Now showing items 21-30 of 64
Carbon dioxide on the early earth
(Kluwer Academic Publishers; D. Reidel Publishing Company ; Springer Science+Business Media, 1985-06)
This paper uses arguments of geochemical mass balance to arrive at an estimate of the partial pressure of carbon dioxide in the terrestrial atmosphere very early in earth history. It appears that this partial pressure could ...
Belowground competition and the response of developing forest communities to atmospheric CO 2 and O 3
(Blackwell Publishing Ltd, 2007-10)
As human activity continues to increase CO 2 and O 3 , broad expanses of north temperate forests will be simultaneously exposed to elevated concentrations of these trace gases. Although both CO 2 and O 3 are potent modifiers ...
Changes in Sr/Ca, Ba/Ca and 87Sr/86Sr ratios between trophic levels in two forest ecosystems in the northeastern U.S.A.
(Kluwer Academic Publishers; Springer Science+Business Media, 2000-04)
The variability and biologicalfractionation of Sr/Ca, Ba/Ca and 87 Sr/ 86 Srratios were studied in a soil–plant–invertebrate–bird food chain in two forested ecosystems withcontrasting calcium availability in the ...
Dissolution of wollastonite during the experimental manipulation of Hubbard Brook Watershed 1
(Kluwer Academic Publishers; Springer Science+Business Media, 2004-02)
Powdered and pelletized wollastonite (CaSiO 3 ) was applied to an 11.8 ha forested watershed at the Hubbard Brook Experimental Forest (HBEF) in northern New Hampshire, U.S.A. during October of 1999. The dissolution of ...
Simulated chronic NO 3 − deposition reduces soil respiration in northern hardwood forests
(Blackwell Science Ltd, 2004-07)
Chronic N additions to forest ecosystems can enhance soil N availability, potentially leading to reduced C allocation to root systems. This in turn could decrease soil CO 2 efflux. We measured soil respiration during the ...
Dynamic Modeling of In-Use Cement Stocks in the United States
(Blackwell Publishing Inc, 2008-08)
A dynamic substance-flow model is developed to characterize the stocks and flows of cement utilized during the 20th century in the United States, using the generic cement life cycle as a systems boundary. The motivation ...
Determining the sources of calcium for migratory songbirds using stable strontium isotopes
(Springer-Verlag, 2001-02)
We investigated natural variations in the stable isotopic composition of strontium (a surrogate for calcium) in the bones of a single species of breeding migratory songbird, as well as in their eggshells, egg contents, and ...
Relationships between plant nitrogen economy and life history in three deciduous-forest herbs
(Blackwell Science Ltd, 2001-06)