DESDynI

Global Vegetation Structure

Dynamics from NASA’s DESDynI

Mission

Ralph Dubayah

University of Maryland

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DESDynI2

DESDynI

DESDynIDESDynI

Deformation, Ecosystem Structure, and Dynamics of 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

DESDynI

OutlineOutline

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

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DESDynI

DESDynI Science Study GroupDESDynI 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

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DESDynI Scientific Focus AreasDESDynI Scientific Focus Areas

Deformation Ecosystems Ice Masses Subsurface Reservoirs

EarthquakesProbability, aftershocks, stress transfer

Aboveground biomassCarbon storage in vegetation

Ice Sheet FlowResponse of ice sheets and shelves to ocean and atmosphere

Aquifers Withdrawal and Recharge

Subsidence

VolcanoesVolume, depth, and migration of magma chamber

Changes in carbon stocksCarbon sources and sinks

Mtn glaciers & ice capsResponse to climate trends

CO2 SequestrationSubsurface migration

LandslidesDetect preslip

Habitat StructureBiodiversity assess-ment, ecosystem processes

Sea IceInteraction between ocean and atmosphere

Oil ReservoirsSubsidence, pipe breakage

Key Challenges Additional Science Benefits

DESDynI addresses a broad-based range of the science questions

DESDynI

Science ObjectivesScience Objectives

CHARACTERIZE THE EFFECTS OF CHANGING CLIMATE AND LAND USE ON TERRESTRIAL CARBON CYCLE, ATMOSPHERIC

CO2, AND SPECIES HABITATS

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

Characterize global distribution of aboveground

vegetation biomass

Characterize habitat structure for biodiversity assessmentsCharacterize habitat structure for biodiversity assessments

DESDynI

Global Biomass and CarbonGlobal 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

DESDynI

Global Carbon BudgetGlobal Carbon Budget

DESDynI

DESDynI Driving Science Questions: BiodiversityDESDynI Driving Science Questions: Biodiversity

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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?

DESDynI

Vegetation 3D Structure and Biomass KeyVegetation 3D Structure and Biomass Key

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Upland coniferLowland coniferNorthern hardwoodsAspen/lowland deciduousGrasslandAgricultureWetlandsOpen waterUrban/barren

Vegetation Type

Vertical Structure & Biomass: the bottom to top configuration or complexity and amount of above-ground vegetation

Vegetation 3D Structure & Biomass: for

Biodiversity and Habitat

Landscape Structure: the spatial heterogeneity of an area composed of interacting habitat patches

High: 30 kg/m2

Biomass

Low: 0 kg/m2

Low: 0 kg/m2

DESDynI

DESDynI: Habitat Rationale - ExampleDESDynI: Habitat Rationale - Example

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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

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

DESDynI

DESDynI: Biodiversity Science RationaleDESDynI: 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).

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Goetz et al. 2006

DESDynI

DESDynI: Biodiversity Science RationaleDESDynI: Biodiversity Science Rationale

Relationships with Height Vertical Profile: Foliage height diversity Index

(FHD) MacArthur & MacArthur (1961)

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Foliage height diversity (FHD) vs. bird species diversity (BSD) (reproduced from Wilson, 1974)

DESDynI

Science Objective 1: BiomassScience Objective 1: Biomass

Characterize global distribution of aboveground vegetation 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)

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)

Measurement Objectives

Forest canopy height and profiles, spatial and vertical structure, biomass from SAR

Forest canopy height and profiles, spatial and vertical structure, biomass from SAR

Instruments Multi-beam lidar, polarimetric L-band SARMulti-beam lidar, polarimetric L-band SAR

DESDynI

Science Objective 2: Biomass ChangeScience Objective 2: Biomass Change

Quantify changes in terrestrial biomass resulting from disturbance and recovery

Quantify changes in terrestrial biomass resulting from disturbance and recovery

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)

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)

Same as for biomass stocks. Additionally, require 100 m tracking of deforestation,

recovery over 5 year epoch. Observe biomass changes from extreme events

Same as for biomass stocks. Additionally, require 100 m tracking of deforestation,

recovery over 5 year epoch. Observe biomass changes from extreme events

Multi-beam lidar, polarimetric L-band SAR, Multi-beam lidar, polarimetric L-band SAR,

Desired Final Data Products

Measurement Objectives

Instruments

DESDynI

Science Objective 3: Habitat StructureScience Objective 3: Habitat Structure

Characterize habitat structure for biodiversity assessments

Characterize habitat structure for biodiversity assessments

Various forest structure products with specified accuracies (includes both gridded

data and ungridded transect data)

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

Forest canopy structure including height, canopy profile, canopy cover, canopy roughness, biomass, vertical diversity

Multi-beam lidar, polarimetric L-band SAR Multi-beam lidar, polarimetric L-band SAR

Desired Final Data Products

Measurement Objectives

Instruments

DESDynI

Variables Required by Biodiversity & Habitat Variables Required by Biodiversity & Habitat DESDynI Science CommunityDESDynI Science Community

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Variable RaDAR LiDAR Comments

crown closure no yes 10-20% M, 5% D

understory crown closure (%, 1-3 m) no ? addn. study, key variable

midstory crown closure (%,e.g., 3-10 m) no yes

dry biomass (Mg/ha) yes yes max[±10% or 10t/ha], 1 se

vertical diversity no yes

e.g., decile heights(m) no yes 1 m LiDAR bins

decile crown closures (%) no yes

HOME = height, median energy (m) yes yes 2 m M, 1 m D

maximum canopy height (m) no yes 2 m M, 1 m D

dbh (cm) no no ± 20%

stem density (#stems/ha) no no ± 20%

basal area (approximates dbh x density) yes yes

species no no

physiognomy (e.g., hardwood, conifer) yes no

snags, standing dead wood (#snags/ha) no no

A. Pixel-level Structural Variables, accuracies and precisions

DESDynI

Variables Required by Biodiversity & Habitat Variables Required by Biodiversity & Habitat DESDynI Science CommunityDESDynI Science Community

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Variable RaDAR LiDAR Comments

canopy roughness (m, sd of heights) ? yes ± 20% M, ± 10% D

Surface (topographic) roughness (m) no yes ± 20% M, ± 10% D

Identification/mapping of edges yes yes within limits of pixel/pulse size

mapping/measuring patch size yes no within limits of pixel/pulse size

landscape metrics (many, e.g., FRAGSTAT or geostatistical)

yes no

dbh size class distribution no no

height size class distribution no yes

B. Landscape-level Structural Variables, accuracies and precisions

DESDynI

Habitat Structure: RequirementsHabitat Structure: Requirements

DESDynI

Measurement ApproachMeasurement Approach

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DESDynI InstrumentsDESDynI Instruments

4. Instrument Design & Performance

~350kmFlight Direction

Interferometric SAR

Dual-Pol 3-Beams

Quad-Pol 6-Beams

Right or Left Point

L-Band Synthetic Aperture Radar

Lasers

LaserRadiators

Star Tracker

Multi-beam Lidar

Beam Spacing1 km

DESDynI

L-band Measurement of StructureL-band Measurement of Structure

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LHH, LHV, LVV

Polarimetric Image of La Selva

Image Segmentation

DESDynI will produce global 25 m images every 8 days

DESDynI

Forest Structure from LidarForest Structure from Lidar

•Tree height

•Crown volume

•Vertical foliage profile

•Canopy cover profile

•Biomass

•Tree density

•Basal area

•LAI

DESDynI

La Selva Vertical Forest StructureLa Selva Vertical Forest Structure

DESDynI

Canopy Height ProfileCumulative Canopy Cover

Lidar Derives LAI and Canopy ProfilesLidar Derives LAI and Canopy Profiles

DESDynI will produce 50 billion canopy profiles

DESDynI

Science ActivitiesScience 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

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DESDynI

Field ActivitiesField Activities

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LVISLarge Footprint

LIDAR UAVSAR

ICESAT LIDARALOS SAR

Small FootprintLIDAR

FieldMeasurements

GroundLIDAR

DESDynI

ECHIDNA Ground LIDARECHIDNA Ground LIDAR

29Alan Strahler – Boston University

DESDynI

TANDEM-LTANDEM-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

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TANDEM-L ConceptTANDEM-L Concept

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SummarySummary

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

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DESDynI

DESDynI ResourcesDESDynI 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

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