Behavior of Cd, Mn, and Pb in forest-canopy throughfall

Conference · Fri Jan 01 04:00:00 EST 1988

OSTI ID:6841495

Lindberg, S E

The concentrations and fluxes of Cd, Mn, and Pb were measured in wet-only precipitation events sampled above and below forest canopies at the Walker Branch Watershed in the southeastern United States over a 2-year period. The interaction of rain with the canopy resulted in a measurable increase in the concentrations of all metals in throughfall, most significantly in the concentration of Mn (which increased by a factor of 160 compared to a factor of 3 to 4 for Cd and Pb). The factors influencing the behavior of these metals in throughfall included their concentrations in the incoming rain, the amount of foliage on the trees, the rain amount, and the storm intensity. The amount of metal removed from the canopy during rain increased significantly as the residence time of the rain on the foliage surface increased. Canopy mass balance calculations using independent estimates of dry deposition suggest that the primary source of Pb in throughfall below these canopies is atmospheric deposition, while the major source of Mn is leaching from internal tree tissues. Both sources are important for Cd. 32 refs., 10 figs., 4 tabs.

• Research Organization: Oak Ridge National Lab., TN (USA)
• DOE Contract Number: AC05-84OR21400
• OSTI ID: 6841495
• Report Number(s): CONF-880970-1; ON: DE88011020
• Country of Publication: United States
• Language: English

Related Subjects

500200* -- Environment
Atmospheric-- Chemicals Monitoring & Transport-- (-1989)
54 ENVIRONMENTAL SCIENCES
ACID RAIN
AIR-BIOSPHERE INTERACTIONS
ATMOSPHERIC PRECIPITATIONS
CADMIUM
CANOPIES
DISTRIBUTION
ELEMENTS
ENVIRONMENTAL EFFECTS
ENVIRONMENTAL TRANSPORT
FORESTS
INFORMATION NEEDS
INTERACTIONS
LEAD
LEAVES
MANGANESE
MASS TRANSFER
METALS
NAPAP
NATIONAL ORGANIZATIONS
OAK RIDGE RESERVATION
RAIN
RETENTION
SPATIAL DISTRIBUTION
TIME DEPENDENCE
TRANSITION ELEMENTS
US DOE
US ERDA
US ORGANIZATIONS
VOLUME