HR: 12:00h
AN: GC52A-11    [Abstracts]
TI: Land surface albedo in forestry management and land use change - possible offsets or augmentation to the radiative impact of carbon sequestration
AU: * McMillan, A M
EM: mcmillaa@uci.edu
AF: University of California, Irvine, Department of Earth System Science, Irvine, CA 92697-3100, United States
AU: Doughty, C E
EM: cdoughty@uci.edu
AF: University of California, Irvine, Department of Earth System Science, Irvine, CA 92697-3100, United States
AU: Goulden, M L
EM: mgoulden@uci.edu
AF: University of California, Irvine, Department of Earth System Science, Irvine, CA 92697-3100, United States
AB: Slowing or reversal of regional warming trends may be achieved by manipulation of land surface albedo. This approach is most feasible in agricultural and forestry areas, where the land surface is already under significant human influence. Afforestation, reforestation and deforestation are activities that not only affect carbon exchange but also affect energy exchange. In areas undergoing land use change to forestry, the "cooling" associated with increased carbon sequestration may be offset, or even canceled, by a "warming" associated with a darker land surface. In existing managed forests, the decision to replace darker conifer tree species with brighter broadleaf species can also potentially reduce surface albedo. We combined satellite and in situ observations of albedo with eddy covariance and inventory measurements of carbon exchange to assess the trade-off between a net warming due the darkening associated with dark forests and the net cooling associated with increased carbon sequestration. We also examined the net radiative effect of converting existing conifer plantations to broadleaf plantations. Initial results from a coupled climate-land surface model indicated that significant surface cooling occurred when darker evergreen forests were replaced by brighter broadleaf forests. Albedo manipulation may cause decreases in latent heat flux rather than decreases in sensible heat fluxes, with possible consequences for cloud formation.
DE: 0315 Biosphere/atmosphere interactions (0426, 1610)
DE: 0428 Carbon cycling (4806)
DE: 0480 Remote sensing
DE: 1631 Land/atmosphere interactions (1218, 1843, 3322)
DE: 1632 Land cover change
SC: Global Environmental Change [GC]
MN: 2007 Fall Meeting