22 CIRCULAR 884, U. S. DEPARTMENT OF AGRICULTURE 



on the grazed. Likewise the total plant cover was very similar, being 

 31.84 percent on the ungrazed plot as compared with 32.84 percent on 

 the grazed. 



Individual species that increased materially in density on meadow B 

 from 1940 to 1948 were much the same for both grazed and ungrazed 

 plots. Kentucky bluegrass became the principal perennial grass. Long- 

 stalk clover made a very rapid increase following gopher removal, in- 

 creasing sevenfold in 3 years. Common dandelion increased rapidly for 

 about 6 years. Bicolor biscuitroot became important. The low-value 

 cluster tarweed decreased from 2.31 percent to 0.50 percent. Annual 

 grasses, principally cheatgrass brome, disappeared from the vegetation 

 by 1943. 2 years after gophers were removed. 



The increase of total density and of perennial forbs and grasses and 

 the decrease of annual weeds and grasses, noted on the grazed plot after 

 it was gopher-free for 8 years, indicates an improvement in range con- 

 dition. The rapid increase of some species of perennial forbs — for ex- 

 ample, longstalk clover and common dandelion — followed by a gradual 

 decrease, is a change characteristic of improvement in mountain meadow 

 vegetation that is in poor condition: perennial forbs ordinarily become 

 dominant and then decrease as perennial grasses increase. Even with this 

 improvement, the range was still in only poor to fair condition in 1948. 



Vegetation 1940 to 1948 on Gopher-Infested Meadow 



The introduction of 16 pocket gophers per acre in meadow A in 1940, 

 when it was in fair condition, did not materially affect the general trend 

 of vegetation development (fig. 12). Despite some variations from year 

 to year, the density of all vegetation and of perennial grasses and per- 

 ennial forbs in 1947 was little different from that in 1940. But in 1948, 

 a year of good moisture, there were significant increases over 1940 

 densities of these plant groups (table 4). The increases in perennial 

 grasses were somewhat more pronounced than those in perennial forbs. 



In the period 1940-48 the amounts of some individual species on the 

 meadow changed. The density of several species increased steadily. Most 

 prominent were Kentucky bluegrass, aster, Oregon checkermallow, and 

 Columbia groundsel. On the other hand, density decreased noticeably 

 in many species, including little oniongrass, agoseris, Lemmon needle- 

 grass, and common dandelion. These changes of individual species, with 

 the possible exception of the increase in Columbia groundsel, are char- 

 acteristic of vegetation on a meadow in the grass-weed stage as it im- 

 proves in range condition. The conclusion, therefore, is that the gophers 

 did not affect the general trend of vegetation development. 



Even though some species would normally be expected to decrease 

 when a meadow is allowed to improve under the conditions that existed, 

 it was concluded from this study that density decreases in some instances 

 were the direct result of pocket gopher foraging. This was particularly 

 true of species that are favored pocket gopher forages. Little oniongrass, 

 agoseris, common dandelion, and small bluebell are plants in this cate- 

 gory. The marked and relatively steady reduction of common dandelion, 

 for example, from a density of 2.25 percent in 1940 to 0.31 percent in 

 1948 on the grazed plot, and from 1.62 percent in 1940 to 0.12 percent 

 in 1918 on the ungrazed plot, resulted directly from the active use of 



