Holocene thermal maximum in the western Arctic (0-180°W)

This paper reports on the boreal forest, a broad, circumpolar mixture of cool coniferous and deciduous tree species which covers over 14.7 million km{sup 2}, or 11%, of the earth's terrestrial surface. At these latitudes, a strong correlation exists between the seasonal dynamics of atmospheric carbon dioxide and the seasonal dynamics of the greenness of the earth. A possible causal relation, in which the dynamics of the forests at these latitudes regulates the atmospheric carbon concentrations, appears to be consistent with the present-day understanding of ecological processes in these ecosystems. Along with its familiar role in plant photosynthesis, carbon dioxide is a greenhouse gas that markedly affects the heat budget of the earth. Thus the possibility that boreal forests may actively participate in the dynamics of atmospheric carbon dioxide is of considerable significance, especially since the climatic response to elevated atmospheric carbon dioxide concentrations seems to be strongly directed to the boreal forests of the world.

Environmental Factors and Ecological Processes in Boreal Forests

The North Atlantic Ocean during the last deglaciation

1. The evolution of knowledge about the Arctic and its climate 2. Physical characteristics and basic climate features 3. The basic atmospheric and ocean energy budgets 4. The atmospheric circulation 5. Energy exchanges at the surface 6. Precipitation, net precipitation, and river discharge 7. Arctic ocean-sea ice-climate interactions 8. Climate regimes of the Arctic 9. Modeling the Arctic climate system 10. Arctic paleoclimates 11. The uncertain future.

/pdf/the-arctic-climate-system-1lpskip818.pdf

The Arctic climate system

Late pleistocene glacial equilibrium-line altitudes in the Colorado Front Range: A comparison of methods

Holocene Pollen Diagrams from Subarctic Labrador-Ungava: Vegetational History and Climatic Change

From palynological studies it appears that northernmost dwarf spruces of the tundra and parts of the forest-tundra boundary may be relicts from times of prior warmth, and if felled might not regenerate. This disequilibrium may help explain the partial incongruence of modern climatic limits with the present forest edge. Seedlings established as a result of recent warming should therefore be found within the northernmost woodlands rather than in the southern tundra.

/pdf/historical-aspects-of-the-northern-canadian-treeline-uav7f2vt8h.pdf

Historical Aspects of the Northern Canadian Treeline

Past and present vegetation of the Isle of Skye : a Palaeoecological study

TRACE amounts of wind-blown tree pollen from the highly productive boreal coniferous forests are a characteristic component of arctic tundra sediments1,2. These exotic pollen are generally regarded as mere contamination or distractions in tundra pollen diagrams3. We report here that traces of exotic pollen in late Holocene sediments from Baffin Island can be used as palaeo-wind indicators, and may be associated with periodic shifts of a trough in the atmosphere.

Holocene palaeo-wind evidence from palynology in Baffin Island

Archaeological research suggests that cultural changes in the Canadian Arctic are closely linked to environmental changes. Current knowledge of postglacial climate and marine conditions in the eastern Canadian Arctic-an area demonstrably sensitive to small fluctuations in these conditions-is reviewed in the context of the prehistoric cultural sequence. Most of the major cultural events since 4500 BP appear to correlate well with the paleoclimatic conditions inferred from environmental data, although specific causal mechanisms cannot be documented.

/pdf/environmental-change-and-cultural-change-in-the-eastern-1mbe9dwqw4.pdf

Harvey Nichols

Papers

Holocene Pollen Diagrams from Subarctic Labrador-Ungava: Vegetational History and Climatic Change

Historical Aspects of the Northern Canadian Treeline

Past and present vegetation of the Isle of Skye : a Palaeoecological study

Holocene palaeo-wind evidence from palynology in Baffin Island

Environmental change and cultural change in the eastern canadian arctic during the last 5000 years