Reinhard Pienitz

TL;DR: Fifty-five paleolimnological records from lakes in the circumpolar Arctic reveal widespread species changes and ecological reorganizations in algae and invertebrate communities since approximately anno Domini 1850, indicating that the opportunity to study arctic ecosystems unaffected by human influences may have disappeared.

TL;DR: In this article, the authors present palaeo-ecological evidence for changes in terrestrial vegetation and lake characteristics during an episode of climate warming that occurred between 5,000 and 4,000 years ago at the boreal treeline in central Canada.

TL;DR: In this article, the diatom assemblages preserved in the surface sediments of 59 lakes located between Whitehorse in the Yukon and Tuktoyaktuk in the Northwest Territories (Canada).

TL;DR: This work uses fossil diatom assemblages in combination with bio-optical models to estimate the magnitude of past variations in the underwater light regime of a lake at the boreal tree line and finds large shifts in underwater UV-B, UV-A and photosynthesis available radiation associated with changes in the input of coloured dissolved organic material into subarctic lakes during the Holocene.

TL;DR: In this article, a series of permafrost thaw ponds in the Canadian Subarctic and Arctic and further investigated how optical properties of the carbon pool, the type of microbial assemblages, and light and mixing regimes influenced the rate of gas release.