نتایج جستجو برای: atmospheric carbon fixation rate

تعداد نتایج: 1322831  

1996
PEDRO MOURA-COSTA

Carbon sequestration through forestry has the potential to play a significant role in ameliorating global environmental problems such as atmospheric accumulation of GHG's and climate change. This chapter provides an overview of various aspects related to carbon sequestration through forestry. It describes the main concepts of carbon fixation; the trends in global environmental policy are discus...

Journal: :Global and planetary change 1992
J C Walker J F Kasting

We develop a numerical simulation of the global biogeochemical cycles of carbon that works over time scales extending from years to millions of years. The ocean is represented by warm and cold shallow water reservoirs, a thermocline reservoir, and deep Atlantic, Indian, and Pacific reservoirs. The atmosphere is characterized by a single carbon reservoir and the global biota by a single biomas...

2018
Peter L. Cummins Babu Kannappan Jill E. Gready

The ubiquitous enzyme Ribulose 1,5-bisphosphate carboxylase-oxygenase (RuBisCO) fixes atmospheric carbon dioxide within the Calvin-Benson cycle that is utilized by most photosynthetic organisms. Despite this central role, RuBisCO's efficiency surprisingly struggles, with both a very slow turnover rate to products and also impaired substrate specificity, features that have long been an enigma as...

Journal: :Science 2005
James Heath Edward Ayres Malcolm Possell Richard D Bardgett Helaina I J Black Helen Grant Phil Ineson Gerhard Kerstiens

Forests have a key role as carbon sinks, which could potentially mitigate the continuing increase in atmospheric carbon dioxide concentration and associated climate change. We show that carbon dioxide enrichment, although causing short-term growth stimulation in a range of European tree species, also leads to an increase in soil microbial respiration and a marked decline in sequestration of roo...

2001
J. Keith Moore Scott C. Doney David M. Glover Inez Y. Fung

A global marine ecosystem mixed-layer model is used to study iron cycling and nutrient-limitation patterns in surface waters of the world ocean. The ecosystem model has a small phytoplankton size class whose growth can be limited by N, P, Fe, and/or light, a diatom class which can also be Si-limited, and a diazotroph phytoplankton class whose growth rates can be limited by P, Fe, and/or light l...

2017
Masahiro Kanno Austin L Carroll Shota Atsumi

Cyanobacteria have attracted much attention as hosts to recycle CO2 into valuable chemicals. Although cyanobacteria have been engineered to produce various compounds, production efficiencies are too low for commercialization. Here we engineer the carbon metabolism of Synechococcus elongatus PCC 7942 to improve glucose utilization, enhance CO2 fixation and increase chemical production. We introd...

2002
R. E. M. Rickaby D. P. Schrag I. Zondervan U. Riebesell

[1] Reconstructing the dissolved carbon dioxide of surface waters from the dC of organic carbon relies on accurate determination of the growth rate of phytoplankton contributing to sedimentary organic matter. We demonstrate that the Sr/Ca ratio in the coccoliths of Emiliania huxleyi is correlated with the rates of both organic carbon fixation and calcification. An investigation of biomineraliza...

2009
Aparna Krishnamurthy J. Keith Moore Natalie Mahowald Chao Luo Scott C. Doney Keith Lindsay Charles S. Zender

[1] We present results from transient sensitivity studies with the Biogeochemical Elemental Cycling (BEC) ocean model to increasing anthropogenic atmospheric inorganic nitrogen (N) and soluble iron (Fe) deposition over the industrial era. Elevated N deposition results from fossil fuel combustion and agriculture, and elevated soluble Fe deposition results from increased atmospheric processing in...

Journal: :Plant physiology 2004
John R Reinfelder Allen J Milligan François M M Morel

The role of a C(4) pathway in photosynthetic carbon fixation by marine diatoms is presently debated. Previous labeling studies have shown the transfer of photosynthetically fixed carbon through a C(4) pathway and recent genomic data provide evidence for the existence of key enzymes involved in C(4) metabolism. Nonetheless, the importance of the C(4) pathway in photosynthesis has been questioned...

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