Skip to main content
U.S. flag

An official website of the United States government

Evaluating the role of land cover and climate uncertainties in computing gross primary production in Hawaiian Island ecosystems

September 18, 2017

Gross primary production (GPP) is the Earth’s largest carbon flux into the terrestrial biosphere and plays a critical role in regulating atmospheric chemistry and global climate. The Moderate Resolution Imaging Spectrometer (MODIS)-MOD17 data product is a widely used remote sensing-based model that provides global estimates of spatiotemporal trends in GPP. When the MOD17 algorithm is applied to regional scale heterogeneous landscapes, input data from coarse resolution land cover and climate products may increase uncertainty in GPP estimates, especially in high productivity tropical ecosystems. We examined the influence of using locally specific land cover and high-resolution local climate input data on MOD17 estimates of GPP for the State of Hawaii, a heterogeneous and discontinuous tropical landscape. Replacing the global land cover data input product (MOD12Q1) with Hawaii-specific land cover data reduced statewide GPP estimates by ~8%, primarily because the Hawaii-specific land cover map had less vegetated land area compared to the global land cover product. Replacing coarse resolution GMAO climate data with Hawaii-specific high-resolution climate data also reduced statewide GPP estimates by ~8% because of the higher spatial variability of photosynthetically active radiation (PAR) in the Hawaii-specific climate data. The combined use of both Hawaii-specific land cover and high-resolution Hawaii climate data inputs reduced statewide GPP by ~16%, suggesting equal and independent influence on MOD17 GPP estimates. Our sensitivity analyses within a heterogeneous tropical landscape suggest that refined global land cover and climate data sets may contribute to an enhanced MOD17 product at a variety of spatial scales.

Citation Information

Publication Year 2017
Title Evaluating the role of land cover and climate uncertainties in computing gross primary production in Hawaiian Island ecosystems
DOI 10.1371/journal.pone.0184466
Authors Heather L. Kimball, Paul Selmants, Alvaro Moreno, Running Steve W, Christian P. Giardina
Publication Type Article
Publication Subtype Journal Article
Series Title PLoS ONE
Series Number
Index ID 70190928
Record Source USGS Publications Warehouse
USGS Organization Western Geographic Science Center