a wealthy 19th century household in Québec City, Canada to examine health as it intersects with ecological cultural factors disease transmission changing urban environments. Nineteen sediment samples two privy structures Canada. The parasite was conducted by examining through acid digestion, deflocculation micro-sieving, observed under brightfield microscope. Pollen followed same method, but sediments were further...

Radiocarbon dating and macrofossil data from a palsa filled thermokarst pond within subarctic permafrost peatland were used to reconstruct their evolution distinguish between allogenic autogenic processes that had been involved in development. Peat began accumulate the basin shortly after 6000 cal. BR The initial stage was shallow bay or salty marsh, followed by wet marsh triggered relatively rapid drop sea level related isostatic uplift of land. By 5640 BP, site transformed into rich fen. A...

Macrofossil analysis of the peat and topographic surveys two palsa fields (Fields 3 4) within a permafrost peatland located in subarctic Québec was conducted to trace factors that contributed their differential development. The are visibly different terms geomorphology, ecology, hydrology. According our results, evolution largely synchronous respective trophic conditions. Moreover, climate certainly played significant role this ecosystem. For example, cooling Neoglacial period would have...

Abstract We reconstructed the late Holocene vegetation of Nain region (northern Labrador, northeastern Canada) in order to assess influence climate and historic land use on past shifts forest composition. Chronostratigraphy was used combination with macrofossil pollen data from monoliths sampled four peatlands. Paleoecological reconstructions produced a history spanning 4900 years for that is largely concordant other studies Labrador. An initial open tundra phase followed by an increase tree...

Abstract This study combines different methods, including grain size, macrofossil, and pollen analyses, to reconstruct paleogeographical paleoclimatological conditions for periods before, during, after the isolation of a small lake (Lake Kachishayoot) in northern Québec. After retreat Laurentide Ice Sheet around 8000 14 C yr B.P., area was submerged by Tyrrell Sea. The transition from marine lacustrine environment occurred about 5400 B.P. Two major water-level fluctuations were inferred...

Abstract In this study, we documented the Holocene history of a peat plateau at arctic tree line in northern Québec using stratigraphic and macrofossil analyses to highlight effects geomorphic setting peatland development. Paludification site began about 6800 cal yr BP. From 6390 4120 BP, experienced series flooding events. The location depression bounded by two small lakes likely explains its sensitivity runoff. proximity large hill bordering south possibly favored inflow mineral-laden...

Extreme weather events such as storms, heavy snow accumulation, rapid snowmelt, and rain have been closely related to slope instability in arctic subarctic regions. In this paper, we investigate the historical activity of processes avalanches debris flows Þistilfjörður, northeastern Iceland, examine their possible role occupation abandonment three archaeological sites located on slopes Mt. Flautafell. The study combines geomorphological stratigraphical surveys with records, notably Jarðabók...

Abstract:Macrofossil data allowed the reconstruction of developmental history a paludified dunefield site in Central St. Lawrence Lowland, Québec. Peat accumulation started between dunes around 7000 years BP after period free drainage reflected by podzolized sands. In interdune depressions, vegetation developed from aquatic communities to damp forests, fen and bog communities. Between ca 7000-4100 BP, slow peat effective plant decomposition depressions while prevailed on dune ridges. After...

Macrofossil and chronostratigraphic data of a peat monolith extracted from palsa within subarctic permafrost peatland were used to reconstruct changes in vegetation trophic conditions the study site during last 4500 cal y BP. The cover developed Carex marsh or wet meadow poor fen, bog, communities. ombrotrophication was favoured by late-Holocene cooling high accumulation. Permafrost inception began about 1660–1630 calibrated BP, at end Sphagnum accumulation stage. A comparison development...

The thawing of ice-rich permafrost soils in northern peatlands leads to the formation thermokarst ponds, surrounded by organic-rich soils. These aquatic ecosystems are sites intense microbial activity, and CO2 CH4 emissions. Many pond systems landscapes their surrounding hydrologically contiguous, but little is known about connectivity concentric habitats around or effects peat accumulation infilling on communities. Here we investigated community structure abundance a pond-peatland system...

Tree-ring data from a mature balsam fir forest, located at the top of Mount Mégantic (elevation 1100 m), southern Quebec, suggest that insect defoliators were major disturbance factors in development high-altitude forests. A comparison between radial growth trend (Abies balsamea (L.) Mill.), host species spruce budworm (Choristoneura fumiferana Clem.), and paper birch (Betula papyrifera Marsh), nonhost species, showed several depressions chronology corrresponded to documented outbreaks...

The object of this study is to document how the I nuit on northern coast L abrador, C anada used terrestrial resources such as peat and wood during ittle ce A ge ( LIA ; A.D. 1500–1870). Paleoecological investigations consisting pollen macrofossil analyses were undertaken in conjunction with archaeological excavations at winter settlement sites O akes B ay 1, located N ain region north‐central abrador. Our data indicate that major changes ecosystems coastal triggered by climate change. From...

Abstract The geoarchaeological study of the Palaeoeskimo Tayara site on Qikirtaq Island (Nunavik) has led to a better understanding archaeological formation in arctic periglacial environment. surrounding geomorphology (extra‐site) is characterized by fine‐grained, low plastic and leached postglacial glaciomarine sediments that have been reworked sheet‐like solifluction. This process buried northern part with mean annual rates between 1.68 2.86 cm/yr over approximately 350 years (1330–980 yr...

Abstract A multidisciplinary study was undertaken at the Qijurittuq Site (IbGk‐3) on Drayton Island in Low‐Arctic Quebec (Canada) to document relationships between climatic, environmental, and cultural changes choice of Thule/Inuit dwelling style eastern Arctic. Several marine terraces were 14 C‐dated with shells order reconstruct area's uplift (glacioisostatic rebound) curve. Plant macrofossil analysis peat conducted past vegetation and, indirectly, climate. Archaeological surveys...

Abstract Data concerning driftwood is of value to researchers in fields as diverse oceanography, geomorphology, and human occupation. Yet studies on the subject Canadian Arctic have only recently been carried out, present study first Nunavik (northeastern Canada). This paper documents composition, characteristics, origin modern pieces beaches eastern coast Hudson Bay. A total 1057 samples from Ivujivik, Akulivik, Inukjuak, Umiujaq were identified belonging four coniferous species ( Picea...

Abstract A detailed taphonomic study was undertaken at the Tayara site in order to determine impact of natural processes such as surface water flow on spatial patterning and formation. The focused Paleoeskimo level II, which contains many lithics significant faunal remains. Level II integrity assessed through analysis by examining size distribution lithic artifacts bone orientation. Experimental knapping aimed replicating technology used assess possible sorting lithics. indicates that...