
TY  - JOUR
A1  - Wilson, JW 
T1  - Errors resulting from thickness of point quadrats
JF  - Australian Journal of Botany
JO  - Aust. J. Bot.
Y1  - 1963
VL  - 11
IS  - 2
SP  - 178
EP  - 188
KW  - 
UR  - https://doi.org/10.1071/BT9630178 
N2  - When the needles used for point quadrat analyses have appreciable thickness, this causes overestimation of leaf area. A theoretical study, supported by practical trials, shows that the resultant error in estimates of "relative frequency" doubles with a doubling of quadrat diameter or a halving of leaf breadth. With the point quadrat techniques that have been in normal use the errors often exceed 50% and the estimates obtained are usually less accurate than visual estimates. However, results of sufficient accuracy for rough work can be obtained by using a narrow quadrat needle and applying correction factors; and errors can be altogether avoided by recording contacts with the sharpened point, but not the sides, of a needle gradually lowered through the vegetation. 
ER  -

