. 2005 Mar 7;102(12):4393–4396. doi: 10.1073/pnas.0500094102

Table 1. Analysis of covariance for log₁₀ phytoplankton species richness.

Source	Type III sum of squares	df	Mean square	F	Significance level
Corrected model	114.734	3	38.245	364.149	<0.001
Intercept	178.164	1	178.164	1696.395	<0.001
CODE	0.001	1	0.001	0.007	0.934
Log₁₀ AREA	24.340	1	24.340	231.758	<0.001
CODE × log₁₀ AREA	0.235	1	0.235	2.236	0.136
Error	39.805	379	0.105
Total	774.272	383
Corrected total	154.539	382

log₁₀ lake area (AREA, km²) is the covariate, and the data is coded as either 0 (natural aquatic ecosystems) or 1 (experimental ecosystems). R² = 0.742 (adjusted R² = 0.740).

Table 1. Analysis of covariance for log10 phytoplankton species richness.

Table 1. Analysis of covariance for log₁₀ phytoplankton species richness.