State 1
Grassland

Community 1.1
Tallgrass Dominant

Figure 9. HPC Tallgrass Dominant

The reference plant community for this site is open tallgrass prairie dominated by big bluestem (in non-sandy areas) or sand bluestem (in the sandy areas), Indiangrass, switchgrass, and little bluestem. The major midgrasses and shortgrasses are sideoats grama, blue grama, dropseed species, and Scribner’s panicum. This site also supports a variety of forbs and legumes including catclaw sensitivebrier, leadplant, wild indigo, heath aster, Englemann's daisy, Maximilian sunflower, dotted gayfeather, western ragweed, Louisiana sagewort, Illinois bundleflower, pitcher's sage, and others. The main lower succession species is prairie three-awn. Scattered prickly pear cactus, and soapweed yucca may be found on this site. This plant community has evolved through the collective influence of extremes in temperature, rain, wind, drought, fire, and seasonal herbivory by large ungulates, primarily bison. The picture was taken in August, 2007 north of Putnam , Custer County, Oklahoma.
Grazing is a common process on Loamy Upland rangeland. Long-term overgrazing (LTO) decreases the more palatable grasses such as big bluestem (Andropogon gerardii, Vitman) and sand bluestem (Andropogon hallii, Hack), Indiangrass, switchgrass as well as palatable forbs and legumes. Under this scenario, coupled with the absence of fire, little bluestem becomes the dominant tallgrass while silver bluestem, prairie three-awn, forbs, other annual grasses, and perennial grasses increase. The rate at which this occurs is dependent upon the initial stocking rate, stocking rate adjustments made during the grazing period, and climatic patterns. In dry years, little bluestem will be the dominant tallgrass. However, when there is high, well-timed precipitation, and fire, the other tallgrasses such as big bluestem, sand bluestem, Indiangrass, and switchgrass dominate to a point where it is difficult to see the little bluestem.
Conservation practices for rangeland use is based upon proper stocking rates and includes prescribed grazing, fencing, water development, proper salt and mineral placement, prescribed burning, and brush management. Depending on the specific site, various combinations of these practices can restore and maintain this plant community indefinitely. Conversely, the absence of grazing, the absence of fire, or both will result in litter buildup and stagnation of ecological functions and subsequent deterioration of the historic plant community.

Community 1.2
Little Bluestem Dominant

This plant community is mixed with midgrasses and shortgrasses. The plant community has deviated in composition percentages from the reference and is now dominated by little bluestem. Little bluestem now makes up approximately 60 to 75 percent of the total annual vegetative production of the site. Other important grasses are big bluestem in the clayey areas, or sand bluestem in the sandy areas, Indiangrass, switchgrass, sideoats grama and blue grama. This community, like the reference, also supports a variety of forbs and legumes including catclaw sensitivebrier, heath aster, dotted gayfeather and many others. The predominant lower succession species are prairie three-awn and western ragweed. Scattered mesquite, eastern redcedar, soapweed yucca, or prickly pear cactus may exist. Long-term overgrazing by domestic animals (usually cattle), or severe climate swings towards drier conditions, or drought, contribute to the increase and dominance of little bluestem. This dominance occurs faster as stocking rates increase because cattle prefer other tallgrasses over little bluestem. During years of dry summers followed by mild, wet winters, brome (Bromus spp.) species become significant. Good range management practices such as prescribed grazing, fencing, water development, salt and mineral placement, prescribed burning and prescribed brush management can restore and maintain this plant community indefinitely.

Community 1.3
Little Little Bluestem Dominant, Beginning Woody Encroachment(At Risk)

In this community phase, which basically comes about because of the absence of fire, important grasses are little bluestem, sideoats grama, blue grama, hairy grama, silver bluestem, buffalograss and prairie three-awn. Western ragweed, pricklypear cactus, common broomweed, wavyleaf thistle, and other forbs are abundant. The important change in this state is that woody species have started to encroach upon the site, thus signaling an imminent threshold crossing to a woody grassland is approaching if preventative measures are not taken. Although this change is primarily caused by the lack of or change in fire regime, carry over residue and plant material from ungrazed plants also provides an area for seed germination and protection of seedlings.

Pathway 1.1A
Community 1.1 to 1.2

When abusive grazing practices persist for multiple growing seasons, the plant community may shift towards community phase 1.2.

Pathway 1.2A
Community 1.2 to 1.1

With adequate rest from grazing the plant community may shift back towards community phase 1.1. Prescribed fire is also essential to keep woody species in check.

Pathway 1.2B
Community 1.2 to 1.3

Without proper grazing and the use of prescribed fire, the plant community may shift to 1.3.

Pathway 1.3A
Community 1.3 to 1.2

With the introduction of prescribed fire or alternative brush management, the site may be shifted back to community 1.2. Careful grazing management is also required to ensure productive prescribed fires.

State 2
Woody Grassland

Community 2.1
Woody Grassland

In this plant community, which basically comes about because of the absence of fire, woody species have increased to approximately 50% canopy cover. The two predominant woody invaders are mesquite and eastern redcedar, depending on where the site is located in the MLRA. Basically, eastern redcedar will be more prominent in the north; mesquite will be more prominent in the south. Important grasses are little bluestem, sideoats grama, blue grama, hairy grama, silver bluestem, buffalograss and prairie three-awn. Western ragweed, pricklypear cactus, common broomweed, wavyleaf thistle, and other forbs are abundant. Woody species have "invaded" the site. The two predominant woody invaders are mesquite and eastern redcedar depending on where the site is located in the MLRA (basically, eastern redcedar in the north; mesquite in the south). When the site gets to this state, significant inputs of chemical or mechanical brush control must be utilized to remove eastern redcedar, mesquite and the other brush/shrub species. Depending on the brush control methods used, the site can be either reseeded or implement prescribed grazing practice to create a more desirable (cattle) plant community.

State 3
Converted

Community 3.1
Cropland/TamePasture

This site may be cultivated for crops, planted to permanent native, or introduced pasture species, or let "go back" to native species. Loamy Prairie is one of the most farmed Ecological Sites in the 78C MLRA. But, even though a Loamy Prairie site was in cultivation for a substantial period of time it is not always impossible for the site to return to something resembling the reference state

State 4
Eroded

Community 4.1
Eroded

This state is the result of water erosion over bare soil. Most of the "A" horizon of the soil profile has been displaced. The remaining subsoil is very low in fertility. Some native grasses and forbs will persist in this state, however, production is greatly reduced.

Transition T1A
State 1 to 2

Long term abusive grazing practices coupled with invasion from woody species may transition the site to State 2.

Transition T1B
State 1 to 3

Through cultivation and planting the site will be transitioned to State 3.

Restoration pathway R2A
State 2 to 1

With the introduction of prescribed fire or alternative brush management, the site may be restored back to State 1. Careful grazing management is also required to ensure productive prescribed fires.

Transition T2A
State 2 to 3

Transition T3A
State 3 to 4

As soil is lost through water erosion the site will transition to State 4.