The ecosystems of the Canadian High Arctic, including freshwater systems, are recognized to be particularly vulnerable to the effects of global environmental change. Although freshwater systems of the High Arctic have undergone dramatic biotic shifts due to recent climatic change, very little information is available about the long-term responses of these systems to fluctuations in …
Aquatic sediments are one of the reliable archives of information that can be interpreted by paleolimnologists. Sediments accumulated much useful information archived from both autochthonous and allochthonous materials. Sediments contain a vast array of physical, biological, chemical, and visual information that follow the present-day environmental variability. Of most important data stored in sediments that can …
The Circumpolar Data base Many data were collected into 18 years of paleolimnological studies supervised by Dr. Pienitz. For most of them, they were added into a data base program which was manage with File Maker© program. At these times, the aim of this system was especially to archive and unify the data into an …
While the planet as a whole is currently undergoing rapid warming, Quebec’s far north is one of the fastest-warming regions in the world. This warming affects the different components of landscapes and ecosystems. It is uncertain how northern lakes will be influenced by these changes, and to what extent they have already undergone …
Lakes of the Bécancour River basin (southern Quebec, Canada) are in a precarious state since many decades as they are suffering from high sediment loads and advanced eutrophication. This situation affects the socio-economic and touristic potential of the neighbouring municipalities and is inconvenient for their residents as it impacts water supply, resort activities and recreational …
Since the discovery of Antarctica in the early 19th Century, the number of humans arriving to the continent has progressively increased. This increased human footprint has generated concern about the threats posed to the region’s fragile ecosystems. The Fildes Peninsula (King George Island, South Shetland Islands) has been the site of year-round human presence since …
Diatoms are siliceous organisms composed of amorphous biogenic silica (SiO2 – nH2O). Siliceous organisms are resistant to dissolution and are ubiquitous in lake ecosystems. Diatoms have strong affinities with their habitat, they reproduce rapidly, and the assemblage of species reliably records changes in their environment. Diatoms preserve in the SiO2structure of their frustule (siliceous shell) …
Quebec’s territory is covered by millions of lakes and those located in densely populated areas in the south are subjected to the influence of human activities in their catchments. An increasing number of these lakes are affected by eutrophication, showing recurring blooms of cyanobacteria (blue-green algae). Since the summer of 1999, cyanobacterial blooms were reported …
Paleolimnological studies into the recent (ca. last 200 years) history of northern lakes have revealed a striking discrepancy between climatic trends inferred for regions roughly located north and south of the Foxe Basin and Hudson Strait (Pienitz et al. 2004; Smol et al. 2005). While most freshwater ecosystems show signs of pronounced changes associated with …
High latitude ecosystems are particularly sensitive to environmental change and are undoubtedly facing challenges due to modern climate change as ecological thresholds are surpassed. Within these regions, lakes offer a unique utility by acting as sentinels of environmental change by archiving past biogeochemical conditions in their sediments. The lakes surrounding Clements Markham Inlet are amongst …
Climate fluctuations are driving increasingly disruptive changes in northern environments and the ecological services these ecosystems provide to Inuit communities in Labrador. Culture and human occupation evolve spatially and temporally in a complex relation with the dynamic natural landscape, for which the functioning and development are still poorly known in Labrador. Modern climate changes pose …
Among high latitude ecosystems, lakes are particularly sensitive to environmental variations. By studying their current and past conditions through their sediments, this project aims to provide a better understanding of the functioning of these high Arctic ecosystems and their roles in the global climate. The series of four lakes in Stuckberry Valley is one of …
Permafrost affects nearly 50% of the Canadian territory, and it is found almost everywhere in Northern Quebec. Recent climatic warming has triggered partial melting of the permafrost in subarctic regions. This process brings a local ground subsidence which creates water-filled depressions called «thermokarst lakes». Recently observed in many northern regions, these lakes seem to have …