Assessing Forest Production Using Terrestrial Monitoring Data

Table 4

Minimum number of plots required to detect a 5% difference in increment estimates using different methods at 90% confidence, with 95% power in a paired 𝑡-test. Numbers in italics are the standard deviation of the differences between each pair of methods, numbers in normal text are the required numbers of plots. Values in brackets are the number of times that a 𝑡-test using the appropriate number of plots (randomly selected) incorrectly suggested that a significant difference of greater than 5% existed, from 1000 iterations.

Method	Fixed plot	Difference	Starting value	End value
Fixed plot	—	3204 (8)	491 (2)	490 (2)
Difference	59.34	—	3032 (4)	2416 (6)
Starting value	23.19	57.72	—	52 (2)
End value	23.17	51.53	7.39	—