MIXED TREE-GRASS AND SHRUB-GRASS VEGETATION ASSOCIATIONS ARE ONE OF THE MOST SPATIALLY EXTENSIVE AND WIDELY DISTRIBUTED FORMS OFTERRESTRIAL VEGETATION ON EARTH. THEY CONSTITUTE SIGNIFICANT FRACTIONS OF ALL CONTINENTS EXCEPT ANTARCTICA IN TROPICAL SUBTROPICAL ANDTEMPERATE BIOCLIMATIC REGIONS. WHILE GLOBAL TREE-GRASS SYSTEMS ARE DIVERSE IN THEIR PHYLOGENY PHYSIOLOGY AND PLANT MORPHOLOGY THEY SHARE THE KEY STRUCTURAL CHARACTERISTIC OF WOODY PLANTS DISTRIBUTED IN THE LANDSCAPE AT DENSITIES LOW ENOUGH TO ALLOW SIGNIFICANTGROWTH OF HERBACEOUS PLANTS (MOSTLY GRASSES) UNDERNEATH AND BETWEEN THEM. DESPITE THE IMPORTANCE OF TREE-GRASS SYSTEMS IN EARTHSYSTEM PROCESSES AND HUMAN WELL-BEING THEY ARE NOT WELL REPRESENTED IN OUR REMOTE SENSING AND MODELING CAPABILITIES. ECOSYSTEMSCHARACTERIZED BY HORIZONTALLY AND VERTICALLY COMPLEX TREE-GRASS MIXTURES ARE INHERENTLY DIFFICULT TO MEASURE WITH REMOTE SENSING ANDDIFFICULT TO REPRESENT IN ECOSYSTEM AND EARTH SYSTEM MODELS. WE CONTEND IN THIS PROPOSAL HOWEVER THAT EMERGING DATA ON SLOWLYVARYING CANOPY STRUCTURE (TREE COVER) PROVIDES US WITH A KEY CONSTRAINT IN THE ESTIMATION OF RAPIDLY (I.E. SEASONALLY) VARYING TREE ANDGRASS LEAF AREA INDEX (LAI) AND FRACTIONAL PAR INTERCEPTION (FPAR). THIS TREE-GRASS SEPARATION IN REMOTE SENSING DATA HAS NOT TOOUR KNOWLEDGE BEEN ATTEMPTED BEFORE AT REGIONAL AND CONTINENTAL SCALES USING MODIS DATA. WE PROPOSE TO CAPITALIZE ON PRIORTE-SPONSORED RESEARCH TO DEVELOP AND TEST A TREE-GRASS SEPARATION METHODOLOGY VALIDATED USING FIELD DATA AND APPLIED FOR AFRICADURING THE MODIS (2002-2012) ERA. WE ANTICIPATE THAT THE METHODOLOGY THUS DEVELOPED WILL LATER BE USED TO ALSO PARTITION VIIRSLAI AND FPAR AGGREGATES. THESE TREE AND GRASS BIOPHYSICAL PARAMETERS WILL BE OF DIRECT USE AS A VALIDATION AND DATA-ASSIMILATIONSTREAM FOR OUR SAVANNA DYNAMIC VEGETATION MODEL (THE TREE-GRASS VEGETATION MODEL TGVM). TGVM MODELS EXPLICITLY THE GROWTHAND DEMOGRAPHICS OF TREES AND GRASSES IN RESPONSE TO CLIMATE DISTURBANCE AND MANAGEMENT. THE NEW TREE-GRASS BIOPHYSICAL DATASETSWILL ADVANCE THE TESTING AND APPLICATION OF TGVM IN BOTH DIAGNOSTIC AND PROGNOSTIC MODES TO EXPLORE HOW TREE-GRASS SYSTEMS ARERESPONDING TO HUMAN MANAGEMENT AND CLIMATE CHANGE. THIS PROJECT WILL (I) REFINE METHODOLOGIES FOR SEPARATION OF TREE AND GRASSLAI AND FPAR BIOPHYSICAL PARAMETERS USING MODIS PRODUCTS FOR ALL AFRICA (II) VALIDATE RESULTS USING FIELD MEASUREMENTS FROM OUROWN AND COLLABORATOR FIELD SITES ACROSS AFRICA (III) GENERATE AND DISTRIBUTE AFRICA-WIDE TREE-GRASS COMPONENT BIOPHYSICAL PARAMETERSFOR 2002-2012 AT 8-DAY AND 1 KM RESOLUTIONS (IV) ANALYZE AND SYNTHESIZE THE NEW LAI AND FPAR PRODUCTS FOR PUBLICATION AND (V) USETHE TREE-GRASS DATA WITH OUR TREE-GRASS VEGETATION MODEL (TGVM) TO TRANSFORM OUR UNDERSTANDING OF AND ABILITY TO SIMULATE THE FUTUREPROVISION OF ECOSYSTEM GOODS AND SERVICES IN TREE-GRASS SYSTEMS. OVER THE PAST TWO DECADES NASA HAS MADE CONSIDERABLE INVESTMENTIN DEVELOPMENT AND DEPLOYMENT OF THE MODIS PLATFORM AND MODIS DATA PRODUCTS. THIS SUCCESSOR PROPOSAL SEEKS TO LEVERAGE THATINVESTMENT USING THE LAI-FPAR PRODUCT TO DIAGNOSE AND BETTER UNDERSTAND THE SEPARATE AND DISTINCT ROLE OF WOODY AND HERBACEOUSCOMPONENTS IN MIXED TREE-GRASS ECOSYSTEMS.