Lesica and Cooper ( 1 999) recommended a 

 number of measures for returning natural distur- 

 bance cycles to the Sandhills at appropriate time 

 intervals (their recommendations do not address 

 the question of spatial scale and patchiness of 

 disturbance that are optimal for the Sandhills). We 

 discuss these recommendations below, emphasiz- 

 ing their implications for the Sandhills' animal 

 species. Additional guidelines appropriate to the 

 Centennial Sandhills are presented in Peterson 

 (1995), Saab etal. (1995), and Paige and Ritter 

 (1999). 



Sagebrush manipulation 



Sagebrush encroachment has contributed to the 

 stabilization of the Sandhills. Sagebrush removal 

 has complex impacts on the plants and animals 

 associated with it (Peterson 1995), but there is 

 good evidence of the immediate and short-term 

 effects on several animal species. Extensive 

 clearing of sagebrush (especially mature big sage) 

 will have negative impacts on Pygmy Rabbit, 

 Black-tailed Jackrabbit, Sage Thrasher, Brewer's 

 Sparrow, and possibly Great Basin Pocket Mouse 

 and Preble's Shrew (Best 1 972, Bock and Bock 

 1987, Verts and Kirkland 1988, Comely et al. 

 1992, Rauscher 1997, Paige and Ritter 1999, 

 Reynolds et al. 1999). However, conversion of 

 sagebrush to grassland benefits Lx)ng-billed 

 Curlew, and Grasshopper Sparrow as long as 

 scattered shrubs are left at low density (Bock and 

 Bock 1987, Vickery 1996). 



Sagebrush manipulation, if conducted, should be 

 limited and dispersed to maintain large expanses of 

 sagebrush cover (over 10%) in various ages and 

 size classes. Stands of dense mature sagebrush 

 should probably be left undisturbed, as they are 

 especially important sites for Pygmy Rabbit and 

 Sage Thrasher (Rauscher 1 997, Paige and Ritter 

 1 999) and are uncommon in the Sandhills. 



Fire 



Fire is a natural process of the Sandhills land- 

 scape. Fire suppression leads to a decline in 

 diversity of successional habitats through vegeta- 

 tion encroachment; in the eastern U. S . , loss of 



some tiger beetle species requiring open habitat 

 has been linked to fire suppression (Knisley and 

 Schultz 1997). The effects of fire will probably be 

 similar to mechanical/chemical removal of sage- 

 brush, producing a decrease in overall shrub cover 

 for several years. However, because fire bums 

 unevenly it creates a mosaic of successional 

 habitats leaving some shrub cover if properly 

 managed. Sage Thrasher and Brewer's Sparrow 

 persist following prescribed fire, if the bum pattem 

 leaves a patchwork of stmctural and cover condi- 

 tions (Rotenberry etal. 1999). Absence of 

 Greater Sage-Grouse in the Sandfiills and else- 

 where in the Centennial Valley may relate to fire, in 

 that spring-cool bums enhance the abundance of 

 three-tip sage. Threetip sage tends to be avoided 

 in summer by sage-grouse because it offers less 

 cover of the appropriate height and density (J. 

 Roscoe personal communication). 



Fire could benefit species like the Grasshopper 

 Sparrow by stimulating increased growth in 

 grasses, thereby providing more nesting cover 

 Some increased availability of grasses is also 

 beneficial to Black-tailed Jackrabbit and Great 

 Basin Pocket Mouse, providing increased cover 

 and food for each. Controlled fire may also be 

 used to reactivate dune dynamics by removing 

 bunchgrasses that stabilize the Sandhills (Lesica 

 and Cooper 1999). However, as Lesica and 

 Cooper ( 1 999) pointed out, effectiveness of fire in 

 creating early and mid-seral conditions will vary 

 depending on a large variety of conditions, includ- 

 ing dune topography and current cover conditions. 

 Invasion of exotic grasses (especially cheatgrass) 

 could affect intensity and fi-equency of natural fires 

 and damage native species habitat, through 

 indefinite loss of sagebrush cover (Paige and Ritter 

 1 999). Close monitoring for invasion of exotic 

 grasses should be a priority. 



Livestock grazing 



Livestock grazing can have many direct impacts 

 on the Sandhills fauna (Saab et al 1995, Lesica 

 and Cooper 1999); these include trampling, 

 competition for food, and mechanical alteration or 

 removal of cover. Cattle compete for food with 



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