Document: ELI-3-27-1

Ecological contributions to global change research .

HOLLAND, E.A.* ^1,2

MPI fuer Biogeochemie, Jena, Germany 07745 ¹
NCAR, POB 3000, Boulder, CO 80307 USA ²

Abstract:
With the leadership of the ecological community, we now understand that global change extends well beyond climate and encompasses fundamental changes to earth's biogeochemical cycles. Our understanding of these cycles and the links among them has expanded dramatically since Dave Keeling first began his measurements of atmospheric carbon dioxide in 1957, and since the ESA meeting a decade ago, when Inez Fung explained that the calculated residual carbon (the so-called 'missing sink') was likely to be found in the terrestrial biosphere of the northern hemisphere. We now know that the size and spatial distribution of the terrestrial carbon sink varies from year to year and is the result of interacting processes: N deposition, carbon dioxide fertilization, ozone pollution, and inter-annual climate variability; It is also sensitive to land use and land use changes. The impact of widespread N deposition is determined by land use, acid and base deposition, and ozone pollution, the combination of which have the potential to fundamentally change biogeochemical cycles and to limit carbon sequestration. Intensification and expansion of agriculture and fossil fuel use in Asia and the tropics are producing further dramatic changes to the Earth system. In the decades to come, we as ecologists will be challenged to determine how we maintain sustainable ecosystems in the face of expanding urbanization and the multiple compounding stresses that accompany it.

Keywords: carbon cycle, nitrogen cycle, atmospheric chemistry, global change

This abstract is being presented at: 9:00 AM in session:
Symposium # 8: Ten Years of the Sustainable Biosphere Initiative.