Join for Free!
112430 members
table of contents table of contents

The projected climatic changes in the Arctic, particularly the projected decrease in …

Biology Articles » Biodiversity » Human impacts on the biodiversity of the Arctic » Tables

- Human impacts on the biodiversity of the Arctic

Table 10.4. Percentage distribution of age classes of coniferous forests in countries with arctic territory[6]. The index, I, is the ratio of the percentage of trees over 80 years old to the percentage less than 40 years old, and so indicates the naturalness of the forests.

0–40 yr 41–80 yr 81–100 yr >100 yr Index (I)
Murmansk (Russia) 31 19 5 45 1.61
Norway 33 21 13 33 1.39
Finland 32 33 13 22 1.09
Karelia (Russia) 40 19 7 34 1.02
Sweden 52 22 10 16 0.50



Table 10.5. Extent of peatland (Data: Hallanaro and Pylvänäinen, 2002)[21]. The index, P, is the proportion of the total peatland not drained (the figure in the second column minus the sum of the figures in the third and fourth columns) to the total peatland area. Because different countries use different definitions for peatland, the data are not comparable between countries, although the values of P are comparable between countries.
Country Total area of peatland (million hectares) Area drained for forestry Area drained for agriculture P
Iceland 1.00 Small 0.13 0.86
Karelia (Russia) 5.40 0.64 0.09 0.86
Norway 3.00 0.41 0.19 0.80
Sweden 10.70 1.50 0.60 0.80
Finland 10.40 5.70 0.60 0.39





Table 10.6. Major groups of pollutants in freshwater ecosystems and species in the Canadian Arctic (Anon, 2001a)[33].
  • mercury is the most important metal in arctic lakes from a toxicological viewpoint
  • observations show, and models confirm, that about a third of the total mercury that enters a high-arctic lake is retained in the sediments, around half is exported downstream, and the rest is lost to the atmosphere
  • mercury concentrations consistently exceed guideline limits in fish for subsistence consumption or commercial sale
  • mercury concentrations in fish tend to increase with increasing fish size
  • subarctic lakes first show PCB concentrations in the (±10 years)
  • high-arctic lakes show no significant PCB concentrations until the 1960s (±10 years)
  • PCB concentrations in fish tend to increase with increasing fish size
  • toxaphene is the major organochlorine contaminant in all fish analyzed
  • highest toxaphene levels are generally seen in fish that are strictly piscivorous
  • toxaphene concentrations in fish tend to increase with increasing fish size
Chlorinated dioxins and furans
  • chlorinated dioxins and furans are found in fishes from some Yukon lakes
  • levels of chlorinated dioxins and furans in fish throughout the Canadian Arctic are low compared to levels in fish obtained either near bleached Kraft mills or in the lower Great Lakes



rating: 3.92 from 12 votes | updated on: 9 Oct 2008 | views: 16847 |

Rate article: