HR: 0800h
AN: B51A-0062    [Abstracts]
TI: Intensive Landscape Phenology
AU: * Liang, L
EM: lliang@uwm.edu
AF: Department of Geography UW-Milwaukee, P.O. Box 413, Milwaukee, WI 53211,
AU: Schwartz, M D
EM: mds@uwm.edu
AF: Department of Geography UW-Milwaukee, P.O. Box 413, Milwaukee, WI 53211,
AB: Plant phenology is typically observed for selected individuals at discrete in-situ locations, lacking representation of complex local ecological relationships. Land Surface Phenology recorded by satellite sensors integrates ecosystem information over large areas, but with less detail and accuracy. A new approach-Landscape Phenology is proposed to study plant phenology in the context of landscape ecology, by intensive sampling of an entire vegetation patch along with the relevant biological and microenvironmental factors. This ongoing research project is collecting intensive tree phenology data near the WLEF AmeriFlux tall-tower site in the northern mixed forest of Wisconsin. Two years (2006 and 2007) spring tree phenologies were observed with bi-daily temporal resolution for 216 forest trees in a 300m by 600m area using cyclic sampling design. Tree phenologies were scored with a customized protocol optimizing the eyeball observation accuracy. Ground cover phenologies were sampled with both eyeball and digital cameras in 2007. Intensive air temperature and humidity were also measured concurrently across the entire sampling area with on-site HOBOs. Additionally, LiDAR data provided high resolution topographic and tree heights information, which are integrated into the analysis. Results so far suggest that at this scale, the phenological behaviors of forest trees are rather individualistic, with no spatial autocorrelation detected. The temporal differences of leaf onset among individuals across the landscape are likely affected by biological differences of plants, rather than microclimatic variations. However, for each species, the average phenological advance rates are apparently correlated with the energy availability over the previous two days. In order to reconstruct the Landscape Phenology time series from the sample data, a simple average may be sufficient for each species, and a spatial average based on plant community distribution and high resolution satellite imagery (IKONOS/Quickbird) should be used to complete the quantification for the entire study area or selected portions of it. Landscape Phenology expands the scope and depth of current phenological studies. A broad application of this project is to calibrate the currently available medium-resolution satellite-based phenological indices for more accurate monitoring of global climatic change impact on terrestrial ecosystem functionalities.
DE: 0426 Biosphere/atmosphere interactions (0315)
DE: 0480 Remote sensing
DE: 1851 Plant ecology (0476)
DE: 4815 Ecosystems, structure, dynamics, and modeling (0439)
SC: Biogeosciences [B]
MN: 2007 Fall Meeting