NASA/Ames Amazon Ecology (AME) Mapping Data Sets

The AME data set is comprised of maps for the country of Brazil,
gridded at 8-km spatial resolution.

Each file contains one binary map layer comprised of 552 rows x 634 cols with
no header lines and consists of:
- soil texture class
- soil plant available water (paw)
- net primary production (NPP)
- net ecosystem production (NEP)- aboveground leaf biomass
- aboveground wood biomass

Soil texture class was determined from percent clay content (for definitions,
see Table 1 in Potter et al., 1998). Classes are 1 = organic, 2 = coarse, 3 =
coarse/medium, 4 = medium, 5= medium/fine, 6 = fine, 7 = lithosol.

Soil paw is maximum plant available water. On a 'per unit depth' basis, paw =
FC(-10 kPa) - WP(-1500 kPa); where FC (field capacity) and WP (wilting point)
are computed from the equations generated for Amazon soils by Tomasella, J. and
M. G. Hodnett. 1998. Estimating soil water retention characteristics from
limited data in Brazilian Amazonia. Soil Science. 163:190-202. By computing
the third layer for a nominal 10 meters depth, one can truncate or expand
paw100_3 to whatever total rooting depth required.

Interpolation method for soils maps. AME soil maps were created using 1000+ RADAM pit profiles and the Brazilian soil class map (brsoil;). Using the soil attribute value from each pit profile, we created country-wide maps at a 8 km x 8 km cell size, using a modified nearest-neighbor spatial fill routine. The soil type of each pit estimate was compared to nearby polygons of the original brsoil coverage. The nearest matching (with respect to soil type) pit estimate was then used as the 'fill value' for the cells within the brsoil polygon. The brsoil map used in these interpolations is the most generalized classification level of Brazilian soil types (19 classes).

NPP is net primary production (for definition and methods, see Potter et al.,
1998). NEP is net ecosystem production. Suffixes for the NEP files are Year
Number (01-09) and Year (82-90), followed by model version number.