Role of functionally dominant species in varying environmental regimes: evidence for the performance-enhancing effect of biodiversity

Table 1 Summary of the statistical regression models used to investigate effects of species richness and species composition on respiratory activity under (A) constant and (B) varying temperature regimes

A Constant temperature regime
Independent variables	Significant terms	L-ratio	d.f.	p-value
1. SR	SR	12.7	6	0.013
2. SC	SC	36	32	<0.0001
B Varying temperature regimes
Independent variable	Significant terms	L-ratio	d.f.	p-value
1. SR, A, F	SR × A	30.1	18	<0.0001
	A × F	5.66	21	0.017
Importance of independent variables:
SR		94.4	14	<0.0001
F		8.34	20	0.0154
A		37.8	16	<0.0001
2. SC, A, F	SC × A × F	132	156	<0.0001
Importance of independent variables:
SC		1485	66	<0.0001
F		338	124	<0.0001
A		540	124	<0.0001

For each model, the highest order terms are presented and, where multiple terms are present, the relative importance of individual terms (and their interactions) within a model can be compared using the likelihood ratios (L-ratios). Note that separate models were run to test the effects of species richness (SR) and species composition (SC). A: amplitude of temperature change, F: frequency of temperature fluctuation. d.f.: degrees of freedom.

ISSN: 1472-6785