Graphical Description of US Soil Taxonomy Soil Temperature Regimes
STRplot(mast, msst, mwst, permafrost = FALSE, pt.cex = 2.75, leg.cex = 0.85)
single value or vector of mean annual soil temperature (deg C)
single value or vector of mean summer soil temperature (deg C)
single value of mean winter soil temperature (deg C)
logical: permafrost presence / absence
Soil Survey Staff. 2015. Illustrated guide to soil taxonomy. U.S. Department of Agriculture, Natural Resources Conservation Service, National Soil Survey Center, Lincoln, Nebraska.