Now showing items 31-40 of 41
Fine-root biomass and fluxes of soil carbon in young stands of paper birch and trembling aspen as affected by elevated atmospheric CO 2 and tropospheric O 3
(Springer-Verlag, 2001-07)
Rising atmospheric CO 2 may stimulate future forest productivity, possibly increasing carbon storage in terrestrial ecosystems, but how tropospheric ozone will modify this response is unknown. Because of the importance of ...
Carbon and nitrogen cycling during old-field succession: Constraints on plant and microbial biomass
(Kluwer Academic Publishers; Springer Science+Business Media, 1990-11)
Soil C and N dynamics were studied in a sequence of old fields of increasing age to determine how these biogeochemical cycles change during secondary succession. In addition, three different late-successional forests were ...
Nitrogen mineralization, nitrification and denitrification in upland and wetland ecosystems
(Springer-Verlag, 1991-10)
Nitrogen mineralization, nitrification, denitrification, and microbial biomass were evaluated in four representative ecosystems in east-central Minnesota. The study ecosystems included: old field, swamp forest, savanna, ...
Determination of aerosol strong acidity losses due to interactions of collected particles: Results from laboratory and field studies
(Elsevier, 1992-04)
Existing methods of measuring atmospheric aerosol strong acidity adequately prevent neutralization of fine-particle acidity by removing course alkaline particles and gaseous ammonia from air samples. However, these techniques ...
Cation-diffusion-induced characteristic beam damage in transmission electron microscope images of micas
(Elsevier, 1986)
Transmission and analytical electron microscopy have been used to characterize the numerous lenticular fissures which were observed in electron micrographs of paragonite. Observations with a very weak electron beam revealed ...
Extractable organic compounds in midwest rain and snow
(Elsevier, 1982)
A portion of the organic compounds in subaqueous sediments originates from airborne materials transported from distant sources. We have analyzed by GC and GC-MS the organic compounds extractable with dichloromethane in ...
Historical trends of airborne trace metals in Detroit from 1971 to 1992
(Kluwer Academic Publishers; Springer Science+Business Media, 1996-03)
Ambient concentrations of particulate Fe, Zn, Ph, Ni, Cr, Cd and Hg were measured at nine sites located in the metropolitan area of Detroit from 1971 to 1992. The ambient concentrations of all the trace metals were found ...
Combined effects of atmospheric CO 2 and N availability on the belowground carbon and nitrogen dynamics of aspen mesocosms
(Springer-Verlag; Springer-Verlag Berlin Heidelberg, 2000-08)
It is uncertain whether elevated atmospheric CO 2 will increase C storage in terrestrial ecosystems without concomitant increases in plant access to N. Elevated CO 2 may alter microbial activities that regulate soil N ...
The flux of anthropogenic trace metals into the arctic from the mid-latitudes in 1979/80
(Elsevier, 1994-05)
The flux of trace metals into the Arctic atmosphere between 0 and 3.5 km altitude for the period July 1979-June 1980 was determined using a chemical transport modeling approach used previously for sulfur. The total annual ...
Soil respiration in northern forests exposed to elevated atmospheric carbon dioxide and ozone
(Springer-Verlag, 2006-02-18)
The aspen free-air CO 2 and O 3 enrichment (FACTS II–FACE) study in Rhinelander, Wisconsin, USA, is designed to understand the mechanisms by which young northern deciduous forest ecosystems respond to elevated atmospheric ...