Among-species responses to abiotic and biotic factors
Responses to abiotic heterogeneity in shade and soil varied by vital rate but were similar among species. Emergence fractions increased along PC1 (higher emergence in more open, low-fertility plots) for 5/9 species, and 2/9 species demonstrated convex responses (Fig. 2, Table S2, p <0.05). One species had low emergence and therefore insufficient replicates to model survival, seed production, or population growth, and hence these responses are reported throughout for the other eight species only. In contrast to emergence responses, survival was only influenced by PC1 for 2/8 species, both of which varied interactively with neighbour abundance (Fig. 2,p <0.05). Seed production decreased with PC1 for two species (more seeds produced in shaded, high-nutrient plots) and the relationship depended on neighbour abundance for a third species (Fig. 2, p <0.05). There was no apparent main effect of PC1 on population growth, however, there was a significant interaction with neighbour presence for half of the species (4/8 species,p <0.05) such that population growth declined along PC1 (as conditions became less shaded and less fertile) in the presence, but not absence, of neighbours (Fig. 2).