Northern regions are experiencing considerable climate change affecting the state of permafrost, peat accumulation rates, and the large pool of carbon (C) stored in soil, thereby emphasizing the importance of monitoring surface C fluxes in different landform sites along a climate gradient. We studied surface net C exchange (NCE) and ecosystem respiration (ER) across different landforms (upland,...

A long-standing hypothesis states that low year-round phytoplankton biomass in the open subarctic Pacific Ocean is maintained by herbivorous grazing. To evaluate the balance between phytoplankton growth and microzooplankton grazing, we carried out seawater dilution experiments at two subarctic Pacific locations in June and September 1987. Pigment-specific phytoplankton growth and grazing rates ...

The subarctic North Pacific is one of three major high nitrate, low chlorophyll (HNLC) oceanic regions, along with the Southern Ocean and the eastern equatorial Pacific. In these regions, uptake of nitrogen by phytoplankton is widely thought to be regulated by the availability of dissolved iron. The supply of dissolved iron is twofold: via atmospheric deposition of dust and via upward transport...

the current state of whitefish population and their organisms have been investigated in subarctic lake chuna exposed to long-term air pollution from copper-nickel industry. both annual and long-term heavy metals and acid oxides loads on the lake have been determined. a qualitative assessment has been made for water and bottom sediments. the investigation results have been compared with those of...

Shark populations are declining globally, yet the movements and habitats of most species are unknown. We used a satellite tag attached to the dorsal fin to track salmon sharks (Lamna ditropis) for up to 3.2 years. Here we show that salmon sharks have a subarctic-to-subtropical niche, ranging from 2 degrees to 24 degrees C, and they spend winter periods in waters as cold as 2 degrees to 8 degree...

Emissions of biogenic volatile organic compounds (BVOCs) have been earlier shown to be highly temperature sensitive in subarctic ecosystems. As these ecosystems experience rapidly advancing pronounced climate warming, we aimed to investigate how warming affects the BVOC emissions in the long term (up to 13 treatment years). We also aimed to assess whether the increased litterfall resulting from...

The climate is warming and it is most noticeable in the arctic and subarctic areas, where the warming trend is expected to be the greatest. Arctic and subarctic freshwater ecosystems, which are a very characteristic feature of the northern landscape, are especially sensitive to climate change. They could be used as early warning systems, but more information about the ecosystem functioning and ...

Rising temperatures are predicted to melt all perennial ice cover in the Arctic by the end of this century, thus opening up suitable habitat for temperate and subarctic species. Canopy-forming seaweeds provide an ideal system to predict the potential impact of climate-change on rocky-shore ecosystems, given their direct dependence on temperature and their key role in the ecological system. Our ...

The wood frog, Rana sylvatica LeConte 1825, is a freeze-tolerant amphibian widely distributed in North America. Subarctic populations of this species can survive experimental freezing to temperatures below -16 °C, whereas temperate populations tolerate freezing only at temperatures above -6 °C. We investigated whether hepatocytes isolated from frogs indigenous to Interior Alaska (subarctic) or ...