Table 4 Characteristics of communities of oribatid mites on branches depending on: cryptogam cover (crustose lichens, foliose lichens, mosses, algae, bare bark); younger vs. older age of the crown of origin; the experimental suppression of dispersal limitation between these crowns by putting their branches into contact; and the interaction between age of the crown of origin and contact between branches.

Response	Variable	Parameter	Lower 95% CI	Upper 95% CI	P value
Total abundance	—	—			ns
Species richness	—	—			ns
Evenness (Pielou’s J)	Intercept	0.78	0.67	0.90	<0.001***
	Foliaceae	0.01	−0.0025	0.02	0.09
	Contact	−0.06	−0.16	0.04	0.240
	Young	−0.16	−0.33	−0.01	0.04*
	*ContactYoung**	0.14	0.01	0.27	0.04*
Body size	Intercept	473.61	416.81	529.23	<0.001***
	Moss	4.88	2.6	7.1	<0.001***
	Contact	−48.23	−109.61	12.32	0.11
	Young	−49.05	−130.45	26.25	0.21
	*ContactYoung**	84.88	4.7	170.17	0.04*
M. brevipes	Intercept	2.48	1.57	3.24	<0.001***
	Foliaceae	−0.09	−0.18	−0.01	0.04*
	Contact	0.29	−0.30	0.93	0.34
	Young	0.72	−0.50	1.87	0.22
	*ContactYoung**	−0.81	−1.78	−0.11	0.06
D. plantivaga	Intercept	2.64	2.11	3.18	<0.001***
	Contact	−0.68	−1.23	−0.04	0.03*
	Young	−0.14	−0.94	0.54	0.73
	*ContactYoung**	0.75	−0.07	1.58	0.07

A significant positive interaction term indicates an effect of dispersal limitation onto younger tree crowns (a negative term would be consistent with replacement by immigrants after suppression of dispersal limitation). Variable selection by backward elimination (Methods) using P = 0.1 as cutoff for inclusion. The table gives parameter estimates (posterior means, taking into account non-independence in the random effects), Bayesian 95% Highest Posterior Density (HPD) intervals and p values (two tailed, but note that those for “young” and “contact” actually test and confirm one-tailed hypotheses from the Introduction). ‘ns’ indicates no variables met the cutoff criteria. Variables that are at least marginally significant are given in bold. N = 16 crowns * 2 treatments. For simplicity we left out varibles that are not selected into the model and the random factor (means and 95%CL always positive). Note that M. brevipes is the smallest among the abundant species, suggesting relatively high dispersal capacity but low performance, and the reverse for the larger D. plantivaga.

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