2023-10-06_PERMIT FILE - M2023036

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back toward the Reference Plant Community. This change can occur in a relatively short time frame with the return of these disturbances. State 2 Warm-Season Shortgrass State This state is characterized by the Warm-Season Shortgrass Plant Community.An ecological threshold has been crossed and a significant amount of production and diversity has been lost when compared to the Reference State. Significant biotic and edaphic(soil characteristics)changes have negatively impacted energy flow and nutrient and hydrologic cycles.This is a very stable state, resistant to change due to the high tolerance of blue grama to grazing, the development of a shallow root system (aka root pan), and subsequent changes in hydrology(reduced infiltration)and nutrient cycling. Extended drought may cause extensive mortality of blue grama (as seen in recent drought years). However,there is insufficient information at this time to determine the outcome of this event. The loss of other functional/structural groups such as warm-season bunchgrasses,forbs, and shrubs, reduces the biodiversity and productivity of this state. Community 2.1 Warm-Season Shortgrass Plant Community This plant community evolves with moderate to heavy continuous grazing caused by lack of adequate recovery periods between grazing events. Blue grama dominates this plant community and has taken on a sodbound appearance. Large amounts of sand dropseed and Fendler threeawn are common.White sage(aka Louisiana sage), lupine, stickleaf, croton, hairy goldaster, loco,wormwood,fringed sage and soapweed have increased. Sand sagebrush may increase on sandy loam or coarser subsoils. Sand bluestem, switchgrass,western sandcherry and fourwing saltbush have been removed. Prairie sandreed and needle and thread may persist in remnant amounts protected by remaining shrubs. Western wheatgrass may be found in small depressions.A significant amount of production and diversity has been lost when compared to the Reference Plant Community. The soil is stable at this stage however, the nutrient cycle,water cycle, community dynamics and energy flow are all impaired do to the substantial increase of blue grama and loss of warm-season tallgrasses, nitrogen fixing legumes and shrubs. Desertification is advancing. Production varies from 200 to 900 pounds of air-dry vegetation per acre per year depending on weather and averages 700 pounds. Figure 10.Plant community growth curve(percent production by month). C06710,Warm-season dominant;MLRA-67B;upland coarse-textured soils.. Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec 0 0 0 5 1 20 40 20 10 1 5 0 0 0 State 3 Increased Bare Ground State The Increased Bare Ground State develops with heavy continuous grazing and/or excessive defoliation. An ecological threshold has been crossed. Erosion and loss of organic matter/carbon reserves are concerns. Sand dropseed and threeawn are the dominant species. Blue grama may persist in localized areas. Introduced annuals such as kochia and Russian thistle are present. Introduced species such as field bindweed and knapweed can also be present. Community 3.1 Increased Bare Ground Plant Community This plant community can develop by long-term heavy continuous grazing, and/or excessive defoliation (i.e. occupation by prairie dogs). Fendler threeawn is the dominant species. Sand dropseed may also be present in varying amounts.A number of annual plants such as Russian thistle, kochia, knapweed and cheatgrass will increase or invade. Field bindweed is often present on prairie dog towns. Litter levels are extremely low. The nutrient cycle,water cycle, and energy flow are greatly reduced. Infiltration is greatly reduced and erosion is occurring. Pedestalling is evident. Organic matter/carbon reserves are greatly reduced. Desertification is obvious. Production can vary from 50 to 400 pounds of air-dry vegetation per acre per year depending on weather conditions and the plants that are present.