THE PALAEOHISTORY OF THE GREY ALDER ( ALNUS INCANA (L.) MOENCH.) AND BLACK ALDER ( A. GLUTINOSA (L.) GAERTN.) IN FENNOSCANDIA
SUMMARY The available 14 C‐dated and broadly context‐dated pollen and macrofossil data for the immigration and spread of the two species of alder within Fennoscandia and certain adjacent countries is presented. The phases of immigration and regional spread take place during certain periods of time (...
| Published in: | New Phytologist |
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| Main Author: | |
| Format: | Article in Journal/Newspaper |
| Language: | English |
| Published: |
Wiley
1974
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| Online Access: | http://dx.doi.org/10.1111/j.1469-8137.1974.tb02131.x https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1111%2Fj.1469-8137.1974.tb02131.x https://nph.onlinelibrary.wiley.com/doi/pdf/10.1111/j.1469-8137.1974.tb02131.x |
| Summary: | SUMMARY The available 14 C‐dated and broadly context‐dated pollen and macrofossil data for the immigration and spread of the two species of alder within Fennoscandia and certain adjacent countries is presented. The phases of immigration and regional spread take place during certain periods of time (e.g. 6500, 6000, 5000 and 4500 14 C years B.C.) and over certain restricted geographical areas. The latter yield a picture of climatic regionalism, with limits akin to that of the present day. Along its present, diffuse northern boundary Alnus glutinosa , on the evidence from Tran‐delag in Norway, appears to have become established only in a late phase of the broad climatic optimum, after 2000 B.C., and to have lost ground again after c. 700 B.C., though the course of later events is confused by human activity. A tabulation of the postulated ecological requirements of the two species of alder at various stages of their life histories is attempted. Details of the sites mapped are included in an appendix. |
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