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).