Polar environments - Fundamentals of the Physical Environment - page 743

FURTHER READING
French, H. M., and Slaymaker, O., eds (1993) Canada's Cold Environments , Montreal: McGill-
Queen's University Press. A collection of studies of Canada's alpine and arctic ecozones and
their physical and biological features. It deals comprehensively with impacts on northern
development, and is especially strong on the role of climate and its impact on the lives of
Canadians.
Hall, C. M., and Johnston, M. E., eds (1995) Polar Tourism in Arctic and Antarctic Regions ,
London: Wiley. Up-to-date discussions on the issues raised by this growing activity.
Hansom, J. D., and Gordon, J. E. (1998) Antarctic Environments and Resources: a geographical
perspective , London: Longman. A most detailed and scholarly account of all geographical
aspects of the continent.
KEY POINTS
1 Polar ecosystems have low productivity and ecological diversities. Animal species have
to hibernate or out-migrate during the harsh winters, and all biological activity is
concentrated in a brief summer period. Soil processes and ecological mechanisms act
at a low intensity.
2 The geomorphology and soils are dominated by the presence of permafrost in the
subsoil. As permafrost is sensitive to any change in the surface vegetation it is easily
disturbed by human activity. Any interference with the insulating properties of soil
and vegetation, and any addition of heat to the surface (perhaps through industry and
building), will inevitably cause permafrost melting and ground subsidence.
3 Polar ecosystems have a low resistance to outside impacts, and low resilience means
that recovery is a long-term process. Polar ecosystems are also very variable in time
and space. Soil and vegetation conditions change quite rapidly over short distances,
under the influence of the catena relations of soils, plants, permafrost and slope. Time
variability causes big contrasts in weather and biological activities from one year to
the next. It is another factor which makes polar environments so fragile and so
unpredictable.