Fig. 1.
Fig. 1.

Timing of critical technologies, data management and mapping methods that have impacted digital soil mapping contrasted by temporal trends of select environmental and anthropogenic forcings that have accelerated in the Anthropocene. †Estimates of global soil carbon stocks (Pg C) from various sources (Post et al., 1982; Batjes, 1996; Jacobson et al., 2004; Intergovernmental Panel on Climate Change, IPCC, 2000; Lal, 2004; and Field et al., 2007—U.S. Climate Change Science Program). ‡Past (U.S. Census Bureau) and projected population in billions (UN, 2004). §Past and projected nitrous oxide (N2O) concentrations (ppm) in the atmosphere under different scenarios for green house gas emissions (IPCC, 2001). ¶Departure in temperature (°C) from 1961 to 1990 average (Mann et al., 1999) and projected global average surface warming at the end of the 21st century in °C (relative to 1980–1999 temperature data) (IPCC, 2007). #Atmospheric CO2 (ppm) (Keeling et al., 1995) and projected CO2 (ppm) according to different best and worse case emission scenarios (IPCC, 2007).

 


Fig. 2.
Fig. 2.

Summary of ratings of polygon vs. pixel soil maps for all participants, participants who had previously used soil surveys, and participants who had not used soil surveys; Vis App = visual appeal, Sp Distr = conveying information about the spatial distribution of soils; Spec Loc = determining soil type mapped for a specific location.

 


Fig. 3.
Fig. 3.

Overview of phenomena of space and time, distributions of soil properties and processes at escalating spatial scales, and predominant current digital soil mapping approaches.

 


Fig. 4.
Fig. 4.

Envisioned future of digital soil mapping and modeling.