Response of a forest ecotone to ionizing radiation. Final report
Compositional and structural characteristics of three forest types, including aspen dominated, maple-birch dominated, and an intervening ecotone (midecotone), were studied before and after irradiation in northern Wisconsin. The cumulative exposure resulting from 3300 hours of point-source gamma irradiation was estimated to be 55 kR at 10 m. In all three areas, the density of seedlings at 10 m was greatly reduced within a year following the 1972 radiation event. In the maple-birch area, seedlings were virtually absent at 10 m until 1982 and 1983 when their numbers were comparable to preirradiation levels, and 1984 when they were more than twice as abundant. In the aspen and midecotone areas, 1984 seedling densities at 10 m were only 42 and 17%, respectively, of the preirradiation levels. Similar but less pronounced seedling trends were observed at 20 m but not beyond that distance. Woody plants of tree stature were eliminated at 10 m in all three areas within two years of irradiation but by 1979 (maple-birch area) and 1982 (midecotone area) this size class was once again represented. By 1984 only the aspen area lacked plants at least 2.5 cm in dbh. In 1984, 12 years subsequent to irradiation, total leaf litter production was 109 and 97% of 1971 preirradiation levels at 10 m in aspen and midecotone areas, respectively. But at 10 m in the maple-birch area, it was only 58% of the preirradiation level.
- Research Organization:
- Michigan State Univ., East Lansing (USA); Savannah River Ecology Lab., Aiken, SC (USA)
- DOE Contract Number:
- AC02-76EV02283
- OSTI ID:
- 5803374
- Report Number(s):
- DOE/EV/02283-6; ON: DE86010943
- Resource Relation:
- Other Information: Portions of this document are illegible in microfiche products
- Country of Publication:
- United States
- Language:
- English
Similar Records
Response of a forest ecotone to ionizing radiation. Progress report, October 15, 1981-April 14, 1983
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Related Subjects
54 ENVIRONMENTAL SCIENCES
FORESTS
BIOLOGICAL RADIATION EFFECTS
ECOLOGICAL SUCCESSION
GAMMA RADIATION
ENVIRONMENTAL EFFECTS
TREES
POPULATION DYNAMICS
CHRONIC EXPOSURE
DOSE-RESPONSE RELATIONSHIPS
EXPERIMENTAL DATA
FOREST LITTER
MORTALITY
SPECIES DIVERSITY
BIOLOGICAL EFFECTS
BIOLOGICAL MATERIALS
DATA
ELECTROMAGNETIC RADIATION
INFORMATION
IONIZING RADIATIONS
MATERIALS
NUMERICAL DATA
PLANTS
RADIATION EFFECTS
RADIATIONS
560141* - Radiation Effects on Plants- Basic Studies- (-1987)
510302 - Environment
Terrestrial- Radioactive Materials Monitoring & Transport- Terrestrial Ecosystems & Food Chains- (-1987)