DALLES POCKET GOPHER 



25 



Table 4. — Average density 1 of vegetation, by class and species, on grazed 



and un grazed plots of meadow A on which pocket gophers were 



introduced in 1940 — Con. 



Grazed Plot 



Class and Species 



1940 



1943 



1945 



1946 



1947 



1948 



Perennial grasses: 



Pet. 



Pet. 



Pet. 



Pet. 



Pet. 



Pet. 









114 



2.15 



2A1 



2.06 



2.25 



Bluegrass, Kentucky 



2.00 



.91 



2.97 



2.41 



2.78 



4.84 



Bluegrass, Sandberg 



.44 



.09 



1.06 



.59 



.44 



.47 



Brome, mountain ....... 



.16 



.31 



.44 



.19 



.44 



.16 



Fescue, red 



1 .65 



.19 



.19 



.38 



.34 



.41 



Needlegrass, Lemmon . . . 



.41 



.06 



.06 



.19 



.28 



.12 



Oniongrass. little 



2.25 



.78 



.44 



.25 



.03 



.09 



Wheatgrass, slender 



.22 



(2) 



.09 



.19 



.19 



.25 



Other 



.41 



.24 



.53 



.50 



.44 



.63 







Total 



7.54 



3.72 



7.93 



7,17 



7.00 



9.22 











.22 



1.12 



.22 



2.12 



.06 







.28 



.16 



.19 



.12 



.16 





1.18 



1.19 



1 .85 



1.60 



.97 



1.06 







Annual weeds:: ' 















Collinsia, littleflower .... 



.22 



.50 



.41 



.56 



(2) 



.34 



Tarweed, cluster 







.12 



.03 















Other 



.28 



1.63 



.25 



1.90 



.31 



.50 







Total 



.50 



2.25 



.69 



2.46 



.31 



.84 







Perennial forbs or weeds: 















Agoseris 



2.41 



.97 



.87 



.59 



.03 





Aster 



.31 



.34 



1.12 



1.47 



.94 



.81 



Biscuitroot, bicolor 









.02 







Bistort, Amcri an 















Bluebell, small 



2.34 



5.31 



3.13 



3.06 



1.56 



2.72 



Buttercup 



.50 



1.00 



.59 



.81 



.28 



.31 



Checkermallow, Oregon . . 



(2) 



.16 



.25 



.16 



.34 



.19 



Cinquefoil 



.22 



.03 



.34 



.25 



.50 



.56 



Clover, longstaik 



(2) 



.09 







(2) 



(2) 







Dandelion, common 



2.25 



.75 



1.22 



.91 



.44 



.31 



Fleabane 



3.01 

 1.06 



1.31 



1.50 



.53 

 1.72 



1.80 

 1.53 



2.03 



Groundsel, Columbia . . . 



3.03 



Penstemon, royal 



.19 



.22 



1.13 



.94 



.62 



1.00 



Vetch 



.44 



.31 



2.44 



.03 



(2) 



1.88 



.16 

 3.12 



(2) 

 (2) 



3.22 



(2) 

 (2) 



4.25 



(2) 



Violet 



.06 



Wyethia, whitehead .... 



4.25 



Yarrow, western .... 



.97 



.78 



.91 



1.09 



.59 



1.84 



Other 



.65 



.72 



1.06 



.66 



.53 



1.11 







Total 



17.10 



I 13.59 



15.40 



15.43 



13.41 



18.22 









26.32 



i 21.25 



27.15 



27.07 



23.93 



29.56 



1 Square feet per hundred of ground covered. 2 Less than 0.005. 



Another characteristic vegetative change resulting from gopher ac- 

 tivity on meadows in fair condition was a fluctuating population of 

 annual weeds and grasses. Annual plants became established on newly 

 worked soil the year following the working, but seldom remained the 

 second year. Thus an ever-shifting population of annual plants occurred, 

 the location and species changing greatly from year to year. Species of 

 littleflower collinsia, willowweed, knotweeds, nemophilas, tarweed, and 

 cheatgrass brome are examples of such plants. This resulted in relatively 

 higher densities of annual weeds and grasses for most years following 

 the introduction of pocket gophers into meadow A. 



