Feb. 24,1923 Effect of Burning on Vegetation in Kansas Pastures 637 
weakens others so that adverse conditions later in the season may cause 
their death. 
It would seem from the above that the effects of burning will depend 
somewhat upon the composition of the pasture. A big bluestem pasture, 
or a Kentucky bluegrass pasture, would apparently be injured unless 
these grasses are replaced by equally or more desirable grasses. In 
many cases this, no doubt, is what would happen. There are undoubtedly 
other instances where they would be replaced by much less desirable 
species, in which instance binning would result in injury. 
EFFECT OF BURNING ON WEEDS 
The number and kind of weeds present was also recorded at each 
charting. This compilation, however, was by specimens and not by 
squares, as was done with grasses. The principal object was to deter¬ 
mine whether burning retards or increases the spread of weeds. If there 
is a steady increase, it can be assumed that retrogression is taking place, 
while if no increases occur it may be assumed that the grasses are hold¬ 
ing their own. It should be noted that there is always a considerable 
variation in the number of weeds present on any given area from year 
to year. Weeds react very quickly to favorable or unfavorable growing 
conditions and this should be kept in mind when analyzing the data. 
The principal weeds found in the order of their importance are prairie 
sage (. Artemesia gnaphaloides Nutt.), dwarf horseweed (Erigeron divarir 
catus Michx.), annual ragweed {Ambrosia artemisiifolia L.), whorled 
milkweed {Ascelepias verticellata L.), perennial ragweed ( Ambrosia 
psilostachya D. C.), daisy fleabane {Erigeron ramosus Watt.), and prairie 
cat’s foot {Antennaria campestris Rydberg). 
Table IV shows the total number of weeds of all kinds present in all 
of the quadrats on the unburned and burned areas for each year. 
Table IV .—Number of weed specimens present on the burned and unburned areas from 
1918 to 1921 
First charting. 
Second charting. 
Third charting. 
Date. 
Burned. 
Un¬ 
bumed. 
Date. 
Burned. 
Un¬ 
bumed. 
Date. 
Burned. 
Un¬ 
bumed. 
Apr. 
9,1918 
None. 
None. 
Apr. 30,1918 
None. 
None. 
June 3,2928 
5 
X 
Apr. 
17,1919 
55 
*3 
May 9,29x9 
85 
53 
May 31, 2919 
80 
92 
May 
St i9*o 
45 
38 
May 22,2920 
47 
60 
June 20,2920 
37 
41 
May 
3 t 19*1 
3 i 
48 
May 27,2922 
41 
6x 
July 2,2922 
29 
56 
When the first and second chartings were made in 1918 no weeds 
were found on either the burned or unbumed areas. The third charting 
showed five specimens on the burned area and one on the unbumed. 
These numbers are so small that but little importance can be attached 
to them except to say that the plots were almost free of weeds. 
In 1919, there was a decided increase in the number of weeds. When 
the first charting was made, there were 55 specimens of weeds on the 
burned and 23 specimens on the unbumed area. On the second date, 
there were 85 and 53 specimens, respectively, and on the third date 80 
and 92, respectively. 
