Comparing trait syndromes between Taiwanese subtropical terrestrial and epiphytic ferns and lycophytes at the species and community level

Abstract

SummaryWhile functional trait-trait and trait-environment relationships are well studied in angiosperms, it is less clear if similar relationships, such as the leaf economics spectrum (LES), hold for ferns and lycophytes. Similarly, studies exploring potential differences in trait-trait and trait-environment relationships between terrestrial and epiphytic fern communities in a given ecosystem are largely lacking.We measured nine leaf traits for 76 terrestrial and 43 epiphytic fern and lycophyte species across 59 vegetation plots along an elevation gradient in the subtropical forest of Northern Taiwan. We explored trait-trait and trait-environment relationships at both the species- and community level for both species groups.Epiphytes differed from terrestrial ferns and lycophytes in species- and community-level trait values, mainly reflecting responses to higher drought and nutrient stress. The angiosperm LES was reflected in the trait-trait correlations of terrestrial ferns, but not of epiphytes. This suggests that epiphytic trait patterns are mainly shaped by water, rather than nutrient availability. Trait-environment relationships were nonetheless more-or-less similar for several drought-related traits across both species’ groups.This study illustrates that ferns and lycophyte trait patterns are not equivalent for epiphytic and terrestrial species or communities, and should not be extrapolated across species groups or between the species- and community-level.