Jennifer A. Lau, Joachim Strengbom, Laurie R. Stone, Peter B. Reich, and Peter Tiffin. 2008. Direct and indirect effects of CO₂, nitrogen, and community diversity on plant–enemy interactions. Ecology 89:226–236.

Appendix A. Summary of results for an ANCOVA testing the effects of CO₂, N addition, diversity, and plant traits on amounts of damage from four classes of natural enemies.

TABLE A1. ANCOVA of the effects of the CO₂, N, and diversity treatments and three plant traits: height, pubescence (“pub”), and specific leaf area (SLA), on the three classes of herbivores.

Source	Generalist	P. laevigatus	Tortriedon sp.	Disease
CO2	0.02	0.44	0.24	0.00
N	0.47	0.02	0.00	2.35
CO2 × N	0.00	0.01	0.07	2.68
Div	18.38****	9.34**	0.26	5.80*
CO2 × Div	0.04	0.60	1.10	5.95*
N × Div	0.00	0.64	0.38	3.73
CO2 × N × Div	0.03	1.43	1.38	0.98
Height	7.95**	1.59	0.01	9.16**
Ht × CO2	0.26	0.10	0.42	0.08
Ht × N	0.66	0.01	0.03	0.90
Ht × Div	8.56**	3.21	0.24	0.03
Height2	11.94***	3.87*	0.15	4.17*
Pub	0.04	4.08*	0.30	0.65
Pub × CO2	0.17	1.04	0.27	1.36
Pub × N	0.63	0.57	0.90	0.77
Pub × Div	1.42	11.19***	0.73	1.62
Pub2	0.87	4.40*	0.56	2.57
SLA	0.99	2.36	2.45	1.91
SLA *CO2	0.39	3.95*	0.14	0.01
SLA *N	3.63	0.93	0.01	3.94*
SLA *Div	0.87	0.23	0.95	1.58
SLA2	4.40*	0.60	1.87	1.84

   Notes: For the herbivore classes, F values are presented, and denominator degrees of freedom ranged from 197–546. For disease, chi-square values are presented from the logistic ANCOVA. Significance is indicated as follows: * < 0.05, ** < 0.01, *** < 0.001, **** < 0.0001.