Table 1

Dependence of ecosystem variables on diversity treatments as determined by multiple regression. Values shown are regression parameters. A separate regression was performed for each ecosystem variable. Regressions have df = 2, 283 to 2, 286. NS,P > 0.05; *, 0.05 ≥ P > 0.01; **, 0.01 ≥ P > 0.001; and ***, P < 0.001 for tests of significant difference of parameter value from 0.

Response variableRegression parametersOverall r2Overall F value
InterceptSpecies diversityFunctional diversity
Productivity81.1*** −0.19NS20.0*** 0.0914.0***
Plant % N1.24*** −0.0003NS−0.072*** 0.1117.15***
Plant total N 104.3*** −0.193NS12.06* 0.023.61*
Soil NH4 1.07*** 0.003NS−0.082** 0.045.60**
Soil NO3 0.37*** 0.001NS−0.041*** 0.0913.4***
Light penetration0.75*** 0.0001NS−0.040*** 0.1118.3***