This table can help forestland owners or managers plan the use of soils for wood crops. Interpretive ratings are given for the soils according to the limitations that affect the potential for fire damage and for seedling mortality. The ratings are both verbal and numerical.

     Rating class terms indicate the potential for fire damage and for seedling mortality. "Low" indicates that the soil has features that reduce its potential for fire damage or seedling mortality. Good performance can be expected, and little or no maintenance is needed. "Moderate" indicates that the soil has features that result in a moderate potential for fire damage or seedling mortality. One or more soil properties are less than desirable, and fair performance can be expected. Some maintenance is needed. "High" indicates that the soil has one or more properties that result in a high potential for fire damage or seedling mortality. Overcoming the unfavorable properties requires special design, extra maintenance, and costly alteration.

     Numerical ratings in the table indicate gradations between the point at which the potential for fire damage or seedling mortality is highest (1.00) and the point at which the potential is lowest (0.00).

     The paragraphs that follow indicate the soil properties considered in rating the soils. More detailed information about the criteria used in the ratings is available in the "National Forestry Manual," which is available in local offices of the Natural Resources Conservation Service or on the Internet.

     Ratings in the column "potential for damage to soil by fire" are based on texture of the surface layer, content of rock fragments and organic matter in the surface layer, thickness of the surface layer, and slope. The soils are described as having a low, moderate, or high potential for this kind of damage. The ratings indicate an evaluation of the potential impact of prescribed fires or wildfires that are intense enough to remove the duff layer and consume organic matter in the surface layer.

     Ratings in the column "potential for seedling mortality" are based on flooding, ponding, depth to a water table, content of lime, reaction, salinity, available water capacity, soil moisture regime, soil temperature regime, aspect, and slope. The soils are described as having a low, moderate, or high potential for seedling mortality.

Reference:
United States Department of Agriculture, Natural Resources Conservation Service. National forestry manual. (http://soils.usda.gov/technical/nfhandbook/)