GLEASON: SOME APPLICATIONS OF THE QUADRAT METHOD 27 
Again, the number of quadrats counted determines the ac- 
curacy of the frequency index as an expression of the ecological 
value of each species. The results from a small series certainly 
can not express the actual conditions as well as those from a large 
TABLE I 
138) ap hgele loots | 
S wo nt Ss te } 
32/32/38 PaRTET eee 
Be | Bo | ef | pe | Bs | Be | a | 58 
il Be ie Te |) Ss es | os | es 53 
WS. 185 "So 165} 88) 88) e8 1 8 
ee eat le Hid Seer) ao 
Seiler tole eee re. aR 
Pteris aquil SP Aisa Ws reise eden: 9 Soe I00 | 1r00 | 99 | 100 | 98 | 100 | 97 | 100 
Vaccinium m Penns ivaniciom ig tien eae 100 $2 95 70 | 82 | 7 97 27 
Gaylussacia baccata............. 80 | 67 | 48 43 | 60 | 25 | 87 2° 
NR ies | 100 68 | 29 302) 937 30 | 23 27 
Carex ete Ss aaalie ge SPORE Balla Te 87 $3 | 24 33 | 57 20 7 | 13 
pe Geena Peery | 73 55 1° 23 2574-33 15 3 / 40 
R WAG Fo eA eee 80} 4o| 21 28 7 33 | 33 12 
Rubus Mu unsi Fie ernane e ae 40 30 1717 18 | 37 i5 1 te 7 
WEE ov er 1 60 351.16 Wi ab 12.127 32 
Danthonia spicata.............. 40 | 22] 15 13 | 2 48 3 7 
G procumbens.......... 474° ay. ta 20 7 20 | 25 5 
Gnaphalium decurrens........... 00 :t 33 4. 52 15 2 vite a yj 8 
Populus grandidentata........... 53 | 32} 11 10 oO 10 8 25 
Hieracium venosum............. 60-}) 98:45:38 7 | 3 Pie 
Erigeron canadensis............. 33 | 20 7 Ee MD. | Oo] 2 22 
Panicum xanthophysum......... 20] 1 6 3 o 2 Oo | 33 
4 LONER BO 13 8 4 3 | -45 o ie ee 
Solidago canadensis............. 33 8 2 2|. 2 o| 3 5 
Rees: oe os oe 27 8 2 S39 2| 0 o 
Lactuca canadensis............. 20 7 2 2 3 o 2 2 
sheds cal ct Mee ee 13 5 I 2 2 3 o © 
Bdigues yebens.... 2 5 I te) 0 0 3 2 
eres valve... 13 3 I 3 2 o 2 o 
Comandra umbellata............ 7 2 I 2 0 3 ogee SP 
Amelanchier canadensis......... 7 2 o o 0 2 ° co) 
Hieracium paniculatum......... 7 2 ) 2; 0 ie ened ° 
hue dig ee 7 2 te) o; 9 aft oe a 
series. Repeated tests have shown that 100 is a satisfactory 
number and that no valuable increase in accuracy is gained by 
increasing the number beyond that, while it eliminates all com- 
putation in determining the frequency index. 
Experience has also shown that better results are obtained if 
the quadrats are not contiguous, but separated by some distance, 
80 as to cover more thoroughly the whole area of the association. 
In small associations, where even contiguous quadrats cover 
most of the area, this treatment is not necessary. If plants were 
