. 2010 Sep 30;260(9):1498–1506. doi: 10.1016/j.foreco.2010.07.048

Table 3.

Coefficient of determination (R²) and standard error of estimate (se) for the equation: ln LA = a + b ln X, with leaf area (LA), as dependent and different substitute variables (X): sapwood area at crown base (SAP_cb), sapwood area at three tenth of the tree height (SAP₀₃), sapwood area at breast height (SAP_dbh), crown surface area (CSA), basal area (BA) and crown projection area (CPA). $Average R^{2} = 1 - (\sum sum of squares residuals / \sum sum of squares total)$ . $Average se = {(\sum sum of squares residuals / \sum degrees of freedom)}^{0.5}$ .

Stands		SAP_cb	SAP₀₃	CSA	SAP_dbh	BA	CPA
Mature-thinned	R²	0.841	0.734	0.676	0.434	0.701	0.649
	se	0.194	0.251	0.276	0.366	0.266	0.288
	sig	^***	^***	^***	^***	^***	^***

Mature un-thinned	R²	0.824	0.805	0.522	0.631	0.758	0.444
	se	0.295	0.310	0.485	0.426	0.345	0.523
	sig	^***	^***	^***	^***	^***	^***

Premature thinned	R²	0.608	0.444	0.410	0.440	0.392	0.152
	se	0.219	0.260	0.268	0.261	0.272	0.322
	sig	^***	^***	^***	^***	^**	^*

Premature un-thinned	R²	0.728	0.707	0.639	0.663	0.620	0.559
	se	0.287	0.298	0.331	0.320	0.339	0.365
	sig	^***	^***	^***	^***	^***	^***

Pole stage thinned, A	R²	0.823	0.669	0.700	0.721	0.724	0.464
	se	0.255	0.350	0.333	0.321	0.319	0.445
	sig	^***	^***	^***	^***	^***	^**

Pole stage un-thinned, A	R²	0.735	0.740	0.721	0.836	0.691	0.803
	se	0.237	0.213	0.243	0.187	0.256	0.204
	sig	^**	^*	^**	^***	^**	^***

Pole stage thinned, B	R²	0.901	0.884	0.755	0.848	0.864	0.342
	se	0.246	0.266	0.387	0.305	0.288	0.634
	sig	^***	^***	^***	^***	^***	^*

Pole stage un-thinned, B	R²	0.725	0.600	0.773	0.422	0.365	0.663
	se	0.502	0.606	0.457	0.729	0.764	0.557
	sig	^***	^**	^***	^*	^*	^***

Average	R²	0.785	0.714	0.656	0.600	0.635	0.515
Average	se	0.281	0.325	0.356	0.384	0.367	0.423

<0.05.

^**

<0.01.

^***

<0.001.