Document: STU-3-4-4

Effects of landscape structure and heterogeneity on terrestrial feedbacks to regional climate.

CHAPINIII, F.S.* ¹, S.CHAMBERS ¹, J.BERINGER ¹, D.DISSING ¹, D.VERBYLA ¹, A.LYNCH ² and A.D.MCGUIRE ³

University of Alaska, Fairbanks, AK 99775 USA ¹
University of Alaska, Fairbanks, AK 99775 USA ²
University of Colorado, Boulder, CO 80309 USA ³
U.S. Geological Survey, Alaska Cooperative Fish and Wildlife Research Unit, Fairbanks, AK 99775 USA ⁴

Abstract:
Landscape patterns of vegetation influence regional climate primarily through their effects on regional water and energy exchange. First-order vegetation effects are governed primarily by albedo, which determines the amount of energy available to transfer to the atmosphere. Energy partitioning between latent, sensible, and ground heat fluxes responds sufficiently strongly to vegetation that vegetation differences in partitioning also significantly affect regional climate. The vegetation properties that affect climate are sensitive to landscape and ecosystem processes. Landscape structure determines vegetation composition through its effects on seed rain and the propagation of disturbance. Soil resource supply and time since disturbance then influence stand-level exchanges with the atmosphere through effects on canopy height, stomatal conductance, and leaf area index. Warming of climate would likely alter resource supply, disturbance regime, and vegetation interactively. The resulting feedbacks to climate may act as a positive feedback to climate warming and to vegetation change in arctic, desert, and tropical ecosystems and as a negative feedback in boreal forests.

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This abstract is being presented at: 4:25 PM in session:
Symposium # 10: Integrating Ecosystem and Landscape Ecology: Causes and Consequences of Spatial Heterogeneity in Ecosystem Processes.