Project Goals and Objectives

This study has been divided into three components to address management concerns relative to 1) native plant recovery in good ecological condition rangeland, 2) success of aerial seeding sagebrush and 3) whether livestock grazing effects native plant recovery on good condition rangeland.

Objective 1:  The evaluation of good condition Wyoming big sagebrush/bluebunch wheatgrass rangeland after wildfire presents a unique opportunity to document the recovery of the vascular plant and biological crust communities.  This information will be used to help managers determine if areas need to be treated following wildfire (vs. allowing natural recovery) and to document trajectories of vegetation change following a wildfire on good ecological condition rangeland. Opportunities to evaluate the natural progress of succession on good condition sagebrush steppe rangelands after a wildfire are very rare in southern Idaho due to the increasing dominance of cheatgrass and other invasive species.  Observations following wildfires suggest that the INEEL has not experienced dominance by cheatgrass and other weedy species.   (ESER INEEL Wildfire page)  

Objective 2:  The second component of the study focuses on the efficiency (economical as well as biological) of artificially seeding sagebrush compared to natural shrub reestablishment on good condition rangeland.  Observations and some studies on past fires in this area indicate that native grasses have fully recovered but sagebrush recruitment is still lacking.  This study provides the opportunity to determine if sagebrush seeding effectively “jump starts” reestablishment of shrubs on burned rangelands.  It also provides baseline studies to assess the long-term timeframes associated with sagebrush recovery on burned good condition rangeland where artificial seeding is not applied.  

Objective 3:  The third component of the study provides information on whether livestock grazing, after the BLM’s required exclusion period of two growing seasons, affects the recovery and persistence of vascular plants and biological crusts.   This information will assist managers in refining guidelines on livestock grazing timeframes and will document invasive species (including but not limited to cheatgrass) increases on grazed and ungrazed rangelands after a wildfire.  Since there is a great deal of controversy about the length of the period that grazing should be excluded following wildfire, this component of the study will provide scientific data to refine the current policy relative to invasive species and recovery of native vegetation.   

Project Design

Objectives 1 and 3 are being addressed by establishing 10 pairs of plots in an area burned by the Tin Cup fire in 2000.  Each pair of plots (see right) includes one plot inside a fenced grazing exclosure.  The exclosures are designed to keep out domestic livestock, but allow native grazing (including elk, mule deer, pronghorn, rabbits, etc.) into the plot.  The plot inside the exclosure will be used to monitor the natural recovery of rangeland vegetation.  The plot outside the exclosure will be used to assess the effect of livestock grazing on recovery of vegetation.  Each of the plots is being surveyed for the amount of plant cover and population densities for each species encountered.  To provide a visual record of each plot, photos are taken of the entire plot and a small photo plot.  

Objective 2 is being addressed by surveying areas aerially seeded with sagebrush for seedlings of sagebrush.  The portion of the area burned in the Tin Cup fire of 2000 that is part of the BLM Deadman Flat grazing allotment was seeded in February of 2001.  Five transects were seeded at the same time on a portion of the same burn that was not previously grazed.  (See figure below)  To survey for new sagebrush seedlings we established several belt transects each 1 kilometer (0.6 miles).   The transects are surveyed by having five or more people walk abreast at 15 foot intervals.  We use a rope knotted at 15-ft intervals to help maintain proper spacing.