Carbon and nitrogen in the ...

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Carbon and Nitrogen in the Terrestrial
Environment
Carbon and Nitrogen
in the Terrestrial
Environment
R. Nieder and D.K. Benbi
R. Nieder
D.K. Benbi
Institut für Geoökologie
Department of Soils
Technische Universität Braunschweig
Punjab Agricultural University
Braunschweig
Ludhiana
Germany
India
ISBN 978-1-4020-8432-4
e-ISBN 978-1-4020-8433-1
Library of Congress Control Number: 2008927744
© 2008 Springer Science + Business Media B.V.
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Preface
One of the biggest reality before us today is the global climate change resulting
from the emission of greenhouse gases (GHGs). There has been an unprecedented
increase in the concentration of carbon and nitrogen containing GHGs in the atmos-
phere, resulting primarily due to intervention in terrestrial carbon (C) and nitrogen
(N) cycles by human beings. Two anthropogenic activities viz. food production and
energy production are mainly responsible for perturbation of C and N cycles.
If drastic remedial measures are not taken, the concentration of GHGs is projected
to increase further. According to Kyoto Protocol, industrial countries are to reduce
their emissions of GHGs by an average of 5% below their 1990 emissions by the
first commitment period, 2008–2012. Therefore, there is an increased focus to look
for options for mitigating the emission of GHGs. Terrestrial C sequestration
through biotic processes is being viewed as a plausible option of reducing the rates
of CO
2
emissions while abiotic processes of carbon storage and alternatives to fossil
fuel take effect.
The importance of the C and N transfer from soils to the atmosphere lies not only
in global warming, but also on soil quality and the potential of soils to perform
ecosystems functions some of which are related to the three major international con-
ventions on Biodiversity, Desertification, and Climate Change. Soil organic matter
(SOM) being the main reservoir of C of the continental biosphere, can either be a
source of CO
2
during mineralization or a sink if C sequestration is favored. During
the last two centuries, soils have lost a considerable amount of C due to land use
changes and expansion of agriculture. These losses from soils are clearly of concern
in relation to future productivity and environment. To ensure sustainable management
of land, it is imperative that organic matter in the soil is maintained and sustained at
satisfactory levels through improved management practices.
As pool changes of C and N are often very slow, and the full impact of a change
in land management practice may take decades to become apparent, long-term
perspectives are required. The cycling of C and N is intimately linked and the two
cannot be studied effectively separately. This necessitates a thorough understanding
of the interdependent and dynamic pools and processes of C and N in the terrestrial
ecosystem. Models could help in formulating or assessing land use strategies,
generating scenarios for optimizing SOM conditions and minimizing emissions and
upscaling research findings at different levels of spatial and temporal aggregation.
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