Chemical, and Biological Effects of Crude Oil Spills Years on a Black Spruce Forest, Interior Alaska
ABSTRACT. The effects of two large experimental crude oil spills conducted in the winter and summer of 1976 in a permafrost-underlain black spruce forest of interior Alaska were assessed 15 years after the spills. Effects on permafrost, as determined from measurements of active layer thaw depths and...
| Main Authors: | , , , |
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| Other Authors: | |
| Format: | Text |
| Language: | English |
| Published: |
1993
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| Online Access: | http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.487.8422 http://pubs.aina.ucalgary.ca/arctic/Arctic47-2-164.pdf |
| Summary: | ABSTRACT. The effects of two large experimental crude oil spills conducted in the winter and summer of 1976 in a permafrost-underlain black spruce forest of interior Alaska were assessed 15 years after the spills. Effects on permafrost, as determined from measurements of active layer thaw depths and of the total amount of ground subsidence, were far more pronounced on the winter spi11 due to a larger surface-oiled area. The winter spi11 also had a more drastic effect on the vegetation. Where the black, asphalt-like surface oil was present, black spruce mortality was 100 % and there was very little live plant cover except for Cotton grass tussocks. Changes in oil chemistry varied with depth; surface samples had signs of microbiological degradation, whereas some subsurface samples taken just above the permafrost had no evidence of degradation and still contained volatile fractions. Key words: crude oil, spill, terrestrial, taiga, permafrost, black spruce forest, interior Alaska RÉSUMÉ. Quinze ans aprks avoir effectut deux grands dtversements exphimentaux de pttrole brut durant l’hiver et 1’Btb de 1976 dans une foret d’tpinettes noires reposant sur le pergtlisol de I’inttrieur de l’Alaska, on en a Bvalub les rbpercussions. Celles sur le pergdlisol, dttermintes d’aprbs les mesures de la profondeur de fonte du mollisol et de la subsidence totale du sol, Btaient beaucoup plus prononckes pour le dtversement ayant eu lieu en hiver, en raison de la plus grande superficie couverte de pktrole. Ce dtversement avait aussi eu des rtpercussions plus radicales sur la vtgttation. LB oh le pktrole de surface ressemblant B de l’asphalte &ait prdsent, le taux de mortalitd de I’kpinette noire &ait de 100 p. cent et le couvert vtgttal vivant ktait rare, m i s B part des buttes de linaigrette de Scheuchzer. Les changements dans la composition chimique du pdtrole variaient avec la profondeur; les dchantillons de surface montraient des signes de dtgradation |
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