Table I . - Summary of atmospheric oonditi-ons, soil and plant moistvire, and burning suc- 

 cess for 30 burning attempts in the White River, Cherry Springs, and Blaokuell 

 Canyon study areas from 1974 to 1976 













Burning conditions 









Bum 









T 



1 empera— 



: Relative 



Wind : 



Soil 



Plant 



Burn 



: Area 







- Loca"tion 



Time' 



ture — 



: humidity 



speed rmoisture^ 



moisture^ 



success 



: burned 











°F 



Percent 



• 



Mv/h 



Percent 



Percent 





Acres 



17 Nov 



74 





1315 



51 



ZD 



0-10 







2 



2 



18 Nov 



74 



IVhits Riv6r 



1230 



53 



z / 



8-12 







3 





24 ApT 



75 



^VhitG RivGr 



1400 



60 



ZD 



5-25 



13 



50 



1 



18 



2 May 



75 



l\nii"te Riv6T 



1445 



58 



zu 



0- 8 



12 



4(5 



2 1 





3 May 



75 



IVliit G RivGr 



1 100 



56 



ZD 



0-10 



12 



4cS 



2 1 



9 



9 May 



75 



Wh i "t e R i V cr 



1510 



65 



16 



2- 8 



12 



50 



1 



19 



1 6 May 



75 





1030 



65 





0- 5 



12 



49 



2 



3 



28 May 



75 



Chsrry Spgs 



1430 



53 



32 



3-10 



13 



o4 



3 





29 May 



75 



V^JLCi. J. y '^l-'s^ 



i o uu 



Do 



20 



0-10 



13 



54 



3 





12 Jun 



75 



l^JTril"?* RiT/fi'r* 



■ •11J.L.C I\ J. V CTJ. 



1400 



11 



8 



0-12 



9 



47 



1 



9 



17 Jun 



75 





1200 



54 



90 



0- 5 



10 



49 



3 





24 Jun 



75 



IjilcXiy '-^Pfe-' 





D / 



5 



10-35 



8 



49 



3 





24 Jun 



75 



^ilCX i y "^x^S^ 



1430 



JO 



35 



0- 5 



8 



49 



3 





26 Jun 



75 





114S 



Do 



26 



0- 8 



8 



48 



3 





26 Jun 



75 



ChcTry Spgs 



1 RAn 



/4 



16 



0- 6 



8 



48 



3 





9 Oct 



75 



Wli n 1- R i -\rc^T 

 H(iiJ.LC rvXVcX 



1 o uu 





18 



0-10 



9 



38 



2 



8 



26 Oct 



75 



^iicxxy opyo 



1 1 00 



o i 



40 



5-20 



17 



35 



■ 3 





1 5 Nov 



75 



iTiixLtr i\xvt?r 



1 /I nn 



c c 



12 



0- 7 



3 





2 



3 



3 May 



76 



DX<H-MVCA X 

























1 o uu 



7H 



/ o 



7 



0- 8 





42 









10 May 



76 



llTh T 1" P Rt If f^T" 

 tiilJ.(,t^ I\i V CX 



17*^0 



/ U 





0- 8 



11 



53 



3 





11 May 



76 



Ifliite River 



1630 



70 



23 



0-10 



11 



S3 



3 





17 May 



76 



White River 



1330 



72 



19 



0-12 







1 



60 



27 May 



76 



IVhite River 



1515 



78 



17 



3-lS 



6 





3 





28 May 



76 



Cherry Spgs 



1400 



72 



19 



2-12 



5 





3 





28 May 



76 



Cherry Spgs 



1730 



65 



9 



5-20 



5 





3 





22 Jun 



76 



IVhite River 



1600 



66 



20 



6-18 



2 



46 



1 



25 



23 Jun 



76 



White River 



1500 



71 



12 



4-15 



2 



46 



1 



45 



9 Nov 



76 



White River 



1300 



56 



28 



0- 8 



7 



49 



1 



6 



10 Nov 



76 



IVhite River 



1430 



50 



40 







7 



49 



3 





9 Dec 



76 



IVhite River 



1130 



36 



52 



2-10 



11 



49 



3 





Time at ignition. 

 ^Sample 0-4 inches deep. 

 ^Percent of green weight pinyon. 

 = too hazardous to light; 1 = fire carried, clean bum; 2 = fire needed lighting 

 assistance; 3 = would not burn. 



Three o£ these five coimnunities are unsuitable for prescribed burning. The open 

 and dispersed communities (fig- 3) are excluded because of the small degree of influ- 

 ence the trees have on the understory vegetation of these communities. The closed 

 stands (fig. 4) are excluded because of the difficulty in burning them out of fire 

 season. Closed communities have few understory shrubs; consequently, hazardous condi- 

 tions capable of producing a crown fire are necessary before these communities will 

 burn successfully. Ten attempts to burn closed stands in this study were unsuccessful. 

 One attempt (table 1, 24 June 75, 12:15) was made during hazardous conditions but still 

 failed to carry the fire. Because of the hazards, closed stands should be pretreated 

 by chaining, windrowing, or other means before attempting to bum them. 



Two communities remain on which burning might best be concentrated--scattered and 

 dense (fig. 5). Blackburn and Tueller (1970) state that the scattered community appears 

 to be the point in the invasion pattern where pinyon and juniper start to exert their 

 influence and begin to dominate the understory species. This causes a sharp reduction 

 in the vigor and frequency of the understory. Pinyon and juniper in dense communities 

 exert even more influence, dominating the understory to an even greater extent. 



4 



