Global Vegetation Structure Dynamics from NASA’s DESDynI Mission

1. Global Vegetation Structure Dynamics from NASA’s DESDynI Mission Ralph Dubayah University of Maryland

2. How are the Earth's carbon cycle and ecosystems changing, and what are the consequences for the Earth's carbon budget, ecosystem sustainability, and biodiversity?

3. DESDynI • Deformation, Ecosystem Structure, and Dynamicsof Ice • Recommended by National Research Council Decadal Survey to measure changes in land, ice and vegetation structure • Lidar and L-band Interferometric SAR • Anticipated Launch around 2015 • Pre-Phase A Planning Stages

4. Outline • DESDynI Background • Science and Measurement Objectives • Science Rationale • Mission Overview • Synthetic Aperture Radar • Multibeam Lidar • Measurement Approach • Lidar/radar and Fusion • Ecosystem Modeling • Current Status • Mission Definition Activities • Science Studies

5. DESDynI Science Study Group • 3 Disciplines and Science Co-Chairs • Solid Earth: Brad Hager, MIT • Cryosphere: Ian Joachin, University of Washington • Ecosystems – Ralph Dubayah, University of Maryland • Kathleen Bergen, University of Michigan • Richard Houghton, Woods Hole Research Center • Josef Kellndorfer, Woods Hole Research Center • Jon Ranson, NASA GSFC • Sassan Saatchi, NASA JPL • Hank Shugart, University of Virginia • Study Group works with NASA’s Vegetation Structure Working Group • NASA Terrestrial Ecology Program, Diane Wickland • Develop Science Definition and Requirements • Perform Science Research Activities

6. DESDynI Scientific Focus Areas DESDynI addresses a broad-based range of the science questions Additional Science Benefits Key Challenges 6

7. Science Objectives CHARACTERIZE THE EFFECTS OF CHANGING CLIMATE AND LAND USE ON TERRESTRIAL CARBON CYCLE, ATMOSPHERIC CO2, AND SPECIES HABITATS Characterize global distribution of aboveground vegetation biomass Quantify changes in terrestrial biomass resulting from disturbance and recovery Characterize habitat structure for biodiversity assessments

8. Global Biomass and Carbon • Accurate estimate of forest biomass critical • Role of forests in global carbon cycle and relation to atmospheric CO2 requires knowledge of stocks, disturbance and recovery • Potential pool when burned or cleared • Important habitat characteristic • Biomass dynamics key • Changes in structure, use and management of forests produces sources and sinks of CO2 • Requires reliable estimates of biomass • Requires quantification of deforestation, disturbance and regrowth • Disturbance and recovery affects habitat structure and biodiversity

9. Global Carbon Budget

10. DESDynI Driving Science Questions: Biodiversity • What is the present distribution and condition of Earth habitat and biodiversity? • How are land-cover change and climate change influencing their distribution and sustainability? • How can we predict future distributions and sustainability of Earth habitat and biodiversity?

11. Vegetation Type Upland conifer Lowland conifer Northern hardwoods Aspen/lowland deciduous Grassland Agriculture Wetlands Open water Urban/barren Vegetation 3D Structure and Biomass Key Landscape Structure: the spatial heterogeneity of an area composed of interacting habitat patches Vertical Structure & Biomass: the bottom to top configuration or complexity and amount of above-ground vegetation Vegetation 3D Structure & Biomass: for Biodiversity and Habitat High: 30 kg/m2 Biomass Low: 0 kg/m2 Low: 0 kg/m2

12. DESDynI: Habitat Rationale - Example • Pine Warbler Habitat: • Closed canopy forest • Uneven or broken canopies • Trees older than 30 years • Overstory taller than 30 ft • Well-developed underlayer (understory) • Large patch sizes (non-fragmented • Upland pine species • DESDynI Variables: • Canopy cover • Biomass (age-height-density) • Height • Canopy vertical profile • Patch size and shape Yes No Example (right): Pine Warbler habitat in the Great Lakes Region is tall, dense (high biomass) pine, but not short sparse pine; also require large patch sizes

13. DESDynI: Biodiversity Science Rationale • Relationships with Biomass/Volume • Total breeding bird density (Miller et al.) • Relationships with Height • Forest bird species richness increased systematically with canopy (Goetz et al., 2007). Goetz et al. 2006

14. DESDynI: Biodiversity Science Rationale • Relationships with Height Vertical Profile: • Foliage height diversity Index (FHD) MacArthur & MacArthur (1961) Foliage height diversity (FHD) vs. bird species diversity (BSD) (reproduced from Wilson, 1974)

15. Science Objective 1: Biomass Characterize global distribution of aboveground vegetation biomass Desired Final Data Products Global biomass at 250 m with accuracy of 10 MgC/ha (or 20%, not to exceed 50 Mg/ha) at 5 years. Resolution increased to 100 m for low biomass areas (<100 Mg/ha) Forest canopy height and profiles, spatial and vertical structure, biomass from SAR Measurement Objectives Multi-beam lidar, polarimetric L-band SAR Instruments

16. Science Objective 2: Biomass Change Quantify changes in terrestrial biomass resulting from disturbance and recovery Desired Final Data Products Annual map of global biomass changes at 1 km resolution, 2-10 MgC/ha/yr (or 20%). Resolution increased to 0.5 km for low biomass areas (<100 Mg/ha) Measurement Objectives Same as for biomass stocks. Additionally, require 100 m tracking of deforestation, recovery over 5 year epoch. Observe biomass changes from extreme events Instruments Multi-beam lidar, polarimetric L-band SAR,

17. Science Objective 3: Habitat Structure Characterize habitat structure for biodiversity assessments Desired Final Data Products Various forest structure products with specified accuracies (includes both gridded data and ungridded transect data) Forest canopy structure including height, canopy profile, canopy cover, canopy roughness, biomass, vertical diversity Measurement Objectives Instruments Multi-beam lidar, polarimetric L-band SAR

18. Variables Required by Biodiversity & Habitat DESDynI Science Community A. Pixel-level Structural Variables, accuracies and precisions

19. Variables Required by Biodiversity & Habitat DESDynI Science Community B. Landscape-level Structural Variables, accuracies and precisions

20. Habitat Structure: Requirements

21. Measurement Approach

22. DESDynI Instruments 4. Instrument Design & Performance Multi-beam Lidar L-Band Synthetic Aperture Radar Laser Radiators Interferometric SAR Dual-Pol 3-Beams Quad-Pol 6-Beams Right or Left Point Star Tracker Lasers ~350km Flight Direction Beam Spacing 1 km

23. L-band Measurement of Structure Polarimetric Image of La Selva LHH, LHV, LVV Image Segmentation DESDynI will produce global 25 m images every 8 days

24. Forest Structure from Lidar • Tree height • Crown volume • Vertical foliage profile • Canopy cover profile • Biomass • Tree density • Basal area • LAI

25. La Selva Vertical Forest Structure

26. Cumulative Canopy Cover Canopy Height Profile Lidar Derives LAI and Canopy Profiles DESDynI will produce 50 billion canopy profiles

27. Science Activities • Algorithm Development • LIDAR/SAR Fusion • Airborne LIDAR and SAR, ICESAT • Sampling Strategies • Field Studies • Ongoing data collection and analysis at legacy West Coast, East Coast, Boreal, Tropical sites • Upcoming Activities • UAVSAR and LVIS flights in Sierra Nevada, La Selva, Hubbard Brook, Harvard Forest, Howland, Quebec • Associated field data collection • Ecosystem Modeling Studies • Modeling requirements for biomass, flux & biodiversity • Global modeling frameworks • NASA Biodiversity and Terrestrial Ecology Research

28. Field Activities ICESAT LIDAR ALOS SAR LVIS Large Footprint LIDAR UAVSAR Small Footprint LIDAR Field Measurements Ground LIDAR

29. ECHIDNA Ground LIDAR Alan Strahler – Boston University

30. TANDEM-L • Temporal decorrelation greatly limits ability of DESDynI InSAR to measure canopy heights • Simultaneous observation by two InSAR instruments overcomes this issue • Could enable recovery of canopy profile • NASA discussion with DLR for joint space mission called TANDEM-L • Use DESDynI InSAR and LIDAR with DLR InSAR • Common requirements/engineering concepts under development

31. TANDEM-L Concept

32. Summary • DESDynI revolutionary mission for ecosystem science • Provide vertical and spatial structure at fine scales globally • Address critical environmental issues on the effects of changing climate and land use on carbon cycling, CO2 and species habitats • Data from DESDynI important for many other applications • Forest fire modeling, hydrology, forest management, etc

33. DESDynI Resources • DESDynI Website: desdyni.jpl.nasa.gov • Science Definition Document and other materials • Two Special Issues • JGR and Remote Sensing of Environment • Data sets • Ongoing Field Studies • Terrestrial Ecology Program (Diane Wickland) • Various Science Working Groups • Contact members • Contact me: dubayah@umd.edu