Comparing variance components calculated in the field and then in the common garden, we estimate that 93% of the among site variation in frond area in the field was environmental, with only 7% genetic, which persisted in the common garden (Fig. 3A&B, Table 3). Likewise, 96% of the among site variation in root length in the field was environmental, with only 4% due to genetic variation, which persisted in the common garden (Fig. 3C&D). Whereas the vast majority of among site phenotypic variation was environmental in origin, within site phenotypic variation had a more substantial genetic component (Frond area: 26%, Root length: 21%), (Table 3).

Table 3. Environmental and genetic components of phenotypic variation. Variation in the field survey (FS) consists of the combined contributions of environmental and genetic variance, whereas variation in the common garden (CG) isolates the genetic component.