Response of a forest ecotone to ionizing radiation. Progress report, October 15, 1980-October 14, 1981

Technical Report · Mon Jun 01 00:00:00 EDT 1981

OSTI ID:6200891

Murphy, P G; Sharitz, R R

The primary objectives of this study are to determine the effects of ionizing radiation on the tree species composition of the ecotone between two forest types in northern Wisconsin and to compare the postirradiation recovery of the tree flora in the ecotone with that in the bordering forest types. Relatively distinct ecotones constitute a spatially significant portion of many second-growth forest ecosystems. Belt transects concentric to the radiation source (/sup 137/Cs) are being used to measure compositional changes in the ecotone from aspen to maple-birch forest types. Information available includes population densities by size class, importance values, and diversity values. Estimates of leaf area index and leaf litter production, by species, have also been obtained. Succession in the radiation areas is presently under study. To date, redevelopment of forest vegetation at up to 20 m from the radiation source has been slowed significantly by the vigorous colonization of heliophytes. Sampling for 1980-81 is on schedule. In all three areas competition from successional ground vegetation has continued to delay re-establishment of tree seedlings under the opened canopy at 10 m. In this regard, only the aspen area has shown any signs of recovering, having experienced an influx of red maple seedlings in 1978. Even that area, however, is still less than half preirradiation levels with respect to seedling densities. As unusually high ratio of shrub leaf litter to tree leaf litter in the 10 to 20 m area reflects the displacement of canopy species by successional shrubs. As the overall impact of the radiation stress depends on the rate of forest re-establishment, observations will continue for several more years.

• Research Organization: Michigan State Univ., East Lansing (USA); Savannah River Ecology Lab., Aiken, SC (USA)
• DOE Contract Number: AS02-76EV02283
• OSTI ID: 6200891
• Report Number(s): DOE/EV/02283-2; ON: DE81025053; TRN: 81-012370
• Country of Publication: United States
• Language: English

Related Subjects

63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
CESIUM 137
BIOLOGICAL RADIATION EFFECTS
FORESTS
PLANT GROWTH
ASPENS
BIRCHES
DISTRIBUTION
LEAVES
MAPLES
REVEGETATION
SHRUBS
SOLID WASTES
TREES
WISCONSIN
ALKALI METAL ISOTOPES
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
BIOLOGICAL EFFECTS
CESIUM ISOTOPES
GREAT LAKES REGION
GROWTH
ISOTOPES
NORTH AMERICA
NUCLEI
ODD-EVEN NUCLEI
PLANTS
RADIATION EFFECTS
RADIOISOTOPES
USA
WASTES
YEARS LIVING RADIOISOTOPES
560113* - Radiation Effects on Biochemicals- In Plants- (-1987)