Sit back and think to yourself, what would be the perfect rangeland management tool? A 3-foot x 3-foot square made from PVC pipe? Useful, but no. A 100-meter transect tape? An absolute must for most monitoring techniques, but also no. If you were to ask me what the perfect range tool is, I would tell you it is an ecological site description (ESD) paired with its corresponding state-and-transition model (STM).

Well, what is an ecological site? In 2011, the United States Department of Agriculture (USDA) stated that ecological sites are based on soil map unit components of the National Cooperative Soil Survey and are classes of land defined by recurring soil, landform, geological and climate characteristics.

With an ecological site, a manager could make a decent guess as to what the land needs to stay in a healthy state, especially when it is paired with its corresponding STM.

Now, what is an STM? In 2011, the USDA stated that STMs describe changes in plant communities and associated dynamic soil properties that can occur on an ecological site. Why is this so important? Well, because it is a visualization of what might be going on in terms of landscape health, on your land, your neighbor’s land, or all our public lands here in Sublette County. A manager could use this tool to make the best management decision for the desired outcome of the ecological site.

With the description of an ecological site and the pairing STMs, a manager could put the pieces of the landscape puzzle together, or at least make an educated attempt. The ESD provides a manager with the descriptions of soils, precipitation, vegetation communities, climatic factors and so much more. The STM is a flow chart that shows how the vegetation communities can transition with types of disturbances based on the climatic factors and soils makeup described in the ESD. If the transitioning phase is not what is desired by interested parties, actions can take place based on the ESD and STM.

What makes the combination of an ecological site and an STM the perfect range management tool? Well, in all truth and honesty, they’re not “perfect.” Ecological sites and STMs can always be taken out, field-tested and proven wrong, but that’s just science. Science is this entity that is built on the shoulders of hypotheses and theories. These hypotheses and theories are constantly being taken to the limit by scientists and have been for hundreds of years.

Ecological site descriptions and STMs are always being developed because they are constantly being field-tested by professionals in rangeland management and other ecological professions. In 2016, Jason Karl and Curtis Talbot said an important concept to this revised ecological site development process is that there is no such thing as a “final” ecological site concept, ESD, or STM – each of these continues to develop over time in response to new knowledge or research.

Even though the opening point has been disproven, there is perfection in many imperfections. Although ecological site descriptions and STMs are never “final,” there is beauty in the fact that they are forever evolving and changing as our knowledge and understanding changes, and as new generations of professionals make their way into the world of ecosystem sciences and management and share their new ways of thinking.

If you are curious about plant communities on your land, give us a call or stop by the Sublette County Conservation District office at 217 Country Club Lane in Pinedale. We are always happy to help our constituents learn about the ground beneath their feet to help them make the best management decisions possible.

Citation: https://www.ars.usda.gov/ARSUserFiles/30501000/ESD_summary.pdf. Karl, J. W., & Talbot, C. J. 2016. The role of data and inference in the development and application of ecological site concepts and state-and-transition models. Rangelands, 38(6), 322-328.i