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Glossary of Terms


Ac - Abbreviation for acre.

AMP – Abbreviation for Allotment Management Plan.

AUM -   Abbreviation for animal-unit-month.  An AUM is the amount of oven-dry forage (forage demand) required by one animal unit for a standardized period of 30 animal-unit-days. Not synonymous with animal month.  The term AUM is commonly used in three ways: (a) stocking rate, as in "X acres per AUM"; (b) forage allocations, as in "X AUMs in Allotment A"; (c) utilization, as in "X AUMs taken from Unit B."

Allowable Use – A term used to provide guidance to livestock permittees on the amount of the current year’s vegetation that can be removed when referring to traditional utilization or the amount of vegetation that has to be remain when livestock are removed when referring to the amount of herbage left measured by the modified Robel pole or stubble height monitoring methods.    


BNFVGG – Abbreviation for Bighorn National Forest Vegetation Grazing Guidelines.  The guideline document approved in the 1990’s provided interim allowable use guidelines for the management of grazing allotments until an allotment management plan could be written and approved.  The document also gave guidance on monitoring methodologies that could be used to determine the amount of use each year. 


Carex – A vast genus of grass like plants in the Cyperaceae family commonly known as sedges.  In this presentation the term is used as a general term for the species Carex rostrata and Carex aquatilis which are wide leaved carices that are typically measured when measuring residual stubble height in riparian areas.  Both species are highly desirable in riparian plant communities on the Bighorn NF and are mostly palatable to livestock.


FEIS – Abbreviation for Final Environmental impact Statement.


Green Line - The first perennial vegetation that forms a lineal grouping of community types on or near the waters edge. 


Herbage Left – The amount of standing vegetation left on the ground, typically measured at the time livestock are removed from a pasture.  Measurements of herbage left can be in inches in the case of measuring riparian stubble height or in the number of bands in the case of measuring uplands with the modified Robel pole.   Synonym for residual standing crop. 


Parker 3-Step – A monitoring methodology used to provide a means for obtaining and interpreting data records of vegetation and soil factors on designated grazing allotments within National Forest system lands.  Records on the Tongue Ranger District show that many of these transects were established in the 1960’s and 1970’s.  Transects are permanently marked by metal stakes and by finding the stakes and following the established protocol the data gathered can be used to determine long term trend or what is happening to the plant community (are individual species increasing, remaining the same or decreasing) over time. 


RHAP – Abbreviation for the Rangeland health and Assessment Program supported by state monies and administered by the Wy Department of Agriculture.  “The short‐term goal of the program is to sustain viable levels of federal land grazing by providing credible data to assist federal land agencies in completing required permit National Environmental Policy Act (NEPA) analysis and to enable agencies and permittees to defend against challenges to grazing permit renewals and management plans.  The long‐term goal of the program is to assess trends in the health of all rangelands and assure the use of credible data in making adjustments in their management where indicated.  Monitoring will help maintain or improve the economic viability of the livestock grazing industry and its contribution to the Wyoming economy.”


Residual – See standing crop.


Riparian Vegetation - Plant communities dependent upon the presence of free water near the ground surface (high water table).


Riparian Zone - The banks and adjacent areas of water bodies, water courses, seeps and springs whose waters provide soil moisture sufficiently in excess of that otherwise available locally so as to provide a more moist habitat than that of contiguous flood plains and uplands.


ROD – Abbreviation for Record of Decision.


Standing Crop – Another term for the residual vegetation remaining at the end of the grazing season.  Standing crop may include both remaining vegetation from the current year as well as previous years.


Stubble Height (SH) - The basal portion of herbaceous plants remaining after the top portion has been harvested either artificially or by grazing animals.  On the Bighorn NF it generally refers to the remaining portion of wide leaved carex species. 


Suitable Range – A term from outdated Forest Service Range Analysis Handbook.  The term basically designated lands that because of plant communities present, elevation and slope the lands could be grazed by livestock (sheep or cattle).  It was up to the land manager to determine if other factors such as steepness of the slope, accessibility and distance from water, etc.  would limit the amount of vegetation that could be grazed and meet all management goals and objectives. 


Trend – A measurement of vegetative conditions the show if conditions are moving farther away from desired (down), remaining static (similar to previous) or moving towards desired (up).


Upland – Land or area of land lying above the level where water flows or where flooding occurs. Areas of suitable range not meeting the definition of riparian are considered uplands.  Typically uplands make up all but a small portion of the grazeable acres in pastures on the Bighorn NF.  


Use or Utilization – 1) The proportion of current year's forage production (palatable species) that is consumed or destroyed by grazing animals. May refer either to a single species or to the vegetation as a whole.  (2) Utilization of range for a purpose such as grazing, bedding, shelter, trailing, watering, watershed, recreation, forestry, etc.

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