Wyoming sage growing alongside rabbitbrush (Artemesia tridentata-wyomingensis and Chrysothamnus viscidiflorus)

As spring dwindled to an end and days began to heat up, it was apparent that summer was upon us. With summer comes the field season for the Bureau of Land Management employees. As an intern with the Kemmerer, WY field office I was ready to begin spending days outside, surrounded by nature with the sun as a constant companion. As each new season begins it is common to have new protocols which must be learned and implemented. For the summer of 2016 AIM, or Assessment Inventory Monitoring, was the new methodology to be learned. AIM was designed to capture a snapshot of overall rangeland health, while maintaining statistical validity. AIM training took place in Rock Springs, WY for the High Desert District employees. After one week of a combination of classroom and field sessions it was time to hit the field. Such was the plan. However, with the implantation of a new rangeland assessment program comes issues. For most monitoring or assessment techniques points to monitor are chosen by the field staff. With AIM points are generated randomly and are assigned to the field office. For the Kemmerer field office points were not assigned until late June. This meant that field work could not begin until then.

Points were assigned and the field staff was champing at the bit to get out and begin checking points off of the lengthy list. As a range technician I was prepared to go out on AIM points every day I worked, but was taken somewhat aback when my life was scheduled up through the first week of August and marked on a calendar.

Early season tailcup lupine (Lupinus caudatus)

As our AIM team approached our first point the training I had earlier was coming back and the cobwebs were shaken loose. AIM encompasses several techniques to capture rangeland health at a given point. Without going into too much detail, AIM protocol includes a soil pit with measurements taken for effervescence, soil color, soil texture and clay percentage.

Three 25 meter lines are laid out in a spoke design. Along each line a line-point-intercept transect is done. This gives an idea of canopy cover and composition as well as litter content. Canopy gap is then measured. This is important for understanding the percent cover of the transect.

25 m transect

Soil stability is the last measurement taken. This is a fairly straightforward test, giving an idea of the level of erodibility of the soil surface. A plant list is also taken for the plot area by simply walking the perimeter and marking each plant identified.

This was essentially my summer. The soil pit was the duty I was most heavily accountable for. Digging the pit to a depth of 80 centimeters, marking the horizons, collecting and sieving samples for each horizon and finally taking measurements for each horizon. I found the soil pit the most fascinating aspect. Identifying key characteristics of the soil can help one understand why the vegetation that is present is there and any underlying issues. One site was especially interesting. Several horizons were present, the A horizon, or topsoil, was low quality without much of an organic matter presence. The B horizon was absent as the next horizon was a Ct, or clayey C. This horizon was compacted so tightly it was apparent that water could only infiltrate at very slow rate. With slow infiltration comes a higher risk of erosion during average precipitation events. This is one reason I hypothesized that the A horizon was of such low quality. It had no chance to become established due to erosion. To test my hypothesis I poured a generous amount of water onto the topsoil. Infiltration was rapid for about 5 cm. Once the water reached the compacted Ct horizon infiltration slowed and water pooled at the surface, creating runoff and erosion. Of course this was a simple test, but it was a great way to induce deeper thought as to the processes responsible for a sites characteristics.

A soil pit with the soil horizons laid out on a sharpshooter shovel. You can clearly see the distinct colors between them

Days began to blend together. Sites that were once quite distinguishable were now one blurry soil pit. Latin names of plants flew through my mind when off of work reading a book. When out fishing I could not help but take a mental note of every plant I came across. My AIM days are behind me for now. How lucky I was to see so much wonderful country. From low desert sites to conifer and aspen sites high in the hills, soil pits were dug.