Carbon and Nitrogen Accumulation in a Savanna Landscape:
Field and Modeling Perspectives
, Thomas W. BOUTTON2
and Chad R. MCMURTRY1
School of Renewable Natural Resources, The University of Arizona,
Tucson, AZ 85721-0043, U.S.A.
Department of Rangeland Ecology & Mangement, Texas A & M University,
College Station, TX 77843-2126, U.S.A.
Abstract. Indirect assessments suggest that increases in woody plants in the
world's drylands during the past 100 y may have had a significant impact on
carbon sequestration. However, these assessments are characterized by a high
degree of uncertainty. A linked succession-biogeochemistry model has recently
been used to estimate changes in ecosystem carbon and nitrogen pools
accompanying the proliferation of woody plants over the past 150 y at a
southern Great Plains site in North America. Here, we evaluate the validity of
that modeling approach using historical aerial photos (1950, 1976, and 1990)