SITEQUAL v2.0-a FORTRAN program to determine bottomland hardwood site quality


Don C. Bragg

USDA Forest Service, Southern Research Station; phone: (870) 367-3465; email:

Abstract – The original SITEQUAL program was written in the BASIC programming language by Harrington and Casson (1986) based on the original field methodology for site evaluation developed by Baker and Broadfoot (1979). SITEQUAL is an expert system that uses a number of easily assessed soil-related conditions (e.g., physical structure, available moisture, available nutrients, and aeration) to estimate site index for 14 southern hardwood species. Unfortunately, because of how SITEQUAL was programmed it did not operate as a stand-alone application, requiring a dated BASIC compiler to run (which no longer works on modern operating systems). I have reprogrammed SITEQUAL (now version 2.0) in FORTRAN for a more user-friendly (if still simple) interface, with a number of minor improvements to aid in the user experience. To demonstrate SITEQUAL’s utility as a teaching and practical management tool, I present several examples of output from a range of bottomland hardwood sites in southeastern Arkansas. Further improvement of SITEQUAL is planned, including the development of a graphical user interface as well as the additional of more species and environmental conditions (as data permits).