Brief description
This dataset is modelled national pasture productivity. It describes the dynamics in grassland/pasture Gross Primary Production (GPP), Net Primary Production (NPP) and Carbon mass.GPP indicates total rate of carbon fixed through photosynthesis, in units gC/m2/day. It is the GPP of grasses only and so describes the production of grasslands and pastures. GPP is estimated separately for C3 and for C3 grasses using the Diffuse model (Donohue et al. 2014, see publication links).
NPP is the net rate of carbon fixed through photosynthesis (GPP minus plant respiration) for grasses, in units of gC/m2/day. Grass carbon mass is the above-ground mass of grasslands and pastures, estimated using the CSP model. These are estimated using the unpublished CSP model (v2) for both live and senesced mass in units t/ha. Biomass is typically approximated as double the carbon mass.
Inputs include MODIS MOD13Q1, minimum and maximum air temperature, elevation data and rainfall as described in the lineage section.
Notes
Supplemental InformationGPP, NPP and Carbon mass datasets are created on every 16 days from 2001 January to Dec 2018. File naming convention for GPP is GPP_
Lineage
GPP inputs are MODIS MOD13Q1 data along with minimum and maximum air temperature and elevation data. GPP is estimated separately for C3 and for C3 grasses using the Diffuse model (Donohue et al. 2014, see publication links). NPP and Grass Carbon Mass have the same inputs as GPP with the addition of rainfall data. NPP and Carbon Mass are estimated using the unpublished CSP model (v2).
Notes
CreditWe at TERN acknowledge the Traditional Owners and Custodians throughout Australia, New Zealand and all nations. We honour their profound connections to land, water, biodiversity and culture and pay our respects to their Elders past, present and emerging.
CSIRO Food and Agriculture TERN landscapes
The aim of the research was to develop a nationally consistent estimate of the productivity and mass of grasslands and pastures, with a particular focus on capturing the temporal dynamics. Integration of satellite imagery was a core component.
Data Quality Assessment Scope
local :
dataset
Due to the scarcity of grass productivity and biomass data, validation of model outputs has only been rudimentary. CSP-modelled GPP has been compared to modelled GPP based on four grassland flux tower observations. Grass biomass has been compared to approximately 30 site observations from south-eastern, central and far northern Australia.
Data Quality Assessment Result
local :
Quality Result
Comparison to 4 grassland Australian flux tower sites, the modelled GPP explained 83% of the tower GPP variability with an RMSE of 1.5 gC/m2/day. Grass biomass estimates had a low r-squared value and an RMSE of 2.1 t/ha. Biomass error was highest in central Australia.
Created: 2020-03-03
Issued: 2020-06-18
Modified: 2024-05-12
Data time period: 2001-01-01 to 2018-12-31
text: Australia
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Point-of-truth metadata URL- URI : geonetwork.tern.org.au/geonetwork/srv/eng/catalog.search#/metadata/02338137-e1dc-4c72-ab92-fa7ac295b102
- global : 02338137-e1dc-4c72-ab92-fa7ac295b102
