Project Funding: 2011 - 2014

NRA: 2010 NASA: Carbon Cycle Science   

Funded by NASA

Abstract:
We propose to investigate the effects of disturbance and seasonality on carbon flux upscaling efforts in northern temperate forests, which is directly relevant to research theme A3.1 (Interactions between land management and land change and the carbon cycle) and theme A3.5 (Synthesis and integrative research). Our goal is to improve diagnostic CO2 flux estimates for northern temperate forests using spatial and temporal variation of historical disturbance and seasonality - two key unknowns in regional scale terrestrial C exchange. This work builds on current research funding ("Probabilistic carbon flux upscaling across a northern forest ecoregion", Davis, Bolstad, Desai, Heinsch, Running and Keller, investigators) in which eddy flux tower data was integrated with sub-pixel scale forest complexity using a light use efficiency model in a Bayesian/Markov Chain-Monte Carlo framework to reduce uncertainty in MODIS NPP outputs. This effort has demonstrated considerable progress towards uncertainty evaluation using model-data fusion. Yet, persistent and unresolved uncertainty in carbon flux estimates remain that we expect reflect regional variation in C flux with stand age and season. Therefore, in this project we propose to answer 3 questions (1) Does incorporation of variation in physiological model parameters improve seasonal and interannual CO2 flux hindcasts from eddy flux towers? (2) Does incorporation of stand-replacement and partial disturbance processes from remotely sensed observations improve yearly to decadal CO2 flux hindcasts from eddy flux towers? And (3) To what degree does model-data integration aid regional and landscape decision-making for forest C storage management? We hypothesize that improvements in CO2 flux hindcasts will occur after accounting for seasonal and interannual variation of key physiological parameters, such as maximum photosynthesis and quantum yield and that residual errors in CO2 flux tower assimilations can be partially accounted for by regional patterns in disturbance observable with NASA remote-sensing products. We expect that model-data integration can be used to prioritize geographic location and timing of active forest C management activities in the face of climate change. We will explicitly compare NASA remote-sensing platforms (Landsat and MODIS) and disturbance detection algorithms (VCT and LandTrendr). Our data-fusion approach will help diagnose and attribute variability in landscape C flux due to input data (disturbance and landcover) as well as parameterization of a light response model that is sensitive to seasonal variation in photosynthesis (driven by variation in EVI and climate). Finally, we will compare our results to the MsTMIP site and regional scale model intercomparison effort and use MsTMIP data to drive our model where appropriate (Collaborators Huntzinger, Michalak). Our uncertainty analysis will aid the MsTMIP synthesis effort. Data will be archived at ORNL DAAC (Collaborator Robert Cook). Ultimately, our work will contribute to the "end-to-end" mission of the NRC (2009) report by directly contributing to a priority landscape identified by the USFS for climate change management climate change.

Publications:

Baldwin, D., Manfreda, S., Keller, K., Smithwick, E. A. H. 2017. Predicting root zone soil moisture with soil properties and satellite near-surface moisture data across the conterminous United States. Journal of Hydrology. 546, 393-404. DOI: 10.1016/j.jhydrol.2017.01.020

2015 NASA Carbon Cycle & Ecosystems Joint Science Workshop Poster(s)

• G-LiHT: Multi-Sensor Airborne Image Data from Denali to the Yucatan   --   (Bruce Cook, Lawrence A Corp, Douglas Morton, Joel McCorkel)   [abstract]   [poster]

2013 NASA Terrestrial Ecology Science Team Meeting Poster(s)

• Incorporating disturbance and associated uncertainty into diagnostic terrestrial carbon flux upscaling   --   (Erica A.H. Smithwick, Kusum J. Naithani, Kenneth James Davis, Robert E Kennedy, Bianchetti Raechel, Parker Linda, Baldwin C. Douglas, Keller Klaus, Jeffrey Masek)   [abstract]

2011 NASA Carbon Cycle & Ecosystems Joint Science Workshop Poster(s)

• Influence of Disturbance and Seasonality on Regional Carbon Flux Upscaling   --   (Erica A.H. Smithwick, Kusum Naithani, Kenneth J. Davis, Klaus Keller, Robert E Kennedy, Jeffrey Masek)   [abstract]

More details may be found in the following project profile(s):

• NASA Terrestrial Ecology (TE) Project Profile
• North American Carbon Program (NACP) Project Profile