Table 4.— List of shrub species reported with winter injury or drought damage 



No. of No. of 



locations locations 

 Shrub species observed Shrub species observed 



Amelanchier ainifolia 



2 



Coleogyne ramosissima 



2 



(Nutt.) Nutt. 





Torr. 





Amelanchier Medic, spp. 



2 







Arctostaphylos patula Greene 



17 



Ephedra L. sp. 



1 



Arctostaphylos Adans. spp. 



32 



Grayia spinosa (Hook.) Moq. 



1 



Artemisia carta Pursh 



3 







Artemisia nova (A. Nels.) Ward 



5 



Juniperus communis L. 



6 



Artemisia spinescens 



1 



Juniperus occidentalis Hook. 



3 



D.C. Eaton 





Juniperus osteosperma Torr. 



11 



Artemisia tridentata Nutt. 



190 



Little 





Artemisia L. spp. 



4 



Juniperus L. spp. 



5 



Atriplex confertifolia 



7 



Pachistima Raf. sp. 



3 



(Ton. & Frem.) 8. Wats. 









Atriplex gardneri (Moq.) 



1 



Pinus edulis Engelm. 



2 



D. Dietr. 









Atriplex nuttallii S. Wats. 



1 



Prunus emarginata (Dougl.) 

 Walp. 



1 



Ceanothus cordulatus Kellogg 



3 



Prunus virginiana L. 



2 



Ceanothus cuneatus (Hook.) 



1 







Nutt. 









Ceanothus integerrimus 



3 



Purshia tridentata (Pursh) DC 



33 



Hook. & Arn. 





Quercus gambelii Nutt. 



5 



Ceanothus leucodermis Greene 



1 



Quercus L. spp. 



1 



Ceanothus prostratus Benth. 



5 







Ceanothus sanguineus Pursh 



6 



Salix anglorum Schenid. 



1 



Ceanothus velutinus Dougl. 



55 



Salix L. spp. 



2 



Ceanothus L. spp. 



44 







Ceratoides lanata (Pursh) 



1 



Sarcobatus vermiculatus 



3 



J. T. Howell 





(Hook.) Torr. 





Cercocarpus ledifolius Nutt. 



1 



Symphoricarpos oreophilus 



1 



Cercocarpus montanus Raf. 



3 



A. Gray 





Cercocarpus HBK. spp. 



1 



Symphoricarpos Duhamel. spp. 



9 



Chrysothamnus nauseosus 



3 



Vaccinium L. spp. 



4 



(Pall.) Britton 









Chrysothamnus Nutt. spp. 



2 







Correlation with Weather Records 



Of the eight Western States included in the study, Oregon, 

 Idaho, California, and Utah had the lowest monthly accumu- 

 lated percentage of normal precipitation (table 5). Montana and 

 Wyoming were the highest, with Nevada and Colorado in- 

 termediate. This agrees rpughly with the reported extent of 

 winter injured shrubs. December had the lowest monthly ac- 

 cumulated percentage of normal, with January, November, and 

 Februar)' slightly higher. Normally, these are months of higher 

 precipitation and snow cover. A comparison of precipitation in 

 climatic divisions corresponding to areas of high winter injury 

 and low winter injury indicates that the average divisional 

 precipitation was from about 20 to 45 percent lower in areas of 

 high winter injury (tables 6 and 7 and fig. 9). The largest 

 percentage difference was during December through April. The 

 average actual monthly accumulated precipitation was nearly 

 the same in the respective areas. 



Table 5.— Monthly accumulated precipitation for October through April, 1976-77' 



Precipitation' 



state 



Oct. 



Nov. 



Dec. 



Jan. 



Feb. 



Mar. 



Apr. 



California 



0.45 



1.11 



1.47 



3.12 



4.35 



5.58 



5.75 





53 



33 



23 



34 



34 



36 



34 



Colorado 



0.56 



0.81 



0.96 



1.25 



1.82 



2.46 



3.93 





48 



43 



37 



41 



44 



47 



60 



Idaho 



0.56 



0.74 



0.93 



1.53 



1.91 



1.78 



2.92 





62 



32 



23 



29 



29 



35 



33 



Montana 



0.60 



1.01 



1.31 



2.07 



2.33 



3.35 



3.68 





70 



68 



65 



81 



76 



86 



72 



Nevada 



0.79 



0.96 



0.99 



1.55 



1.87 



2.34 



2.51 





135 



70 



45 



50 



46 



49 



44 



Oregon 



0.80 



1.58 



2.22 



3.07 



4.34 



6,89 



7.44 





29 



24 



19 



22 



25 



32 



31 



Utah 



0.76 



0.83 



0.87 



0.98 



1.82 



2.52 



2.80 





70 



42 



28 



34 



35 



38 



37 



Wyoming 



0.66 



1.04 



1.29 



1.89 



2.21 



3.41 



4.43 





73 



66 



59 



67 



65 



78 



75 



'Average precipitation of the climatic divisions within the distributional 

 zone of Artemisia tridentata. 



^Upper figure represents the actual precipitation in inches. Lower figure 

 represents the percent of nornnal based on the 1941-70 record. 



12 



