A5031302092- Geology and Paleoclimatology Research
- Diatoms and Algae Research
- Aquatic Ecosystems and Phytoplankton Dynamics
- Isotope Analysis in Ecology
- Tree-ring climate responses
- Aeolian processes and effects
- Marine and coastal ecosystems
- Geological formations and processes
- Ecology and biodiversity studies
- Methane Hydrates and Related Phenomena
- Geological Studies and Exploration
- Archaeology and ancient environmental studies
- Soil erosion and sediment transport
- Freshwater macroinvertebrate diversity and ecology
- Soil and Water Nutrient Dynamics
- Climate change and permafrost
- Water Quality and Pollution Assessment
- Hydrology and Sediment Transport Processes
- Fish Ecology and Management Studies
- Winter Sports Injuries and Performance
- Botany and Plant Ecology Studies
- Identification and Quantification in Food
- Yersinia bacterium, plague, ectoparasites research
- Water Governance and Infrastructure
- Mercury impact and mitigation studies
Drexel University
2013-2016
University of Arkansas at Fayetteville
2006-2013
Université Laval
2002-2011
University of Bern
2001-2005
Center for Northern Studies
2002
A comprehensive database of paleoclimate records is needed to place recent warming into the longer-term context natural climate variability. We present a global compilation quality-controlled, published, temperature-sensitive proxy extending back 12,000 years through Holocene. Data were compiled from 679 sites where time series cover at least 4000 years, are resolved sub-millennial scale (median spacing 400 or finer) and have one age control point every 3000 with cut-off values slackened in...
Summary Priority question exercises are becoming an increasingly common tool to frame future agendas in conservation and ecological science. They effective way identify research foci that advance the field also have high policy relevance. To date, there has been no coherent synthesis of key questions priority areas for palaeoecology, which combines biological, geochemical molecular techniques order reconstruct past environmental systems on time‐scales from decades millions years. We adapted...
We developed a quantitative chironomid-July air temperature inference model based on surface sediments from 81 Swiss lakes and applied it to the Holocene subfossil chironomid record of Hinterburgsee, small subalpine lake in northern Alps (present-day mean July 11.3°C). After smoothing reduce high between-sample variability inferred temperatures, reconstruction indicates temperatures 10.4– 10.9°C at end Younger Dryas, 11.9–12.8°C during early mid-Holocene (11500–4000 cal. BP), slightly lower...
This paper presents a multiproxy high-resolution study of the past 2600 years for Seebergsee, small Swiss lake with varved sediments at present tree-line ecotone. The laminae were identified as varves by numerical analysis diatom counts in thin-sections. hypothesis two blooms per year was corroborated 210Pb and 137Cs chronology. A period intensive pasturing during ‘Little Ice Age’ between ad 1346 1595 is suggested coprophilous fungal spores, well pollen indicators grazing, diatom-inferred...
Sedimentary diatom assemblages from three lakes in the southeastern Swiss Alps were analysed at high temporal resolution since AD 1800. Altered land-use patterns, increasing population and exploitation through tourism are clearly reflected annually laminated sediments of Lej da San Murezzan (Lake St Moritz) Silvaplauna Silvaplana). Diatom originally dominated by Cyclotella taxa replaced indicating higher total phosphorus (TP) concentrations, such as Asterionella formosa, Fragilaria...
Fourier transform infrared spectroscopy (FTIRS) can provide detailed information on organic and minerogenic constituents of sediment records. Based a large number samples varying age (0-340,000 yrs) from very diverse lake settings in Antarctica, Argentina, Canada, Macedonia/Albania, Siberia, Sweden, we have developed universally applicable calibration models for the quantitative determination biogenic silica (BSi; n = 816), total inorganic carbon (TIC; 879), (TOC; 3164) using FTIRS. These...
Paleo surface wind for southern Quebec was inferred quantitatively the past 9500 years from diatom assemblages archived in sediment of shallow mountain Lac du Sommet using biweekly trap samples along an elevation gradient study area. The reconstruction compared with diatom-inferred dissolved organic carbon concentration, chironomid-inferred mean August air temperature, pollen, grain size and loss-on-ignition. Increased lake circulation, interpreted as indicating stronger winds, diatoms...
1. The morphologically complex taxon Cyclotella comensis Grunow had no clear relationship with environmental parameters in a study using sediment surface samples from the Swiss Alps. morphological heterogeneity of was investigated by applying principal component analysis (PCA) to 9000 presence/absence descriptions valves six lakes different altitudes (15 characteristics, 100 each lake). PCA allowed classification morphs, which differed mainly size and length striae. Photographs morphs are...
Changing rainfall patterns resulting from climate change are predicted to influence cyanobacterial blooms and associated production of toxins other metabolites, but few studies have demonstrated this link. We explored seasonal interannual trends in 2-methylisoborneol (MIB) concentrations the correlation these data with hydrologic 2000 2013. also conducted a detailed study abundances MIB during 2 hydrologically extreme years, prolonged drought 2007 followed by an extremely wet year 2008. The...
Pingualuk Lake fills a deep crater in the Parc National des Pingualuit on Ungava Peninsula (Nunavik, Canada) and is isolated from nearby surface waters. The main objectives of this study were to determine compare concentrations two atmospherically derived contaminants, mercury perfluorinated chemicals (PFCs), lake water column fish assess physical biological factors influencing contaminant concentrations. Mercury arctic char muscle tissue comparable those other Arctic lakes, while total...
Zoological remains were examined from the sediments of Pingualuit Crater Lake, Nunavik, Canada. Our objective was to describe past climate events in area delayed deglaciation northernmost Ungava Peninsula. record covers 3 separate sections deglacial and postglacial invertebrate dynamics interrupted by laminated proglacial a basin-scale erosive slumping event. The abundance animal ultra-oligotrophic extremely deep arctic lake low, but distinct faunal assemblages found among intervals, results...
Abstract Arctic and sub-arctic lake sediment sequences from the Pleistocene are uncommon due to multiple glacial–interglacial cycles associated advances retreats of ice sheets. strata preserved in a 9-m-long core recovered Pingualuit Crater Lake, Nunavik, northern Québec (Canada). In addition tychoplanktonic Aulacoseira species, planktonic flora comprises representatives thalassiosiroid genera Cyclotella, Discostella Puncticulata, which most species extant perennially ice-free arctic lakes....
PAGES International Floodplain Lakes Workshop; Fayetteville, Arkansas, 16–19 September 2010 ; Human alteration of the major rivers and floodplains world is a global concern because they sustain aquatic ecosystems supply food energy to society. When in flood stage, influence river extends across floodplain can revitalize productive wetlands. The condition many has declined worldwide, but degree degradation hard assess due natural variability flow uncertainty baseline status. Evidence changes...