Fig. 3.

Significant relationships between plant size characteristics of Elodea canadensis (A, B, n = 7 sites) and Lagarosiphon major (C, D, n = 10 sites) and the amount of free CO₂ and ammonium on the sites for E. canadensis and free CO₂ and dissolved phosphorous (DRP) for L. major. This implies that within-species differences in plant size of E. canadensis and L. major can be explained by local nutrient conditions. Plants were sampled from invasive populations representing a broad range of habitat types in New Zealand. No significant relationships were present for Egeria major.