TY - JOUR T1 - Using Lidar and Radar measurements to constrain predictions of forest ecosystem structure and function JF - Ecol Appl Y1 - 2011 A1 - Antonarakis, A. S. A1 - Saatchi, S. S. A1 - Chazdon, R. L. A1 - Moorcroft, P. R. KW - *Ecosystem KW - *Radar KW - biomass KW - canopy height KW - Carbon KW - Carbon/metabolism KW - costa rica KW - costa-rica KW - ecosystem demography KW - ecosystem modeling KW - forest composition KW - forest structure KW - la selva biological station KW - lidar KW - model KW - nasa's desdyni mission KW - net primary production, npp KW - old-growth KW - radar KW - rain-forests KW - reducing modeling error KW - Remote Sensing Technology/*methods KW - sar interferometry KW - Time Factors KW - Trees/*physiology KW - tropical trees KW - vegetation KW - wood density AB -

Insights into vegetation and aboveground biomass dynamics within terrestrial ecosystems have come almost exclusively from ground-based forest inventories that are limited in their spatial extent. Lidar and synthetic-aperture Radar are promising remote-sensing-based techniques for obtaining comprehensive measurements of forest structure at regional to global scales. In this study we investigate how Lidar-derived forest heights and Radar-derived aboveground biomass can be used to constrain the dynamics of the ED2 terrestrial biosphere model. Four-year simulations initialized with Lidar and Radar structure variables were compared against simulations initialized from forest-inventory data and output from a long-term potential-vegtation simulation. Both height and biomass initializations from Lidar and Radar measurements significantly improved the representation of forest structure within the model, eliminating the bias of too many large trees that arose in the potential-vegtation-initialized simulation. The Lidar and Radar initializations decreased the proportion of larger trees estimated by the potential vegetation by approximately 20-30%, matching the forest inventory. This resulted in improved predictions of ecosystem-scale carbon fluxes and structural dynamics compared to predictions from the potential-vegtation simulation. The Radar initialization produced biomass values that were 75% closer to the forest inventory, with Lidar initializations producing canopy height values closest to the forest inventory. Net primary production values for the Radar and Lidar initializations were around 6-8% closer to the forest inventory. Correcting the Lidar and Radar initializations for forest composition resulted in improved biomass and basal-area dynamics as well as leaf-area index. Correcting the Lidar and Radar initializations for forest composition and fine-scale structure by combining the remote-sensing measurements with ground-based inventory data further improved predictions, suggesting that further improvements of structural and carbon-flux metrics will also depend on obtaining reliable estimates of forest composition and accurate representation of the fine-scale vertical and horizontal structure of plant canopies.

VL - 21 SN - 1051-0761 (Print)1051-0761 (Linking) N1 -

Antonarakis, Alexander SSaatchi, Sassan SChazdon, Robin LMoorcroft, Paul RengResearch Support, U.S. Gov't, Non-P.H.S.2011/07/22 06:00Ecol Appl. 2011 Jun;21(4):1120-37.

JO - Ecological applications : a publication of the Ecological Society of America ER -