Large‐scale ecological field data for satellite validation in deciduous forests and grasslands.

In situ accurate data sets of leaf area index (LAI), above‐ground biomass (AGB), and fraction of absorbed photosynthetically active radiation (fAPAR) are indispensable to validate and improve ecological products obtained from satellites. In situ data for satellite validation must be created not from a single‐point data but from areal data (such as multiple‐points data) representing a satellite footprint. Using multiple‐points data, the error of in situ data can be calculated statistically. The quantification of the error in the in situ data enables us to evaluate the discrepancy between the satellites' products and the in situ data as the error in the in situ data and the estimation error in the products separately. Besides, the accuracy of the in situ data is required to be much higher than the accuracy of the satellite products which was officially set. To obtain such in situ data, we have established observation sites for typical land cover types in East Asia, from temperate to cool ecosystems: deciduous needle‐leaved forest (DNF), evergreen needle‐leaved forest (ENF), deciduous broad‐leaved forest (DBF), and grassland (GL). We conducted the observations in 500 m × 500 m areas, which is the footprint scale of the Global Change Observation Mission‐Climate satellite. In this paper, the data of LAI, AGB, and fAPAR observed at DNF, DBF, and GL (i.e., except at ENF) are reported. These data are useful even for the validation of other satellite products, especially with higher spatial resolution. Also, the long‐term tree census data from 2005 to 2018 at DNF are reported. The complete data set for this abstract published in the Data Paper section of the journal is available in electronic format in MetaCat in JaLTER at http://db.cger.nies.go.jp/JaLTER/metacat/metacat/ERDP-2020-16.1/jalter-en. [ABSTRACT FROM AUTHOR]